The DW_AT_data_bit_offset attribute was introduced by DWARF V4 and
allows specifying the offset of a data member within its containing
entity. But although the new attribute was intended to replace
DW_AT_bit_offset for this purpose, GDB ignores it, and thus GCC still
emits DW_AT_bit_offset instead. See also
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71669.
This change fixes GDB's lack of support for DW_AT_data_bit_offset and
adds an appropriate test case.
gdb/ChangeLog:
PR gdb/12616
* dwarf2read.c (dwarf2_add_field): Handle the DWARF V4 attribute
DW_AT_data_bit_offset.
gdb/testsuite/ChangeLog:
PR gdb/12616
* gdb.dwarf2/nonvar-access.exp: New testcase. Check that GDB
respects the DW_AT_data_bit_offset attribute.
This replaces most of the remaining ui_file_xstrdup calls with
ui_file_as_string calls. Whenever a call was replaced, that led to a
cascade of other necessary adjustments throughout, to make the code
use std::string instead of raw pointers. And then whenever I added a
std::string as member of a struct, I needed to adjust
allocation/destruction of said struct to use new/delete instead of
xmalloc/xfree.
The stopping point was once gdb built again. These doesn't seem to be
a way to reasonably split this out further.
Maybe-not-obvious changes:
- demangle_for_lookup returns a cleanup today. To get rid of that,
and avoid unnecessary string dupping/copying, this introduces a
demangle_result_storage type that the caller instantiates and
passes to demangle_for_lookup.
- Many methods returned a "char *" to indicate that the caller owns
the memory and must free it. Those are switched to return a
std::string instead. Methods that return a "view" into some
internal string return a "const char *" instead. I.e., we only
copy/allocate when necessary.
gdb/ChangeLog:
2016-11-08 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_name_for_lookup, type_as_string): Use and return
std::string.
(type_as_string_and_cleanup): Delete.
(ada_lookup_struct_elt_type): Use type_as_string.
* ada-lang.h (ada_name_for_lookup): Now returns std::string.
* ada-varobj.c (ada_varobj_scalar_image): Return a std::string.
(ada_varobj_describe_child): Make 'child_name' and
'child_path_expr' parameters std::string pointers.
(ada_varobj_describe_struct_child, ada_varobj_describe_ptr_child):
Likewise, and use string_printf.
(ada_varobj_describe_simple_array_child)
(ada_varobj_describe_child): Likewise.
(ada_varobj_get_name_of_child, ada_varobj_get_path_expr_of_child)
(ada_varobj_get_value_image)
(ada_varobj_get_value_of_array_variable)
(ada_varobj_get_value_of_variable, ada_name_of_variable)
(ada_name_of_child, ada_path_expr_of_child)
(ada_value_of_variable): Now returns std::string. Use
string_printf.
(ada_value_of_child): Adjust.
* break-catch-throw.c (check_status_exception_catchpoint): Adjust
to use std::string.
* breakpoint.c (watch_command_1): Adjust to use std::string.
* c-lang.c (c_get_string): Adjust to use std::string.
* c-typeprint.c (print_name_maybe_canonical): Use std::string.
* c-varobj.c (varobj_is_anonymous_child): Use ==/!= std::string
operators.
(c_name_of_variable): Now returns a std::string.
(c_describe_child): The 'cname' and 'cfull_expression' output
parameters are now std::string pointers. Adjust.
(c_name_of_child, c_path_expr_of_child, c_value_of_variable)
(cplus_number_of_children): Adjust to use std::string and
string_printf.
(cplus_name_of_variable): Now returns a std::string.
(cplus_describe_child): The 'cname' and 'cfull_expression' output
parameters are now std::string pointers. Adjust.
(cplus_name_of_child, cplus_path_expr_of_child)
(cplus_value_of_variable): Now returns a std::string.
* cp-abi.c (cplus_typename_from_type_info): Return std::string.
* cp-abi.h (cplus_typename_from_type_info): Return std::string.
(struct cp_abi_ops) <get_typename_from_type_info>: Return
std::string.
* cp-support.c (inspect_type): Use std::string.
(cp_canonicalize_string_full, cp_canonicalize_string_no_typedefs)
(cp_canonicalize_string): Return std::string and adjust.
* cp-support.h (cp_canonicalize_string)
(cp_canonicalize_string_no_typedefs, cp_canonicalize_string_full):
Return std::string.
* dbxread.c (read_dbx_symtab): Use std::string.
* dwarf2read.c (dwarf2_canonicalize_name): Adjust to use std::string.
* gdbcmd.h (lookup_struct_elt_type): Adjust to use std::string.
* gnu-v3-abi.c (gnuv3_get_typeid): Use std::string.
(gnuv3_get_typename_from_type_info): Return a std::string and
adjust.
(gnuv3_get_type_from_type_info): Adjust to use std::string.
* guile/guile.c (gdbscm_execute_gdb_command): Adjust to use
std::string.
* infcmd.c (print_return_value_1): Adjust to use std::string.
* linespec.c (find_linespec_symbols): Adjust to
demangle_for_lookup API change. Use std::string.
* mi/mi-cmd-var.c (print_varobj, mi_cmd_var_set_format)
(mi_cmd_var_info_type, mi_cmd_var_info_path_expression)
(mi_cmd_var_info_expression, mi_cmd_var_evaluate_expression)
(mi_cmd_var_assign, varobj_update_one): Adjust to use std::string.
* minsyms.c (lookup_minimal_symbol): Use std::string.
* python/py-varobj.c (py_varobj_iter_next): Use new instead of
XNEW. vitem->name is a std::string now, adjust.
* rust-exp.y (convert_ast_to_type, convert_name): Adjust to use
std::string.
* stabsread.c (define_symbol): Adjust to use std::string.
* symtab.c (demangle_for_lookup): Now returns 'const char *'. Add
a demangle_result_storage parameter. Use it for storage.
(lookup_symbol_in_language)
(lookup_symbol_in_objfile_from_linkage_name): Adjust to new
demangle_for_lookup API.
* symtab.h (struct demangle_result_storage): New type.
(demangle_for_lookup): Now returns 'const char *'. Add a
demangle_result_storage parameter.
* typeprint.c (type_to_string): Return std::string and use
ui_file_as_string.
* value.h (type_to_string): Change return type to std::string.
* varobj-iter.h (struct varobj_item) <name>: Now a std::string.
(varobj_iter_delete): Use delete instead of xfree.
* varobj.c (create_child): Return std::string instead of char * in
output parameter.
(name_of_variable, name_of_child, my_value_of_variable): Return
std::string instead of char *.
(varobj_create, varobj_get_handle): Constify 'objname' parameter.
Adjust to std::string fields.
(varobj_get_objname): Return a const char * instead of a char *.
(varobj_get_expression): Return a std::string.
(varobj_list_children): Adjust to use std::string.
(varobj_get_type): Return a std::string.
(varobj_get_path_expr): Return a const char * instead of a char *.
Adjust to std::string fields.
(varobj_get_formatted_value, varobj_get_value): Return a
std::string.
(varobj_set_value): Change type of 'expression' parameter to
std::string. Use std::string.
(install_new_value): Use std::string.
(delete_variable_1): Adjust to use std::string.
(create_child): Change the 'name' parameter to a std::string
reference. Swap it into the new item's name.
(create_child_with_value): Swap item's name into the new child's
name. Use string_printf.
(new_variable): Use new instead of XNEW.
(free_variable): Don't xfree fields that are now std::string.
(name_of_variable, name_of_child): Now returns std::string.
(value_of_root): Adjust to use std::string.
(my_value_of_variable, varobj_value_get_print_value): Return
and use std::string.
(varobj_value_get_print_value): Adjust to use ui_file_as_string
and std::string.
* varobj.h (struct varobj) <name, path_expr, obj_name,
print_value>: Now std::string's.
<name_of_variable, name_of_child, path_expr_of_child,
value_of_variable>: Return std::string.
(varobj_create, varobj_get_handle): Constify 'objname' parameter.
(varobj_get_objname): Return a const char * instead of a char *.
(varobj_get_expression, varobj_get_type): Return a std::string.
(varobj_get_path_expr): Return a const char * instead of a char *.
(varobj_get_formatted_value, varobj_get_value): Return a
std::string.
(varobj_set_value): Constify 'expression' parameter.
(varobj_value_get_print_value): Return a std::string.
At this point, all TYPE_CODE_FLT types carry their floating-point format,
except for those creating from reading DWARF or stabs debug info. Those
will be addressed by this commit.
The main issue here is that we actually have to determine which floating-
point format to use. Currently, we only have the type length as input
to this decision. In the future, we may hopefully get --at least in
DWARF-- additional information to help disambiguate multiple different
formats of the same length. For now, we can still look at the type name
as a hint.
This decision logic is encapsulated in a gdbarch callback to allow
platform-specific overrides. The default implementation use the same
logic (compare type length against the various gdbarch_..._bit sizes)
that is currently implemented in floatformat_from_length.
With this commit, all platforms still use the default logic, so there
should be no actual change in behavior. A follow-on commit will add
support for __float128 on Intel and Power.
Once dwarf2read.c and stabsread.c make use of the new callback to
determine floating-point formats, we're now sure every TYPE_CODE_FLT
type will always carry its format. The commit therefore adds asserts
to verify_floatformat to ensure new code will continue to always
provide formats, and removes the code in floatformat_from_type that
used to handle types with a NULL TYPE_FLOATFORMAT.
gdb/ChangeLog:
* gdbarch.sh (floatformat_for_type): New gdbarch callback.
* gdbarch.h, gdbarch.c: Re-generate.
* arch-utils.h (default_floatformat_for_type): New prototype.
* arch-utils.c (default_floatformat_for_type): New function.
* doublest.c (floatformat_from_length): Remove.
(floatformat_from_type): Assume TYPE_FLOATFORMAT is non-NULL.
* gdbtypes.c (verify_floatformat): Require non-NULL format.
* dwarf2read.c (dwarf2_init_float_type): New function.
(read_base_type): Use it.
* stabsread.c (dbx_init_float_type): New function.
(read_sun_floating_type): Use it.
(read_range_type): Likewise.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
This adds a number of helper routines for creating objfile-owned types;
these correspond 1:1 to the already existing helper routines for creating
gdbarch-owned types, and are intended to be used instead of init_type.
A shared fragment of init_float_type and arch_float_type is extracted into
a separate subroutine verify_subroutine.
The commit also brings the interface of init_type in line with the one for
arch_type. In particular, this means removing the FLAGS argument; callers
now set the required flags directly. (Since most callers use the new
helper routines, very few callers actually need to set any additional
flags directly any more.)
Note that this means all the TYPE_FLAGS_... defined are no longer needed
anywhere; they will be removed by a follow-on commit.
All users of init_type are changed to use on of the new helpers where
possible. No functional change intended.
gdb/ChangeLog:
* gdbtypes.h (init_type): Remove FLAGS argument. Move OBJFILE
argument to first position.
(init_integer_type): New prototype.
(init_character_type): Likewise.
(init_boolean_type): Likewise.
(init_float_type): Likewise.
(init_decfloat_type): Likewise.
(init_complex_type): Likewise.
(init_pointer_type): Likewise.
* gdbtypes.c (verify_floatflormat): New function.
(init_type): Remove FLAGS argument and processing. Move OBJFILE
argument to first position.
(init_integer_type): New function.
(init_character_type): Likewise.
(init_boolean_type): Likewise.
(init_float_type): Likewise.
(init_decfloat_type): Likewise.
(init_complex_type): Likewise.
(init_pointer_type): Likewise.
(arch_float_type): Use verify_floatflormat.
(objfile_type): Use init_..._type helpers instead of calling
init_type directly.
* dwarf2read.c (fixup_go_packaging): Update to changed init_type
prototype.
(read_namespace_type): Likewise.
(read_module_type): Likewise.
(read_typedef): Likewise.
(read_unspecified_type): Likewise.
(build_error_marker_type): Likewise.
(read_base_type): Use init_..._type helpers.
* mdebugread.c (basic_type): Use init_..._type helpers.
(parse_type): Update to changed init_type prototype.
(cross_ref): Likewise.
* stabsread.c (rs6000_builtin_type): Use init_..._type helpers.
(read_sun_builtin_type): Likewise.
(read_sun_floating_type): Likewise.
(read_range_type): Likewise. Also update to changed init_type
prototype.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Currently gdb supports DW_OP_GNU_push_tls_address, but not
DW_OP_form_tls_address. I think it would be better if the toolchain
as a whole moved to using the standard opcode, and the prerequisite to
this is getting gdb to recognize it.
GCC can sometimes emit DW_OP_form_tls_address for emultls targets. As
far as I know, nobody has ever tried this with gdb (since it wouldn't
work at all).
I don't think there's a major drawback to using a single opcode for
all targets, because computing the location of a thread-local is
already target specific.
This is PR gdb/11616.
I don't know how to write a test case for this; though it's worth
noting that there aren't explicit tests for DW_OP_GNU_push_tls_address
either -- and if I change GCC, these paths will be tested to the same
extent they are now.
2016-09-02 Tom Tromey <tom@tromey.com>
PR gdb/11616:
* dwarf2read.c (decode_locdesc): Handle DW_OP_form_tls_address.
* dwarf2loc.c (dwarf2_compile_expr_to_ax): Handle
DW_OP_form_tls_address.
(locexpr_describe_location_piece): Likewise.
* dwarf2expr.h (struct dwarf_expr_context_funcs): Update comment.
* dwarf2expr.c (execute_stack_op): Handle DW_OP_form_tls_address.
(ctx_no_get_tls_address): Mention DW_OP_form_tls_address.
* compile/compile-loc2c.c (struct insn_info): Update comment.
(compute_stack_depth_worker): Handle DW_OP_form_tls_address.
PR rust/20162 started life as a reminder to test gdb with versions of
rust after 1.8; but now concerns some gdb regressions seen with rust
1.10 ("beta") and 1.11 ("nightly").
The failures turn out to be a discrepancy between how rustc emits
DWARF and how gdb interprets it. In particular, rustc will emit DWARF
like:
<2><bc>: Abbrev Number: 9 (DW_TAG_structure_type)
<bd> DW_AT_name : (indirect string, offset: 0x46a): HasMethods
<c1> DW_AT_byte_size : 4
...
<3><cc>: Abbrev Number: 11 (DW_TAG_subprogram)
...
<df> DW_AT_name : (indirect string, offset: 0x514f): new
gdb wants to see a separate top-level DW_TAG_subprogram that refers to
this one via DW_AT_specification; but rustc doesn't emit one. By my
reading of DWARF 4 5.5.7, this is ok, and gdb is incorrect here.
Fixing this involved a new case in scan_partial_symbols, and then a
further change in process_structure_scope to account for the fact
that, in Rust, such functions are not methods and should not be
attached to the structure type.
Next, it turns out that rust is emitting bad values for
DW_AT_linkage_name, e.g.:
<db> DW_AT_linkage_name: (indirect string, offset: 0x422): _ZN7methods8{{impl}}3newE
The the "{{impl}}" stuff is apparently some side effect of a change to
the compiler's internal representation. Oops!
This also had a simple fix -- disregard these mangled names.
With these changes, there are no regressions in the gdb Rust tests
with either 1.10 or 1.11. 1.9, the stable release, is still pretty
broken, but I think there's nothing much to do about that.
These changes are a bit hackish, but no worse, I think, than other
kinds of quirk handling already done in the DWARF parser. I have
reported all the rustc bugs upstream. I plan to remove these hacks
from gdb some suitable time after they have been fixed in released
versions of Rust.
2016-07-22 Tom Tromey <tom@tromey.com>
PR rust/20162:
* dwarf2read.c (scan_partial_symbols) <DW_TAG_structure_type>:
Call scan_partial_symbols for children when reading a Rust CU.
(dwarf2_physname): Ignore invalid DW_AT_linkage_name generated by
rustc.
(process_structure_scope) <DW_TAG_subprogram>: Call
read_func_scope for Rust.
This patch consolidates the (possibly-questionable) spots where we
remove a declaration but continue to call some function for side
effects. In a couple of cases it wasn't entirely clear to me that
this mattered; and in some other cases it might be more aesthetically
pleasing to use ATTRIBUTE_UNUSED. So, I broke this out into a
separate patch for simpler review.
2016-07-14 Tom Tromey <tom@tromey.com>
* arch-utils.c (default_skip_permanent_breakpoint): Remove
"bp_insn".
* disasm.c (do_assembly_only): Remove "num_displayed".
* dwarf2read.c (read_abbrev_offset): Remove "length".
(dwarf_decode_macro_bytes) <DW_MACINFO_vendor_ext>: Remove
"constant".
* m32c-tdep.c (make_regs): Remove "r2hl", "r3hl", and "intbhl".
* microblaze-tdep.c (microblaze_frame_cache): Remove "func".
* tracefile.c (trace_save): Remove "status".
Local variables in lambdas are not accessible
https://sourceware.org/bugzilla/show_bug.cgi?id=15231
GDB: read_lexical_block_scope
/* Ignore blocks with missing or invalid low and high pc attributes. */
[...]
if (!dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL))
return;
But sometimes there is:
FAIL: gcc-5.3.1-6.fc23.x86_64
<2><92>: Abbrev Number: 11 (DW_TAG_lexical_block)
<3><9c>: Abbrev Number: 13 (DW_TAG_structure_type)
<9d> DW_AT_name : (indirect string, offset: 0x3c): <lambda()>
[...]
Where DW_TAG_lexical_block has no attributes. Such whole subtree is currently
dropped by GDB while I think it should just import all its children DIEs.
It even XFAIL->XPASSes gdb.ada/out_of_line_in_inlined.exp:
commit 0fa7fe506c
Author: Joel Brobecker <brobecker@adacore.com>
out of line functions nested inside inline functions.
So I have removed that xfail.
gdb/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* dwarf2read.c (enum pc_bounds_kind): Add PC_BOUNDS_INVALID.
(process_psymtab_comp_unit_reader, read_func_scope): Adjust callers.
(read_lexical_block_scope): Import DIEs from bare DW_TAG_lexical_block.
(read_call_site_scope): Adjust callers.
(dwarf2_get_pc_bounds): Implement pc_bounds_invalid.
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
gdb/testsuite/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* gdb.ada/out_of_line_in_inlined.exp: Remove xfails.
* gdb.dwarf2/dw2-lexical-block-bare.exp: New file.
Make the code (maybe) more readable + primarily prepare it for [patch 2/2]
enum extension.
This change should have no code change impact.
gdb/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
Code cleanup: dwarf2_get_pc_bounds: -1/0/+1 -> enum
* dwarf2read.c (enum pc_bounds_kind) New.
(dwarf2_get_pc_bounds): Use it in the declaration.
(process_psymtab_comp_unit_reader): Adjust caller. Rename has_pc_info
to cu_bounds_kind.
(read_func_scope, read_lexical_block_scope, read_call_site_scope):
Adjust callers.
(dwarf2_get_pc_bounds): Use enum pc_bounds_kind in the definition.
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
PR symtab/19914
* dwarf2read.c (open_and_init_dwp_file): Look at backlink if objfile
is separate debug file.
testsuite/
* gdb.dwarf2/dwp-sepdebug.c: New file.
* gdb.dwarf2/dwp-sepdebug.exp: New file.
This patch fixes a SIGSEGV when trying to open a Fortran program
compiled with ifort (reproduced using version using version 16.0.1.150).
The error can be reproduce with most, if not any program. For instance,
a single file only containing "end", compiled with no additional flag,
suffices.
gdb/ChangeLog:
PR gdb/19208
* dwarf2read.c (read_partial_die): Do not call set_objfile_main_name
if the function has no name.
It is possible to use multiple base addresses within a single address
range series, within the .debug_ranges section. The following is a
simplified example for 32-bit addresses:
.section ".debug_ranges"
.4byte 0xffffffff
.4byte BASE_1
.4byte START_OFFSET_1
.4byte END_OFFSET_1
.4byte START_OFFSET_2
.4byte END_OFFSET_2
.4byte 0xffffffff
.4byte BASE_2
.4byte START_OFFSET_3
.4byte END_OFFSET_3
.4byte 0
.4byte 0
In this example START/END 1 and 2 are relative to BASE_1, while
START/END 3 are relative to BASE_2.
Currently gdb does not correctly parse this DWARF, resulting in
corrupted address range information. This commit fixes this issue, and
adds a new test to cover this case.
In order to support testing of this feature extensions were made to the
testsuite dwarf assembler, additional functionality was added to the
.debug_line generation function, and a new function for generating the
.debug_ranges section was added.
gdb/ChangeLog:
* dwarf2read.c (dwarf2_ranges_read): Unify and fix base address
reading code.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-ranges-base.c: New file.
* gdb.dwarf2/dw2-ranges-base.exp: New file.
* lib/dwarf.exp (namespace eval Dwarf): Add new variables to
support additional line table, and debug ranges generation.
(Dwarf::ranges): New function, generate .debug_ranges.
(Dwarf::lines): Support generating simple line table programs.
(Dwarf::assemble): Initialise new namespace variables.
Using the gdb.ada/var_rec_arr.exp test, where the program declares
an array of variant records...
type Record_Type (I : Small_Type := 0) is record
S : String (1 .. I);
end record;
type Array_Type is array (Integer range <>) of Record_Type;
... and then a variable A1 of type Array_Type, the following command
ocassionally trigger an internal error trying to allocate more memory
than we have left:
(gdb) ptype a1(1)
[...]/utils.c:1089: internal-error: virtual memory exhausted.
A problem internal to GDB has been detected,
[...]
What happens is that recent versions of GNAT are able to generate
DWARF expressions for type Record_Type, and therefore the record's
DW_AT_byte_size is not a constant, which unfortunately breaks
an assumption made by dwarf2read.c:read_structure_type when it does:
attr = dwarf2_attr (die, DW_AT_byte_size, cu);
if (attr)
{
TYPE_LENGTH (type) = DW_UNSND (attr);
}
As a result of this, when ada_evaluate_subexp tries to create
a value_zero for a1(1) while processing the OP_FUNCALL operator
as part of evaluating the subscripting operation in no-side-effect
mode, we try to allocate a value with a bogus size, potentially
triggering the out-of-memory internal error.
This patch avoids this issue by setting the length to zero in
this case. Until we decide to start supporting dynamic type
lengths in GDB's type struct, and it's not clear yet that
this is worth the effort (see added comment), that's probably
the best we can do.
gdb/ChangeLog:
* dwarf2read.c (read_structure_type): Set the type's length
to zero if it has a DW_AT_byte_size attribute which is not
a constant.
gdb/testsuite/ChangeLog:
* testsuite/gdb.ada/var_rec_arr.exp: Add "ptype a1(1)" test.
This patch fixes all occurences of left-shifting negative constants in C cod
which is undefined by the C standard.
gdb/ChangeLog:
* hppa-tdep.c (hppa_sign_extend, hppa_low_hppa_sign_extend)
(prologue_inst_adjust_sp, hppa_frame_cache): Fix left shift of negative
value.
* dwarf2read.c (read_subrange_type): Likewise.
There is no enum value representing 0. It seems like the value of the
name field is irrelevant here.
gdb/ChangeLog:
* dwarf2read.c (partial_die_full_name): Add cast.
Fortran provide types whose values may be dynamically allocated
or associated with a variable under explicit program control.
The purpose of this commit is:
* to read allocated/associated DWARF tags and store them in
the dynamic property list of main_type.
* enable GDB to print the value of a dynamic array in Fortran
in case the type is allocated or associated (pointer to
dynamic array).
Examples:
(gdb) p vla_not_allocated
$1 = <not allocated>
(gdb) p vla_allocated
$1 = (1, 2, 3)
(gdb) p vla_ptr_not_associated
$1 = <not associated>
(gdb) p vla_ptr_associated
$1 = (1, 2, 3)
Add basic test coverage for most dynamic array use-cases in Fortran.
The commit contains the following tests:
* Ensure that values of Fortran dynamic arrays
can be evaluated correctly in various ways and states.
* Ensure that Fortran primitives can be evaluated
correctly when used as a dynamic array.
* Dynamic arrays passed to subroutines and handled
in different ways inside the routine.
* Ensure that the ptype of dynamic arrays in
Fortran can be printed in GDB correctly.
* Ensure that dynamic arrays in different states
(allocated/associated) can be evaluated.
* Dynamic arrays passed to functions and returned from
functions.
* History values of dynamic arrays can be accessed and
printed again with the correct values.
* Dynamic array evaluations using MI protocol.
* Sizeof output of dynamic arrays in various states.
The patch was tested using the test suite on Ubuntu 12.04 64bit.
gdb/ChangeLog:
* dwarf2read.c (set_die_type): Add read of
DW_AT_allocated and DW_AT_associated.
* f-typeprint.c: New include of typeprint.h
(f_print_type): Add check for allocated/associated
status of type.
(f_type_print_varspec_suffix): Add check for
allocated/associated status of type.
* gdbtypes.c (create_array_type_with_stride):
Add check for valid data location of type in
case allocated or associated attributes are set.
Length of an array should be only calculated if
allocated or associated is resolved as true.
(is_dynamic_type_internal): Add check for allocated/
associated.
(resolve_dynamic_array): Evaluate allocated/associated
properties.
* gdbtypes.h (enum dynamic_prop_node_kind): <DYN_PROP_ALLOCATED>
<DYN_PROP_ASSOCIATED>: New enums.
(TYPE_ALLOCATED_PROP, TYPE_ASSOCIATED_PROP): New macros.
(type_not_allocated): New function.
(type_not_associated): New function.
* valarith.c (value_subscripted_rvalue): Add check for
allocated/associated.
* valprint.c: New include of typeprint.h.
(valprint_check_validity): Add check for allocated/associated.
(value_check_printable): Add check for allocated/
associated.
* typeprint.h (val_print_not_allocated): New function.
(val_print_not_associated): New function.
* typeprint.c (val_print_not_allocated): New function.
(val_print_not_associated): New function.
gdb/testsuite/ChangeLog:
* gdb.fortran/vla-alloc-assoc.exp: New file.
* gdb.fortran/vla-datatypes.exp: New file.
* gdb.fortran/vla-datatypes.f90: New file.
* gdb.fortran/vla-history.exp: New file.
* gdb.fortran/vla-ptype-sub.exp: New file.
* gdb.fortran/vla-ptype.exp: New file.
* gdb.fortran/vla-sizeof.exp: New file.
* gdb.fortran/vla-sub.f90: New file.
* gdb.fortran/vla-value-sub-arbitrary.exp: New file.
* gdb.fortran/vla-value-sub-finish.exp: New file.
* gdb.fortran/vla-value-sub.exp: New file.
* gdb.fortran/vla-value.exp: New file.
* gdb.fortran/vla-ptr-info.exp: New file.
* gdb.mi/mi-vla-fortran.exp: New file.
* gdb.mi/vla.f90: New file.
GDB's current behavior when dealing with non-local references in the
context of nested fuctions is approximative:
- code using valops.c:value_of_variable read the first available stack
frame that holds the corresponding variable (whereas there can be
multiple candidates for this);
- code directly relying on read_var_value will instead read non-local
variables in frames where they are not even defined.
This change adds the necessary context to symbol reads (to get the block
they belong to) and to blocks (the static link property, if any) so that
GDB can make the proper decisions when dealing with non-local varibale
references.
gdb/ChangeLog:
* ada-lang.c (ada_read_var_value): Add a var_block argument
and pass it to default_read_var_value.
* block.c (block_static_link): New accessor.
* block.h (block_static_link): Declare it.
* buildsym.c (finish_block_internal): Add a static_link
argument. If there is a static link, associate it to the new
block.
(finish_block): Add a static link argument and pass it to
finish_block_internal.
(end_symtab_get_static_block): Update calls to finish_block and
to finish_block_internal.
(end_symtab_with_blockvector): Update call to
finish_block_internal.
* buildsym.h: Forward-declare struct dynamic_prop.
(struct context_stack): Add a static_link field.
(finish_block): Add a static link argument.
* c-exp.y: Remove an obsolete comment (evaluation of variables
already start from the selected frame, and now they climb *up*
the call stack) and propagate the block information to the
produced expression.
* d-exp.y: Likewise.
* f-exp.y: Likewise.
* go-exp.y: Likewise.
* jv-exp.y: Likewise.
* m2-exp.y: Likewise.
* p-exp.y: Likewise.
* coffread.c (coff_symtab_read): Update calls to finish_block.
* dbxread.c (process_one_symbol): Likewise.
* xcoffread.c (read_xcoff_symtab): Likewise.
* compile/compile-c-symbols.c (convert_one_symbol): Promote the
"sym" parameter to struct block_symbol, update its uses and pass
its block to calls to read_var_value.
(convert_symbol_sym): Update the calls to convert_one_symbol.
* compile/compile-loc2c.c (do_compile_dwarf_expr_to_c): Update
call to read_var_value.
* dwarf2loc.c (block_op_get_frame_base): New.
(dwarf2_block_frame_base_locexpr_funcs): Implement the
get_frame_base method.
(dwarf2_block_frame_base_loclist_funcs): Likewise.
(dwarf2locexpr_baton_eval): Add a frame argument and use it
instead of the selected frame in order to evaluate the
expression.
(dwarf2_evaluate_property): Add a frame argument. Update call
to dwarf2_locexpr_baton_eval to provide a frame in available and
to handle the absence of address stack.
* dwarf2loc.h (dwarf2_evaluate_property): Add a frame argument.
* dwarf2read.c (attr_to_dynamic_prop): Add a forward
declaration.
(read_func_scope): Record any available static link description.
Update call to finish_block.
(read_lexical_block_scope): Update call to finish_block.
* findvar.c (follow_static_link): New.
(get_hosting_frame): New.
(default_read_var_value): Add a var_block argument. Use
get_hosting_frame to handle non-local references.
(read_var_value): Add a var_block argument and pass it to the
LA_READ_VAR_VALUE method.
* gdbtypes.c (resolve_dynamic_range): Update calls to
dwarf2_evaluate_property.
(resolve_dynamic_type_internal): Likewise.
* guile/scm-frame.c (gdbscm_frame_read_var): Update call to
read_var_value, passing it the block coming from symbol lookup.
* guile/scm-symbol.c (gdbscm_symbol_value): Update call to
read_var_value (TODO).
* infcmd.c (finish_command_continuation): Update call to
read_var_value, passing it the block coming from symbol lookup.
* infrun.c (insert_exception_resume_breakpoint): Likewise.
* language.h (struct language_defn): Add a var_block argument to
the LA_READ_VAR_VALUE method.
* objfiles.c (struct static_link_htab_entry): New.
(static_link_htab_entry_hash): New.
(static_link_htab_entry_eq): New.
(objfile_register_static_link): New.
(objfile_lookup_static_link): New.
(free_objfile): Free the STATIC_LINKS hashed map if needed.
* objfiles.h: Include hashtab.h.
(struct objfile): Add a static_links field.
(objfile_register_static_link): New.
(objfile_lookup_static_link): New.
* printcmd.c (print_variable_and_value): Update call to
read_var_value.
* python/py-finishbreakpoint.c (bpfinishpy_init): Likewise.
* python/py-frame.c (frapy_read_var): Update call to
read_var_value, passing it the block coming from symbol lookup.
* python/py-framefilter.c (extract_sym): Add a sym_block
parameter and set the pointed value to NULL (TODO).
(enumerate_args): Update call to extract_sym.
(enumerate_locals): Update calls to extract_sym and to
read_var_value.
* python/py-symbol.c (sympy_value): Update call to
read_var_value (TODO).
* stack.c (read_frame_local): Update call to read_var_value.
(read_frame_arg): Likewise.
(return_command): Likewise.
* symtab.h (struct symbol_block_ops): Add a get_frame_base
method.
(struct symbol): Add a block field.
(SYMBOL_BLOCK): New accessor.
* valops.c (value_of_variable): Remove frame/block handling and
pass the block argument to read_var_value, which does this job
now.
(value_struct_elt_for_reference): Update calls to
read_var_value.
(value_of_this): Pass the block found to read_var_value.
* value.h (read_var_value): Add a var_block argument.
(default_read_var_value): Likewise.
gdb/testsuite/ChangeLog:
* gdb.base/nested-subp1.exp: New file.
* gdb.base/nested-subp1.c: New file.
* gdb.base/nested-subp2.exp: New file.
* gdb.base/nested-subp2.c: New file.
* gdb.base/nested-subp3.exp: New file.
* gdb.base/nested-subp3.c: New file.
Fixes:
../../src/gdb/dwarf2read.c:127:15: error: declaration of ‘asection* dwarf2_section_info::<anonymous union>::asection’ [-fpermissive]
asection *asection;
^
In file included from ../../src/gdb/common/common-types.h:35:0,
from ../../src/gdb/common/common-defs.h:44,
from ../../src/gdb/defs.h:28,
from ../../src/gdb/dwarf2read.c:31:
../bfd/bfd.h:1596:3: error: changes meaning of ‘asection’ from ‘typedef struct bfd_section asection’ [-fpermissive]
} asection;
^
gdb/ChangeLog:
2015-08-21 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (struct dwarf2_section_info): Rename field
'asection' to 'section'.
(dwarf2_has_info, get_section_bfd_owner, get_section_bfd_section)
(dwarf2_locate_sections, dwarf2_locate_sections)
(locate_dwz_sections, locate_v1_virtual_dwo_sections)
(dwarf2_locate_dwo_sections, dwarf2_locate_dwo_sections)
(dwarf2_locate_v2_dwp_sections): Adjust.
Here, in dwarfread.c:process_full_comp_unit:
/* Set symtab language to language from DW_AT_language. If the
compilation is from a C file generated by language preprocessors, do
not set the language if it was already deduced by start_subfile. */
if (!(cu->language == language_c
&& COMPUNIT_FILETABS (cust)->language != language_c))
COMPUNIT_FILETABS (cust)->language = cu->language;
in case start_subfile doesn't manage to deduce a language
COMPUNIT_FILETABS(cust)->language ends up as language_unknown, not
language_c. So the condition above evals false and we never set the
language from the cu's language.
gdb/ChangeLog:
2015-08-20 Pedro Alves <palves@redhat.com>
* dwarf2read.c (process_full_comp_unit): To tell whether
start_subfile managed to deduce a language, test for
language_unknown instead of language_c.
gdb/testsuite/ChangeLog:
2015-08-20 Pedro Alves <palves@redhat.com>
* gdb.dwarf2/comp-unit-lang.exp: New file.
* gdb.dwarf2/comp-unit-lang.c: New file.
This change introduces a new function, dwarf2_string_attr(), which is
a wrapper for dwarf2_attr(). dwarf2read.c has been updated to
call dwarf2_string_attr in most instances where a string-valued
attribute is decoded to produce a string value. In most cases, it
simplifies the code; in some instances, the complexity of the code
remains unchanged.
I performed this change by looking for instances where the
result of DW_STRING was used in an assignment. Many of these
had a pattern which (roughly) looks something like this:
struct attribute *attr = NULL;
attr = dwarf2_attr (die, name, cu);
if (attr != NULL && DW_STRING (attr))
{
const char *str;
...
str = DW_STRING (attr);
... /* Use str in some fashion. */
}
Code of this form is transformed to look like this instead:
const char *str;
str = dwarf2_string_attr (die, name, cu)
if (str != NULL)
{
...
/* Use str in some fashion. */
...
}
In addition to invoking dwarf2_attr() and DW_STRING(),
dwarf2_string_attr() checks to make sure that the attribute's
`form' field matches one of DW_FORM_strp, DW_FORM_string, or
DW_FORM_GNU_strp_alt. If it does not match one of these forms,
it will return a NULL value in addition to calling complaint().
An earlier version of this patch did this type checking for one
particular instance where a string attribute was being decoded.
The situation that I was attempting to handle in that earlier patch is
this:
The Texas Instruments compiler uses the encoding for
DW_AT_MIPS_linkage_name for other purposes. TI uses the encoding,
0x2007, for TI_AT_TI_end_line which, unlike DW_AT_MIPS_linkage_name,
does not have a string-typed value. In this instance, GDB was attempting
to use an integer value as a string pointer, with predictable results.
(GDB would die with a segmentation fault.)
I've added a test which reproduces the problem that I was orignally
wanting to fix. It uses DW_AT_MIPS_linkage name with an associate
value which is a string, and again, where the value is a small
integer.
My test case causes GDB to segfault in an unpatched GDB. There
will be two PASSes in a patched GDB.
Unpatched GDB:
(gdb) ptype f
ERROR: Process no longer exists
UNRESOLVED: gdb.dwarf2/dw2-bad-mips-linkage-name.exp: ptype f
ERROR: Couldn't send ptype g to GDB.
UNRESOLVED: gdb.dwarf2/dw2-bad-mips-linkage-name.exp: ptype g
Patched GDB:
(gdb) ptype f
type = bool ()
(gdb) PASS: gdb.dwarf2/dw2-bad-mips-linkage-name.exp: ptype f
ptype g
type = bool ()
(gdb) PASS: gdb.dwarf2/dw2-bad-mips-linkage-name.exp: ptype g
I see no regressions on an x86_64 native target.
gdb/ChangeLog:
* dwarf2read.c (dwarf2_string_attr): New function.
(lookup_dwo_unit, process_psymtab_comp_unit_reader)
(dwarf2_compute_name, dwarf2_physname, find_file_and_directory)
(read_call_site_scope, namespace_name, guess_full_die_structure_name)
(anonymous_struct_prefix, prepare_one_comp_unit): Use
dwarf2_string_attr in place of dwarf2_attr and DW_STRING.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-bad-mips-linkage-name.c: New file.
* gdb.dwarf2/dw2-bad-mips-linkage-name.exp: New file.
Consider the following declaration:
function Foo (I : Integer) return Integer renames Pack.Bar;
As Foo is not materialized as a routine whose name is derived from Foo,
GDB currently cannot use it:
(gdb) print foo(0)
No definition of "foo" in current context.
However, compilers can emit DW_TAG_imported_declaration in order to
materialize the fact that Foo is actually another name for Pack.Bar.
This commit enhances the DWARF reader to record global renamings (it
used to put global ones in a static block) and enhances the Ada engine
to leverage this information during symbol lookup.
gdb/ChangeLog:
* ada-lang.c: Include namespace.h
(aux_add_nonlocal_symbols): Fix a function name in comment.
(ada_add_block_renamings): New.
(add_nonlocal_symbols): Add global renamings handling.
(ada_lookup_symbol_list_worker): Move the symbol lookup part
to...
(ada_add_all_symbols): ... this new function.
(ada_add_block_symbols): Try to match the input name against the
"using directives list", perform a recursive symbol lookup on
the matched declarations.
* block.h (struct block): Move the_namespace to top-level as
namespace_info. Remove the language_specific field.
(BLOCK_NAMESPACE): Update access to the namespace_info field.
* buildsym.h (using_directives): Rename into...
(local_using_directives): ... this.
(global_using_directives): New.
(struct context_stack): Rename the using_directives field into
local_using_directives.
* buildsym.c (finish_block_internal): Deal with the proper
using directives repository (local or global).
(prepare_for_building): Reset local_using_directives. Assert
that there is no pending global using directive.
(reset_symtab_globals): Reset global_using_directives and
local_using_directives.
(end_symtab_get_static_block): Don't ignore symtabs that have
only using directives.
(push_context): Update references to local_using_directives.
(buildsym_init): Do not reset using_directives.
* cp-support.c: Include namespace.h.
* cp-support.h (struct using_direct): Move to namespace.h.
(cp_add_using_directives): Move to namespace.h.
* cp-namespace.c: Include namespace.h
(cp_add_using_directive): Move to namespace.c, rename it to
add_using_directive, add a "using_directives" argument and use
it as the pending using directives repository. All callers
updated.
* dwarf2read.c (using_directives): New.
(read_import_statement): Call using_directives.
(read_func_scope): Update references to local_using_directives.
(read_lexical_block_scope): Likewise.
(read_namespace): Update the heading comment, call
using_directives.
* namespace.h: New file.
* namespace.c: New file.
* Makefile.in (SFILES): Add namespace.c.
(COMMON_OBS): Add namespace.o
gdb/testsuite/ChangeLog:
* gdb.ada/fun_renaming.exp: New testcase.
* gdb.ada/fun_renaming/fun_renaming.adb: New file.
* gdb.ada/fun_renaming/pack.adb: New file.
* gdb.ada/fun_renaming/pack.ads: New file.
Tested on x86_64-linux. Support for this in GCC is in the pipeline: see
<https://gcc.gnu.org/ml/gcc-patches/2015-07/msg02166.html>.
This patch is mostly extracted from Pedro's C++ branch. It adds explicit
casts from integer to enum types, where it is really the intention to do
so. This could be because we are ...
* iterating on enum values (we need to iterate on an equivalent integer)
* converting from a value read from bytes (dwarf attribute, agent
expression opcode) to the equivalent enum
* reading the equivalent integer value from another language (Python/Guile)
An exception to that is the casts in regcache.c. It seems to me like
struct regcache's register_status field could be a pointer to an array of
enum register_status. Doing so would waste a bit of memory (4 bytes
used by the enum vs 1 byte used by the current signed char, for each
register). If we switch to C++11 one day, we can define the underlying
type of an enum type, so we could have the best of both worlds.
gdb/ChangeLog:
* arm-tdep.c (set_fp_model_sfunc): Add cast from integer to enum.
(arm_set_abi): Likewise.
* ax-general.c (ax_print): Likewise.
* c-exp.y (exp : string_exp): Likewise.
* compile/compile-loc2c.c (compute_stack_depth_worker): Likewise.
(do_compile_dwarf_expr_to_c): Likewise.
* cp-name-parser.y (demangler_special : DEMANGLER_SPECIAL start):
Likewise.
* dwarf2expr.c (execute_stack_op): Likewise.
* dwarf2loc.c (dwarf2_compile_expr_to_ax): Likewise.
(disassemble_dwarf_expression): Likewise.
* dwarf2read.c (dwarf2_add_member_fn): Likewise.
(read_array_order): Likewise.
(abbrev_table_read_table): Likewise.
(read_attribute_value): Likewise.
(skip_unknown_opcode): Likewise.
(dwarf_decode_macro_bytes): Likewise.
(dwarf_decode_macros): Likewise.
* eval.c (value_f90_subarray): Likewise.
* guile/scm-param.c (gdbscm_make_parameter): Likewise.
* i386-linux-tdep.c (i386_canonicalize_syscall): Likewise.
* infrun.c (handle_command): Likewise.
* memory-map.c (memory_map_start_memory): Likewise.
* osabi.c (set_osabi): Likewise.
* parse.c (operator_length_standard): Likewise.
* ppc-linux-tdep.c (ppc_canonicalize_syscall): Likewise, and use
single return point.
* python/py-frame.c (gdbpy_frame_stop_reason_string): Likewise.
* python/py-symbol.c (gdbpy_lookup_symbol): Likewise.
(gdbpy_lookup_global_symbol): Likewise.
* record-full.c (record_full_restore): Likewise.
* regcache.c (regcache_register_status): Likewise.
(regcache_raw_read): Likewise.
(regcache_cooked_read): Likewise.
* rs6000-tdep.c (powerpc_set_vector_abi): Likewise.
* symtab.c (initialize_ordinary_address_classes): Likewise.
* target-debug.h (target_debug_print_signals): Likewise.
* utils.c (do_restore_current_language): Likewise.
Dummy CUs are used by the incremental linker to pre-allocate space
in the output file. They have a DWARF header but no contents.
gdb/ChangeLog:
* dwarf2read.c (dwarf2_per_cu_data): Add comment.
(load_cu): Handle dummy CUs.
(dw2_do_instantiate_symtab, process_queuef): Ditto.
(dwarf2_fetch_die_loc_sect_off, dwarf2_fetch_constant_bytes): Ditto.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-dummy-cu.S: New file.
* gdb.dwarf2/dw2-dummy-cu.exp: New file.
GDB already allows statically initialized variables, located in
SEC_LOAD sections, to be placed at address 0. This change allows
uninitialized variables (which are in SEC_ALLOC sections) to be placed
address 0 as well.
gdb/ChangeLog:
* dwarf2read.c (dwarf2_locate_sections): Allow has_section_at_zero
to be set for SEC_ALLOC sections too.
Extends existing support for namespaces/modules in C++/Fortran/Java to
include language_d too. However unlike Fortran/C++, the separator for
qualified names is a single dot.
2015-07-14 Iain Buclaw <ibuclaw@gdcproject.org>
* dwarf2read.c (find_slot_in_mapped_hash): Extend language support to
also test for language_d.
(dwarf2_compute_name): Likewise.
(read_func_scope): Likewise.
(read_structure_type): Likewise.
(determine_prefix): Likewise.
(read_import_statement): Use dot as the separator for language_d.
(typename_concat): Likewise, but don't prefix the D main function.
Commit d9b3de22f3 introduced a behaviour
change where dwarf_finish_line was not called anymore when ending a
sequence of machine instructions. This patch restores the original
behaviour.
gdb/ChangeLog:
* dwarf2read.c (dwarf_record_line): Call dwarf_record_line if
end_sequence is true.
gdb/ChangeLog:
* dwarf2read.c (lnp_state_machine): New typedef.
(lnp_reader_state): New typedef.
(dwarf_record_line_1): Renamed from dwarf_record_line.
All callers updated.
(dwarf_record_line): New function.
(init_lnp_state_machine): New function.
(check_line_address): Replace p_record_line parameter with state.
All callers updated.
(dwarf_decode_lines_1): Call dwarf_record_line, init_lnp_state_machine.
Update to record state in lnp_state_machine.
2015-05-08 Yao Qi <yao@codesourcery.com>
Sandra Loosemore <sandra@codesourcery.com>
gdb/
* dwarf2read.c (setup_type_unit_groups): Do NULL pointer check
to 'lh->include_dirs' before accessing to it.
(psymtab_include_file_name): Likewise.
(dwarf_decode_lines_1): Likewise.
(dwarf_decode_lines): Likewise.
(file_file_name): Likewise.
Consider the following declarations...
type Obj_T (Selected_Flights_Length : Natural) is
record
Selected_Flights : Flights.List.T (1 .. Selected_Flights_Length);
end record;
Broken : Obj_T;
... which defines a variable named "broken" which is a discrimated
record where broken.Selected_Flights is an array whose upper bound
is stored in the record's Selected_Flights_Length component.
Trying to print the value of that object currently fails:
(gdb) print broken
cannot find reference address for offset property
Looking at the debugging info, we see that variable "Broken" is
a reference...
<1><8e3>: Abbrev Number: 21 (DW_TAG_const_type)
<8e4> DW_AT_type : <0x8e8>
<1><8e8>: Abbrev Number: 22 (DW_TAG_reference_type)
<8e9> DW_AT_byte_size : 8
<8ea> DW_AT_type : <0x7ec>
... to ...
<1><7ec>: Abbrev Number: 12 (DW_TAG_structure_type)
<7ed> DW_AT_name : (indirect string, offset: 0xc6d): reprod__obj_t
<7f1> DW_AT_decl_file : 2
<7f2> DW_AT_decl_line : 15
<7f3> DW_AT_GNAT_descriptive_type: <0x87e>
<7f7> DW_AT_sibling : <0x87e>
... which has 2 members, the first one being the discriminant...
<2><7fb>: Abbrev Number: 9 (DW_TAG_member)
<7fc> DW_AT_name : (indirect string, offset: 0xc98): selected_flights_length
<800> DW_AT_decl_file : 2
<801> DW_AT_decl_line : 15
<802> DW_AT_type : <0x807>
<806> DW_AT_data_member_location: 0
... and the second one being the one that causes trouble...
<2><83d>: Abbrev Number: 9 (DW_TAG_member)
<83e> DW_AT_name : (indirect string, offset: 0xd17): selected_flights
<842> DW_AT_decl_file : 2
<843> DW_AT_decl_line : 17
<844> DW_AT_type : <0x815>
<848> DW_AT_data_member_location: 4
The second field's type is an array....
<2><815>: Abbrev Number: 14 (DW_TAG_array_type)
<816> DW_AT_name : (indirect string, offset: 0xd2f): reprod__obj_t__T5sP
<81a> DW_AT_GNAT_descriptive_type: <0x7e1>
<81e> DW_AT_type : <0x748>
<822> DW_AT_sibling : <0x830>
... whose uppper bound is a reference to <0x7fb>...
<3><826>: Abbrev Number: 15 (DW_TAG_subrange_type)
<827> DW_AT_type : <0x830>
<82b> DW_AT_upper_bound : <0x7fb>
<3><82f>: Abbrev Number: 0
Because the upper bound is dynamic, we try to resolve it.
As it happens, the upper-bound resolution for this range type
works fine. What breaks is when we try to resolve this range
type's target type, which is:
<2><830>: Abbrev Number: 16 (DW_TAG_subrange_type)
<831> DW_AT_upper_bound : <0x7fb>
<835> DW_AT_name : (indirect string, offset: 0xc7b): reprod__obj_t__T4s___XDLU_1__selected_flights_length
<839> DW_AT_type : <0x766>
<83d> DW_AT_artificial : 1
It is actually pretty much the same as the first subrange type,
so you might ask why this is causing trouble, when the resolution
of the previous DIE worked like a charm???
Well, for that, we need to backtrack a bit, and notice that, ahead
of the DW_TAG_structure_type's DIE, there is the following DIE:
<1><7e1>: Abbrev Number: 6 (DW_TAG_typedef)
<7e2> DW_AT_name : (indirect string, offset: 0xbae): reprod__obj_t__T5s
<7e6> DW_AT_decl_file : 2
<7e7> DW_AT_decl_line : 17
<7e8> DW_AT_type : <0x849>
... and that DIE references an array type...
<2><849>: Abbrev Number: 14 (DW_TAG_array_type)
<84a> DW_AT_name : (indirect string, offset: 0xbae): reprod__obj_t__T5s
<84e> DW_AT_GNAT_descriptive_type: <0x864>
<852> DW_AT_type : <0x748>
<856> DW_AT_sibling : <0x864>
... whose subrange is...
<3><85a>: Abbrev Number: 15 (DW_TAG_subrange_type)
<85b> DW_AT_type : <0x830>
<85f> DW_AT_upper_bound : <0x7fb>
... where the subrange's base type is the DW_TAG_subrange_type DIE
that is causing problem.
In summary, we process the typedef first, which causes us to process
the second subrange BEFORE we process the struct DIE itself, and
therefore the struct's discriminent (DW_TAG_member #1). As a result,
while trying to handle the reference to that DW_TAG_member #1 as
the upper bound of the second range type, we do...
case DW_AT_data_member_location:
{
[...]
baton->referenced_type = get_die_type (target_die->parent,
target_cu);
... where target_die->parent (DW_TAG_member #1) hasn't been processed
yet, and thus get_die_type returns NULL.
This is what later causes us problems trying to find the right address
to use as the base address for our field, which then triggers the
error message we are seeing.
This patch fixes the issue by calling read_type_die instead of
get_die_type. If the DIE has already been processed, then this
is the same as get_die_type. If not, the it'll get the parent
die to be read, and then get its type.
gdb/ChangeLog:
* dwarf2read.c (attr_to_dynamic_prop)
<DW_AT_data_member_location>: Use read_type_die isntead of
get_die_type.
Tested on x86_64-linux, no regression.
No testcase, unfortunately, as the reproducer was given to us by
a customer, and it's been otherwise surprisingly difficult to
reproduce the same error outside of that reproducer.
Consider the following code, which defines a function, Child2,
which is itself nested inside Child1:
procedure Foo_O224_021 is
O1 : constant Object_Type := Get_Str ("Foo");
procedure Child1 is
O2 : constant Object_Type := Get_Str ("Foo");
function Child2 (S : String) return Boolean is -- STOP
begin
for C of S loop
Do_Nothing (C);
if C = 'o' then
return True;
end if;
end loop;
return False;
end Child2;
R : Boolean;
begin
R := Child2 ("Foo");
R := Child2 ("Bar");
R := Child2 ("Foobar");
end Child1;
begin
Child1;
end Foo_O224_021;
On x86_64-linux, when compiled at -O2, GDB is unable to insert
a breakpoint on Child2:
% gnatmake -g -O2 foo_o224_021
% gdb foo_o224_021
(gdb) b child2
Function "child2" not defined.
(gdb) b foo_o224_021.child1.child2
Function "foo_o224_021.child1.child2" not defined.
The problem is caused by the fact that GDB did not create a symbol
for Child2, and this, in turn, is caused by the fact that the compiler
decided to inline Child1, but not Child2. The DWARF debugging info
first provides an abstract instance tree for Child1...
<3><1b7b>: Abbrev Number: 29 (DW_TAG_subprogram)
<1b7c> DW_AT_name : (indirect string, offset: 0x23f8): foo_o224_021__child1
<1b82> DW_AT_inline : 1 (inlined)
<1b83> DW_AT_sibling : <0x1c01>
... where that subprogram is given the DW_AT_inline attribute.
Inside that function there is a lexical block which has no PC
range (corresponding to the fact that this is the abstract tree):
<4><1b87>: Abbrev Number: 30 (DW_TAG_lexical_block)
... inside which our subprogram Child2 is described:
<5><1b92>: Abbrev Number: 32 (DW_TAG_subprogram)
<1b93> DW_AT_name : (indirect string, offset: 0x2452): foo_o224_021__child1__child2
<1b99> DW_AT_type : <0x1ab1>
<1b9d> DW_AT_low_pc : 0x402300
<1ba5> DW_AT_high_pc : 0x57
[...]
Then, later on, we get the concrete instance tree, starting at:
<3><1c5e>: Abbrev Number: 41 (DW_TAG_inlined_subroutine)
<1c5f> DW_AT_abstract_origin: <0x1b7b>
<1c63> DW_AT_entry_pc : 0x4025fd
<1c6b> DW_AT_ranges : 0x150
... which refers to Child1. One of that inlined subroutine children
is the concrete instance of the empty lexical block we saw above
(in the abstract instance tree), which gives the actual address
range for this inlined instance:
<5><1c7a>: Abbrev Number: 43 (DW_TAG_lexical_block)
<1c7b> DW_AT_abstract_origin: <0x1b87>
<1c7f> DW_AT_ranges : 0x180
This is the DIE which provides the context inside which we can
record Child2. But unfortunately, GDB does not take the abstract
origin into account when handling lexical blocks, causing it
to miss the fact that this block contains some symbols described
in the abstract instance tree. This is the first half of this patch:
modifying GDB to follow DW_AT_abstract_origin attributes for
lexical blocks.
But this not enough to fix the issue, as we're still unable to
break on Child2 with just that change. The second issue can be
traced to the way inherit_abstract_dies determines the list of
DIEs to inherit from. For that, it iterates over all the DIEs in
the concrete instance tree, and finds the list of DIEs from the
abstract instance tree that are not referenced from the concrete
instance tree. As it happens, there is one type of DIE in the
concrete instance tree which does reference Child2's DIE, but
in fact does otherwise define a concrete instance of the reference
DIE; that's (where <0x1b92> is Child2's DIE):
<6><1d3c>: Abbrev Number: 35 (DW_TAG_GNU_call_site)
<1d3d> DW_AT_low_pc : 0x4026a4
<1d45> DW_AT_abstract_origin: <0x1b92>
So, the second part of the patch is to modify inherit_abstract_dies
to ignore DW_TAG_GNU_call_site DIEs when iterating over the concrete
instance tree.
This patch also includes a testcase which can be used to reproduce
the issue. Unfortunately, for it to actually pass, a smal patch in
GCC is also necessary to make sure that GCC provides lexical blocks'
DW_AT_abstract_origin attributes from the concrete tree back to
the abstract tree. We hope to be able to submit and integrate that
patch in the GCC tree soon. Meanwhile, a setup_xfail has been added.
gdb/ChangeLog:
2014-05-05 Pierre-Marie de Rodat <derodat@adacore.com>
* dwarf2read.c (inherit_abstract_dies): Skip
DW_TAG_GNU_call_site dies while inheriting children of an
abstract DIE into a scope.
(read_lexical_block_scope): Inherit abstract DIE's for
lexical scopes.
gdb/testsuite/ChangeLog:
* gdb.ada/out_of_line_in_inlined: New testcase.
"info fun foo" can be a pain when it's not interruptable,
especially if you're not exactly sure of what you're looking for
and provide something that matches too much.
gdb/ChangeLog:
* dwarf2read.c (dw2_expand_symtabs_matching): Add some QUIT calls.
Variables with a DW_AT_const_value but without a DW_AT_location were not
getting added to the partial symbol table. They are added to the full
symbol table, however, when the compilation unit's psymtabs are
expanded.
Before:
(gdb) p one
No symbol "one" in current context.
(gdb) mt flush-symbol-cache
(gdb) mt expand one.c
(gdb) p one
$1 = 1
After:
(gdb) p one
$1 = 1
To the user it's pretty strange, as depending on whether tab completion
has forced expansion of all CUs or not the lookup might succeed, or not
if the failure was already added to the symbol cache.
This commit simply makes sure to add constants to the partial symbol
tables.
gdb/testsuite/ChangeLog:
PR symtab/18148
* gdb.dwarf2/dw2-intercu.S (one, two): Add variables that have a
const_value but not a location.
* gdb.dwarf2/dw2-intercu.exp: Add tests that constants without
location defined in non-main CUs are visible.
gdb/ChangeLog:
PR symtab/18148
* dwarf2read.c (struct partial_die_info): Add has_const_value
member.
(add_partial_symbol): Don't punt on symbols that have const_value
attributes.
(read_partial_die): Detect DW_AT_const_value.
The terminology we've been using is (dynamic) "property" rather than
"attribute", so this patch renames an enum to use the same terminology.
No behavior change.
gdb/ChangeLog:
* gdbtypes.h (enum dynamic_prop_node_kind) <DYN_PROP_DATA_LOCATION>:
Renames DYN_ATTR_DATA_LOCATION.
(TYPE_DATA_LOCATION): Use DYN_PROP_DATA_LOCATION instead of
DYN_ATTR_DATA_LOCATION.
* dwarf2read.c (set_die_type): Use DYN_PROP_DATA_LOCATION
instead of DYN_ATTR_DATA_LOCATION.
Tested on x86_64-linux.
This bug appears to be caused by bad debuginfo. The method
causing the sefault in the reporter's test case is marked both static
and virtual.
This patch simply safegaurds against this case in dwarf2_add_member_fn,
where the code assumes that there is a `this' pointer when a virtual method
is seen (more specifically, when DW_AT_vtable_elem is seen).
It previously dereferenced the first formal parameter
(`this' pointer), which in this case doesn't exist. GDB consequently
segfaulted dereferencing a NULL pointer.
gdb/ChangeLog
PR gdb/18021
* dwarf2read.c (dwarf2_add_member_fn): Issue a complaint
if we find a static method with DW_AT_vtable_elem_location.
gdb/testsuite/ChangeLog
PR gdb/18021
* gdb.dwarf2/staticvirtual.exp: New test.
This patch introduces a linked list for dynamic attributes of a type.
This is a pre-work for the Fortran dynamic array support. The Fortran
dynamic array support will add more dynamic attributes to a type.
As only a few types will have such dynamic attributes set, a linked
list is more efficient in terms of memory consumption than adding
multiple attributes to main_type.
gdb/ChangeLog:
* gdbtypes.c (resolve_dynamic_type_internal): Adapt
data_location usage to linked list.
(resolve_dynamic_type_internal): Adapt data_location to
linked list.
(get_dyn_prop, add_dyn_prop, copy_dynamic_prop_list): New function.
(copy_type_recursive, copy_type): Add copy of linked list.
* gdbtypes.h (enum dynamic_prop_node_kind): New enum.
(struct dynamic_prop_list): New struct.
* dwarf2read.c (set_die_type): Set data_location data.
This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
This commit introduces a new inline common function "startswith"
which takes two string arguments and returns nonzero if the first
string starts with the second. It also updates the 295 places
where this logic was written out longhand to use the new function.
gdb/ChangeLog:
* common/common-utils.h (startswith): New inline function.
All places where this logic was used updated to use the above.
In C, an enum or structure defined inside other structure has global
scope just like it had been defined outside the struct in the first
place. However, in C++, such a nested structure is given a name that
is nested inside the structure. This patch moves such affected
structures/enums out to global scope, so that code using them works
the same in C++ as it works today in C.
gdb/ChangeLog:
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
* dwarf2-frame.c (enum cfa_how_kind, struct
dwarf2_frame_state_reg_info): Move out of struct
dwarf2_frame_state.
* dwarf2read.c (struct tu_stats): Move out of struct
dwarf2_per_objfile.
(struct file_entry): Move out of struct line_header.
(struct nextfield, struct nextfnfield, struct fnfieldlist, struct
typedef_field_list): Move out of struct field_info.
* gdbtypes.h (enum dynamic_prop_kind, union dynamic_prop_data):
Move out of struct dynamic_prop.
(union type_owner, union field_location, struct field, struct
range_bounds, union type_specific): Move out of struct main_type.
(struct fn_fieldlist, struct fn_field, struct typedef_field)
(VOFFSET_STATIC): Move out of struct cplus_struct_type.
(struct call_site_target, union call_site_parameter_u, struct
call_site_parameter): Move out of struct call_site.
* m32c-tdep.c (enum m32c_prologue_kind): Move out of struct
m32c_prologue.
(enum srcdest_kind): Move out of struct srcdest.
* main.c (enum cmdarg_kind): Move out of struct cmdarg.
* prologue-value.h (enum prologue_value_kind): Move out of struct
prologue_value.
* s390-linux-tdep.c (enum s390_abi_kind): Move out of struct
gdbarch_tdep.
* stabsread.c (struct nextfield, struct next_fnfieldlist): Move
out of struct field_info.
* symfile.h (struct other_sections): Move out of struct
section_addr_info.
* symtab.c (struct symbol_cache_slot): Move out struct
block_symbol_cache.
* target-descriptions.c (enum tdesc_type_kind): Move out of
typedef struct tdesc_type.
* tui/tui-data.h (enum tui_line_or_address_kind): Move out of
struct tui_line_or_address.
* value.c (enum internalvar_kind, union internalvar_data): Move
out of struct internalvar.
* xtensa-tdep.h (struct ctype_cache): Move out of struct
gdbarch_tdep.
This patch renames symbols that happen to have names which are
reserved keywords in C++.
Most of this was generated with Tromey's cxx-conversion.el script.
Some places where later hand massaged a bit, to fix formatting, etc.
And this was rebased several times meanwhile, along with re-running
the script, so re-running the script from scratch probably does not
result in the exact same output. I don't think that matters anyway.
gdb/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
gdb/gdbserver/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
This patch addresses two issues.
The basic problem is that "(anonymous namespace)" doesn't get entered
into the symbol table because when dwarf2read.c:new_symbol_full is called
the DIE has no name (dwarf2_name returns NULL).
PR 17976: ptype '(anonymous namespace)' should work like any namespace
PR 17821: perf issue looking up (anonymous namespace)
bash$ gdb monster-program
(gdb) mt set per on
(gdb) mt set symbol-cache-size 0
(gdb) break (anonymous namespace)::foo
Before:
Command execution time: 3.266289 (cpu), 6.169030 (wall)
Space used: 811429888 (+12910592 for this command)
After:
Command execution time: 1.264076 (cpu), 4.057408 (wall)
Space used: 798781440 (+0 for this command)
gdb/ChangeLog:
PR c++/17976, symtab/17821
* cp-namespace.c (cp_search_static_and_baseclasses): New parameter
is_in_anonymous. All callers updated.
(find_symbol_in_baseclass): Ditto.
(cp_lookup_nested_symbol_1): Ditto. Don't search all static blocks
for symbols in an anonymous namespace.
* dwarf2read.c (namespace_name): Don't call dwarf2_name, fetch
DW_AT_name directly.
(dwarf2_name): Convert missing namespace name to
CP_ANONYMOUS_NAMESPACE_STR.
gdeb/testsuite/ChangeLog:
* gdb.cp/anon-ns.exp: Add test for ptype '(anonymous namespace)'.
DWARFv5 defines and GCC5 may output two new DW_LANG constants for the
Fortran 2003 and Fortran 2008 standards. Recognize both as variants of
language_fortran.
gdb/ChangeLog:
* dwarf2read.c (set_cu_language): Recognize DW_LANG_Fortran03 and
DW_LANG_Fortran08 as language_fortran.
http://dwarfstd.org/ShowIssue.php?issue=141121.1
Every type has to pay the price in memory usage for their presence.
The proper place for them is in the type_specific field which exists
for this purpose.
gdb/ChangeLog:
* dwarf2read.c (process_structure_scope): Update setting of
TYPE_VPTR_BASETYPE, TYPE_VPTR_FIELDNO.
* gdbtypes.c (internal_type_vptr_fieldno): New function.
(set_type_vptr_fieldno): New function.
(internal_type_vptr_basetype): New function.
(set_type_vptr_basetype): New function.
(get_vptr_fieldno): Update setting of TYPE_VPTR_FIELDNO,
TYPE_VPTR_BASETYPE.
(allocate_cplus_struct_type): Initialize vptr_fieldno.
(recursive_dump_type): Printing of vptr_fieldno, vptr_basetype ...
(print_cplus_stuff): ... moved here.
(copy_type_recursive): Don't copy TYPE_VPTR_BASETYPE.
* gdbtypes.h (struct main_type): Members vptr_fieldno, vptr_basetype
moved to ...
(struct cplus_struct_type): ... here. All uses updated.
(TYPE_VPTR_FIELDNO, TYPE_VPTR_BASETYPE): Rewrite.
(internal_type_vptr_fieldno, set_type_vptr_fieldno): Declare.
(internal_type_vptr_basetype, set_type_vptr_basetype): Declare.
* stabsread.c (read_tilde_fields): Update setting of
TYPE_VPTR_FIELDNO, TYPE_VPTR_BASETYPE.
gdb/testsuite/ChangeLog:
* gdb.base/maint.exp <maint print type argc>: Update expected output.
This patch moves TYPE_SELF_TYPE into new field type_specific.self_type
for MEMBERPTR,METHODPTR types, and into type_specific.func_stuff
for METHODs, and then updates everything to use that.
TYPE_CODE_METHOD could share some things with TYPE_CODE_FUNC
(e.g. TYPE_NO_RETURN) and it seemed simplest to keep them together.
Moving TYPE_SELF_TYPE into type_specific.func_stuff for TYPE_CODE_METHOD
is also nice because when we allocate space for function types we assume
they're TYPE_CODE_FUNCs. If TYPE_CODE_METHODs don't need or use that
space then that space would be wasted, and cleaning that up would involve
more invasive changes.
In order to catch errant uses I've added accessor functions
that do some checking.
One can no longer assign to TYPE_SELF_TYPE like this:
TYPE_SELF_TYPE (foo) = bar;
One instead has to do:
set_type_self_type (foo, bar);
But I've left reading of the type to the macro:
bar = TYPE_SELF_TYPE (foo);
In order to discourage bypassing the TYPE_SELF_TYPE macro
I've named the underlying function that implements it
internal_type_self_type.
While testing this I found the stabs reader leaving methods
as TYPE_CODE_FUNCs, hitting my newly added asserts.
Since the dwarf reader smashes functions to methods (via
smash_to_method) I've done a similar thing for stabs.
gdb/ChangeLog:
* cp-valprint.c (cp_find_class_member): Rename parameter domain_p
to self_p.
(cp_print_class_member): Rename local domain to self_type.
* dwarf2read.c (quirk_gcc_member_function_pointer): Rename local
domain_type to self_type.
(set_die_type) <need_gnat_info>: Handle
TYPE_CODE_METHODPTR, TYPE_CODE_MEMBERPTR, TYPE_CODE_METHOD.
* gdb-gdb.py (StructMainTypePrettyPrinter): Handle
TYPE_SPECIFIC_SELF_TYPE.
* gdbtypes.c (internal_type_self_type): New function.
(set_type_self_type): New function.
(smash_to_memberptr_type): Rename parameter domain to self_type.
Update setting of TYPE_SELF_TYPE.
(smash_to_methodptr_type): Update setting of TYPE_SELF_TYPE.
(smash_to_method_type): Rename parameter domain to self_type.
Update setting of TYPE_SELF_TYPE.
(check_stub_method): Call smash_to_method_type.
(recursive_dump_type): Handle TYPE_SPECIFIC_SELF_TYPE.
(copy_type_recursive): Ditto.
* gdbtypes.h (enum type_specific_kind): New value
TYPE_SPECIFIC_SELF_TYPE.
(struct main_type) <type_specific>: New member self_type.
(struct cplus_struct_type) <fn_field.type>: Update comment.
(TYPE_SELF_TYPE): Rewrite.
(internal_type_self_type, set_type_self_type): Declare.
* gnu-v3-abi.c (gnuv3_print_method_ptr): Rename local domain to
self_type.
(gnuv3_method_ptr_to_value): Rename local domain_type to self_type.
* m2-typeprint.c (m2_range): Replace TYPE_SELF_TYPE with
TYPE_TARGET_TYPE.
* stabsread.c (read_member_functions): Mark methods with
TYPE_CODE_METHOD, not TYPE_CODE_FUNC. Update setting of
TYPE_SELF_TYPE.
This commit adds a new callback parameter, "expansion_notify", to the
top-level expand_symtabs_matching function and to all the vectorized
functions it defers to. If expansion_notify is non-NULL, it will be
called every time a symbol table is expanded.
gdb/ChangeLog:
* symfile.h (expand_symtabs_exp_notify_ftype): New typedef.
(struct quick_symbol_functions) <expand_symtabs_matching>:
New argument expansion_notify. All uses updated.
(expand_symtabs_matching): New argument expansion_notify.
All uses updated.
* symfile-debug.c (debug_qf_expand_symtabs_matching):
Also print expansion notify.
* symtab.c (expand_symtabs_matching_via_partial): Call
expansion_notify whenever a partial symbol table is expanded.
* dwarf2read.c (dw2_expand_symtabs_matching): Call
expansion_notify whenever a symbol table is instantiated.
Both dwarf2read.c (checkproducer) and utils.c (producer_is_gcc_ge_4)
implemented a GCC producer parser that tried to extract the major and minor
version of GCC. Merge them into one GCC producer parser used by both. Also
allow digits in the identifier after "GNU " such as used by GCC5 like:
"GNU C11 5.0.0 20150123 (experimental) -mtune=generic -march=x86-64 -gdwarf-5"
gdb/ChangeLog:
* dwarf2read.c (checkproducer): Call producer_is_gcc.
* utils.c (producer_is_gcc_ge_4): Likewise.
(producer_is_gcc): New function.
* utils.h (producer_is_gcc): New declaration.
Consider the following declarations:
type Array_Type is array (Integer range <>) of Integer;
type Record_Type (N : Integer) is record
A : Array_Type (1 .. N);
end record;
R : Record_Type := Get (10);
It defines what Ada programers call a "discriminated record", where
"N" is a component of that record called a "discriminant", and where
"A" is a component defined as an array type whose upper bound is
equal to the value of the discriminant.
So far, we rely on a number of fairly complex GNAT-specific encodings
to handle this situation. This patch is to enhance GDB to be able to
print this record in the case where the compiler has been modified
to replace those encodings by pure DWARF constructs.
In particular, the debugging information generated for the record above
looks like the following. "R" is a record..
.uleb128 0x10 # (DIE (0x13e) DW_TAG_structure_type)
.long .LASF17 # DW_AT_name: "foo__record_type"
... whose is is of course dynamic (not our concern here)...
.uleb128 0xd # DW_AT_byte_size
.byte 0x97 # DW_OP_push_object_address
.byte 0x94 # DW_OP_deref_size
.byte 0x4
.byte 0x99 # DW_OP_call4
.long 0x19b
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x7
.byte 0x9 # DW_OP_const1s
.byte 0xfc
.byte 0x1a # DW_OP_and
.byte 0x1 # DW_AT_decl_file (foo.adb)
.byte 0x6 # DW_AT_decl_line
... and then has 2 members, fist "n" (our discriminant);
.uleb128 0x11 # (DIE (0x153) DW_TAG_member)
.ascii "n\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file (foo.adb)
.byte 0x6 # DW_AT_decl_line
.long 0x194 # DW_AT_type
.byte 0 # DW_AT_data_member_location
... and "A"...
.uleb128 0x11 # (DIE (0x181) DW_TAG_member)
.ascii "a\0" # DW_AT_name
.long 0x15d # DW_AT_type
.byte 0x4 # DW_AT_data_member_location
... which is an array ...
.uleb128 0x12 # (DIE (0x15d) DW_TAG_array_type)
.long .LASF18 # DW_AT_name: "foo__record_type__T4b"
.long 0x194 # DW_AT_type
... whose lower bound is implicitly 1, and the upper bound
a reference to DIE 0x153 = "N":
.uleb128 0x13 # (DIE (0x16a) DW_TAG_subrange_type)
.long 0x174 # DW_AT_type
.long 0x153 # DW_AT_upper_bound
This patch enhanced GDB to understand references to other DIEs
where the DIE's address is at an offset of its enclosing type.
The difficulty was that the address used to resolve the array's
type (R's address + 4 bytes) is different from the address used
as the base to compute N's address (an offset to R's address).
We're solving this issue by using a stack of addresses rather
than a single address when trying to resolve a type. Each address
in the stack corresponds to each containing level. For instance,
if resolving the field of a struct, the stack should contain
the address of the field at the top, and then the address of
the struct. That way, if the field makes a reference to an object
of the struct, we can retrieve the address of that struct, and
properly resolve the dynamic property references that struct.
gdb/ChangeLog:
* gdbtypes.h (struct dynamic_prop): New PROP_ADDR_OFFSET enum
kind.
* gdbtypes.c (resolve_dynamic_type_internal): Replace "addr"
parameter by "addr_stack" parameter.
(resolve_dynamic_range): Replace "addr" parameter by
"stack_addr" parameter. Update function documentation.
Update code accordingly.
(resolve_dynamic_array, resolve_dynamic_union)
(resolve_dynamic_struct, resolve_dynamic_type_internal): Likewise.
(resolve_dynamic_type): Update code, following the changes made
to resolve_dynamic_type_internal's interface.
* dwarf2loc.h (struct property_addr_info): New.
(dwarf2_evaluate_property): Replace "address" parameter
by "addr_stack" parameter. Adjust function documentation.
(struct dwarf2_offset_baton): New.
(struct dwarf2_property_baton): Update documentation of
field "referenced_type" to be more general. New field
"offset_info" in union data field.
* dwarf2loc.c (dwarf2_evaluate_property): Replace "address"
parameter by "addr_stack" parameter. Adjust code accordingly.
Add support for PROP_ADDR_OFFSET properties.
* dwarf2read.c (attr_to_dynamic_prop): Add support for
DW_AT_data_member_location attributes as well. Use case
statements instead of if/else condition.
gdb/testsuite/ChangeLog:
* gdb.ada/disc_arr_bound: New testcase.
Tested on x86_64-linux, no regression.
Since Fedora started to use DWZ DWARF compressor:
http://fedoraproject.org/wiki/Features/DwarfCompressor
GDB has slowed down a lot. To make it clear - DWZ is DWARF structure
rearrangement, "compressor" does not mean any zlib style data compression.
This patch reduces LibreOffice backtrace from 5 minutes to 3 seconds (100x)
and it also reduces memory consumption 20x.
[ benchmark is at the bottom of this mail ]
Example of DWZ output:
------------------------------------------------------------------------------
Compilation Unit @ offset 0xc4:
<0><cf>: Abbrev Number: 17 (DW_TAG_partial_unit)
<d0> DW_AT_stmt_list : 0x0
<d4> DW_AT_comp_dir : (indirect string, offset: 0x6f): /usr/src/debug/gdb-7.7.1/build-x86_64-redhat-linux-gnu/gdb
<1><d8>: Abbrev Number: 9 (DW_TAG_typedef)
<d9> DW_AT_name : (indirect string, offset: 0x827dc): size_t
<dd> DW_AT_decl_file : 4
<de> DW_AT_decl_line : 212
<df> DW_AT_type : <0xae>
Compilation Unit @ offset 0xe4:
<0><ef>: Abbrev Number: 13 (DW_TAG_partial_unit)
<f0> DW_AT_stmt_list : 0x0
<f4> DW_AT_comp_dir : (indirect string, offset: 0x6f): /usr/src/debug/gdb-7.7.1/build-x86_64-redhat-linux-gnu/gdb
<1><f8>: Abbrev Number: 45 (DW_TAG_typedef)
<f9> DW_AT_name : (indirect string, offset: 0x251): __off_t
<fd> DW_AT_decl_file : 3
<fe> DW_AT_decl_line : 131
<ff> DW_AT_type : <0x68>
Compilation Unit @ offset 0x62d9f9:
<0><62da04>: Abbrev Number: 20 (DW_TAG_compile_unit)
[...]
<62da12> DW_AT_low_pc : 0x807e10
<62da1a> DW_AT_high_pc : 134
<62da1c> DW_AT_stmt_list : 0xf557e
<1><62da20>: Abbrev Number: 7 (DW_TAG_imported_unit)
<62da21> DW_AT_import : <0xcf> [Abbrev Number: 17]
------------------------------------------------------------------------------
One can see all DW_TAG_partial_unit have DW_AT_stmt_list 0x0 which causes
repeated decoding of that .debug_line unit on each DW_TAG_imported_unit.
This was OK before as each DW_TAG_compile_unit has its own .debug_line unit.
But since the introduction of DW_TAG_partial_unit by DWZ one should cache
read-in DW_AT_stmt_list .debug_line units.
Fortunately one does not need to cache whole
struct linetable *symtab->linetable
and other data from .debug_line mapping PC<->lines
------------------------------------------------------------------------------
Line Number Statements:
Extended opcode 2: set Address to 0x45c880
Advance Line by 25 to 26
Copy
------------------------------------------------------------------------------
as the only part of .debug_line which GDB needs for DW_TAG_partial_unit is:
------------------------------------------------------------------------------
The Directory Table:
../../gdb
/usr/include/bits
[...]
The File Name Table:
Entry Dir Time Size Name
1 1 0 0 gdb.c
2 2 0 0 string3.h
[...]
------------------------------------------------------------------------------
specifically referenced in GDB for DW_AT_decl_file at a single place:
------------------------------------------------------------------------------
fe = &cu->line_header->file_names[file_index - 1];
SYMBOL_SYMTAB (sym) = fe->symtab;
------------------------------------------------------------------------------
This is because for some reason DW_TAG_partial_unit never contains PC-related
DWARF information. I do not know exactly why, the compression ratio is a bit
lower due to it but thanksfully currently it is that way:
dwz.c:
------------------------------------------------------------------------------
/* These attributes reference code, prevent moving
DIEs with them. */
case DW_AT_low_pc:
case DW_AT_high_pc:
case DW_AT_entry_pc:
case DW_AT_ranges:
die->die_ck_state = CK_BAD;
+
/* State of checksum computation. Not computed yet, computed and
suitable for moving into partial units, currently being computed
and finally determined unsuitable for moving into partial units. */
enum { CK_UNKNOWN, CK_KNOWN, CK_BEING_COMPUTED, CK_BAD } die_ck_state : 2;
------------------------------------------------------------------------------
I have also verified also real-world Fedora debuginfo files really comply with
that assumption with dwgrep
https://github.com/pmachata/dwgrep
using:
------------------------------------------------------------------------------
dwgrep -e 'entry ?DW_TAG_partial_unit child* ( ?DW_AT_low_pc , ?DW_AT_high_pc , ?DW_AT_ranges )' /usr/lib/debug/**
------------------------------------------------------------------------------
BTW I think GDB already does not support the whole DW_TAG_imported_unit and
DW_TAG_partial_unit usage possibilities as specified by the DWARF standard.
I think GDB would not work if DW_TAG_imported_unit was used in some inner
level and not at the CU level (readelf -wi level <1>) - this is how DWZ is
using DW_TAG_imported_unit. Therefore I do not think further assumptions
about DW_TAG_imported_unit and DW_TAG_partial_unit usage by DWZ are a problem
for GDB.
One could save the whole .debug_line decoded PC<->lines mapping (and not just
the DW_AT_decl_file table) but:
* there are some problematic corner cases so one could do it incorrectly
* there are no real world data to really test such patch extension
* such extension could be done perfectly incrementally on top of this patch
------------------------------------------------------------------------------
benchmark - on Fedora 20 x86_64 and FSF GDB HEAD:
echo -e 'thread apply all bt\nset confirm no\nq'|./gdb -p `pidof soffice.bin` -ex 'set pagination off' -ex 'maintenance set per-command
space' -ex 'maintenance set per-command symtab' -ex 'maintenance set per-command time'
FSF GDB HEAD ("thread apply all bt"):
Command execution time: 333.693000 (cpu), 335.587539 (wall)
---sec
Space used: 1736404992 (+1477189632 for this command)
----MB
vs.
THIS PATCH ("thread apply all bt"):
Command execution time: 2.595000 (cpu), 2.607573 (wall)
-sec
Space used: 340058112 (+85917696 for this command)
--MB
FSF GDB HEAD ("thread apply all bt full"):
Command execution time: 466.751000 (cpu), 468.345837 (wall)
---sec
Space used: 2330132480 (+2070974464 for this command)
----MB
vs.
THIS PATCH ("thread apply all bt full"):
Command execution time: 18.907000 (cpu), 18.964125 (wall)
--sec
Space used: 364462080 (+110325760 for this command)
---MB
------------------------------------------------------------------------------
gdb/ChangeLog
2015-01-24 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix 100x slowdown regression on DWZ files.
* dwarf2read.c (struct dwarf2_per_objfile): Add line_header_hash.
(struct line_header): Add offset and offset_in_dwz.
(dwarf_decode_lines): Add parameter decode_mapping to the declaration.
(free_line_header_voidp): New declaration.
(line_header_hash, line_header_hash_voidp, line_header_eq_voidp): New
functions.
(dwarf2_build_include_psymtabs): Update dwarf_decode_lines caller.
(handle_DW_AT_stmt_list): Use line_header_hash.
(free_line_header_voidp): New function.
(dwarf_decode_line_header): Initialize offset and offset_in_dwz.
(dwarf_decode_lines): New parameter decode_mapping, use it.
(dwarf2_free_objfile): Free line_header_hash.
Add a flag field is_noreturn to struct func_type. Make calling_convention
a small bit field to not increase the size of the struct. Set is_noreturn
if the new GCC5/DWARF5 DW_AT_noreturn is set on a DW_TAG_subprogram.
Use this information to warn the user before doing a finish or return from
a function that does not return normally to its caller.
(gdb) finish
warning: Function endless does not return normally.
Try to finish anyway? (y or n)
(gdb) return
warning: Function does not return normally to caller.
Make endless return now? (y or n)
gdb/ChangeLog
* dwarf2read.c (read_subroutine_type): Set TYPE_NO_RETURN from
DW_AT_noreturn.
* gdbtypes.h (struct func_type): Add is_noreturn field flag. Make
calling_convention an 8 bit bit field.
(TYPE_NO_RETURN): New macro.
* infcmd.c (finish_command): Query if function does not return
normally.
* stack.c (return_command): Likewise.
gdb/testsuite/ChangeLog
* gdb.base/noreturn-return.c: New file.
* gdb.base/noreturn-return.exp: New file.
* gdb.base/noreturn-finish.c: New file.
* gdb.base/noreturn-finish.exp: New file.
include/ChangeLog
* dwarf2.def (DW_AT_noreturn): New DWARF5 attribute.
The dwarf2.h addition and the code to emit the new attribute is already in
the gcc tree.
gdb/ChangeLog:
* buildsym.c: Add comments describing how the buildsym machinery
is used by the various file formats.
(really_free_pendings): Enhance function comment.
See pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildsym_compunit.
(free_buildsym_compunit): Set current_subfile to NULL.
(prepare_for_building): New function.
(start_symtab): Call it. Remove call to set_last_source_file.
(restart_symtab): New arg "cust". All callers updated.
Simplify, call prepare_for_building. Re-initialize buildsym_compunit.
(reset_symtab_globals): Enhance function comment.
Set local_symbols, file_symbols, global_symbols to NULL.
Set pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildysym_compunit.
(end_symtab_without_blockvector): Delete. All callers updated.
(end_symtab_with_blockvector): Remove redundant call to
free_buildsym_compunit.
(augment_type_symtab): Remove arg "cust". All callers updated.
(buildsym_init): Remove resetting of free_pendings, file_symbols,
global_symbols, pending_blocks, pending_macros. Instead make
handling consistent with pending_addrmap: Assert value was reset
at end of previous symtab building. Initialize context_stack here.
1. Background information
The MIPS architecture, as originally designed and implemented in
mid-1980s has a uniform instruction word size that is 4 bytes, naturally
aligned. As such all MIPS instructions are located at addresses that
have their bits #1 and #0 set to zeroes, and any attempt to execute an
instruction from an address that has any of the two bits set to one
causes an address error exception. This may for example happen when a
jump-register instruction is executed whose register value used as the
jump target has any of these bits set.
Then in mid 1990s LSI sought a way to improve code density for their
TinyRISC family of MIPS cores and invented an alternatively encoded
instruction set in a joint effort with MIPS Technologies (then a
subsidiary of SGI). The new instruction set has been named the MIPS16
ASE (Application-Specific Extension) and uses a variable instruction
word size, which is 2 bytes (as the name of the ASE suggests) for most,
but there are a couple of exceptions that take 4 bytes, and then most of
the 2-byte instructions can be treated with a 2-byte extension prefix to
expand the range of the immediate operands used.
As a result instructions are no longer 4-byte aligned, instead they are
aligned to a multiple of 2. That left the bit #0 still unused for code
references, be it for the standard MIPS (i.e. as originally invented) or
for the MIPS16 instruction set, and based on that observation a clever
trick was invented that on one hand allowed the processor to be
seamlessly switched between the two instruction sets at any time at the
run time while on the other avoided the introduction of any special
control register to do that.
So it is the bit #0 of the instruction address that was chosen as the
selector and named the ISA bit. Any instruction executed at an even
address is interpreted as a standard MIPS instruction (the address still
has to have its bit #1 clear), any instruction executed at an odd
address is interpreted as a MIPS16 instruction.
To switch between modes ordinary jump instructions are used, such as
used for function calls and returns, specifically the bit #0 of the
source register used in jump-register instructions selects the execution
(ISA) mode for the following piece of code to be interpreted in.
Additionally new jump-immediate instructions were added that flipped the
ISA bit to select the opposite mode upon execution. They were
considered necessary to avoid the need to make register jumps in all
cases as the original jump-immediate instructions provided no way to
change the bit #0 at all.
This was all important for cases where standard MIPS and MIPS16 code had
to be mixed, either for compatibility with the existing binary code base
or to access resources not reachable from MIPS16 code (the MIPS16
instruction set only provides access to general-purpose registers, and
not for example floating-point unit registers or privileged coprocessor
0 registers) -- pieces of code in the opposite mode can be executed as
ordinary subroutine calls.
A similar approach has been more recently adopted for the MIPS16
replacement instruction set defined as the so called microMIPS ASE.
This is another instruction set encoding introduced to the MIPS
architecture. Just like the MIPS16 ASE, the microMIPS instruction set
uses a variable-length encoding, where each instruction takes a multiple
of 2 bytes. The ISA bit has been reused and for microMIPS-capable
processors selects between the standard MIPS and the microMIPS mode
instead.
2. Statement of the problem
To put it shortly, MIPS16 and microMIPS code pointers used by GDB are
different to these observed at the run time. This results in the same
expressions being evaluated producing different results in GDB and in
the program being debugged. Obviously it's the results obtained at the
run time that are correct (they define how the program behaves) and
therefore by definition the results obtained in GDB are incorrect.
A bit longer description will record that obviously at the run time the
ISA bit has to be set correctly (refer to background information above
if unsure why so) or the program will not run as expected. This is
recorded in all the executable file structures used at the run time: the
dynamic symbol table (but not always the static one!), the GOT, and
obviously in all the addresses embedded in code or data of the program
itself, calculated by applying the appropriate relocations at the static
link time.
While a program is being processed by GDB, the ISA bit is stripped off
from any code addresses, presumably to make them the same as the
respective raw memory byte address used by the processor to access the
instruction in the instruction fetch access cycle. This stripping is
actually performed outside GDB proper, in BFD, specifically
_bfd_mips_elf_symbol_processing (elfxx-mips.c, see the piece of code at
the very bottom of that function, starting with an: "If this is an
odd-valued function symbol, assume it's a MIPS16 or microMIPS one."
comment).
This function is also responsible for symbol table dumps made by
`objdump' too, so you'll never see the ISA bit reported there by that
tool, you need to use `readelf'.
This is however unlike what is ever done at the run time, the ISA bit
once present is never stripped off, for example a cast like this:
(short *) main
will not strip the ISA bit off and if the resulting pointer is intended
to be used to access instructions as data, for example for software
instruction decoding (like for fault recovery or emulation in a signal
handler) or for self-modifying code then the bit still has to be
stripped off by an explicit AND operation.
This is probably best illustrated with a simple real program example.
Let's consider the following simple program:
$ cat foobar.c
int __attribute__ ((mips16)) foo (void)
{
return 1;
}
int __attribute__ ((mips16)) bar (void)
{
return 2;
}
int __attribute__ ((nomips16)) foo32 (void)
{
return 3;
}
int (*foo32p) (void) = foo32;
int (*foop) (void) = foo;
int fooi = (int) foo;
int
main (void)
{
return foop ();
}
$
This is plain C with no odd tricks, except from the instruction mode
attributes. They are not necessary to trigger this problem, I just put
them here so that the program can be contained in a single source file
and to make it obvious which function is MIPS16 code and which is not.
Let's try it with Linux, so that everyone can repeat this experiment:
$ mips-linux-gnu-gcc -mips16 -g -O2 -o foobar foobar.c
$
Let's have a look at some interesting symbols:
$ mips-linux-gnu-readelf -s foobar | egrep 'table|foo|bar'
Symbol table '.dynsym' contains 7 entries:
Symbol table '.symtab' contains 95 entries:
55: 00000000 0 FILE LOCAL DEFAULT ABS foobar.c
66: 0040068c 4 FUNC GLOBAL DEFAULT [MIPS16] 12 bar
68: 00410848 4 OBJECT GLOBAL DEFAULT 21 foo32p
70: 00410844 4 OBJECT GLOBAL DEFAULT 21 foop
78: 00400684 8 FUNC GLOBAL DEFAULT 12 foo32
80: 00400680 4 FUNC GLOBAL DEFAULT [MIPS16] 12 foo
88: 00410840 4 OBJECT GLOBAL DEFAULT 21 fooi
$
Hmm, no sight of the ISA bit, but notice how foo and bar (but not
foo32!) have been marked as MIPS16 functions (ELF symbol structure's
`st_other' field is used for that).
So let's try to run and poke at this program with GDB. I'll be using a
native system for simplicity (I'll be using ellipses here and there to
remove unrelated clutter):
$ ./foobar
$ echo $?
1
$
So far, so good.
$ gdb ./foobar
[...]
(gdb) break main
Breakpoint 1 at 0x400490: file foobar.c, line 23.
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb)
Yay, it worked! OK, so let's poke at it:
(gdb) print main
$1 = {int (void)} 0x400490 <main>
(gdb) print foo32
$2 = {int (void)} 0x400684 <foo32>
(gdb) print foo32p
$3 = (int (*)(void)) 0x400684 <foo32>
(gdb) print bar
$4 = {int (void)} 0x40068c <bar>
(gdb) print foo
$5 = {int (void)} 0x400680 <foo>
(gdb) print foop
$6 = (int (*)(void)) 0x400681 <foo>
(gdb)
A-ha! Here's the difference and finally the ISA bit!
(gdb) print /x fooi
$7 = 0x400681
(gdb) p/x $pc
p/x $pc
$8 = 0x400491
(gdb)
And here as well...
(gdb) advance foo
foo () at foobar.c:4
4 }
(gdb) disassemble
Dump of assembler code for function foo:
0x00400680 <+0>: jr ra
0x00400682 <+2>: li v0,1
End of assembler dump.
(gdb) finish
Run till exit from #0 foo () at foobar.c:4
main () at foobar.c:24
24 }
Value returned is $9 = 1
(gdb) continue
Continuing.
[Inferior 1 (process 14103) exited with code 01]
(gdb)
So let's be a bit inquisitive...
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb)
Actually we do not like to run foo here at all. Let's run bar instead!
(gdb) set foop = bar
(gdb) print foop
$10 = (int (*)(void)) 0x40068c <bar>
(gdb)
Hmm, no ISA bit. Is it going to work?
(gdb) advance bar
bar () at foobar.c:9
9 }
(gdb) p/x $pc
$11 = 0x40068c
(gdb) disassemble
Dump of assembler code for function bar:
=> 0x0040068c <+0>: jr ra
0x0040068e <+2>: li v0,2
End of assembler dump.
(gdb) finish
Run till exit from #0 bar () at foobar.c:9
Program received signal SIGILL, Illegal instruction.
bar () at foobar.c:9
9 }
(gdb)
Oops!
(gdb) p/x $pc
$12 = 0x40068c
(gdb)
We're still there!
(gdb) continue
Continuing.
Program terminated with signal SIGILL, Illegal instruction.
The program no longer exists.
(gdb)
So let's try something else:
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) set foop = foo
(gdb) advance foo
foo () at foobar.c:4
4 }
(gdb) disassemble
Dump of assembler code for function foo:
=> 0x00400680 <+0>: jr ra
0x00400682 <+2>: li v0,1
End of assembler dump.
(gdb) finish
Run till exit from #0 foo () at foobar.c:4
Program received signal SIGILL, Illegal instruction.
foo () at foobar.c:4
4 }
(gdb) continue
Continuing.
Program terminated with signal SIGILL, Illegal instruction.
The program no longer exists.
(gdb)
The same problem!
(gdb) run
Starting program:
/net/build2-lucid-cs/scratch/macro/mips-linux-fsf-gcc/isa-bit/foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) set foop = foo32
(gdb) advance foo32
foo32 () at foobar.c:14
14 }
(gdb) disassemble
Dump of assembler code for function foo32:
=> 0x00400684 <+0>: jr ra
0x00400688 <+4>: li v0,3
End of assembler dump.
(gdb) finish
Run till exit from #0 foo32 () at foobar.c:14
main () at foobar.c:24
24 }
Value returned is $14 = 3
(gdb) continue
Continuing.
[Inferior 1 (process 14113) exited with code 03]
(gdb)
That did work though, so it's the ISA bit only!
(gdb) quit
Enough!
That's the tip of the iceberg only though. So let's rebuild the
executable with some dynamic symbols:
$ mips-linux-gnu-gcc -mips16 -Wl,--export-dynamic -g -O2 -o foobar-dyn foobar.c
$ mips-linux-gnu-readelf -s foobar-dyn | egrep 'table|foo|bar'
Symbol table '.dynsym' contains 32 entries:
6: 004009cd 4 FUNC GLOBAL DEFAULT 12 bar
8: 00410b88 4 OBJECT GLOBAL DEFAULT 21 foo32p
9: 00410b84 4 OBJECT GLOBAL DEFAULT 21 foop
15: 004009c4 8 FUNC GLOBAL DEFAULT 12 foo32
17: 004009c1 4 FUNC GLOBAL DEFAULT 12 foo
25: 00410b80 4 OBJECT GLOBAL DEFAULT 21 fooi
Symbol table '.symtab' contains 95 entries:
55: 00000000 0 FILE LOCAL DEFAULT ABS foobar.c
69: 004009cd 4 FUNC GLOBAL DEFAULT 12 bar
71: 00410b88 4 OBJECT GLOBAL DEFAULT 21 foo32p
72: 00410b84 4 OBJECT GLOBAL DEFAULT 21 foop
79: 004009c4 8 FUNC GLOBAL DEFAULT 12 foo32
81: 004009c1 4 FUNC GLOBAL DEFAULT 12 foo
89: 00410b80 4 OBJECT GLOBAL DEFAULT 21 fooi
$
OK, now the ISA bit is there for a change, but the MIPS16 `st_other'
attribute gone, hmm... What does `objdump' do then:
$ mips-linux-gnu-objdump -Tt foobar-dyn | egrep 'SYMBOL|foo|bar'
foobar-dyn: file format elf32-tradbigmips
SYMBOL TABLE:
00000000 l df *ABS* 00000000 foobar.c
004009cc g F .text 00000004 0xf0 bar
00410b88 g O .data 00000004 foo32p
00410b84 g O .data 00000004 foop
004009c4 g F .text 00000008 foo32
004009c0 g F .text 00000004 0xf0 foo
00410b80 g O .data 00000004 fooi
DYNAMIC SYMBOL TABLE:
004009cc g DF .text 00000004 Base 0xf0 bar
00410b88 g DO .data 00000004 Base foo32p
00410b84 g DO .data 00000004 Base foop
004009c4 g DF .text 00000008 Base foo32
004009c0 g DF .text 00000004 Base 0xf0 foo
00410b80 g DO .data 00000004 Base fooi
$
Hmm, the attribute (0xf0, printed raw) is back, and the ISA bit gone
again.
Let's have a look at some DWARF-2 records GDB uses (I'll be stripping
off a lot here for brevity) -- debug info:
$ mips-linux-gnu-readelf -wi foobar
Contents of the .debug_info section:
[...]
Compilation Unit @ offset 0x88:
Length: 0xbb (32-bit)
Version: 4
Abbrev Offset: 62
Pointer Size: 4
<0><93>: Abbrev Number: 1 (DW_TAG_compile_unit)
<94> DW_AT_producer : (indirect string, offset: 0x19e): GNU C 4.8.0 20120513 (experimental) -meb -mips16 -march=mips32r2 -mhard-float -mllsc -mplt -mno-synci -mno-shared -mabi=32 -g -O2
<98> DW_AT_language : 1 (ANSI C)
<99> DW_AT_name : (indirect string, offset: 0x190): foobar.c
<9d> DW_AT_comp_dir : (indirect string, offset: 0x225): [...]
<a1> DW_AT_ranges : 0x0
<a5> DW_AT_low_pc : 0x0
<a9> DW_AT_stmt_list : 0x27
<1><ad>: Abbrev Number: 2 (DW_TAG_subprogram)
<ae> DW_AT_external : 1
<ae> DW_AT_name : foo
<b2> DW_AT_decl_file : 1
<b3> DW_AT_decl_line : 1
<b4> DW_AT_prototyped : 1
<b4> DW_AT_type : <0xc2>
<b8> DW_AT_low_pc : 0x400680
<bc> DW_AT_high_pc : 0x400684
<c0> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<c2> DW_AT_GNU_all_call_sites: 1
<1><c2>: Abbrev Number: 3 (DW_TAG_base_type)
<c3> DW_AT_byte_size : 4
<c4> DW_AT_encoding : 5 (signed)
<c5> DW_AT_name : int
<1><c9>: Abbrev Number: 4 (DW_TAG_subprogram)
<ca> DW_AT_external : 1
<ca> DW_AT_name : (indirect string, offset: 0x18a): foo32
<ce> DW_AT_decl_file : 1
<cf> DW_AT_decl_line : 11
<d0> DW_AT_prototyped : 1
<d0> DW_AT_type : <0xc2>
<d4> DW_AT_low_pc : 0x400684
<d8> DW_AT_high_pc : 0x40068c
<dc> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<de> DW_AT_GNU_all_call_sites: 1
<1><de>: Abbrev Number: 2 (DW_TAG_subprogram)
<df> DW_AT_external : 1
<df> DW_AT_name : bar
<e3> DW_AT_decl_file : 1
<e4> DW_AT_decl_line : 6
<e5> DW_AT_prototyped : 1
<e5> DW_AT_type : <0xc2>
<e9> DW_AT_low_pc : 0x40068c
<ed> DW_AT_high_pc : 0x400690
<f1> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<f3> DW_AT_GNU_all_call_sites: 1
<1><f3>: Abbrev Number: 5 (DW_TAG_subprogram)
<f4> DW_AT_external : 1
<f4> DW_AT_name : (indirect string, offset: 0x199): main
<f8> DW_AT_decl_file : 1
<f9> DW_AT_decl_line : 21
<fa> DW_AT_prototyped : 1
<fa> DW_AT_type : <0xc2>
<fe> DW_AT_low_pc : 0x400490
<102> DW_AT_high_pc : 0x4004a4
<106> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<108> DW_AT_GNU_all_tail_call_sites: 1
[...]
$
-- no sign of the ISA bit anywhere -- frame info:
$ mips-linux-gnu-readelf -wf foobar
[...]
Contents of the .debug_frame section:
00000000 0000000c ffffffff CIE
Version: 1
Augmentation: ""
Code alignment factor: 1
Data alignment factor: -4
Return address column: 31
DW_CFA_def_cfa_register: r29
DW_CFA_nop
00000010 0000000c 00000000 FDE cie=00000000 pc=00400680..00400684
00000020 0000000c 00000000 FDE cie=00000000 pc=00400684..0040068c
00000030 0000000c 00000000 FDE cie=00000000 pc=0040068c..00400690
00000040 00000018 00000000 FDE cie=00000000 pc=00400490..004004a4
DW_CFA_advance_loc: 6 to 00400496
DW_CFA_def_cfa_offset: 32
DW_CFA_offset: r31 at cfa-4
DW_CFA_advance_loc: 6 to 0040049c
DW_CFA_restore: r31
DW_CFA_def_cfa_offset: 0
DW_CFA_nop
DW_CFA_nop
DW_CFA_nop
[...]
$
-- no sign of the ISA bit anywhere -- range info (GDB doesn't use arange):
$ mips-linux-gnu-readelf -wR foobar
Contents of the .debug_ranges section:
Offset Begin End
00000000 00400680 00400690
00000000 00400490 004004a4
00000000 <End of list>
$
-- no sign of the ISA bit anywhere -- line info:
$ mips-linux-gnu-readelf -wl foobar
Raw dump of debug contents of section .debug_line:
[...]
Offset: 0x27
Length: 78
DWARF Version: 2
Prologue Length: 31
Minimum Instruction Length: 1
Initial value of 'is_stmt': 1
Line Base: -5
Line Range: 14
Opcode Base: 13
Opcodes:
Opcode 1 has 0 args
Opcode 2 has 1 args
Opcode 3 has 1 args
Opcode 4 has 1 args
Opcode 5 has 1 args
Opcode 6 has 0 args
Opcode 7 has 0 args
Opcode 8 has 0 args
Opcode 9 has 1 args
Opcode 10 has 0 args
Opcode 11 has 0 args
Opcode 12 has 1 args
The Directory Table is empty.
The File Name Table:
Entry Dir Time Size Name
1 0 0 0 foobar.c
Line Number Statements:
Extended opcode 2: set Address to 0x400681
Special opcode 6: advance Address by 0 to 0x400681 and Line by 1 to 2
Special opcode 7: advance Address by 0 to 0x400681 and Line by 2 to 4
Special opcode 55: advance Address by 3 to 0x400684 and Line by 8 to 12
Special opcode 7: advance Address by 0 to 0x400684 and Line by 2 to 14
Advance Line by -7 to 7
Special opcode 131: advance Address by 9 to 0x40068d and Line by 0 to 7
Special opcode 7: advance Address by 0 to 0x40068d and Line by 2 to 9
Advance PC by 3 to 0x400690
Extended opcode 1: End of Sequence
Extended opcode 2: set Address to 0x400491
Advance Line by 21 to 22
Copy
Special opcode 6: advance Address by 0 to 0x400491 and Line by 1 to 23
Special opcode 60: advance Address by 4 to 0x400495 and Line by -1 to 22
Special opcode 34: advance Address by 2 to 0x400497 and Line by 1 to 23
Special opcode 62: advance Address by 4 to 0x40049b and Line by 1 to 24
Special opcode 32: advance Address by 2 to 0x40049d and Line by -1 to 23
Special opcode 6: advance Address by 0 to 0x40049d and Line by 1 to 24
Advance PC by 7 to 0x4004a4
Extended opcode 1: End of Sequence
[...]
-- a-ha, the ISA bit is there! However it's not always right for some
reason, I don't have a small test case to show it, but here's an excerpt
from MIPS16 libc, a prologue of a function:
00019630 <__libc_init_first>:
19630: e8a0 jrc ra
19632: 6500 nop
00019634 <_init>:
19634: f000 6a11 li v0,17
19638: f7d8 0b08 la v1,15e00 <_DYNAMIC+0x15c54>
1963c: f400 3240 sll v0,16
19640: e269 addu v0,v1
19642: 659a move gp,v0
19644: 64f6 save 48,ra,s0-s1
19646: 671c move s0,gp
19648: d204 sw v0,16(sp)
1964a: f352 984c lw v0,-27828(s0)
1964e: 6724 move s1,a0
and the corresponding DWARF-2 line info:
Line Number Statements:
Extended opcode 2: set Address to 0x19631
Advance Line by 44 to 45
Copy
Special opcode 8: advance Address by 0 to 0x19631 and Line by 3 to 48
Special opcode 66: advance Address by 4 to 0x19635 and Line by 5 to 53
Advance PC by constant 17 to 0x19646
Special opcode 25: advance Address by 1 to 0x19647 and Line by 6 to 59
Advance Line by -6 to 53
Special opcode 33: advance Address by 2 to 0x19649 and Line by 0 to 53
Special opcode 39: advance Address by 2 to 0x1964b and Line by 6 to 59
Advance Line by -6 to 53
Special opcode 61: advance Address by 4 to 0x1964f and Line by 0 to 53
-- see that "Advance PC by constant 17" there? It clears the ISA bit,
however code at 0x19646 is not standard MIPS code at all. For some
reason the constant is always 17, I've never seen DW_LNS_const_add_pc
used with any other value -- is that a binutils bug or what?
3. Solution:
I think we should retain the value of the ISA bit in code references,
that is effectively treat them as cookies as they indeed are (although
trivially calculated) rather than raw memory byte addresses.
In a perfect world both the static symbol table and the respective
DWARF-2 records should be fixed to include the ISA bit in all the cases.
I think however that this is infeasible.
All the uses of `_bfd_mips_elf_symbol_processing' can not necessarily be
tracked down. This function is used by `elf_slurp_symbol_table' that in
turn is used by `bfd_canonicalize_symtab' and
`bfd_canonicalize_dynamic_symtab', which are public interfaces.
Similarly DWARF-2 records are used outside GDB, one notable if a bit
questionable is the exception unwinder (libgcc/unwind-dw2.c) -- I have
identified at least bits in `execute_cfa_program' and
`uw_frame_state_for', both around the calls to `_Unwind_IsSignalFrame',
that would need an update as they effectively flip the ISA bit freely;
see also the comment about MASK_RETURN_ADDR in gcc/config/mips/mips.h.
But there may be more places. Any change in how DWARF-2 records are
produced would require an update there and would cause compatibility
problems with libgcc.a binaries already distributed; given that this is
a static library a complex change involving function renames would
likely be required.
I propose therefore to accept the existing inconsistencies and deal with
them entirely within GDB. I have figured out that the ISA bit lost in
various places can still be recovered as long as we have symbol
information -- that'll have the `st_other' attribute correctly set to
one of standard MIPS/MIPS16/microMIPS encoding.
Here's the resulting change. It adds a couple of new `gdbarch' hooks,
one to update symbol information with the ISA bit lost in
`_bfd_mips_elf_symbol_processing', and two other ones to adjust DWARF-2
records as they're processed. The ISA bit is set in each address
handled according to information retrieved from the symbol table for the
symbol spanning the address if any; limits are adjusted based on the
address they point to related to the respective base address.
Additionally minimal symbol information has to be adjusted accordingly
in its gdbarch hook.
With these changes in place some complications with ISA bit juggling in
the PC that never fully worked can be removed from the MIPS backend.
Conversely, the generic dynamic linker event special breakpoint symbol
handler has to be updated to call the minimal symbol gdbarch hook to
record that the symbol is a MIPS16 or microMIPS address if applicable or
the breakpoint will be set at the wrong address and either fail to work
or cause SIGTRAPs (this is because the symbol is handled early on and
bypasses regular symbol processing).
4. Results obtained
The change fixes the example above -- to repeat only the crucial steps:
(gdb) break main
Breakpoint 1 at 0x400491: file foobar.c, line 23.
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) print foo
$1 = {int (void)} 0x400681 <foo>
(gdb) set foop = bar
(gdb) advance bar
bar () at foobar.c:9
9 }
(gdb) disassemble
Dump of assembler code for function bar:
=> 0x0040068d <+0>: jr ra
0x0040068f <+2>: li v0,2
End of assembler dump.
(gdb) finish
Run till exit from #0 bar () at foobar.c:9
main () at foobar.c:24
24 }
Value returned is $2 = 2
(gdb) continue
Continuing.
[Inferior 1 (process 14128) exited with code 02]
(gdb)
-- excellent!
The change removes about 90 failures per MIPS16 multilib in mips-sde-elf
testing too, results for MIPS16 are now similar to that for standard
MIPS; microMIPS results are a bit worse because of host-I/O problems in
QEMU used instead of MIPSsim for microMIPS testing only:
=== gdb Summary ===
# of expected passes 14299
# of unexpected failures 187
# of expected failures 56
# of known failures 58
# of unresolved testcases 11
# of untested testcases 52
# of unsupported tests 174
MIPS16:
=== gdb Summary ===
# of expected passes 14298
# of unexpected failures 187
# of unexpected successes 2
# of expected failures 54
# of known failures 58
# of unresolved testcases 12
# of untested testcases 52
# of unsupported tests 174
microMIPS:
=== gdb Summary ===
# of expected passes 14149
# of unexpected failures 201
# of unexpected successes 2
# of expected failures 54
# of known failures 58
# of unresolved testcases 7
# of untested testcases 53
# of unsupported tests 175
2014-12-12 Maciej W. Rozycki <macro@codesourcery.com>
Maciej W. Rozycki <macro@mips.com>
Pedro Alves <pedro@codesourcery.com>
gdb/
* gdbarch.sh (elf_make_msymbol_special): Change type to `F',
remove `predefault' and `invalid_p' initializers.
(make_symbol_special): New architecture method.
(adjust_dwarf2_addr, adjust_dwarf2_line): Likewise.
(objfile, symbol): New declarations.
* arch-utils.h (default_elf_make_msymbol_special): Remove
prototype.
(default_make_symbol_special): New prototype.
(default_adjust_dwarf2_addr): Likewise.
(default_adjust_dwarf2_line): Likewise.
* mips-tdep.h (mips_unmake_compact_addr): New prototype.
* arch-utils.c (default_elf_make_msymbol_special): Remove
function.
(default_make_symbol_special): New function.
(default_adjust_dwarf2_addr): Likewise.
(default_adjust_dwarf2_line): Likewise.
* dwarf2-frame.c (decode_frame_entry_1): Call
`gdbarch_adjust_dwarf2_addr'.
* dwarf2loc.c (dwarf2_find_location_expression): Likewise.
* dwarf2read.c (create_addrmap_from_index): Likewise.
(process_psymtab_comp_unit_reader): Likewise.
(add_partial_symbol): Likewise.
(add_partial_subprogram): Likewise.
(process_full_comp_unit): Likewise.
(read_file_scope): Likewise.
(read_func_scope): Likewise. Call `gdbarch_make_symbol_special'.
(read_lexical_block_scope): Call `gdbarch_adjust_dwarf2_addr'.
(read_call_site_scope): Likewise.
(dwarf2_ranges_read): Likewise.
(dwarf2_record_block_ranges): Likewise.
(read_attribute_value): Likewise.
(dwarf_decode_lines_1): Call `gdbarch_adjust_dwarf2_line'.
(new_symbol_full): Call `gdbarch_adjust_dwarf2_addr'.
* elfread.c (elf_symtab_read): Don't call
`gdbarch_elf_make_msymbol_special' if unset.
* mips-linux-tdep.c (micromips_linux_sigframe_validate): Strip
the ISA bit from the PC.
* mips-tdep.c (mips_unmake_compact_addr): New function.
(mips_elf_make_msymbol_special): Set the ISA bit in the symbol's
address appropriately.
(mips_make_symbol_special): New function.
(mips_pc_is_mips): Set the ISA bit before symbol lookup.
(mips_pc_is_mips16): Likewise.
(mips_pc_is_micromips): Likewise.
(mips_pc_isa): Likewise.
(mips_adjust_dwarf2_addr): New function.
(mips_adjust_dwarf2_line): Likewise.
(mips_read_pc, mips_unwind_pc): Keep the ISA bit.
(mips_addr_bits_remove): Likewise.
(mips_skip_trampoline_code): Likewise.
(mips_write_pc): Don't set the ISA bit.
(mips_eabi_push_dummy_call): Likewise.
(mips_o64_push_dummy_call): Likewise.
(mips_gdbarch_init): Install `mips_make_symbol_special',
`mips_adjust_dwarf2_addr' and `mips_adjust_dwarf2_line' gdbarch
handlers.
* solib.c (gdb_bfd_lookup_symbol_from_symtab): Get
target-specific symbol address adjustments.
* gdbarch.h: Regenerate.
* gdbarch.c: Regenerate.
2014-12-12 Maciej W. Rozycki <macro@codesourcery.com>
gdb/testsuite/
* gdb.base/func-ptrs.c: New file.
* gdb.base/func-ptrs.exp: New file.
Currently "symtabs" in gdb are stored as a single linked list of
struct symtab that contains both symbol symtabs (the blockvectors)
and file symtabs (the linetables).
This has led to confusion, bugs, and performance issues.
This patch is conceptually very simple: split struct symtab into
two pieces: one part containing things common across the entire
compilation unit, and one part containing things specific to each
source file.
Example.
For the case of a program built out of these files:
foo.c
foo1.h
foo2.h
bar.c
foo1.h
bar.h
Today we have a single list of struct symtabs:
objfile -> foo.c -> foo1.h -> foo2.h -> bar.c -> foo1.h -> bar.h -> NULL
where "->" means the "next" pointer in struct symtab.
With this patch, that turns into:
objfile -> foo.c(cu) -> bar.c(cu) -> NULL
| |
v v
foo.c bar.c
| |
v v
foo1.h foo1.h
| |
v v
foo2.h bar.h
| |
v v
NULL NULL
where "foo.c(cu)" and "bar.c(cu)" are struct compunit_symtab objects,
and the files foo.c, etc. are struct symtab objects.
So now, for example, when we want to iterate over all blockvectors
we can now just iterate over the compunit_symtab list.
Plus a lot of the data that was either unused or replicated for each
symtab in a compilation unit now lives in struct compunit_symtab.
E.g., the objfile pointer, the producer string, etc.
I thought of moving "language" out of struct symtab but there is
logic to try to compute the language based on previously seen files,
and I think that's best left as is for now.
With my standard monster benchmark with -readnow (which I can't actually
do, but based on my calculations), whereas today the list requires
77MB to store all the struct symtabs, it now only requires 37MB.
A modest space savings given the gigabytes needed for all the debug info,
etc. Still, it's nice. Plus, whereas today we create a copy of dirname
for each source file symtab in a compilation unit, we now only create one
for the compunit.
So this patch is basically just a data structure reorg,
I don't expect significant performance improvements from it.
Notes:
1) A followup patch can do a similar split for struct partial_symtab.
I have left that until after I get the changes I want in to
better utilize .gdb_index (it may affect how we do partial syms).
2) Another followup patch *could* rename struct symtab.
The term "symtab" is ambiguous and has been a source of confusion.
In this patch I'm leaving it alone, calling it the "historical" name
of "filetabs", which is what they are now: just the file-name + line-table.
gdb/ChangeLog:
Split struct symtab into two: struct symtab and compunit_symtab.
* amd64-tdep.c (amd64_skip_xmm_prologue): Fetch producer from compunit.
* block.c (blockvector_for_pc_sect): Change "struct symtab *" argument
to "struct compunit_symtab *". All callers updated.
(set_block_compunit_symtab): Renamed from set_block_symtab. Change
"struct symtab *" argument to "struct compunit_symtab *".
All callers updated.
(get_block_compunit_symtab): Renamed from get_block_symtab. Change
result to "struct compunit_symtab *". All callers updated.
(find_iterator_compunit_symtab): Renamed from find_iterator_symtab.
Change result to "struct compunit_symtab *". All callers updated.
* block.h (struct global_block) <compunit_symtab>: Renamed from symtab.
hange type to "struct compunit_symtab *". All uses updated.
(struct block_iterator) <d.compunit_symtab>: Renamed from "d.symtab".
Change type to "struct compunit_symtab *". All uses updated.
* buildsym.c (struct buildsym_compunit): New struct.
(subfiles, buildsym_compdir, buildsym_objfile, main_subfile): Delete.
(buildsym_compunit): New static global.
(finish_block_internal): Update to fetch objfile from
buildsym_compunit.
(make_blockvector): Delete objfile argument.
(start_subfile): Rewrite to use buildsym_compunit. Don't initialize
debugformat, producer.
(start_buildsym_compunit): New function.
(free_buildsym_compunit): Renamed from free_subfiles_list.
All callers updated.
(patch_subfile_names): Rewrite to use buildsym_compunit.
(get_compunit_symtab): New function.
(get_macro_table): Delete argument comp_dir. All callers updated.
(start_symtab): Change result to "struct compunit_symtab *".
All callers updated. Create the subfile of the main source file.
(watch_main_source_file_lossage): Rewrite to use buildsym_compunit.
(reset_symtab_globals): Update.
(end_symtab_get_static_block): Update to use buildsym_compunit.
(end_symtab_without_blockvector): Rewrite.
(end_symtab_with_blockvector): Change result to
"struct compunit_symtab *". All callers updated.
Update to use buildsym_compunit. Don't set symtab->dirname,
instead set it in the compunit.
Explicitly make sure main symtab is first in its list.
Set debugformat, producer, blockvector, block_line_section, and
macrotable in the compunit.
(end_symtab_from_static_block): Change result to
"struct compunit_symtab *". All callers updated.
(end_symtab, end_expandable_symtab): Ditto.
(set_missing_symtab): Change symtab argument to
"struct compunit_symtab *". All callers updated.
(augment_type_symtab): Ditto.
(record_debugformat): Update to use buildsym_compunit.
(record_producer): Update to use buildsym_compunit.
* buildsym.h (struct subfile) <dirname>: Delete.
<producer, debugformat>: Delete.
<buildsym_compunit>: New member.
(get_compunit_symtab): Declare.
* dwarf2read.c (struct type_unit_group) <compunit_symtab>: Renamed
from primary_symtab. Change type to "struct compunit_symtab *".
All uses updated.
(dwarf2_start_symtab): Change result to "struct compunit_symtab *".
All callers updated.
(dwarf_decode_macros): Delete comp_dir argument. All callers updated.
(struct dwarf2_per_cu_quick_data) <compunit_symtab>: Renamed from
symtab. Change type to "struct compunit_symtab *". All uses updated.
(dw2_instantiate_symtab): Change result to "struct compunit_symtab *".
All callers updated.
(dw2_find_last_source_symtab): Ditto.
(dw2_lookup_symbol): Ditto.
(recursively_find_pc_sect_compunit_symtab): Renamed from
recursively_find_pc_sect_symtab. Change result to
"struct compunit_symtab *". All callers updated.
(dw2_find_pc_sect_compunit_symtab): Renamed from
dw2_find_pc_sect_symtab. Change result to
"struct compunit_symtab *". All callers updated.
(get_compunit_symtab): Renamed from get_symtab. Change result to
"struct compunit_symtab *". All callers updated.
(recursively_compute_inclusions): Change type of immediate_parent
argument to "struct compunit_symtab *". All callers updated.
(compute_compunit_symtab_includes): Renamed from
compute_symtab_includes. All callers updated. Rewrite to compute
includes of compunit_symtabs and not symtabs.
(process_full_comp_unit): Update to work with struct compunit_symtab.
(process_full_type_unit): Ditto.
(dwarf_decode_lines_1): Delete argument comp_dir. All callers updated.
(dwarf_decode_lines): Remove special case handling of main subfile.
(macro_start_file): Delete argument comp_dir. All callers updated.
(dwarf_decode_macro_bytes): Ditto.
* guile/scm-block.c (bkscm_print_block_syms_progress_smob): Update to
use struct compunit_symtab.
* i386-tdep.c (i386_skip_prologue): Fetch producer from compunit.
* jit.c (finalize_symtab): Build compunit_symtab.
* jv-lang.c (get_java_class_symtab): Change result to
"struct compunit_symtab *". All callers updated.
* macroscope.c (sal_macro_scope): Fetch macro table from compunit.
* macrotab.c (struct macro_table) <compunit_symtab>: Renamed from
comp_dir. Change type to "struct compunit_symtab *".
All uses updated.
(new_macro_table): Change comp_dir argument to cust,
"struct compunit_symtab *". All callers updated.
* maint.c (struct cmd_stats) <nr_compunit_symtabs>: Renamed from
nr_primary_symtabs. All uses updated.
(count_symtabs_and_blocks): Update to handle compunits.
(report_command_stats): Update output, "primary symtabs" renamed to
"compunits".
* mdebugread.c (new_symtab): Change result to
"struct compunit_symtab *". All callers updated.
(parse_procedure): Change type of search_symtab argument to
"struct compunit_symtab *". All callers updated.
* objfiles.c (objfile_relocate1): Loop over blockvectors in a
separate loop.
* objfiles.h (struct objfile) <compunit_symtabs>: Renamed from
symtabs. Change type to "struct compunit_symtab *". All uses updated.
(ALL_OBJFILE_FILETABS): Renamed from ALL_OBJFILE_SYMTABS.
All uses updated.
(ALL_OBJFILE_COMPUNITS): Renamed from ALL_OBJFILE_PRIMARY_SYMTABS.
All uses updated.
(ALL_FILETABS): Renamed from ALL_SYMTABS. All uses updated.
(ALL_COMPUNITS): Renamed from ALL_PRIMARY_SYMTABS. All uses updated.
* psympriv.h (struct partial_symtab) <compunit_symtab>: Renamed from
symtab. Change type to "struct compunit_symtab *". All uses updated.
* psymtab.c (psymtab_to_symtab): Change result type to
"struct compunit_symtab *". All callers updated.
(find_pc_sect_compunit_symtab_from_partial): Renamed from
find_pc_sect_symtab_from_partial. Change result type to
"struct compunit_symtab *". All callers updated.
(lookup_symbol_aux_psymtabs): Change result type to
"struct compunit_symtab *". All callers updated.
(find_last_source_symtab_from_partial): Ditto.
* python/py-symtab.c (stpy_get_producer): Fetch producer from compunit.
* source.c (forget_cached_source_info_for_objfile): Fetch debugformat
and macro_table from compunit.
* symfile-debug.c (debug_qf_find_last_source_symtab): Change result
type to "struct compunit_symtab *". All callers updated.
(debug_qf_lookup_symbol): Ditto.
(debug_qf_find_pc_sect_compunit_symtab): Renamed from
debug_qf_find_pc_sect_symtab, change result type to
"struct compunit_symtab *". All callers updated.
* symfile.c (allocate_symtab): Delete objfile argument.
New argument cust.
(allocate_compunit_symtab): New function.
(add_compunit_symtab_to_objfile): New function.
* symfile.h (struct quick_symbol_functions) <lookup_symbol>:
Change result type to "struct compunit_symtab *". All uses updated.
<find_pc_sect_compunit_symtab>: Renamed from find_pc_sect_symtab.
Change result type to "struct compunit_symtab *". All uses updated.
* symmisc.c (print_objfile_statistics): Compute blockvector count in
separate loop.
(dump_symtab_1): Update test for primary source symtab.
(maintenance_info_symtabs): Update to handle compunit symtabs.
(maintenance_check_symtabs): Ditto.
* symtab.c (set_primary_symtab): Delete.
(compunit_primary_filetab): New function.
(compunit_language): New function.
(iterate_over_some_symtabs): Change type of arguments "first",
"after_last" to "struct compunit_symtab *". All callers updated.
Update to loop over symtabs in each compunit.
(error_in_psymtab_expansion): Rename symtab argument to cust,
and change type to "struct compunit_symtab *". All callers updated.
(find_pc_sect_compunit_symtab): Renamed from find_pc_sect_symtab.
Change result type to "struct compunit_symtab *". All callers updated.
(find_pc_compunit_symtab): Renamed from find_pc_symtab.
Change result type to "struct compunit_symtab *". All callers updated.
(find_pc_sect_line): Only loop over symtabs within selected compunit
instead of all symtabs in the objfile.
* symtab.h (struct symtab) <blockvector>: Moved to compunit_symtab.
<compunit_symtab> New member.
<block_line_section>: Moved to compunit_symtab.
<locations_valid>: Ditto.
<epilogue_unwind_valid>: Ditto.
<macro_table>: Ditto.
<dirname>: Ditto.
<debugformat>: Ditto.
<producer>: Ditto.
<objfile>: Ditto.
<call_site_htab>: Ditto.
<includes>: Ditto.
<user>: Ditto.
<primary>: Delete
(SYMTAB_COMPUNIT): New macro.
(SYMTAB_BLOCKVECTOR): Update definition.
(SYMTAB_OBJFILE): Update definition.
(SYMTAB_DIRNAME): Update definition.
(struct compunit_symtab): New type. Common members among all source
symtabs within a compilation unit moved here. All uses updated.
(COMPUNIT_OBJFILE): New macro.
(COMPUNIT_FILETABS): New macro.
(COMPUNIT_DEBUGFORMAT): New macro.
(COMPUNIT_PRODUCER): New macro.
(COMPUNIT_DIRNAME): New macro.
(COMPUNIT_BLOCKVECTOR): New macro.
(COMPUNIT_BLOCK_LINE_SECTION): New macro.
(COMPUNIT_LOCATIONS_VALID): New macro.
(COMPUNIT_EPILOGUE_UNWIND_VALID): New macro.
(COMPUNIT_CALL_SITE_HTAB): New macro.
(COMPUNIT_MACRO_TABLE): New macro.
(ALL_COMPUNIT_FILETABS): New macro.
(compunit_symtab_ptr): New typedef.
(DEF_VEC_P (compunit_symtab_ptr)): New vector type.
gdb/testsuite/ChangeLog:
* gdb.base/maint.exp: Update expected output.
gdb/ChangeLog:
* dwarf2read.c (dw2_instantiate_symtab): Add assert.
(dw2_lookup_symbol): Remove unnecessary test for primary symbol table.
* psymtab.c (lookup_symbol_aux_psymtabs): Ditto.
(psymtab_to_symtab): Add comment and assert.
(map_matching_symbols_psymtab): Remove unnecessary test for
non-primary symtab.
There is another function, lookup_symbol_aux_block, and
the names lookup_block_symbol and lookup_symbol_aux_block don't
convey any real difference between them.
The difference is that lookup_block_symbol lives in the lower level
block API, and lookup_symbol_aux_block lives in the higher level symtab API.
This patch makes this distinction clear.
gdb/ChangeLog:
* symtab.c (lookup_block_symbol): Moved to ...
* block.c (block_lookup_symbol): ... here and renamed.
All callers updated.
* block.h (block_lookup_symbol): Declare.
* symtab.h (lookup_block_symbol): Delete.
I see the following fail on arm-none-eabi target,
(gdb) b 24^M
Breakpoint 1 at 0x4: file
../../../../git/gdb/testsuite/gdb.base/break-on-linker-gcd-function.cc,
line 24.^M
(gdb) FAIL: gdb.base/break-on-linker-gcd-function.exp: b 24
Currently, we are using flag has_section_at_zero to determine whether
address zero in debug info means the corresponding code has been
GC'ed, like this:
case DW_LNE_set_address:
address = read_address (abfd, line_ptr, cu, &bytes_read);
if (address == 0 && !dwarf2_per_objfile->has_section_at_zero)
{
/* This line table is for a function which has been
GCd by the linker. Ignore it. PR gdb/12528 */
However, this is incorrect on some bare metal targets, as .text
section is located at 0x0, so dwarf2_per_objfile->has_section_at_zero
is true. If a function is GC'ed by linker, the address is zero. GDB
thinks address zero is a function's address rather than this function
is GC'ed.
In this patch, we choose 'lowpc' got in read_file_scope to check
whether 'lowpc' is greater than zero. If it isn't, address zero really
means the function is GC'ed. In this patch, we pass 'lowpc' in
read_file_scope through handle_DW_AT_stmt_list and dwarf_decode_lines,
and to dwarf_decode_lines_1 finally.
This patch fixes the fail above. This patch also covers the path that
partial symbol isn't used, which is tested by starting gdb with
--readnow option.
It is regression tested on x86-linux with
target_board=dwarf4-gdb-index, and arm-none-eabi. OK to apply?
gdb:
2014-09-19 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (dwarf_decode_lines): Update declaration.
(handle_DW_AT_stmt_list): Add argument 'lowpc'. Update
comments. Callers update.
(dwarf_decode_lines): Likewise.
(dwarf_decode_lines_1): Add argument 'lowpc'. Update
comments. Skip the line table if 'lowpc' is greater than
'address'. Don't check
dwarf2_per_objfile->has_section_at_zero.
gdb/testsuite:
2014-09-19 Yao Qi <yao@codesourcery.com>
* gdb.base/break-on-linker-gcd-function.exp: Move test into new
proc set_breakpoint_on_gcd_function. Invoke
set_breakpoint_on_gcd_function. Restart GDB with --readnow and
invoke set_breakpoint_on_gcd_function again.
Hi,
dwarf_decode_lines is called in two functions,
dwarf2_build_include_psymtabs and handle_DW_AT_stmt_list, in which, 1
is passed to argument 'want_line_info' and 'want_line_info' is a
conditional variable in dwarf_decode_lines. We can simplify it by
removing 'want_line_info' and propagating the constant 1 into
dwarf_decode_lines. This is what this patch does. This patch also
remove one line comment about WANT_LINE_INFO in
handle_DW_AT_stmt_list, as handle_DW_AT_stmt_list doesn't have such
argument.
gdb:
2014-08-28 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (dwarf_decode_lines): Update declaration.
(handle_DW_AT_stmt_list): Remove comment about WANT_LINE_INFO.
(dwarf_decode_lines): Remove argument
want_line_info. Remove condition check on want_line_info.
Callers update.
I read comment of scan_partial_symbols about NEED_PC and how *LOWPC
and *HIGHPC are updated:
DW_AT_ranges). If NEED_PC is set, then this function will set
*LOWPC and *HIGHPC to the lowest and highest PC values found in CU
and record the covered ranges in the addrmap.
NEED_PC is only used in the callee of scan_partial_symbols,
add_partial_subprogram,
if (pdi->tag == DW_TAG_subprogram)
{
if (pdi->has_pc_info)
{
if (pdi->lowpc < *lowpc)
*lowpc = pdi->lowpc;
if (pdi->highpc > *highpc)
*highpc = pdi->highpc;
if (need_pc)
*LOWPC and *HIGHPC is updated regardless of NEED_PC. When NEED_PC is
true, addrmap is updated. It would be clear to rename NEED_PC to
SET_ADDRMAP. That is what this patch does. Beside this, this patch
also adjust comments in related functions.
gdb:
2014-08-24 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (scan_partial_symbols): Update comments.
Rename argument 'need_pc' with 'set_addrmap'.
（add_partial_namespace): Rename argument 'need_pc' with
'set_addrmap'.
(add_partial_module): Likewise.
(add_partial_subprogram): Likewise. Update comments.
(dwarf2_name): Fix typo.
See the description here:
https://sourceware.org/ml/gdb-patches/2014-08/msg00283.html
This patch keeps track of whether the current line has seen a
non-zero discriminator, and if so coalesces consecutive entries
for the same line (by ignoring all entries after the first).
gdb/ChangeLog:
PR 17276
* dwarf2read.c (dwarf_record_line_p): New function.
(dwarf_decode_lines_1): Ignore subsequent line number entries
for the same line if any entry had a non-zero discriminator.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-single-line-discriminators.S: New file.
* gdb.dwarf2/dw2-single-line-discriminators.c: New file.
* gdb.dwarf2/dw2-single-line-discriminators.exp: New file.
gdb/ChangeLog:
* buildsym.h (record_line_ftype): New typedef.
(record_line): Use it.
* dwarf2read.c (dwarf_record_line, dwarf_finish_line): New functions.
(dwarf_decode_lines_1): Call them.
We would like to wrap examples, output or code snippet in comments with
blank lines, and move */ to a new line if the comment is ended with the
example.
gdb:
2014-08-20 Yao Qi <yao@codesourcery.com>
* amd64-tdep.c (amd64_classify): Add a blank line after the
example. Move "*/" to a new line.
* arm-tdep.c (arm_vfp_cprc_sub_candidate): Likewise.
* arm-wince-tdep.c (arm_pe_skip_trampoline_code): Likewise.
* dwarf2read.c (psymtab_include_file_name): Likewise.
gdb/ChangeLog:
* gdbtypes.h (struct main_type): Add field "data_location".
(TYPE_DATA_LOCATION, TYPE_DATA_LOCATION_BATON)
(TYPE_DATA_LOCATION_ADDR, TYPE_DATA_LOCATION_KIND): New macros.
* gdbtypes.c (is_dynamic_type): Return 1 if the type has
a dynamic data location.
(resolve_dynamic_type): Add DW_AT_data_location handling.
(copy_recursive, copy_type): Copy the data_location information
when present.
* dwarf2read.c (set_die_type): Add DW_AT_data_location handling.
* value.c (value_from_contents_and_address): Add
DW_AT_data_location handling.
Hi,
Parameter 'pst' of function dwarf_decode_lines_1 isn't used except
to compute decode_for_pst_p, which has been got in the caller
dwarf_decode_lines. I wonder it would be good if we just pass
'decode_for_pst_p'.
gdb:
2014-08-15 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (dwarf_decode_lines_1): Remove parameter 'pst'.
Add parameter 'decode_for_pst_p'. Callers update.
When I read the comments to field 'u' of struct dwarf2_per_cu_data,
I don't think the comments say anything useful. I update it per
my understanding.
gdb:
2014-08-07 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (struct dwarf2_per_cu_data) <u>: Tweak comments.
When I read dwarf_decode_lines_1 comments today, it should be called
"special opcode" rather than "special operand", as said in DWARF spec.
It is obvious to me. I'll push it in if no comments in three days.
gdb:
2014-08-06 Yao Qi <yao@codesourcery.com>
* dwarf2read.c (dwarf_decode_lines_1): Replace "Special
operand" with "Special opcode" in comments.
read_tag_const_type propagates the cv-qualifier to the array element type,
but read_tag_volatile_type didn't. Make sure that both cv-qualifiers that
apply to array types are handled the same.
gdb/ChangeLog
* dwarf2read.c (add_array_cv_type): New function.
(read_tag_const_type): Call add_array_cv_type for TYPE_CODE_ARRAY.
(read_tag_volatile_type): Likewise.
gdb/testsuite/ChangeLog
* gdb.base/constvars.c (violent, violet, vips, virgen, vulgar,
vulture, vilify, villar): New volatile array constants.
(vindictive, vegetation): New const volatile array constants.
* gdb.base/volatile.exp: Test volatile and const volatile array
types.
This fixes a regression that Jan pointed out.
The bug is that some names were allocated by dwarf2read on the objfile
obstack, but then passed to SYMBOL_SET_NAMES with copy_name=0. This
violates the invariant that the names must have a lifetime tied to the
lifetime of the BFD.
The fix is to allocate names on the per-BFD obstack.
I looked at all callers, direct or indirect, of SYMBOL_SET_NAMES that
pass copy_name=0. Note that only the ELF and DWARF readers do this;
other symbol readers were never updated (and perhaps cannot be,
depending on the details of the formats). This is why the patch is
relatively small.
Built and regtested on x86-64 Fedora 20.
2014-06-26 Tom Tromey <tromey@redhat.com>
PR symtab/16902:
* dwarf2read.c (fixup_go_packaging, dwarf2_compute_name)
(dwarf2_physname, read_partial_die)
(guess_partial_die_structure_name, fixup_partial_die)
(guess_full_die_structure_name, anonymous_struct_prefix)
(dwarf2_name): Use per-BFD obstack.
This changes OBSTACK_ZALLOC and OBSTACK_CALLOC to cast their value to
the correct type. This is more type-safe and also is more in line
with the other object-allocation macros in libiberty.h.
Making this change revealed one trivial error in dwarf2read.c.
On the whole that seems pretty good to me.
Tested by rebuilding.
2014-06-20 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (dw2_get_real_path): Use correct type in
OBSTACK_CALLOC.
* gdb_obstack.h (OBSTACK_ZALLOC, OBSTACK_CALLOC): Cast result.
Generally, the blockvector ought to be readonly. So, this patch makes
the blockvector const in the symtab, and also changes various
blockvector APIs to be const.
This patch has a couple of spots that cast away const. I consider
these to be ok because they occur in mdebugread and are used while
constructing the blockvector. I have added comments at these spots.
2014-06-18 Tom Tromey <tromey@redhat.com>
* symtab.h (struct symtab) <blockvector>: Now const.
* ada-lang.c (ada_add_global_exceptions): Update.
* buildsym.c (augment_type_symtab): Update.
* dwarf2read.c (dw2_lookup_symbol): Update.
* jit.c (finalize_symtab): Update.
* jv-lang.c (add_class_symtab_symbol): Update.
* mdebugread.c (parse_symbol, add_block, sort_blocks, new_symtab):
Update.
* objfiles.c (objfile_relocate1): Update.
* psymtab.c (lookup_symbol_aux_psymtabs)
(maintenance_check_psymtabs): Update.
* python/py-symtab.c (stpy_global_block, stpy_static_block):
Update.
* spu-tdep.c (spu_catch_start): Update.
* symmisc.c (dump_symtab_1): Update.
* symtab.c (lookup_global_symbol_from_objfile)
(lookup_symbol_aux_objfile, lookup_symbol_aux_quick)
(basic_lookup_transparent_type_quick)
(basic_lookup_transparent_type, find_pc_sect_symtab)
(find_pc_sect_line, search_symbols): Update.
* block.c (find_block_in_blockvector): Make "bl" const.
(blockvector_for_pc_sect, blockvector_for_pc): Make return type
const.
(blockvector_contains_pc): Make "bv" const.
(block_for_pc_sect): Update.
* block.h (blockvector_for_pc, blockvector_for_pc_sect)
(blockvector_contains_pc): Update.
* breakpoint.c (resolve_sal_pc): Update.
* inline-frame.c (block_starting_point_at): Update.
Currently there are many calls to help_list that pass the constant -1
as the "class" value. However, the parameter is declared as being of
type enum command_class, and uses of the constant violate this
abstraction.
This patch fixes the error everywhere it occurs in the gdb sources.
Tested by rebuilding.
2014-06-13 Tom Tromey <tromey@redhat.com>
* cp-support.c (maint_cplus_command): Pass all_commands, not -1,
to help_list.
* guile/guile.c (info_guile_command): Pass all_commands, not -1,
to help_list.
* tui/tui-win.c (tui_command): Pass all_commands, not -1, to
help_list.
* tui/tui-regs.c (tui_reg_command): Pass all_commands, not -1, to
help_list.Pass all_commands, not -1, to help_list.
* cli/cli-dump.c (dump_command, append_command)
(srec_dump_command, ihex_dump_command, tekhex_dump_command)
(binary_dump_command, binary_append_command): Pass all_commands,
not -1, to help_list.
* cli/cli-cmds.c (info_command, set_debug): Pass all_commands, not
-1, to help_list.
* valprint.c (set_print, set_print_raw): Pass all_commands, not
-1, to help_list.
* typeprint.c (set_print_type): Pass all_commands, not -1, to
help_list.
* top.c (set_history): Pass all_commands, not -1, to help_list.
* target-descriptions.c (set_tdesc_cmd, unset_tdesc_cmd): Pass
all_commands, not -1, to help_list.
* symfile.c (overlay_command): Pass all_commands, not -1, to
help_list.
* spu-tdep.c (info_spu_command): Pass all_commands, not -1, to
help_list.
* serial.c (serial_set_cmd): Pass all_commands, not -1, to
help_list.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Pass all_commands, not
-1, to help_list.
* remote.c (remote_command, set_remote_cmd): Pass all_commands,
not -1, to help_list.
* ravenscar-thread.c (set_ravenscar_command): Pass all_commands,
not -1, to help_list.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_print_command, maintenance_set_cmd): Pass
all_commands, not -1, to help_list.
* macrocmd.c (macro_command): Pass all_commands, not -1, to
help_list.
* language.c (set_check): Pass all_commands, not -1, to help_list.
* infcmd.c (unset_command): Pass all_commands, not -1, to
help_list.
* frame.c (set_backtrace_cmd): Pass all_commands, not -1, to
help_list.
* dwarf2read.c (set_dwarf2_cmd): Pass all_commands, not -1, to
help_list.
* dcache.c (set_dcache_command): Pass all_commands, not -1, to
help_list.
* breakpoint.c (save_command): Pass all_commands, not -1, to
help_list.
* ada-lang.c (maint_set_ada_cmd, set_ada_command): Pass
all_commands, not -1, to help_list.
* dwarf2read.c (struct dwarf2_per_objfile): New member
n_allocated_type_units.
(struct dwarf2_per_objfile) <tu_stats>: New member
nr_all_type_units_reallocs.
(create_signatured_type_table_from_index): Initialize
n_allocated_type_units
(create_all_type_units): Ditto.
(add_type_unit): Move up in file. New arg slot.
All callers updated. Increase space for all_type_units more
efficiently.
(fill_in_sig_entry_from_dwo_entry): Handle psymtabs.
(lookup_dwo_signatured_type): Handle skeletonless TUs.
(lookup_dwp_signatured_type): Ditto.
(init_tu_and_read_dwo_dies): New arg use_existing_cu.
All callers updated.
(build_type_psymtabs_1): Leave type_unit_groups as
NULL if no TUs present.
(print_tu_stats): New function.
(process_skeletonless_type_unit): New function.
(process_dwo_file_for_skeletonless_type_units): New
function.
(process_skeletonless_type_units): New function.
(dwarf2_build_psymtabs_hard): Handle skeletonless TUs.
Call print tu_stats if debugging enabled.
* dwarf2read.c (build_type_psymtabs_1): Renamed from
build_type_unit_groups and moved closer to only caller. Remove
arguments. All references updated. Remove outdated .gdb_index
comment.
(struct tu_abbrev_offset, sort_tu_by_abbrev_offset): Move with
build_type_psymtabs_1.
Currently, read_subrange_type handles dynamicity only in the case of
the upper bound, and assumes that the lower bound is always static.
That's rooted in the fact that dynamicity was added to support C99
variable-length arrays, where the lower bound is always zero, and
therefore never dynamic. But the lower bound can, in fact, be dynamic
in other languages such as Ada.
Consider for instance the following declaration in Ada...
type Array_Type is array (L .. U) of Natural;
... where L and U are parameters of the function where the declaration
above was made, and whose value are 5 and 10. Currently, the debugger
is able to print the value of the upper bound correctly, but not the
lower bound:
(gdb) ptype array_type
type = array (1 .. 10) of natural
After this patch, the debugger now prints:
(gdb) ptype array_type
type = array (5 .. 10) of natural
gdb/ChangeLog:
* dwarf2read.c (read_subrange_type): Handle dynamic
DW_AT_lower_bound attributes.
Install some sanity checks that sibling DIE offsets are not beyond the
defined limits of the DWARF input buffer in read_partial_die and skip_one_die.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* dwarf2read.c (skip_one_die): Check that all relative-offset
sibling DIEs fall within range of the current reader's buffer.
(read_partial_die): Likewise.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* gdb.dwarf2/corrupt.c: New file.
* gdb.dwarf2/corrupt.exp: New file.
This adds support for the C++11 "enum class" feature. This is
PR c++/15246.
I chose to use the existing TYPE_DECLARED_CLASS rather than introduce
a new type code. This seemed both simple and clear to me.
I made overloading support for the new enum types strict. This is how
it works in C++; and it didn't seem like an undue burden to keep this,
particularly because enum constants are printed symbolically by gdb.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
PR c++/15246:
* c-exp.y (type_aggregate_p): New function.
(qualified_name, classify_inner_name): Use it.
* c-typeprint.c (c_type_print_base): Handle TYPE_DECLARED_CLASS
and TYPE_TARGET_TYPE of an enum type.
* dwarf2read.c (read_enumeration_type): Set TYPE_DECLARED_CLASS on
an enum type.
(determine_prefix) <case DW_TAG_enumeration_type>: New case;
handle TYPE_DECLARED_CLASS.
* gdbtypes.c (rank_one_type): Handle TYPE_DECLARED_CLASS on enum
types.
* gdbtypes.h (TYPE_DECLARED_CLASS): Update comment.
* valops.c (enum_constant_from_type): New function.
(value_aggregate_elt): Use it.
* cp-namespace.c (cp_lookup_nested_symbol): Handle
TYPE_CODE_ENUM.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.cp/classes.exp (test_enums): Handle underlying type.
* gdb.dwarf2/enum-type.exp: Add test for enum with underlying
type.
* gdb.cp/enum-class.exp: New file.
* gdb.cp/enum-class.cc: New file.
DWARF allows an enumeration type to have a DW_AT_type. GDB doesn't
recognize this, but there is a patch to change GCC to emit it, and a
DWARF proposal to further allow an enum type with a DW_AT_type to omit
the DW_AT_byte_size. This patch changes gdb to implement this.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (read_enumeration_type): Handle DW_AT_type.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.dwarf2/enum-type.exp: New file.
This patch adds support for DW_AT_count as requested in the code review:
https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html
gdb/ChangeLog:
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
The dwarf standard allow certain attributes to be expressed as dwarf
expressions rather than constants. For instance upper-/lowerbound attributes.
In case of a c99 variable length array the upperbound is a dynamic attribute.
With this change c99 vla behave the same as with static arrays.
1| void foo (size_t n) {
2| int ary[n];
3| memset(ary, 0, sizeof(ary));
4| }
(gdb) print ary
$1 = {0 <repeats 42 times>}
gdb/ChangeLog:
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
This reverts the following patch series, as they cause some regresssions.
commit 37c1ab67a3
type: add c99 variable length array support
gdb/
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
commit 26cb189f8b
vla: enable sizeof operator to work with variable length arrays
gdb/
* eval.c (evaluate_subexp_for_sizeof) <OP_VAR_VALUE>: If the type
passed to sizeof is dynamic evaluate the argument to compute the length.
commit 04b19544ef
vla: enable sizeof operator for indirection
gdb/
* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
value and retrieve the dynamic type size.
commit bcd629a44f
vla: update type from newly created value
gdb/
* ada-lang.c (ada_value_primitive_packed_val): Re-fetch type from value.
(ada_template_to_fixed_record_type_1): Likewise.
(ada_to_fixed_type_1): Likewise.
* cp-valprint.c (cp_print_value_fields_rtti): Likewise.
(cp_print_value): Likewise.
* d-valprint.c (dynamic_array_type): Likewise.
* eval.c (evaluate_subexp_with_coercion): Likewise.
* findvar.c (address_of_variable): Likewise.
* jv-valprint.c (java_value_print): Likewise.
* valops.c (value_ind): Likewise.
* value.c (coerce_ref): Likewise.
commit b86138fb04
vla: print "variable length" for unresolved dynamic bounds
gdb/
* c-typeprint.c (c_type_print_varspec_suffix): Added
check for not yet resolved high bound. If unresolved, print
"variable length" string to the console instead of random
length.
commit e1969afbd4
vla: support for DW_AT_count
gdb/
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
commit 92b09522dc
vla: resolve dynamic bounds if value contents is a constant byte-sequence
gdb/
* findvar.c (default_read_var_value): Resolve dynamic bounds if location
points to a constant blob.
commit 3bce82377f
vla: evaluate operand of sizeof if its type is a vla
gdb/
* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
(evaluate_subexp_standard): Pass noside argument.
(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
if noside equals EVAL_NORMAL. If the subscript yields a vla type
re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.
gdb/testsuite
* gdb.base/vla-sideeffect.c: New file.
* gdb.base/vla-sideeffect.exp: New file.
commit 504f34326e
test: cover subranges with present DW_AT_count attribute
gdb/testsuite/
* gdb.dwarf2/count.exp: New file.
commit 1a237e0ee5
test: multi-dimensional c99 vla.
gdb/testsuite/
* gdb.base/vla-multi.c: New file.
* gdb.base/vla-multi.exp: New file.
commit 024e13b46f
test: evaluate pointers to C99 vla correctly.
gdb/testsuite/
* gdb.base/vla-ptr.c: New file.
* gdb.base/vla-ptr.exp: New file.
commit c8655f75e2
test: basic c99 vla tests for C primitives
gdb/testsuite/
* gdb.base/vla-datatypes.c: New file.
* gdb.base/vla-datatypes.exp: New file.
commit 58a84dcf29
test: add mi vla test
gdb/testsuite/
* gdb.mi/mi-vla-c99.exp: New file.
* gdb.mi/vla.c: New file.
This patch adds support for DW_AT_count as requested in the code review:
https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
The dwarf standard allow certain attributes to be expressed as dwarf
expressions rather than constants. For instance upper-/lowerbound attributes.
In case of a c99 variable length array the upperbound is a dynamic attribute.
With this change c99 vla behave the same as with static arrays.
1| void foo (size_t n) {
2| int ary[n];
3| memset(ary, 0, sizeof(ary));
4| }
(gdb) print ary
$1 = {0 <repeats 42 times>}
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
The rational behind this patch is to get started to implement the feature
described in dwarf4 standard (2.19) Static and Dynamic Values of Attributes.
It adds new BOUND_PROP to store either a constant, exprloc, or reference to
describe an upper-/lower bound of a subrange. Other than that no new features
are introduced.
* dwarf2read.c (read_subrange_type): Use struct bound_prop for
declaring high/low bounds and change uses accordingly. Call
create_range_type instead of create_static_range_type.
* gdbtypes.c (create_range_type): New function.
(create_range_type): Convert bounds into struct bound_prop and pass
them to create_range_type.
* gdbtypes.h (struct bound_prop): New struct.
(create_range_type): New function prototype.
(struct range_bounds): Use struct bound_prop instead of LONGEST for
high/low bounds. Remove low_undefined/high_undefined and adapt all uses.
(TYPE_LOW_BOUND,TYPE_HIGH_BOUND): Adapt macros to refer to the static
part of the bound.
* parse.c (follow_types): Set high bound kind to BOUND_UNDEFINED.
* gdbtypes.c (create_static_range_type): Renamed from create_range_type.
* gdbtypes.h (create_static_range_type): Renamed from create_range_type.
* ada-lang.c: All uses of create_range_type updated.
* coffread.c: All uses of create_range_type updated.
* dwarf2read.c: All uses of create_range_type updated.
* f-exp.y: All uses of create_range_type updated.
* m2-valprint.c: All uses of create_range_type updated.
* mdebugread.c: All uses of create_range_type updated.
* stabsread.c: All uses of create_range_type updated.
* valops.c: All uses of create_range_type updated.
* valprint.c: All uses of create_range_type updated.
* dwarf2read.c (read_cutu_die_from_dwo): Fix function comment.
Remove unused local comp_dir_attr. Assert exactly one of
stub_comp_unit_die, stub_comp_dir is non-NULL.
Starting with DWARF version 4, the description of the DW_AT_high_pc
attribute was amended to say:
if it is of class constant, the value is an unsigned integer offset
which when added to the low PC gives the address of the first
location past the last instruction associated with the entity.
A change was made in Apr 27th, 2012 to reflect that change:
| commit 91da14142c
| Author: Mark Wielaard <mjw@redhat.com>
| Date: Fri Apr 27 18:55:19 2012 +0000
|
| * dwarf2read.c (dwarf2_get_pc_bounds): Check DW_AT_high_pc form to
| see whether it is an address or a constant offset from DW_AT_low_pc.
| (dwarf2_record_block_ranges): Likewise.
| (read_partial_die): Likewise.
Unfortunately, this new interpretation is now used regardless of
the CU's DWARF version. It turns out that one of WindRiver's compilers
(FTR: Diabdata 4.4) is generating DWARF version 2 info with
DW_AT_high_pc attributes improperly using the data4 form. Because of
that, we miscompute all high PCs incorrectly. This leads to a lot of
symtabs having overlapping ranges, which in turn causes havoc in
pc-to-symtab-and-line translations.
One visible effect is when inserting a breakpoint on a given function:
(gdb) b world
Breakpoint 1 at 0x4005c4
The source location of the breakpoint is missing. The output should be:
(gdb) b world
Breakpoint 1 at 0x4005c8: file dw2-rel-hi-pc-world.c, line 24.
What happens in this case is that the pc-to-SAL translation first
starts be trying to find the symtab associated to our PC using
each symtab's ranges. Because of the high_pc miscomputation,
many symtabs end up matching, and the heuristic trying to select
the most probable one unfortunately returns one that is unrelated
(it really had no change in this case to do any better). Once we
have the wrong symtab, the start searching the associated linetable,
where the addresses are correct, thus finding no match, and therefore
no SAL.
This patch is an attempt at handling the situation as gracefully
as we can, without guarantees. It introduces a new function
"attr_value_as_address" which uses the correct accessor for getting
the value of a given attribute. It then adjust the code throughout
this unit to use this function instead of assuming that addresses always
have the DW_FORM_addr format.
It also fixes the original issue of miscomputing the high_pc
by limiting the new interpretation of constant form DW_AT_high_pc
attributes to units using DWARF version 4 or later.
gdb/ChangeLog:
* dwarf2read.c (attr_value_as_address): New function.
(dwarf2_find_base_address, read_call_site_scope): Use
attr_value_as_address in place of DW_ADDR.
(dwarf2_get_pc_bounds): Use attr_value_as_address to get
the low and high addresses. Slight rework of the handling
of the high pc being a constant form, and limit it to
DWARF verson 4 or higher.
(dwarf2_record_block_ranges): Likewise.
(read_partial_die): Likewise.
(new_symbol_full): Use attr_value_as_address in place of DW_ADDR.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-abs-hi-pc-hello-dbg.S: New file.
* gdb.dwarf2/dw2-abs-hi-pc-hello.c: New file.
* gdb.dwarf2/dw2-abs-hi-pc-world-dbg.S: New file.
* gdb.dwarf2/dw2-abs-hi-pc-world.c: New file.
* gdb.dwarf2/dw2-abs-hi-pc.c: New file.
* gdb.dwarf2/dw2-abs-hi-pc.exp: New file.
Tested on x86_64-linux.
This comment explains why we sometimes sign-extend the range type
bounds when we normally shouldn't have to.
gdb/ChangeLog:
* dwarf2read.c (read_subrange_type): Add comment.
Consider the following Ada code:
-- An array whose index is an enumeration type with 128 enumerators.
type Enum_T is (Enum_000, Enum_001, [...], Enum_128);
type Table is array (Enum_T) of Boolean;
When the compiler is configured to generate pure DWARF debugging info,
trying to print type Table's description yields:
ptype pck.table
type = array (enum_000 .. -128) of boolean
The expected output was:
ptype pck.table
type = array (enum_000 .. enum_128) of boolean
The DWARF debugging info for our array looks like this:
<1><44>: Abbrev Number: 5 (DW_TAG_array_type)
<45> DW_AT_name : pck__table
<50> DW_AT_type : <0x28>
<2><54>: Abbrev Number: 6 (DW_TAG_subrange_type)
<55> DW_AT_type : <0x5c>
<59> DW_AT_lower_bound : 0
<5a> DW_AT_upper_bound : 128
The array index type is, by construction with the DWARF standard,
a subrange of our enumeration type, defined as follow:
<2><5b>: Abbrev Number: 0
<1><5c>: Abbrev Number: 7 (DW_TAG_enumeration_type)
<5d> DW_AT_name : pck__enum_t
<69> DW_AT_byte_size : 1
<2><6b>: Abbrev Number: 8 (DW_TAG_enumerator)
<6c> DW_AT_name : pck__enum_000
<7a> DW_AT_const_value : 0
[etc]
Therefore, while processing these DIEs, the array index type ends
up being a TYPE_CODE_RANGE whose target type is our enumeration type.
But the problem is that we read the upper bound as a negative value
(-128), which is then used as is by the type printer to print the
array upper bound. This negative value explains the "-128" in the
output.
To understand why the range type's upper bound is read as a negative
value, one needs to look at how it is determined, in read_subrange_type:
orig_base_type = die_type (die, cu);
base_type = check_typedef (orig_base_type);
[... high is first correctly read as 128, but then ...]
if (!TYPE_UNSIGNED (base_type) && (high & negative_mask))
high |= negative_mask;
The negative_mask is applied, here, because BASE_TYPE->FLAG_UNSIGNED
is not set. And the reason for that is because the base_type was only
partially constructed during the call to die_type. While the enum
is constructed on the fly by read_enumeration_type, its flag_unsigned
flag is only set later on, while creating the symbols corresponding to
the enum type's enumerators (see process_enumeration_scope), after
we've already finished creating our range type - and therefore too
late.
My first naive attempt at fixing this problem consisted in extracting
the part in process_enumeration_scope which processes all enumerators,
to generate the associated symbols, but more importantly set the type's
various flags when necessary. However, this does not always work well,
because we're still in the subrange_type's scope, and it might be
different from the scope where the enumeration type is defined.
So, instead, what this patch does to fix the issue is to extract
from process_enumeration_scope the part that determines whether
the enumeration type should have the flag_unsigned and/or the
flag_flag_enum flags set. It turns out that, aside from the code
implementing the loop, this part is fairly independent of the symbol
creation. With that part extracted, we can then use it at the end
of our enumeration type creation, to produce a type which should now
no longer need any adjustment.
Once the enumeration type produced is correctly marked as unsigned,
the subrange type's upper bound is then correctly read as an unsigned
value, therefore giving us an upper bound of 128 instead of -128.
gdb/ChangeLog:
* dwarf2read.c (update_enumeration_type_from_children): New
function, mostly extracted from process_structure_scope.
(read_enumeration_type): Call update_enumeration_type_from_children.
(process_enumeration_scope): Do not set THIS_TYPE's flag_unsigned
and flag_flag_enum fields.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/arr-subrange.c, gdb.dwarf2/arr-subrange.exp: New files.
Andreas Arnez
Pedro Alves
Tom Tromey
Ulrich Weigand
Jan Kratochvil
Trevor Saunders
Doug Evans
Bernhard Heckel
Jonas Hahnfeld
Joel Brobecker
Andrew Burgess
Dominik Vogt
Simon Marchi
Keven Boell
Simon Marchi
Doug Evans
Pierre-Marie de Rodat
Tom Tromey
Kevin Buettner
Iain Buclaw
Martin Galvan
Sandra Loosemore
Andy Wingo
Keith Seitz
Gary Benson
Mark Wielaard
Maciej W. Rozycki
Yao Qi
Michael Eager
Sanimir Agovic