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.
Tom Tromey
Jan Kratochvil
Trevor Saunders
Doug Evans
Pedro Alves
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