Compilers can materialize renamings of arrays (or of accesses to arrays)
in Ada into variables whose types are references to the actual array
types. Before this change, trying to use such an array renaming yielded
an error in GDB:
(gdb) print my_array(1)
cannot subscript or call a record
(gdb) print my_array_ptr(1)
cannot subscript or call something of type `(null)'
This behavior comes from bad handling for array renamings, in particular
the OP_FUNCALL expression operator handling from ada-lang.c
(ada_evaluate_subexp): in one place we turn the reference into a
pointer, but the code that follows expect the value to be an array.
This patch fixes how we handle references in call/subscript evaluation
so that we turn these references into the actual array values instead of
pointers to them.
gdb/ChangeLog:
* ada-lang.c (ada_evaluate_subexp) <OP_FUNCALL>: When the input
value is a reference, actually dereference it in order to get
the underlying value.
gdb/testsuite/ChangeLog:
* gdb.ada/array_ptr_renaming.exp: New testcase.
* gdb.ada/array_ptr_renaming/foo.adb: New file.
* gdb.ada/array_ptr_renaming/pack.ads: New file.
Tested on x86_64-linux, no regression.
This change is relevant only for standard DWARF (as opposed to the GNAT
encodings extensions): at the time of writing it only makes a difference
with GCC patches that are to be integrated: see in particular
<https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01364.html>.
Given the following Ada declarations:
type Small is mod 2 ** 6;
type Array_Type is array (0 .. 9) of Small
with Pack;
type Array_Access is access all Array_Type;
A : aliased Array_Type := (1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
AA : constant Array_Type := A'Access;
Before this change, we would get the following GDB session:
(gdb) print aa.all(2)
$1 = 3
(gdb) print aa(2)
$2 = 16
This is wrong: both expression should yield the same value: 3. The
problem is simply that the routine which handles accesses to arrays lack
general handling for packed arrays. After this patch, we have the
expected output:
(gdb) print aa.all(2)
$1 = 3
(gdb) print aa(2)
$2 = 3
gdb/ChangeLog:
* ada-lang.c (ada_value_ptr_subscript): Update the heading
comment. Handle packed arrays.
gdb/testsuite/ChangeLog:
* gdb.ada/access_to_packed_array.exp: New testcase.
* gdb.ada/access_to_packed_array/foo.adb: New file.
* gdb.ada/access_to_packed_array/pack.adb: New file.
* gdb.ada/access_to_packed_array/pack.ads: New file.
Tested on x86_64-linux, no regression.
I found this const/not const mixup found by building in C++ mode.
gdb/ChangeLog:
* ada-lang.c (ada_search_struct_field): Constify parameters
and/or variables..
(xget_renaming_scope): Likewise.
(ada_is_redundant_range_encoding): Likewise.
(scan_discrim_bound): Likewise.
(to_fixed_range_type): Likewise.
Before this change, trying to call an overloaded function with at least
one character literal in argument would fail. For instance, given these
two functions:
function F (C : Character) return Integer is
begin
return Character'Pos (C);
end F;
function F (I : Integer) return Integer is
begin
return -I;
end F;
We would get the following GDB session:
(gdb) p f('A')
$1 = -65
(gdb) p f(1)
$1 = -1
This is wrong because the first call should select the first F function
and thus return 65.
The root problem is that ada-lang.c:ada_language_arch_info stores in
string_char_type a type whose code is TYPE_CODE_INT instead of
TYPE_CODE_CHAR. As a result, all parsed character literals are turned
into integer values and during overload matching, the TYPE_CODE_CHAR
formal rejects the TYPE_CODE_INT actual.
This change turns string_char_type into a true TYPE_CODE_CHAR type in
ada-lang.c so that we have instead the expected:
(gdb) p f('A')
$1 = 65
gdb/ChangeLog:
* ada-lang.c (ada_language_arch_info): Create a TYPE_CODE_CHAR
type instead of a TYPE_CODE_INT one for the string_char_type
and the ada_primitive_type_char types.
gdb/testsuite/ChangeLog:
* gdb.ada/funcall_char.exp: New testcase.
* gdb.ada/funcall_char/foo.adb: New file.
Tested on x86_64-linux, no regression.
Before this change, trying to complete an expression ending with an
ambiguous function name (i.e. for which there are multiple matches)
would display a menu with a prompt for the user to pick one. For
instance:
(gdb) p func<tab>Multiple matches for func
[0] cancel
[1] pack2.func at pack2.adb:5
[2] pack.func at pack.adb:5
>
This is not user friendly and actually triggered a segmentation fault
after the user did pick one. It is not clear whether the segmentation
fault needs a separate fix, but this is the only known case which
exhibits it at the moment, and this case must be fixed itself.
The problem lies in ada-lang.c (ada_resolve_function): when we got
multiple matches, we should not display the menu if we are in completion
mode. This patch adjusts the corresponding condition accordingly.
gdb/ChangeLog:
* ada-lang.c (ada_resolve_function): Do not ask the user what
match to use when in completion mode.
gdb/testsuite/ChangeLog:
* gdb.ada/complete.exp: Add "pck.ambiguous_func" to the relevant
expected outputs. Add two testcases for completing ambiguous
functions.
* gdb.ada/complete/aux_pck.adb: New file.
* gdb.ada/complete/aux_pck.ads: New file.
* gdb.ada/complete/foo.adb: Pull Aux_Pck and call the two
Ambiguous_Func functions.
* gdb.ada/complete/pck.ads: Add an Ambiguous_Func function.
* gdb.ada/complete/pck.adb: Likewise.
Tested on x86_64-linux, no regression.
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.
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>.
As Pedro suggested on gdb-patches@ (see
https://sourceware.org/ml/gdb-patches/2015-05/msg00714.html), this
change makes symbol lookup functions return a structure that includes
both the symbol found and the block in which it was found. This makes
it possible to get rid of the block_found global variable and thus makes
block hunting explicit.
gdb/
* ada-exp.y (write_object_renaming): Replace struct
ada_symbol_info with struct block_symbol. Update field
references accordingly.
(block_lookup, select_possible_type_sym): Likewise.
(find_primitive_type): Likewise. Also update call to
ada_lookup_symbol to extract the symbol itself.
(write_var_or_type, write_name_assoc): Likewise.
* ada-lang.h (struct ada_symbol_info): Remove.
(ada_lookup_symbol_list): Replace struct ada_symbol_info with
struct block_symbol.
(ada_lookup_encoded_symbol, user_select_syms): Likewise.
(ada_lookup_symbol): Return struct block_symbol instead of a
mere symbol.
* ada-lang.c (defns_collected): Replace struct ada_symbol_info
with struct block_symbol.
(resolve_subexp, ada_resolve_function, sort_choices,
user_select_syms, is_nonfunction, add_defn_to_vec,
num_defns_collected, defns_collected,
symbols_are_identical_enums, remove_extra_symbols,
remove_irrelevant_renamings, add_lookup_symbol_list_worker,
ada_lookup_symbol_list, ada_iterate_over_symbols,
ada_lookup_encoded_symbol, get_var_value): Likewise.
(ada_lookup_symbol): Return a block_symbol instead of a mere
symbol. Replace struct ada_symbol_info with struct
block_symbol.
(ada_lookup_symbol_nonlocal): Likewise.
(standard_lookup): Make block passing explicit through
lookup_symbol_in_language.
* ada-tasks.c (get_tcb_types_info): Update the calls to
lookup_symbol_in_language to extract the mere symbol out of the
returned value.
(ada_tasks_inferior_data_sniffer): Likewise.
* ax-gdb.c (gen_static_field): Likewise for the call to
lookup_symbol.
(gen_maybe_namespace_elt): Deal with struct symbol_in_block from
lookup functions.
(gen_expr): Likewise.
* c-exp.y: Likewise. Remove uses of block_found.
(lex_one_token, classify_inner_name, c_print_token): Likewise.
(classify_name): Likewise. Rename the "sym" local variable to
"bsym".
* c-valprint.c (print_unpacked_pointer): Likewise.
* compile/compile-c-symbols.c (convert_symbol_sym): Promote the
"sym" parameter from struct symbol * to struct block_symbol.
Use it to remove uses of block_found. Deal with struct
symbol_in_block from lookup functions.
(gcc_convert_symbol): Likewise. Update the call to
convert_symbol_sym.
* compile/compile-object-load.c (compile_object_load): Deal with
struct symbol_in_block from lookup functions.
* cp-namespace.c (cp_lookup_nested_symbol_1,
cp_lookup_nested_symbol, cp_lookup_bare_symbol,
cp_search_static_and_baseclasses,
cp_lookup_symbol_in_namespace, cp_lookup_symbol_via_imports,
cp_lookup_symbol_imports_or_template,
cp_lookup_symbol_via_all_imports, cp_lookup_symbol_namespace,
lookup_namespace_scope, cp_lookup_nonlocal,
find_symbol_in_baseclass): Return struct symbol_in_block instead
of mere symbols and deal with struct symbol_in_block from lookup
functions.
* cp-support.c (inspect_type, replace_typedefs,
cp_lookup_rtti_type): Deal with struct symbol_in_block from
lookup functions.
* cp-support.h (cp_lookup_symbol_nonlocal,
cp_lookup_symbol_from_namespace,
cp_lookup_symbol_imports_or_template, cp_lookup_nested_symbol):
Return struct symbol_in_block instead of mere symbols.
* d-exp.y (d_type_from_name, d_module_from_name, push_variable,
push_module_name):
Deal with struct symbol_in_block from lookup functions. Remove
uses of block_found.
* eval.c (evaluate_subexp_standard): Update call to
cp_lookup_symbol_namespace.
* f-exp.y: Deal with struct symbol_in_block from lookup
functions. Remove uses of block_found.
(yylex): Likewise.
* gdbtypes.c (lookup_typename, lookup_struct, lookup_union,
lookup_enum, lookup_template_type, check_typedef): Deal with
struct symbol_in_block from lookup functions.
* guile/scm-frame.c (gdbscm_frame_read_var): Likewise.
* guile/scm-symbol.c (gdbscm_lookup_symbol): Likewise.
(gdbscm_lookup_global_symbol): Likewise.
* gnu-v3-abi.c (gnuv3_get_typeid_type): Likewise.
* go-exp.y: Likewise. Remove uses of block_found.
(package_name_p, classify_packaged_name, classify_name):
Likewise.
* infrun.c (insert_exception_resume_breakpoint): Likewise.
* jv-exp.y (push_variable): Likewise.
* jv-lang.c (java_lookup_class, get_java_object_type): Likewise.
* language.c (language_bool_type): Likewise.
* language.h (struct language_defn): Update
la_lookup_symbol_nonlocal to return a struct symbol_in_block
rather than a mere symbol.
* linespec.c (find_label_symbols): Deal with struct
symbol_in_block from lookup functions.
* m2-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* mi/mi-cmd-stack.c (list_args_or_locals): Likewise.
* objc-lang.c (lookup_struct_typedef, find_imps): Likewise.
* p-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* p-valprint.c (pascal_val_print): Likewise.
* parse.c (write_dollar_variable): Likewise. Remove uses of
block_found.
* parser-defs.h (struct symtoken): Turn the SYM field into a
struct symbol_in_block.
* printcmd.c (address_info): Deal with struct symbol_in_block
from lookup functions.
* python/py-frame.c (frapy_read_var): Likewise.
* python/py-symbol.c (gdbpy_lookup_symbol,
gdbpy_lookup_global_symbol): Likewise.
* skip.c (skip_function_command): Likewise.
* solib-darwin.c (darwin_lookup_lib_symbol): Return a struct
symbol_in_block instead of a mere symbol.
* solib-spu.c (spu_lookup_lib_symbol): Likewise.
* solib-svr4.c (elf_lookup_lib_symbol): Likewise.
* solib.c (solib_global_lookup): Likewise.
* solist.h (solib_global_lookup): Likewise.
(struct target_so_ops): Update lookup_lib_global_symbol to
return a struct symbol_in_block rather than a mere symbol.
* source.c (select_source_symtab): Deal with struct
symbol_in_block from lookup functions.
* stack.c (print_frame_args, iterate_over_block_arg_vars):
Likewise.
* symfile.c (set_initial_language): Likewise.
* symtab.c (SYMBOL_LOOKUP_FAILED): Turn into a struct
symbol_in_block.
(SYMBOL_LOOKUP_FAILED_P): New predicate as a macro.
(struct symbol_cache_slot): Turn the FOUND field into a struct
symbol_in_block.
(block_found): Remove.
(eq_symbol_entry): Update to deal with struct symbol_in_block in
cache slots.
(symbol_cache_lookup): Return a struct symbol_in_block rather
than a mere symbol.
(symbol_cache_mark_found): Add a BLOCK parameter to fill
appropriately the cache slots. Update callers.
(symbol_cache_dump): Update cache slots handling to the type
change.
(lookup_symbol_in_language, lookup_symbol, lookup_language_this,
lookup_symbol_aux, lookup_local_symbol,
lookup_symbol_in_objfile, lookup_global_symbol_from_objfile,
lookup_symbol_in_objfile_symtabs,
lookup_symbol_in_objfile_from_linkage_name,
lookup_symbol_via_quick_fns, basic_lookup_symbol_nonlocal,
lookup_symbol_in_static_block, lookup_static_symbol,
lookup_global_symbol):
Return a struct symbol_in_block rather than a mere symbol. Deal
with struct symbol_in_block from other lookup functions. Remove
uses of block_found.
(lookup_symbol_in_block): Remove uses of block_found.
(struct global_sym_lookup_data): Turn the RESULT field into a
struct symbol_in_block.
(lookup_symbol_global_iterator_cb): Update references to the
RESULT field.
(search_symbols): Deal with struct symbol_in_block from lookup
functions.
* symtab.h (struct symbol_in_block): New structure.
(block_found): Remove.
(lookup_symbol_in_language, lookup_symbol,
basic_lookup_symbol_nonlocal, lookup_symbol_in_static_block,
looku_static_symbol, lookup_global_symbol,
lookup_symbol_in_block, lookup_language_this,
lookup_global_symbol_from_objfile): Return a struct
symbol_in_block rather than just a mere symbol. Update comments
to remove mentions of block_found.
* valops.c (find_function_in_inferior,
value_struct_elt_for_reference, value_maybe_namespace_elt,
value_of_this): Deal with struct symbol_in_block from lookup
functions.
* value.c (value_static_field, value_fn_field): Likewise.
... to avoid a build failure when building with C++ compiler
(when configured with --enable-build-with-cxx). We cannot use
"typename" as it is a C++ reserved keyword.
gdb/ChangeLog:
* ada-lang.c (to_fixed_array_type): Rename local variable
typename into type_name.
In Ada, index types of arrays can be enumeration types, and enumeration
types can be non-contiguous. In which case the address of elements is
not given by the value of the index, but by its position in the enumeration
type.
In other words, in this example:
type Color is (Blue, Red);
for Color use (Blue => 8, Red => 12, Green => 16);
type A is array (Color) of Integer;
type B is array (1 .. 3) of Integer;
Arrays of type A and B will have the same layout in memory, even if
the enumeration Color has a hole in its set of integer value.
Since recently support for such a feature was in ada-lang.c, where the
array was casted to a regular continuous index range. We were losing
the information of index type. And this was not quite working for
subranges in variable-length fields; their bounds are expressed using
the integer value of the bounds, not its position in the enumeration,
and there was some confusion all over ada-lang.c as to whether we had
the position or the integer value was used for indexes.
The idea behind this patch is to clean this up by keeping the real
representation of these array index types and bounds when representing
the value, and only use the position when accessing the elements or
computing the length. This first patch fixes the printing of such
an array.
To the best of my knowledge, this feature only exists in Ada so it
should only affect this language.
gdb/ChangeLog:
Jerome Guitton <guitton@adacore.com>:
* ada-lang.c (ada_value_ptr_subscript): Use enum position of
index to get element instead of enum value.
(ada_value_slice_from_ptr, ada_value_slice): Use enum position
of index to compute length, but enum values to compute bounds.
(ada_array_length): Use enum position of index instead of enum value.
(pos_atr): Move position computation to...
(ada_evaluate_subexp): Use enum values to compute bounds.
* gdbtypes.c (discrete_position): ...this new function.
* gdbtypes.h (discrete_position): New function declaration.
* valprint.c (val_print_array_elements): Call discrete_position
to handle array indexed by non-contiguous enumeration types.
gdb/testsuite/ChangeLog:
* gdb.ada/arr_enum_with_gap: New testcase.
In the case of non bit-packed arrays, GNAT does not generate its
traditional XP encoding; it is not needed. However, it still generates
the so-called "implementation type" with a P suffix. This
implementation type shall be skipped when looking for other
descriptive types such as XA encodings for variable-length
fields.
Note also that there may be an intermediate typedef between the
implementation type and its XA description. It shall be skipped
as well.
gdb/ChangeLog:
Jerome Guitton <guitton@adacore.com>
* ada-lang.c (find_parallel_type_by_descriptive_type):
Go through typedefs during lookup.
(to_fixed_array_type): Add support for non-bit packed arrays
as variable-length fields.
gdb/testsuite/ChangeLog:
* gdb.ada/byte_packed_arr: New testcase.
Consider the following declarations:
type Signed_Small is new Integer range - (2 ** 5) .. (2 ** 5 - 1);
type Signed_Simple_Array is array (1 .. 4) of Signed_Small;
pragma Pack (Signed_Simple_Array);
SSA : Signed_Simple_Array := (-1, 2, -3, 4);
GDB currently print its value incorrectly for the elements that
are negative:
(gdb) print ssa
$1 = (65535, 2, 1048573, 4)
(gdb) print ssa(1)
$2 = 65535
(gdb) print ssa(2)
$3 = 2
(gdb) print ssa(3)
$4 = 1048573
(gdb) print ssa(4)
$5 = 4
What happens is that the sign-extension is not working because
we're trying to do left shift with a negative count. In
ada_value_primitive_packed_val, we have a loop which populates
the extra bits of the target (unpacked) value, after extraction
of the data from the original (packed) value:
while (ntarg > 0)
{
accum |= sign << accumSize;
unpacked[targ] = accum & ~(~0L << HOST_CHAR_BIT);
!!! -> accumSize -= HOST_CHAR_BIT;
accum >>= HOST_CHAR_BIT;
ntarg -= 1;
targ += delta;
}
At each iteration, accumSize gets decremented by HOST_CHAR_BIT,
which can easily cause it to become negative, particularly on
little endian targets, where accumSize is at most HOST_CHAR_BIT - 1.
This causes us to perform a left-shift operation with a negative
accumSize at the next loop iteration, which is undefined, and
acutally does not produce the effect we wanted (value left untouched)
when the code is compiled with GCC.
This patch fixes the issue by simply setting accumSize to zero
if negative.
gdb/ChangeLog:
* ada-lang.c (ada_value_primitive_packed_val): Make sure
accumSize is never negative.
gdb/testsuite/ChangeLog:
* gdb.ada/pckd_neg: New testcase.
We observed on x86-windows that trying to call a function from
GDB leads to a mysterious "Invalid cast" error. This can be
observed in gdb.ada/float_param.exp:
(gdb) call set_long_double(1, global_small_struct, 4.0)
Invalid cast.
This happens because the 3rd parameter, a Long_Long_Float, is
actually passed wrapped inside a PAD structure. As documented
in GNAT's exp_dbug.ads, PAD types are simple wrappers that GNAT
uses to handle types with size or alignment constraints.
We already support those when printing an object encapsulated
in a PAD type, but not when trying to pass an argument that
is wrapped inside a PAD type. As a result, what happens is that
call_function_by_hand ends up with an argument with a type
that looks incompatible with the expected type of the argument.
The error comes when trying to push the arguments in inferior
memory, while trying to coerce each one of them to their expected
types (in value_arg_coerce).
Note that the problem is not specific to Windows, but so far, this is
the only platform where we've seen this happen.
gdb/ChangeLog:
* ada-lang.c (ada_convert_actual): Add handling of formals
passed inside an aligner type.
Tested on x86-windows (AdaCore testsuite) and x86_64-linux (official
testsuite as well as AdaCore's testsuite).
This patch improves the documentation of ada-lang.c's
value_assign_to_component to publish the fact that it also works
with not_lval values.
And touching this area of the code showed that there were a number
of whitespace issues, as well as a formatting issue of the main comment
(no leading '*' on each line). This patch fixes those while at it.
No functional change, however.
gdb/ChangeLog:
* ada-lang.c (value_assign_to_component): Reformat and improve
documentation. Remove all trailing spaces.
This is an issue which I noticed while working on trying to print
an array of variant records. For instance, trying to print "A1",
an array of elements whose size is variable, defined as follow
(see gdb.ada/var_rec_arr testcase):
subtype Small_Type is Integer range 0 .. 10;
type Record_Type (I : Small_Type := 0) is record
S : String (1 .. I);
end record;
function Ident (R : Record_Type) return Record_Type;
type Array_Type is array (Integer range <>) of Record_Type;
A1 : Array_Type := (1 => (I => 0, S => <>),
2 => (I => 1, S => "A"),
3 => (I => 2, S => "AB"));
The debugger sometimes prints the array as follow:
(gdb) print A1
$1 = ((i => 0, s => ""), (i => 0, s => ""), (i => 0, s => ""))
The problem happens inside the part of the loop printing the array's
elements, while trying to count the number of consecutive elements
that have the same value (in order to replace them by the "<repeats
nnn times>" message when the number exceeds a threshold). In particular,
in ada-valprint.c::val_print_packed_array_elements:
elttype = TYPE_TARGET_TYPE (type);
eltlen = TYPE_LENGTH (check_typedef (elttype));
while (...)
{
if (!value_contents_eq (v0, value_embedded_offset (v0),
v1, value_embedded_offset (v1),
eltlen))
break;
The value comparison is performed using value_contents_eq but makes
the assumption that elttype is not dynamic, which is not always true.
In particular, in the case above, elttype is dynamic and therefore
its TYPE_LENGTH changes from element to element.
As it happens in this case, the eltlen is zero, which causes the call
to value_contents_eq to return true, and therefore GDB thinks all
3 elements of the array are equal.
This patch fixes the issue by making sure that both v0 and v1, which
are values whose type we expect to be resolved, have identical lengths.
If not, then the two elements of the array cannot possibly have the
same value and we do not even need to do the binary comparison.
Unfortunately, this is still not enough to get GDB to print the correct
value for our array, because the assumption that v0 and v1 have a type
which has been resolved is actually not met. So, the second part of
the patch modifies the function that constructed the values to make
sure dynamic types do get resolved.
gdb/ChangeLog:
* ada-valprint.c (val_print_packed_array_elements): Delete
variable "len". Add a type-length check when comparing two
consecutive elements of the array. Use the element's actual
length in call to value_contents_eq.
* ada-lang.c (ada_value_primitive_packed_val): Always return
a value whose type has been resolved.
Consider the following declarations:
subtype Small_Type is Integer range 0 .. 10;
type Record_Type (I : Small_Type := 0) is record
S : String (1 .. I);
end record;
A2 : Array_Type := (1 => (I => 2, S => "AB"),
2 => (I => 1, S => "A"),
3 => (I => 0, S => <>));
Compiled with -fgnat-encodings=minimal, and trying to print
one element of our array, valgrind reports an invalid memory
access. On certain GNU/Linux boxes, malloc even reports it as
well, and causes GDB to crash.
(gdb) print a2(1)
*** glibc detected *** /[...]/gdb:
malloc(): memory corruption: 0x0a30ba48 ***
[crash]
The invalid memory access occurs because of a simple buffer
overflow in ada_value_primitive_packed_val. When this function
is called, it is given a bit_size of 128 (or 16 bytes), which
corresponds to the stride of our array. But the actual size of
each element depends on its value. In particular, A2(1) is a record
whose size is only 6 bytes.
What happens in our example is that we start building a new value
(v) where the element is to be unpacked, with any of its dynamic
properties getting resolved as well. We then unpack the data into
this value's buffer:
unpacked = (unsigned char *) value_contents (v);
[...]
nsrc = len;
[...]
while (nsrc > 0)
{
[...]
unpacked[targ] = accum & ~(~0L << HOST_CHAR_BIT);
[...]
targ += delta;
[...]
nsrc -= 1;
[...]
}
In the loop above, targ starts at zero (for LE architectures),
and len is 16. With delta being +1, we end up iterating 16 times,
writing 16 bytes into a 6-bytes buffer.
This patch fixes the issue by adjusting BIT_SIZE and recomputing
LEN after having resolved our type if the resolved type turns out
to be smaller than bit_size.
gdb/ChangeLog:
* ada-lang.c (ada_value_primitive_packed_val): Recompute
BIT_SIZE and LEN if the size of the resolved type is smaller
than BIT_SIZE * HOST_CHAR_BIT.
Consider the following (Ada) array...
A1 : Array_Type := (1 => (I => 0, S => <>),
2 => (I => 1, S => "A"),
3 => (I => 2, S => "AB"));
... where Array_Type is declared as follow:
subtype Small_Type is Integer range 0 .. 10;
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;
Trying to print the value of each element individually does not
always work. Printing the value of the first one does:
(gdb) p a1(1)
$1 = (i => 0, s => "")
But printing the value of the subsequent ones often does not.
For instance:
(gdb) p a1(2)
$2 = (i => 1, s => "") <<<--- s should be "A"
(gdb) p a1(3)
$3 = (i => 2, s => "") <<<--- s should be "AB"
I traced the problem to ada_value_primitive_packed_val,
which is trying to perform the array subscripting by
extracting the value of the corresponding array element
into a buffer where the contents is now byte-aligned.
The element type that ada_value_primitive_packed_val gets passed
is a dynamic type. As it happens, that dynamic type can get resolved
thanks to:
v = value_at (type, value_address (obj));
type = value_type (v);
However, obj represents the array, so the address given in the call
to value_at represents the value of the first element. As a result,
the solution of component S's upper bound always gets resolved based
on the value of component I in the first element of the array, whose
value is 0, thus leading to GDB mistakely resolving the element type
where S's upper bound is always 0.
The proper fix would be to systematically resolve the element type
first. But, this requires us to extract-and-realign the element's
value so as to be able to pass it as "valaddr" to resolve_dynamic_type.
In the meantime, it's easy to make the situation a little better by
passing "value_address (obj) + offset" as the object address. This
only works when BIT_OFFSET is nul, but that should be the case when
the element type is anything but a scalar, which seems to be the only
situation where it seems important to resolve the type now. And we're
not that worse off otherwise.
But we'll try to find a better solution in a separate patch.
gdb/ChangeLog:
* ada-lang.c (ada_value_primitive_packed_val): Use a more
correct address in call to value_at. Adjust call to
value_address accordingly.
This is the second part of enhancing the debugger to print the value
of arrays of records whose size is variable when only standard DWARF
info is available (no GNAT encoding). For instance:
subtype Small_Type is Integer range 0 .. 10;
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;
A1 : Array_Type := (1 => (I => 0, S => <>),
2 => (I => 1, S => "A"),
3 => (I => 2, S => "AB"));
Currently, GDB prints the following output:
(gdb) p a1
$1 = (
The error happens while the ada-valprint module is trying to print
the value of an element of our array. Because of the fact that
the array's element (type Record_Type) has a variant size, the DWARF
info for our array provide the array's stride:
<1><749>: Abbrev Number: 10 (DW_TAG_array_type)
<74a> DW_AT_name : (indirect string, offset: 0xb6d): pck__T18s
<74e> DW_AT_byte_stride : 16
<74f> DW_AT_type : <0x6ea>
And because our array has a stride, ada-valprint treats it the same
way as packed arrays (see ada-valprint.c::ada_val_print_array):
if (TYPE_FIELD_BITSIZE (type, 0) > 0)
val_print_packed_array_elements (type, valaddr, offset_aligned,
0, stream, recurse,
original_value, options);
The first thing that we should notice in the call above is that
the "valaddr" buffer and the associated offset (OFFSET_ALIGNED)
is passed, but that the corresponding array's address is not.
This can be explained by looking inside val_print_packed_array_elements,
where we see that the function unpacks each element of our array from
the buffer alone (ada_value_primitive_packed_val), and then prints
the resulting artificial value instead:
v0 = ada_value_primitive_packed_val (NULL, valaddr + offset,
(i0 * bitsize) / HOST_CHAR_BIT,
(i0 * bitsize) % HOST_CHAR_BIT,
bitsize, elttype);
[...]
val_print (elttype, value_contents_for_printing (v0),
value_embedded_offset (v0), 0, stream,
recurse + 1, v0, &opts, current_language);
Of particular interest, here, is the fact that we call val_print
with a null address, which is OK, since we're providing a buffer
instead (value_contents_for_printing). Also, providing an address
might not always possible, since packing could place elements at
boundaries that are not byte-aligned.
Things go south when val_print tries to see if there is a pretty-printer
that could be applied. In particular, one of the first things that
the Python pretty-printer does is to create a value using our buffer,
and the given address, which in this case is null (see call to
value_from_contents_and_address in gdbpy_apply_val_pretty_printer).
value_from_contents_and_address, in turn immediately tries to resolve
the type, using the given address, which is null. But, because our
array element is a record containing an array whose bound is the value
of one of its elements (the "s" component), the debugging info for
the array's upper bound is a reference...
<3><71a>: Abbrev Number: 7 (DW_TAG_subrange_type)
<71b> DW_AT_type : <0x724>
<71f> DW_AT_upper_bound : <0x703>
... to component "i" of our record...
<2><703>: Abbrev Number: 5 (DW_TAG_member)
<704> DW_AT_name : i
<706> DW_AT_decl_file : 2
<707> DW_AT_decl_line : 6
<708> DW_AT_type : <0x6d1>
<70c> DW_AT_data_member_location: 0
... where that component is located at offset 0 of the start
of the record. dwarf2_evaluate_property correctly determines
the offset where to load the value of the bound from, but then
tries to read that value from inferior memory using the address
that was given, which is null. See case PROP_ADDR_OFFSET in
dwarf2_evaluate_property:
val = value_at (baton->offset_info.type,
pinfo->addr + baton->offset_info.offset);
This triggers a memory error, which then causes the printing to terminate.
Since there are going to be situations where providing an address
alone is not going to be sufficient (packed arrays where array elements
are not stored at byte boundaries), this patch fixes the issue by
enhancing the type resolution to take both address and data. This
follows the same principle as the val_print module, where both
address and buffer ("valaddr") can be passed as arguments. If the data
has already been fetched from inferior memory (or provided by the
debugging info in some form -- Eg a constant), then use that data
instead of reading it from inferior memory.
Note that this should also be a good step towards being able to handle
dynamic types whose value is stored outside of inferior memory
(Eg: in a register).
With this patch, GDB isn't able to print all of A1, but does perform
a little better:
(gdb) p a1
$1 = ((i => 0, s => , (i => 1, s => , (i => 2, s => )
There is another issue which is independent of this one, and will
therefore be patched separately.
gdb/ChangeLog:
* dwarf2loc.h (struct property_addr_info): Add "valaddr" field.
* dwarf2loc.c (dwarf2_evaluate_property): Add handling of
pinfo->valaddr.
* gdbtypes.h (resolve_dynamic_type): Add "valaddr" parameter.
* gdbtypes.c (resolve_dynamic_struct): Set pinfo.valaddr.
(resolve_dynamic_type_internal): Set pinfo.valaddr.
Add handling of addr_stack->valaddr.
(resolve_dynamic_type): Add "valaddr" parameter.
Set pinfo.valaddr field.
* ada-lang.c (ada_discrete_type_high_bound): Update call to
resolve_dynamic_type.
(ada_discrete_type_low_bound): Likewise.
* findvar.c (default_read_var_value): Likewise.
* value.c (value_from_contents_and_address): Likewise.
Currently, ada-lang.c:template_to_static_fixed_type (working on
structure types only) caches its result into the unused TYPE_TARGET_TYPE
field. This introduces inconsistencies when the input type is
specialized, for instance during type resolution: the cached static
fixed type is copied along with the original type, but it's no longer
adapted to the copy once the copy is modified:
template_to_static_fixed_type has to compute another static fixed type
for it.
This change first introduces a cache reset during type resolution for
structure types so that this inconsistency does not happen anymore. It
also makes template_to_static_fixed_type smarter with respect to types
that do not need static fixed copies so that less computations is done
in general.
This inconsistency was spotted thanks to code reading, not because of
any sort of failure and we did not manage to exhibit a failure yet, so
no testcase for this.
gdb/ChangeLog:
* ada-lang.c (template_to_static_fixed_type): Return input type
when it is already fixed. Cache the input type itself when not
creating a static fixed copy. Make it explicit that we never
molestate the input type.
* gdbtypes.c (resolve_dynamic_struct): Reset the
TYPE_TARGET_TYPE field for resolved copies.
Consider the following declarations:
type Int_Access is access Integer;
type Record_Type is record
IA : Int_Access;
end record;
R : Record_Type;
Printing the type name of "R.IA" yields:
(gdb) whatis r.ia
type = access integer
It should be:
(gdb) whatis r.ia
type = bar.int_access
Looking at the debugging info, field "r.ia" is defined as
a typedef which has the name of the field type:
.uleb128 0x3 # (DIE (0x4e) DW_TAG_typedef)
.long .LASF4 # DW_AT_name: "bar__int_access"
.long 0x8b # DW_AT_type
... with the typedef's target type being an anonymous pointer
type:
.uleb128 0x7 # (DIE (0x8b) DW_TAG_pointer_type)
.byte 0x8 # DW_AT_byte_size
.long 0x91 # DW_AT_type
What happens here is that a couple of function in ada-lang.c
always start by stripping all typedef layers when handling
struct fields, with the effect of making us lose the type name
in this case.
We did not understand this at the time the code was written,
but typedefs should be stripped only when we know we do not
need them. So this patch, adjust the code to avoid the stripping
while handling the fields, and adds it back in the lone place
which handles the result of processing and didn't know how to
handle typedefs struct fields yet.
gdb/ChangeLog:
* ada-lang.c (ada_is_tagged_type): Add call to ada_check_typedef.
(ada_lookup_struct_elt_type): Remove calls to ada_check_typedef.
(template_to_static_fixed_type): Call ada_check_typedef only
when necessary.
gdb/testsuite/ChangeLog:
* gdb.ada/rec_comp: New testcase.
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.
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.
When ada-lang.c:ada_lookup_symbol_list_worker finds a match in
the symbol cache, it caches the result again, which is unecessary.
This patch fixes the code to avoid that.
gdb/ChangeLog:
PR gdb/17856:
* ada-lang.c (ada_lookup_symbol_list_worker): Do not re-cache
results found in the cache.
Tested on x86_64-linux, no regression.
The Ada symbol cache has been designed to have one instance of that
of that cache per program space, and for each instance to be created
on-demand. ada_get_symbol_cache is the function responsible for both
lookup and creation on demand.
Unfortunately, ada_get_symbol_cache forgot to store the reference
to newly created caches, thus causing it to:
- Leak old caches;
- Allocate a new cache each time the cache is being searched or
a new entry is to be inserted.
This patch fixes the issue by avoiding the use of the local variable,
which indirectly allowed the bug to happen. We manipulate the reference
in the program-space data instead.
gdb/ChangeLog:
PR gdb/17854:
* ada-lang.c (ada_get_symbol_cache): Set pspace_data->sym_cache
when allocating a new one.
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.
Consider the following code:
type Table is array (Positive range <>) of Integer;
type Object (N : Integer) is record
Data : Table (1 .. N);
end record;
My_Object : Object := (N => 3, Data => (3, 5, 8));
Trying to print the range and length of the My_Object.Data array yields:
(gdb) print my_object.data'first
$1 = 1
(gdb) print my_object.data'last
$2 = 0
(gdb) print my_object.data'length
$3 = 0
The first one is correct, and that is thanks to the fact that
the lower bound is statically known. However, for the upper
bound, and consequently the array's length, the values are incorrect.
It should be:
(gdb) print my_object.data'last
$2 = 3
(gdb) print my_object.data'length
$3 = 3
What happens here is that ada_array_bound_from_type sees that
our array has a parallel "___XA" type, and therefore tries to
use it. In particular, it described our array's index type as:
[...]___XDLU_1__n, which means lower bound = 1, and upper bound
is value of "n". Unfortunately, ada_array_bound_from_type does
not have access to the discriminant, and is therefore unable to
compute the bound correctly.
Fortunately, at this stage, the bound has already been computed
a while ago, and therefore doesn't need to be re-computed here.
This patch fixes the issue by ignoring that ___XA type if the array
is marked as already fixed.
This also fixes the same issue with packed arrays.
gdb/ChangeLog:
* ada-lang.c (ada_array_bound_from_type): Ignore array's parallel
___XA type if the array has already been fixed.
gdb/testsuite/ChangeLog:
* gdb.ada/var_arr_attrs: New testcase.
The following change...
commit 1994afbf19
Date: Tue Dec 23 07:55:39 2014 -0800
Subject: Look up primitive types as symbols.
... caused the following regression:
% gdb
(gdb) set lang ada
(gdb) python print gdb.lookup_type('character')
Traceback (most recent call last):
File "<string>", line 1, in <module>
gdb.error: No type named character.
Error while executing Python code.
This is because the language_lookup_primitive_type_as_symbol call
was moved to the la_lookup_symbol_nonlocal hook. A couple of
implementations have been upated accordingly, but the Ada version
has not. This patch fixes this omission.
gdb/ChangeLog:
* ada-lang.c (ada_lookup_symbol_nonlocal): If name not found
in static block, then try searching for primitive types.
gdb/testsuite/ChangeLog:
* gdb.python/py-lookup-type.exp: New file.
gdb/ChangeLog:
* ada-lang.c (user_select_syms): Only fetch symtab if symbol is
objfile-owned.
(cache_symbol): Ignore symbols that are not objfile-owned.
* block.c (block_objfile): New function.
(block_gdbarch): New function.
* block.h (block_objfile): Declare.
(block_gdbarch): Declare.
* c-exp.y (classify_name): Remove call to
language_lookup_primitive_type. No longer necessary.
* gdbtypes.c (lookup_typename): Call lookup_symbol_in_language.
Remove call to language_lookup_primitive_type. No longer necessary.
* guile/scm-symbol.c (syscm_gdbarch_data_key): New static global.
(syscm_gdbarch_data): New struct.
(syscm_init_arch_symbols): New function.
(syscm_get_symbol_map): Renamed from syscm_objfile_symbol_map.
All callers updated. Handle symbols owned by arches.
(gdbscm_symbol_symtab): Handle symbols owned by arches.
(gdbscm_initialize_symbols): Initialize syscm_gdbarch_data_key.
* language.c (language_lookup_primitive_type_1): New function.
(language_lookup_primitive_type): Call it.
(language_alloc_type_symbol): New function.
(language_init_primitive_type_symbols): New function.
(language_lookup_primitive_type_as_symbol): New function.
* language.h (struct language_arch_info) <primitive_type_symbols>:
New member.
(language_lookup_primitive_type): Add function comment.
(language_lookup_primitive_type_as_symbol): Declare.
* printcmd.c (address_info): Handle arch-owned symbols.
* python/py-symbol.c (sympy_get_symtab): Ditto.
(set_symbol): Ditto.
(sympy_dealloc): Ditto.
* symmisc.c (print_symbol): Ditto.
* symtab.c (fixup_symbol_section): Ditto.
(lookup_symbol_aux): Initialize block_found.
(basic_lookup_symbol_nonlocal): Try looking up the symbol as a
primitive type.
(initialize_objfile_symbol_1): New function.
(initialize_objfile_symbol): Call it.
(allocate_symbol): Call it.
(allocate_template_symbol): Call it.
(symbol_objfile): Assert symbol is objfile-owned.
(symbol_arch, symbol_symtab, symbol_set_symtab): Ditto.
* symtab.h (struct symbol) <owner>: Replaces member "symtab".
(struct symbol) <is_objfile_owned>: New member.
(SYMBOL_OBJFILE_OWNED): New macro.
* cp-namespace.c (cp_lookup_bare_symbol): New arg langdef.
All callers updated. Try to find the symbol as a primitive type.
(lookup_namespace_scope): New arg langdef. All callers updated.
Call cp_lookup_bare_symbol directly for simple bare symbols.
Trying to print the value of a string whose size is not known at
compile-time before it gets assigned a value can lead to the following
internal error:
(gdb) p my_str
$1 =
/[...]/utils.c:1089: internal-error: virtual memory exhausted.
What happens is that my_str is described as a reference to an array
type whose bounds are dynamic. During the read of that variable's
value (in default_read_var_value), we end up resolving dynamic types
which, for reference types, makes us also resolve the target of that
reference type. This means we resolve our variable to a reference
to an array whose bounds are undefined, and unfortunately very far
appart.
So, when we pass that value to ada-valprint, and in particular to
da_val_print_ref, we eventually try to allocate too large of a buffer
corresponding to the (bogus) size of our array, hence the internal
error.
This patch fixes the problem by adding a size_check before trying
to print the dereferenced value. To perform this check, a function
that was previously specific to ada-lang.c (check_size) gets
exported, and renamed to something less prone to name collisions
(ada_ensure_varsize_limit).
gdb/ChangeLog:
* ada-lang.h (ada_ensure_varsize_limit): Declare.
* ada-lang.c (check_size): Remove advance declaration.
(ada_ensure_varsize_limit): Renames check_size.
Replace calls to check_size by calls to ada_ensure_varsize_limit
throughout.
* ada-valprint.c (ada_val_print_ref): Add call to
ada_ensure_varsize_limit. Add comment explaining why.
gdb/testsuite/ChangeLog:
* gdb.ada/str_uninit: New testcase.
This final patch adds the new "compile" command and subcommands, and
all the machinery needed to make it work.
A shared library supplied by gcc is used for all communications with
gcc. Types and most aspects of symbols are provided directly by gdb
to the compiler using this library.
gdb provides some information about the user's code using plain text.
Macros are emitted this way, and DWARF location expressions (and
bounds for VLA) are compiled to C code.
This hybrid approach was taken because, on the one hand, it is better
to provide global declarations and such on demand; but on the other
hand, for local variables, translating DWARF location expressions to C
was much simpler than exporting a full compiler API to gdb -- the same
result, only easier to implement, understand, and debug.
In the ordinary mode, the user's expression is wrapped in a dummy
function. After compilation, gdb inserts the resulting object code
into the inferior, then calls this function.
Access to local variables is provided by noting which registers are
used by location expressions, and passing a structure of register
values into the function. Writes to registers are supported by
copying out these values after the function returns.
This approach was taken so that we could eventually implement other
more interesting features based on this same infrastructure; for
example, we're planning to investigate inferior-side breakpoint
conditions.
gdb/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Update.
* symtab.h (struct symbol_computed_ops) <generate_c_location>: New
field.
* p-lang.c (pascal_language_defn): Update.
* opencl-lang.c (opencl_language_defn): Update.
* objc-lang.c (objc_language_defn): Update.
* m2-lang.c (m2_language_defn): Update.
* language.h (struct language_defn) <la_get_compile_instance,
la_compute_program>: New fields.
* language.c (unknown_language_defn, auto_language_defn)
(local_language_defn): Update.
* jv-lang.c (java_language_defn): Update.
* go-lang.c (go_language_defn): Update.
* f-lang.c (f_language_defn): Update.
* dwarf2loc.h (dwarf2_compile_property_to_c): Declare.
* dwarf2loc.c (dwarf2_compile_property_to_c)
(locexpr_generate_c_location, loclist_generate_c_location): New
functions.
(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
* defs.h (enum compile_i_scope_types): New.
(enum command_control_type) <compile_control>: New constant.
(struct command_line) <control_u>: New field.
* d-lang.c (d_language_defn): Update.
* compile/compile.c: New file.
* compile/compile-c-support.c: New file.
* compile/compile-c-symbols.c: New file.
* compile/compile-c-types.c: New file.
* compile/compile.h: New file.
* compile/compile-internal.h: New file.
* compile/compile-loc2c.c: New file.
* compile/compile-object-load.c: New file.
* compile/compile-object-load.h: New file.
* compile/compile-object-run.c: New file.
* compile/compile-object-run.h: New file.
* cli/cli-script.c (multi_line_command_p, print_command_lines)
(execute_control_command, process_next_line)
(recurse_read_control_structure): Handle compile_control.
* c-lang.h (c_get_compile_context, c_compute_program): Declare.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Update.
* ada-lang.c (ada_language_defn): Update.
* Makefile.in (SUBDIR_GCC_COMPILE_OBS, SUBDIR_GCC_COMPILE_SRCS):
New variables.
(SFILES): Add SUBDIR_GCC_COMPILE_SRCS.
(HFILES_NO_SRCDIR): Add compile.h.
(COMMON_OBS): Add SUBDIR_GCC_COMPILE_OBS.
(INIT_FILES): Add SUBDIR_GCC_COMPILE_SRCS.
(compile.o, compile-c-types.o, compile-c-symbols.o)
(compile-object-load.o, compile-object-run.o, compile-loc2c.o)
(compile-c-support.o): New targets.
gdb/doc/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Altering): Update.
(Compiling and Injecting Code): New node.
gdb/testsuite/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* configure.ac: Add gdb.compile/.
* configure: Regenerate.
* gdb.compile/Makefile.in: New file.
* gdb.compile/compile-ops.exp: New file.
* gdb.compile/compile-ops.c: New file.
* gdb.compile/compile-tls.c: New file.
* gdb.compile/compile-tls.exp: New file.
* gdb.compile/compile-constvar.S: New file.
* gdb.compile/compile-constvar.c: New file.
* gdb.compile/compile-mod.c: New file.
* gdb.compile/compile-nodebug.c: New file.
* gdb.compile/compile-setjmp-mod.c: New file.
* gdb.compile/compile-setjmp.c: New file.
* gdb.compile/compile-setjmp.exp: New file.
* gdb.compile/compile-shlib.c: New file.
* gdb.compile/compile.c: New file.
* gdb.compile/compile.exp: New file.
* lib/gdb.exp (skip_compile_feature_tests): New proc.
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.
Jan noticed that gdb.ada/arrayidx.exp regressed after I applied
the following patch:
commit 8908fca577
Author: Joel Brobecker <brobecker@adacore.com>
Date: Sat Sep 27 09:09:34 2014 -0700
Subject: [Ada] Ignore __XA types when redundant.
What happens is that we're trying to print the value of
r_two_three, which is defined as follow:
type Index is (One, Two, Three);
type RTable is array (Index range Two .. Three) of Integer;
R_Two_Three : RTable := (2, 3);
The expected output is:
(gdb) p r_two_three
$1 = (two => 2, 3)
But after the patch above was applied, with the program program
compiled using gcc-gnat-4.9.2-1.fc21.x86_64 (x86_64-linux),
the output becomes:
(gdb) p r_two_three
$1 = (2, 3)
(the name of the first bound is missing). The problem comes from
the fact that the compiler described the array's index type as
a plain base type, instead of as a subrange of the enumerated type.
More particularly, this is what gcc-gnat-4.9.2-1.fc21.x86_64
generated:
<3><7ce>: Abbrev Number: 9 (DW_TAG_array_type)
<7cf> DW_AT_name : (indirect string, offset: 0xc13): p__rtable
[...]
<7d7> DW_AT_GNAT_descriptive_type: <0x98a>
[...]
<4><7df>: Abbrev Number: 8 (DW_TAG_subrange_type)
<7e0> DW_AT_type : <0xa79>
where DIE 0xa79 is:
<1><a79>: Abbrev Number: 2 (DW_TAG_base_type)
<a7a> DW_AT_byte_size : 8
<a7b> DW_AT_encoding : 7 (unsigned)
<a7c> DW_AT_name : (indirect string, offset: 0xfc): sizetype
The actual array subrange type can be found in the array's
parallel XA type (the DW_AT_GNAT_descriptive_type).
The recent commit correctly found that that bounds taken from
the descriptive type are the same as bounds of our array's index
type. But it failed to notice that ignoring this descriptive
type would make us lose the actual array index type, making us
think that we're printing an array indexed by integers.
I hadn't seen that problem, because the compiler I used produced
debugging info where the array's index type is correctly described:
<3><79f>: Abbrev Number: 10 (DW_TAG_array_type)
<7a0> DW_AT_name : (indirect string, offset: 0xb3d): p__rtable
[...]
<4><7b0>: Abbrev Number: 8 (DW_TAG_subrange_type)
<7b1> DW_AT_type : <0x9b2>
<7b5> DW_AT_upper_bound : 2
... where DIE 0x9b2 leads us to ...
<3><9b2>: Abbrev Number: 9 (DW_TAG_subrange_type)
[...]
<9b8> DW_AT_type : <0x962>
<2><962>: Abbrev Number: 22 (DW_TAG_enumeration_type)
<963> DW_AT_name : (indirect string, offset: 0xb34): p__index
[...]
This patch fixes the issue by also making sure that the subtype
of the original range type does match the subtype found in the
descriptive type.
gdb/ChangeLog:
* ada-lang.c (ada_is_redundant_range_encoding): Return 0
if the TYPE_CODE of range_type's base type does not match
the TYPE_CODE of encoding_type's base type.
Using the example in gdb.ada/complete.exp, the following command
on x86_64-windows returns one unwanted completion choice :
(gdb) complete p pck
p <pck_E>>
[all following completions entries snipped, all expected]
I tracked down this suprising entry to a minimal symbol whose name
is ".refptr.pck_E". The problem occurs while trying to see if
this symbol matches "pck" when doing wild-matching as we are doing
here:
/* Second: Try wild matching... */
if (!match && wild_match_p)
{
/* Since we are doing wild matching, this means that TEXT
may represent an unqualified symbol name. We therefore must
also compare TEXT against the unqualified name of the symbol. */
sym_name = ada_unqualified_name (ada_decode (sym_name));
if (strncmp (sym_name, text, text_len) == 0)
match = 1;
}
What happens is that ada_decode correctly identifies the fact that
SYM_NAME (".refptr.pck_E") is not following any GNAT encoding, and
therefore returns that same name, but bracketed: "<.refptr.pck_E>".
This is the convention we use for telling GDB that the decoded name
is not a real Ada name - and therefore should not be encoded for
operations such as name matching, symbol lookups, etc. So far, so good.
Next is the call to ada_unqualified_name, which unfortunately does
not notice that the decoded name it is being given isn't a natural
symbol, and just blindly strips everything up to the last do, returning
"pck_E>". And of course, "pck_E>" matches "pck" now, and so we end
up accepting this symbol as a match.
This patch fixes the problem by making ada_unqualified_name a little
smarter by making sure that the given decoded symbol name does not
start with '<'.
gdb/ChangeLog:
* ada-lang.c (ada_unqualified_name): Return DECODED_NAME if
it starts with '<'.
Tested on x86_64-windows using AdaCore's testsuite as well as
on x86_64-linux.
Consider the following code which declares a variable A2 which
is an array of arrays of integers.
type Array2_First is array (24 .. 26) of Integer;
type Array2_Second is array (1 .. 2) of Array2_First;
A1 : Array1_Second := ((10, 11, 12), (13, 14, 15));
Trying to print the type of that variable currently yields:
(gdb) ptype A2
type = array (1 .. 2, 24 .. 26) of integer
This is not correct, as this is the description of a two-dimension
array, which is different from an array of arrays. The expected
output is:
(gdb) ptype a2
type = array (1 .. 2) of foo_n926_029.array2_first
GDB's struct type currently handles multi-dimension arrays the same
way arrays of arrays, where each dimension is stored as a sub-array.
The ada-valprint module considers that consecutive array layers
are in fact multi-dimension arrays. For array of arrays, a typedef
layer is introduced between the two arrays, creating a break between
each array type.
In our situation, A2 is a described as a typedef of an array type...
.uleb128 0x8 # (DIE (0x125) DW_TAG_variable)
.ascii "a2\0" # DW_AT_name
.long 0xfc # DW_AT_type
.uleb128 0x4 # (DIE (0xfc) DW_TAG_typedef)
.long .LASF5 # DW_AT_name: "foo__array2_second"
.long 0x107 # DW_AT_type
.uleb128 0x5 # (DIE (0x107) DW_TAG_array_type)
.long .LASF5 # DW_AT_name: "foo__array2_second"
.long 0xb4 # DW_AT_type
.uleb128 0x6 # (DIE (0x114) DW_TAG_subrange_type)
.long 0x11b # DW_AT_type
.byte 0x2 # DW_AT_upper_bound
.byte 0 # end of children of DIE 0x107
... whose element type is, as expected, a typedef to the sub-array
type:
.uleb128 0x4 # (DIE (0xb4) DW_TAG_typedef)
.long .LASF4 # DW_AT_name: "foo__array2_first"
.long 0xbf # DW_AT_type
.uleb128 0x9 # (DIE (0xbf) DW_TAG_array_type)
.long .LASF4 # DW_AT_name: "foo__array2_first"
.long 0xd8 # DW_AT_GNAT_descriptive_type
.long 0x1c5 # DW_AT_type
.uleb128 0xa # (DIE (0xd0) DW_TAG_subrange_type)
.long 0xf0 # DW_AT_type
.byte 0x18 # DW_AT_lower_bound
.byte 0x1a # DW_AT_upper_bound
.byte 0 # end of children of DIE 0xbf
The reason why things fails is that, during expression evaluation,
GDB tries to "fix" A1's type. Because the sub-array has a parallel
(descriptive) type (DIE 0xd8), GDB thinks that our array's index
type must be dynamic and therefore needs to be fixed. This in turn
causes the sub-array to be "fixed", which itself results in the
typedef layer to be stripped.
However, looking closer at the parallel type, we see...
.uleb128 0xb # (DIE (0xd8) DW_TAG_structure_type)
.long .LASF8 # DW_AT_name: "foo__array2_first___XA"
[...]
.uleb128 0xc # (DIE (0xe4) DW_TAG_member)
.long .LASF10 # DW_AT_name: "foo__Tarray2_firstD1___XDLU_24__26"
... that all it tells us is that the array bounds are 24 and 26,
which is already correctly provided by the array's DW_TAG_subrange_type
bounds, meaning that this parallel type is just redundant.
Parallel types in general are slowly being removed in favor of
standard DWARF constructs. But in the meantime, this patch kills
two birds with one stone:
1. It recognizes this situation where the XA type is useless,
and saves an unnecessary range-type fixing;
2. It fixes the issue at hand because ignoring the XA type results
in no type fixing being required, which allows the typedef layer
to be preserved.
gdb/ChangeLog:
* ada-lang.c (ada_is_redundant_range_encoding): New function.
(ada_is_redundant_index_type_desc): New function.
(to_fixed_array_type): Ignore parallel XA type if redundant.
gdb/testsuite/ChangeLog:
* gdb.ada/arr_arr: New testcase.
Tested on x86_64-linux.
... when that packed array is part of a discriminated record and
one of the bounds is a discriminant.
Consider the following code:
type FUNNY_CHAR_T is (NUL, ' ', '"', '#', [etc]);
type FUNNY_STR_T is array (POSITIVE range <>) of FUNNY_CHAR_T;
pragma PACK (FUNNY_STR_T);
type FUNNY_STRING_T (SIZE : NATURAL := 1) is
record
STR : FUNNY_STR_T (1 .. SIZE) := (others => '0');
LENGTH : NATURAL := 4;
end record;
TEST: FUNNY_STRING_T(100);
GDB is able to print the value of variable "test" and "test.str".
But not "test.str(1)":
(gdb) p test
$1 = (size => 100, str => (33 'A', nul <repeats 99 times>), length => 1)
(gdb) p test.str
$2 = (33 'A', nul <repeats 99 times>)
(gdb) p test.str(1)
object size is larger than varsize-limit
The problem occurs during the phase where we are trying to resolve
the expression subscript operation. On the one hand of the subscript
operator, we have the result of the evaluation of "test.str", which
is our packed array. We have the following code to handle packed
arrays in particular:
if (ada_is_constrained_packed_array_type
(desc_base_type (value_type (argvec[0]))))
argvec[0] = ada_coerce_to_simple_array (argvec[0]);
This eventually leads to a call to constrained_packed_array_type
to return the "simple array". This function relies on a parallel
___XA type, when available, to determine the bounds. In our case,
we find type...
failure__funny_string_t__T4b___XA"
... which has one field describing the bounds of our array as:
failure__funny_string_t__T3b___XDLU_1__size
The part that interests us is after the ___XD suffix or,
in other words: "LU_1__size". What this means in GNAT encoding
parlance is that the lower bound is 1, and that the upper bound
is the value of "size". "size" is our discriminant in this case.
Normally, we would access the record's discriminant in order to
get the upper bound's value, but we do not have that information,
here. We are in a mode where we are just trying to "fix" the type
without an actual value. This is what the call to to_fixed_range_type
is doing, and because the fix'ing fails, it ends up returning
the ___XDLU type unmodified as our index type.
This shouldn't be a problem, except that the later part of
constrained_packed_array_type then uses that index_type to
determine the array size, via a call to get_discrete_bounds.
The problem is that the upper bound of the ___XDLU type is
dynamic (in the DWARF sense) while get_discrete_bounds implicitly
assumes that the bounds are static, and therefore accesses
them using macros that assume the bounds values are constants:
case TYPE_CODE_RANGE:
*lowp = TYPE_LOW_BOUND (type);
*highp = TYPE_HIGH_BOUND (type);
This therefore returns a bogus value for the upper bound,
leading to an unexpectedly large size for our array, which
later triggers the varsize-limit guard we've seen above.
This patch avoids the problem by adding special handling
of dynamic range types. It also extends the documentation
of the constrained_packed_array_type function to document
what happens in this situation.
gdb/ChangeLog:
* ada-lang.c (constrained_packed_array_type): Set the length
of the return array as if both bounds where zero if that
returned array's index type is dynamic.
gdb/testsuite/ChangeLog:
* gdb.ada/pkd_arr_elem: New Testcase.
Tested on x86_64-linux.
Non-primary symtabs share the block vector with their primary symtabs.
In these cases there's no need to use ALL_SYMTABS.
gdb/ChangeLog:
* ada-lang.c (ada_make_symbol_completion_list): Use
ALL_PRIMARY_SYMTABS instead of ALL_SYMTABS.
* symtab.c (lookup_objfile_from_block): Ditto.
When trying to evaluate an expression which adds a pointer and
an integral, the evaluation succeeds if the pointer is on
the left handside of the operator, but not when it is on the right
handside:
(gdb) p something'address + 0
$1 = (system.address) 0x613418 <pck.something>
(gdb) p 0 + something'address
Argument to arithmetic operation not a number or boolean.
Same issue when doing subtractions:
(gdb) p something'address - 0
$2 = (system.address) 0x613418 <pck.something>
(gdb) p 0 - something'address
Argument to arithmetic operation not a number or boolean.
This patch enhances the Ada expression evaluator to handle
these two situations.
gdb/ChangeLog:
* ada-lang.c (ada_evaluate_subexp) <BINOP_ADD>: Add handling
of the case where the second operand is a pointer.
<BINOP_SUB>: Likewise.
gdb/testsuite/ChangeLog:
* gdb.ada/addr_arith: New testcase.
Tested on x86_64-linux.
Trying to print the bounds or the length of a pointer to an array
whose bounds are dynamic results in the following error:
(gdb) p foo.three_ptr.all'first
Location address is not set.
(gdb) p foo.three_ptr.all'length
Location address is not set.
This is because, after having dereferenced our array pointer, we
use the type of the resulting array value, instead of the enclosing
type. The former is the original type where the bounds are unresolved,
whereas we need to get the actual array bounds.
Similarly, trying to apply those attributes to the array pointer
directly (without explicitly dereferencing it with the '.all'
operator) yields the same kind of error:
(gdb) p foo.three_ptr'first
Location address is not set.
(gdb) p foo.three_ptr'length
Location address is not set.
This is caused by the fact that the dereference was done implicitly
in this case, and perform at the type level only, which is not
sufficient in order to resolve the array type.
This patch fixes both issues, thus allowing us to get the expected output:
(gdb) p foo.three_ptr.all'first
$1 = 1
(gdb) p foo.three_ptr.all'length
$2 = 3
(gdb) p foo.three_ptr'first
$3 = 1
(gdb) p foo.three_ptr'length
$4 = 3
gdb/ChangeLog:
* ada-lang.c (ada_array_bound): If ARR is a TYPE_CODE_PTR,
dereference it first. Use value_enclosing_type instead of
value_type.
(ada_array_length): Likewise.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dynarr-ptr.exp: Add 'first, 'last and 'length tests.
Pierre-Marie de Rodat
Doug Evans
Simon Marchi
Joel Brobecker
Jerome Guitton
Pedro Alves
Gary Benson
Tom Tromey