binutils-gdb/gdb/testsuite/gdb.dwarf2/main-foo.c

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[gdb/symtab] Handle struct decl with DW_AT_signature Consider a test-case with sources 36.c: ... struct s { int i; }; extern void f (void); int main (void) { struct s a; f (); return 0; } ... and 36b.c: ... struct s { int j; }; void f (void) { struct s b; } ... compiled like this: ... $ gcc 36.c 36b.c -g ... It contains DWARF like this: ... <0><d2>: Abbrev Number: 1 (DW_TAG_compile_unit) <d8> DW_AT_name : 36.c <1><f4>: Abbrev Number: 2 (DW_TAG_structure_type) <f5> DW_AT_name : s <2><fe>: Abbrev Number: 3 (DW_TAG_member) <ff> DW_AT_name : i <1><110>: Abbrev Number: 5 (DW_TAG_subprogram) <111> DW_AT_name : main <2><12d>: Abbrev Number: 6 (DW_TAG_variable) <12e> DW_AT_name : a <132> DW_AT_type : <0xf4> <0><146>: Abbrev Number: 1 (DW_TAG_compile_unit) <14c> DW_AT_name : 36b.c <1><168>: Abbrev Number: 2 (DW_TAG_structure_type) <169> DW_AT_name : s <2><172>: Abbrev Number: 3 (DW_TAG_member) <173> DW_AT_name : j <1><184>: Abbrev Number: 5 (DW_TAG_subprogram) <185> DW_AT_name : f <2><19b>: Abbrev Number: 6 (DW_TAG_variable) <19c> DW_AT_name : b <1a0> DW_AT_type : <0x168> ... And when printing "struct s", we get first a random one (with int j), and then context-specific ones (with int i in main, and int j in f): ... $ gdb -batch a.out \ -ex "ptype struct s" \ -ex start \ -ex "ptype struct s" \ -ex "break f" -ex continue \ -ex "ptype struct s" \ | grep "int [ij];" int j; int i; int j; ... Same for -readnow. However, if we use -fdebug-types-section: ... $ gcc 36.c 36b.c -g -fdebug-types-section ... we get: ... $ gdb ... | grep "int [ij];" int j; int i; int i; $ gdb -readnow ... | grep "int [ij];" int j; int j; int j; ... This is due to the fact that both "struct s" DIEs have been moved to the .debug_types section: ... Compilation Unit @ offset 0x0: Signature: 0xfd1462823bb6f7b7 <0><17>: Abbrev Number: 1 (DW_TAG_type_unit) <1><1d>: Abbrev Number: 2 (DW_TAG_structure_type) <1e> DW_AT_name : s <2><27>: Abbrev Number: 3 (DW_TAG_member) <28> DW_AT_name : i Compilation Unit @ offset 0x3a: Signature: 0x534310fbefba324d <0><51>: Abbrev Number: 1 (DW_TAG_type_unit) <1><57>: Abbrev Number: 2 (DW_TAG_structure_type) <58> DW_AT_name : s <2><61>: Abbrev Number: 3 (DW_TAG_member) <62> DW_AT_name : j ... and there's no longer a "struct s" DIE in the 36.c and and 36b.c CUs to specify which "struct s" belongs in the CU. This is gcc PR90232. However, using a tentative patch for gcc that adds these DIEs (according to DWARF standard: If the complete declaration of a type has been placed in a separate type unit, an incomplete declaration of that type in the compilation unit may provide the unique 64-bit signature of the type using a DW_AT_signature attribute): ... <0><d2>: Abbrev Number: 5 (DW_TAG_compile_unit) <d8> DW_AT_name : 36.c + <1><f4>: Abbrev Number: 6 (DW_TAG_structure_type) + <f5> DW_AT_name : s + <f7> DW_AT_signature : signature: 0xfd1462823bb6f7b7 + <ff> DW_AT_declaration : 1 <0><13c>: Abbrev Number: 5 (DW_TAG_compile_unit) <142> DW_AT_name : 36b.c + <1><15e>: Abbrev Number: 6 (DW_TAG_structure_type) + <15f> DW_AT_name : s + <161> DW_AT_signature : signature: 0x534310fbefba324d + <169> DW_AT_declaration : 1 ... still does not help, because they're declarations, so new_symbol is not called for them in process_structure_scope. Fix this by calling new_symbol for these decls. Build and tested on x86_64-linux. Also tested with target board enabling by default -fdebug-types-section -gdwarf-4, and with gcc with aforementioned tentative patch. In this configuration, the patch reduces number of FAILs from 2888 to 238. gdb/ChangeLog: 2020-04-28 Tom de Vries <tdevries@suse.de> * dwarf2/read.c (process_structure_scope): Add symbol for struct decl with DW_AT_signature. gdb/testsuite/ChangeLog: 2020-04-28 Tom de Vries <tdevries@suse.de> * gdb.dwarf2/main-foo.c: New test. * gdb.dwarf2/struct-with-sig.exp: New file.
2020-04-28 12:12:35 +08:00
/* This testcase is part of GDB, the GNU debugger.
Copyright 2020 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Dummy foo function. */
void
foo (void)
{
asm ("foo_label: .globl foo_label");
}
/* Dummy main function. */
int
main()
{
asm ("main_label: .globl main_label");
foo ();
return 0;
}