Message ID | Zc8naK+FA9aT8nqC@tucnak |
---|---|
State | New |
Headers | show |
Series | dwarf2out: Emit DW_AT_export_symbols on anon unions/structs [PR113918] | expand |
On 2/16/24 04:14, Jakub Jelinek wrote: > Hi! > > DWARF5 added DW_AT_export_symbols both for use on inline namespaces (where > we emit it), but also on anonymous unions/structs (and we didn't emit that > attribute there). > The following patch fixes it. Should this involve cp_decl_dwarf_attribute like the namespace handling? > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2024-02-16 Jakub Jelinek <jakub@redhat.com> > > PR debug/113918 > * dwarf2out.cc (gen_field_die): Emit DW_AT_export_symbols > on anonymous unions or structs for -gdwarf-5 or -gno-strict-dwarf. > > * c-c++-common/dwarf2/pr113918.c: New test. > > --- gcc/dwarf2out.cc.jj 2024-02-10 11:25:09.836476263 +0100 > +++ gcc/dwarf2out.cc 2024-02-15 13:38:14.485675460 +0100 > @@ -25153,6 +25153,20 @@ gen_field_die (tree decl, struct vlr_con > > add_accessibility_attribute (decl_die, decl); > > + /* Add DW_AT_export_symbols to anonymous unions or structs. */ > + if ((dwarf_version >= 5 || !dwarf_strict) && DECL_NAME (decl) == NULL_TREE) > + if (tree type = member_declared_type (decl)) > + { > + tree type_id = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type)); > + if (RECORD_OR_UNION_TYPE_P (type) > + && (type_id == NULL_TREE || IDENTIFIER_ANON_P (type_id))) > + { > + dw_die_ref type_die = lookup_type_die (TYPE_MAIN_VARIANT (type)); > + if (type_die && get_AT (type_die, DW_AT_export_symbols) == NULL) > + add_AT_flag (type_die, DW_AT_export_symbols, 1); > + } > + } > + > /* Equate decl number to die, so that we can look up this decl later on. */ > equate_decl_number_to_die (decl, decl_die); > } > --- gcc/testsuite/c-c++-common/dwarf2/pr113918.c.jj 2024-02-15 13:26:53.935984554 +0100 > +++ gcc/testsuite/c-c++-common/dwarf2/pr113918.c 2024-02-15 13:26:48.773055181 +0100 > @@ -0,0 +1,33 @@ > +/* PR debug/113918 */ > +/* { dg-do compile } */ > +/* { dg-options "-gdwarf-5 -dA -fno-merge-debug-strings" } */ > + > +struct S { > + union { > + int i; > + long long j; > + }; > + struct { > + int k; > + long long l; > + }; > + union { > + int m; > + long long n; > + } u; > + struct { > + int o; > + long long p; > + } v; > +} s; > + > +int > +main () > +{ > + s.i = 1; > + s.k = 2; > + s.u.m = 3; > + s.v.o = 4; > +} > + > +/* { dg-final { scan-assembler-times "DW_AT_export_symbols" 4 } } */ > > Jakub >
On Fri, Feb 16, 2024 at 10:48:28AM -0500, Jason Merrill wrote: > On 2/16/24 04:14, Jakub Jelinek wrote: > > DWARF5 added DW_AT_export_symbols both for use on inline namespaces (where > > we emit it), but also on anonymous unions/structs (and we didn't emit that > > attribute there). > > The following patch fixes it. > > Should this involve cp_decl_dwarf_attribute like the namespace handling? I wrote it in dwarf2out.cc because the same thing needs to be done for C and C++ (admittedly dunno if other languages have something similar). Sure, it could be done in cp_decl_dwarf_attribute too but then it has to be done in c_decl_dwarf_attribute which doesn't exist. Though, it is slightly complicated by DW_AT_export_symbols not actually going on the DW_TAG_member die but on the DW_TAG_{structure,class,union}_type which DW_TAG_member uses as its DW_AT_type. But in order to ask the langhook, we likely need to pass the FIELD_DECL and not the type... Jakub
--- gcc/dwarf2out.cc.jj 2024-02-10 11:25:09.836476263 +0100 +++ gcc/dwarf2out.cc 2024-02-15 13:38:14.485675460 +0100 @@ -25153,6 +25153,20 @@ gen_field_die (tree decl, struct vlr_con add_accessibility_attribute (decl_die, decl); + /* Add DW_AT_export_symbols to anonymous unions or structs. */ + if ((dwarf_version >= 5 || !dwarf_strict) && DECL_NAME (decl) == NULL_TREE) + if (tree type = member_declared_type (decl)) + { + tree type_id = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type)); + if (RECORD_OR_UNION_TYPE_P (type) + && (type_id == NULL_TREE || IDENTIFIER_ANON_P (type_id))) + { + dw_die_ref type_die = lookup_type_die (TYPE_MAIN_VARIANT (type)); + if (type_die && get_AT (type_die, DW_AT_export_symbols) == NULL) + add_AT_flag (type_die, DW_AT_export_symbols, 1); + } + } + /* Equate decl number to die, so that we can look up this decl later on. */ equate_decl_number_to_die (decl, decl_die); } --- gcc/testsuite/c-c++-common/dwarf2/pr113918.c.jj 2024-02-15 13:26:53.935984554 +0100 +++ gcc/testsuite/c-c++-common/dwarf2/pr113918.c 2024-02-15 13:26:48.773055181 +0100 @@ -0,0 +1,33 @@ +/* PR debug/113918 */ +/* { dg-do compile } */ +/* { dg-options "-gdwarf-5 -dA -fno-merge-debug-strings" } */ + +struct S { + union { + int i; + long long j; + }; + struct { + int k; + long long l; + }; + union { + int m; + long long n; + } u; + struct { + int o; + long long p; + } v; +} s; + +int +main () +{ + s.i = 1; + s.k = 2; + s.u.m = 3; + s.v.o = 4; +} + +/* { dg-final { scan-assembler-times "DW_AT_export_symbols" 4 } } */