llvm-6502/test/DebugInfo/X86/fission-inline.ll
David Blaikie f49ead7098 Provide gmlt-like inline scope information in the skeleton CU to facilitate symbolication without needing the .dwo files
Clang -gsplit-dwarf self-host -O0, binary increases by 0.0005%, -O2,
binary increases by 25%.

A large binary inside Google, split-dwarf, -O0, and other internal flags
(GDB index, etc) increases by 1.8%, optimized build is 35%.

The size impact may be somewhat greater in .o files (I haven't measured
that much - since the linked executable -O0 numbers seemed low enough)
due to relocations. These relocations could be removed if we taught the
llvm-symbolizer to handle indexed addressing in the .o file (GDB can't
cope with this just yet, but GDB won't be reading this info anyway).
Also debug_ranges could be shared between .o and .dwo, though ideally
debug_ranges would get a schema that could used index(+offset)
addressing, and move to the .dwo file, then we'd be back to sharing
addresses in the address pool again.

But for now, these sizes seem small enough to go ahead with this.

Verified that no other DW_TAGs are produced into the .o file other than
subprograms and inlined_subroutines.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221306 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-04 22:12:25 +00:00

120 lines
6.3 KiB
LLVM

; RUN: llc -split-dwarf=Enable -O0 < %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj | llvm-dwarfdump -debug-dump=info - | FileCheck %s
; Test the emission of gmlt-like inlining information into the skeleton unit.
; This allows inline-aware symbolication/backtracing given only the linked
; executable, without needing access to the .dwos.
; A simple example of inlining generated with clang -gsplit-dwarf
; A member function is used to force emission of the declaration of the
; function into the .dwo file, which may be shared with other CUs in the dwo ;
; under fission, but should not be shared with the skeleton's CU. This also
; tests the general case of context emission, which is suppressed in gmlt-like
; data.
; Include a template just to test template parameters are not emitted in
; gmlt-like data.
; And some varargs to make sure DW_TAG_unspecified_parameters is not emitted.
; And a using declaration in a nested lexical_block... because that shouldn't
; be emitted either.
; Minor complication: after generating the LLVM IR, it was manually edited so
; that the 'f1()' call from f3 was reordered to appear between the two inlined
; f1 calls from f2. This causes f2's inlined_subroutine to use DW_AT_ranges,
; thus exercising range list generation/referencing which was buggy.
; struct foo {
; template<typename T>
; static void f2();
; static void f3(...);
; };
;
; void f1();
;
; template<typename T>
; inline __attribute__((always_inline)) void foo::f2() {
; f1();
; f1();
; }
;
; void foo::f3(...) {
; if (true) {
; f1();
; f2<int>();
; using ::foo;
; }
; }
; Check that we emit the usual gmlt-like data for this file, including brief
; descriptions of subprograms with inlined scopes.
; FIXME: Once tools support indexed addresses in the skeleton CU, we should use
; those (DW_FORM_addr would become DW_FORM_GNU_addr_index below) since those
; addresses will already be in the address pool anyway.
; CHECK: DW_TAG_subprogram
; CHECK-NEXT: DW_AT_name {{.*}} "f2<int>"
; CHECK-NOT: DW_
; CHECK: DW_TAG_subprogram
; CHECK-NEXT: DW_AT_low_pc [DW_FORM_addr]
; CHECK-NEXT: DW_AT_high_pc
; CHECK-NEXT: DW_AT_name {{.*}} "f3"
; CHECK-NOT: {{DW_|NULL}}
; CHECK: DW_TAG_inlined_subroutine
; CHECK-NEXT: DW_AT_abstract_origin {{.*}} "f2<int>"
; CHECK-NEXT: DW_AT_ranges
; CHECK-NEXT: DW_AT_call_file
; CHECK-NEXT: DW_AT_call_line {{.*}} (18)
; CHECK-NOT: DW_
; Function Attrs: uwtable
define void @_ZN3foo2f3Ez(...) #0 align 2 {
entry:
call void @_Z2f1v(), !dbg !26
call void @_Z2f1v(), !dbg !25
call void @_Z2f1v(), !dbg !28
ret void, !dbg !29
}
declare void @_Z2f1v() #1
attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!22, !23}
!llvm.ident = !{!24}
!0 = metadata !{metadata !"0x11\004\00clang version 3.6.0 \000\00\000\00fission-inline.dwo\001", metadata !1, metadata !2, metadata !3, metadata !9, metadata !2, metadata !18} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/fission-inline.cpp] [DW_LANG_C_plus_plus]
!1 = metadata !{metadata !"fission-inline.cpp", metadata !"/tmp/dbginfo"}
!2 = metadata !{}
!3 = metadata !{metadata !4}
!4 = metadata !{metadata !"0x13\00foo\001\008\008\000\000\000", metadata !1, null, null, metadata !5, null, null, metadata !"_ZTS3foo"} ; [ DW_TAG_structure_type ] [foo] [line 1, size 8, align 8, offset 0] [def] [from ]
!5 = metadata !{metadata !6}
!6 = metadata !{metadata !"0x2e\00f3\00f3\00_ZN3foo2f3Ez\004\000\000\000\000\00256\000\004", metadata !1, metadata !"_ZTS3foo", metadata !7, null, null, null, null, null} ; [ DW_TAG_subprogram ] [line 4] [f3]
!7 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null, null, null, metadata !8, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!8 = metadata !{null, null}
!9 = metadata !{metadata !10, metadata !11}
!10 = metadata !{metadata !"0x2e\00f3\00f3\00_ZN3foo2f3Ez\0015\000\001\000\000\00256\000\0015", metadata !1, metadata !"_ZTS3foo", metadata !7, null, void (...)* @_ZN3foo2f3Ez, null, metadata !6, metadata !2} ; [ DW_TAG_subprogram ] [line 15] [def] [f3]
!11 = metadata !{metadata !"0x2e\00f2<int>\00f2<int>\00_ZN3foo2f2IiEEvv\0010\000\001\000\000\00256\000\0010", metadata !1, metadata !"_ZTS3foo", metadata !12, null, null, metadata !14, metadata !17, metadata !2} ; [ DW_TAG_subprogram ] [line 10] [def] [f2<int>]
!12 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null, null, null, metadata !13, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!13 = metadata !{null}
!14 = metadata !{metadata !15}
!15 = metadata !{metadata !"0x2f\00T\000\000", null, metadata !16, null} ; [ DW_TAG_template_type_parameter ]
!16 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
!17 = metadata !{metadata !"0x2e\00f2<int>\00f2<int>\00_ZN3foo2f2IiEEvv\0010\000\000\000\000\00256\000\0010", metadata !1, metadata !"_ZTS3foo", metadata !12, null, null, metadata !14, null, null} ; [ DW_TAG_subprogram ] [line 10] [f2<int>]
!18 = metadata !{metadata !19}
!19 = metadata !{metadata !"0x8\0019\00", metadata !20, metadata !"_ZTS3foo"} ; [ DW_TAG_imported_declaration ]
!20 = metadata !{metadata !"0xb\0016\0013\001", metadata !1, metadata !21} ; [ DW_TAG_lexical_block ] [/tmp/dbginfo/fission-inline.cpp]
!21 = metadata !{metadata !"0xb\0016\007\000", metadata !1, metadata !10} ; [ DW_TAG_lexical_block ] [/tmp/dbginfo/fission-inline.cpp]
!22 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
!23 = metadata !{i32 2, metadata !"Debug Info Version", i32 2}
!24 = metadata !{metadata !"clang version 3.6.0 "}
!25 = metadata !{i32 17, i32 5, metadata !20, null}
!26 = metadata !{i32 11, i32 3, metadata !11, metadata !27}
!27 = metadata !{i32 18, i32 5, metadata !20, null}
!28 = metadata !{i32 12, i32 3, metadata !11, metadata !27}
!29 = metadata !{i32 21, i32 1, metadata !10, null}