[PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.
Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.
Motivation
----------
Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.
We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.
Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.
http://reviews.llvm.org/D19034
<rdar://problem/25256815>
llvm-svn: 266446
diff --git a/llvm/test/DebugInfo/Generic/inheritance.ll b/llvm/test/DebugInfo/Generic/inheritance.ll
index b7cbf21..31f6bf8 100644
--- a/llvm/test/DebugInfo/Generic/inheritance.ll
+++ b/llvm/test/DebugInfo/Generic/inheritance.ll
@@ -109,7 +109,7 @@
!0 = !DILocalVariable(name: "tst", line: 13, scope: !1, file: !4, type: !8)
!1 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !2)
!2 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !3)
-!3 = distinct !DISubprogram(name: "main", linkageName: "main", line: 11, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, scope: !4, type: !5)
+!3 = distinct !DISubprogram(name: "main", linkageName: "main", line: 11, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !4, scope: !4, type: !5)
!4 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: FullDebug, file: !44, enums: !45, retainedTypes: !45)
!5 = !DISubroutineType(types: !6)
!6 = !{!7}
@@ -131,7 +131,7 @@
!22 = !DILocation(line: 13, scope: !1)
!23 = !DILocation(line: 14, scope: !1)
!24 = !DILocalVariable(name: "this", line: 13, arg: 1, scope: !25, file: !4, type: !26)
-!25 = distinct !DISubprogram(name: "test1", linkageName: "_ZN5test1C1Ev", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, scope: !4, type: !15)
+!25 = distinct !DISubprogram(name: "test1", linkageName: "_ZN5test1C1Ev", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !4, scope: !4, type: !15)
!26 = !DIDerivedType(tag: DW_TAG_const_type, size: 64, align: 64, flags: DIFlagArtificial, file: !4, baseType: !27)
!27 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, file: !4, baseType: !8)
!28 = !DILocation(line: 1, scope: !25)
@@ -139,13 +139,13 @@
!30 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !31)
!31 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !25)
!32 = !DILocalVariable(name: "this", line: 4, arg: 1, scope: !33, file: !4, type: !26)
-!33 = distinct !DISubprogram(name: "~test1", linkageName: "_ZN5test1D1Ev", line: 4, isLocal: false, isDefinition: true, virtuality: DW_VIRTUALITY_virtual, virtualIndex: 6, isOptimized: false, scope: !8, type: !15, containingType: !8)
+!33 = distinct !DISubprogram(name: "~test1", linkageName: "_ZN5test1D1Ev", line: 4, isLocal: false, isDefinition: true, virtuality: DW_VIRTUALITY_virtual, virtualIndex: 6, isOptimized: false, unit: !4, scope: !8, type: !15, containingType: !8)
!34 = !DILocation(line: 4, scope: !33)
!35 = !DILocation(line: 5, scope: !36)
!36 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !33)
!37 = !DILocation(line: 6, scope: !36)
!38 = !DILocalVariable(name: "this", line: 4, arg: 1, scope: !39, file: !4, type: !26)
-!39 = distinct !DISubprogram(name: "~test1", linkageName: "_ZN5test1D0Ev", line: 4, isLocal: false, isDefinition: true, virtuality: DW_VIRTUALITY_virtual, virtualIndex: 6, isOptimized: false, scope: !8, type: !15, containingType: !8)
+!39 = distinct !DISubprogram(name: "~test1", linkageName: "_ZN5test1D0Ev", line: 4, isLocal: false, isDefinition: true, virtuality: DW_VIRTUALITY_virtual, virtualIndex: 6, isOptimized: false, unit: !4, scope: !8, type: !15, containingType: !8)
!40 = !DILocation(line: 4, scope: !39)
!41 = !DILocation(line: 5, scope: !42)
!42 = distinct !DILexicalBlock(line: 0, column: 0, file: !44, scope: !39)