DI: Require subprogram definitions to be distinct

As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'.  Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.

While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore.  Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node.  The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.

I updated almost all the IR with the following script:

    git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'

Likely some variant of would work for out-of-tree testcases.

llvm-svn: 246327

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/test/DebugInfo/X86/InlinedFnLocalVar.ll b/llvm/test/DebugInfo/X86/InlinedFnLocalVar.ll
index 184554ee80b..d140d023a50 100644
--- a/llvm/test/DebugInfo/X86/InlinedFnLocalVar.ll
+++ b/llvm/test/DebugInfo/X86/InlinedFnLocalVar.ll
@@ -25,13 +25,13 @@ entry:
 !llvm.dbg.cu = !{!2}
 !llvm.module.flags = !{!28}
 
-!0 = !DISubprogram(name: "foo", line: 9, isLocal: true, isDefinition: true, virtualIndex: 6, isOptimized: true, scopeLine: 9, file: !27, scope: !1, type: !3, variables: !24)
+!0 = distinct !DISubprogram(name: "foo", line: 9, isLocal: true, isDefinition: true, virtualIndex: 6, isOptimized: true, scopeLine: 9, file: !27, scope: !1, type: !3, variables: !24)
 !1 = !DIFile(filename: "bar.c", directory: "/tmp/")
 !2 = distinct !DICompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: 0, file: !27, enums: !20, retainedTypes: !20, subprograms: !25, globals: !26, imports:  !20)
 !3 = !DISubroutineType(types: !4)
 !4 = !{!5, !5}
 !5 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
-!6 = !DISubprogram(name: "bar", linkageName: "bar", line: 14, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: true, file: !27, scope: !1, type: !7, function: i32 ()* @bar)
+!6 = distinct !DISubprogram(name: "bar", linkageName: "bar", line: 14, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: true, file: !27, scope: !1, type: !7, function: i32 ()* @bar)
 !7 = !DISubroutineType(types: !8)
 !8 = !{!5}
 !9 = !DILocalVariable(name: "j", line: 9, arg: 1, scope: !0, file: !1, type: !5)