[PATCH] D37791: [XRay][CodeGen] Use the current function symbol as the associated symbol for the instrumentation map

[Dean Michael Berris via Phabricator via llvm-commits]

dberris updated this revision to Diff 115167.
dberris edited the summary of this revision.
dberris added reviewers: dblaikie, echristo.
dberris added a comment.
Herald added a subscriber: JDevlieghere.

Reworded description, added a test.


https://reviews.llvm.org/D37791

Files:
  lib/CodeGen/AsmPrinter/AsmPrinter.cpp
  test/DebugInfo/X86/xray-split-dwarf-interaction.ll


Index: test/DebugInfo/X86/xray-split-dwarf-interaction.ll
===================================================================
--- /dev/null
+++ test/DebugInfo/X86/xray-split-dwarf-interaction.ll
@@ -0,0 +1,76 @@
+; RUN: %llc_dwarf -split-dwarf-file=input.dwo -O3 -function-sections -data-sections \
+; RUN:     -relocation-model=pic -filetype=obj -generate-type-units -debug-compile -o %t %s
+; RUN: llvm-readelf -sections %t | FileCheck %s
+; Created from:
+; input.cc:
+;
+; class a {
+;   int b();
+; };
+; int a::b() {
+;   for (;;)
+;     ;
+; }
+;
+; ModuleID = 'input.cc'
+source_filename = "input.cc"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-linux"
+
+%class.a = type { i8 }
+
+; Function Attrs: nounwind readnone uwtable
+define i32 @_ZN1a1bEv(%class.a* nocapture readnone) local_unnamed_addr #0 align 2 !dbg !8 {
+  tail call void @llvm.dbg.value(metadata %class.a* %0, metadata !17, metadata !DIExpression()), !dbg !19
+  br label %2, !dbg !20
+
+; <label>:2:                                      ; preds = %2, %1
+  br label %2, !dbg !21, !llvm.loop !25
+}
+
+; In this test we want to make sure that the xray_instr_map section for `a::b()` is actually
+; associated with the per-function section defined for the function instead of associating with
+; the .debug_types.dwo section.
+;
+; CHECK-DAG: [[FSECT:[0-9]+]]] .text._ZN1a1bEv PROGBITS
+; CHECK-DAG: [{{.*}}] .debug_types.dwo PROGBITS
+; CHECK-DAG: [{{.*}}] xray_instr_map PROGBITS {{.*}} {{.*}} {{.*}} {{.*}} WAL [[FSECT]]
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" "xray-instruction-threshold"="200" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version trunk (trunk r312634)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, debugInfoForProfiling: true)
+!1 = !DIFile(filename: "input.cc", directory: "/usr/local/google/home/dberris/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 7, !"PIC Level", i32 2}
+!6 = !{i32 7, !"PIE Level", i32 2}
+!7 = !{!"clang version trunk (trunk r312634)"}
+!8 = distinct !DISubprogram(name: "b", linkageName: "_ZN1a1bEv", scope: !9, file: !1, line: 4, type: !12, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, declaration: !11, variables: !16)
+!9 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "a", file: !1, line: 1, size: 8, elements: !10, identifier: "_ZTS1a")
+!10 = !{!11}
+!11 = !DISubprogram(name: "b", linkageName: "_ZN1a1bEv", scope: !9, file: !1, line: 2, type: !12, isLocal: false, isDefinition: false, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!16 = !{!17}
+!17 = !DILocalVariable(name: "this", arg: 1, scope: !8, type: !18, flags: DIFlagArtificial | DIFlagObjectPointer)
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
+!19 = !DILocation(line: 0, scope: !8)
+!20 = !DILocation(line: 5, column: 3, scope: !8)
+!21 = !DILocation(line: 5, column: 3, scope: !22)
+!22 = !DILexicalBlockFile(scope: !23, file: !1, discriminator: 2)
+!23 = distinct !DILexicalBlock(scope: !24, file: !1, line: 5, column: 3)
+!24 = distinct !DILexicalBlock(scope: !8, file: !1, line: 5, column: 3)
+!25 = distinct !{!25, !26, !27}
+!26 = !DILocation(line: 5, column: 3, scope: !24)
+!27 = !DILocation(line: 6, column: 5, scope: !24)
Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2785,7 +2785,7 @@
   MCSection *InstMap = nullptr;
   MCSection *FnSledIndex = nullptr;
   if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
-    auto Associated = dyn_cast<MCSymbolELF>(PrevSection->getBeginSymbol());
+    auto Associated = dyn_cast<MCSymbolELF>(CurrentFnSym);
     assert(Associated != nullptr);
     auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
     std::string GroupName;


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