[llvm] a740af4 - [CodeView][DebugInfo] Update the code for removing template arguments from the display name of a codeview function id.

[Amy Huang via llvm-commits]

Author: Amy Huang
Date: 2021-02-05T09:49:11-08:00
New Revision: a740af4de970405fd7196219307a1e4cc53a35cf

URL: https://github.com/llvm/llvm-project/commit/a740af4de970405fd7196219307a1e4cc53a35cf
DIFF: https://github.com/llvm/llvm-project/commit/a740af4de970405fd7196219307a1e4cc53a35cf.diff

LOG: [CodeView][DebugInfo] Update the code for removing template arguments from the display name of a codeview function id.

Previously the code split the string at the first '<', which
incorrectly truncated names like `operator<`.

Differential Revision: https://reviews.llvm.org/D95893

Added: 
    

Modified: 
    llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
    llvm/test/DebugInfo/COFF/cpp-mangling.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index b15e750aaf85..08eb206a9bae 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -358,6 +358,25 @@ TypeIndex CodeViewDebug::getScopeIndex(const DIScope *Scope) {
   return recordTypeIndexForDINode(Scope, TI);
 }
 
+static StringRef removeTemplateArgs(StringRef Name) {
+  // Remove template args from the display name. Assume that the template args
+  // are the last thing in the name.
+  if (Name.empty() || Name.back() != '>')
+    return Name;
+
+  int OpenBrackets = 0;
+  for (size_t i = Name.size() - 1; i >= 0; --i) {
+    if (Name[i] == '>')
+      ++OpenBrackets;
+    else if (Name[i] == '<') {
+      --OpenBrackets;
+      if (OpenBrackets == 0)
+        return Name.substr(0, i);
+    }
+  }
+  return Name;
+}
+
 TypeIndex CodeViewDebug::getFuncIdForSubprogram(const DISubprogram *SP) {
   assert(SP);
 
@@ -367,8 +386,9 @@ TypeIndex CodeViewDebug::getFuncIdForSubprogram(const DISubprogram *SP) {
     return I->second;
 
   // The display name includes function template arguments. Drop them to match
-  // MSVC.
-  StringRef DisplayName = SP->getName().split('<').first;
+  // MSVC. We need to have the template arguments in the DISubprogram name
+  // because they are used in other symbol records, such as S_GPROC32_IDs.
+  StringRef DisplayName = removeTemplateArgs(SP->getName());
 
   const DIScope *Scope = SP->getScope();
   TypeIndex TI;

diff  --git a/llvm/test/DebugInfo/COFF/cpp-mangling.ll b/llvm/test/DebugInfo/COFF/cpp-mangling.ll
index d94de78514e0..558a27f5c728 100644
--- a/llvm/test/DebugInfo/COFF/cpp-mangling.ll
+++ b/llvm/test/DebugInfo/COFF/cpp-mangling.ll
@@ -8,8 +8,11 @@
 ; template <typename T, int (*)(int)>
 ; void fn_tmpl() {}
 ; template void fn_tmpl<int, foo::bar>();
+; struct S { void operator<<(int i) {} };
 ; void f() {
 ;   fn_tmpl<int, foo::bar>();
+;   S s;
+;   s << 3;
 ; }
 
 ; CHECK:        {{.*}}Proc{{.*}}Sym {
@@ -17,6 +20,11 @@
 ; CHECK:         DisplayName: foo::bar{{$}}
 ; CHECK-NEXT:    LinkageName: ?bar at foo@@YAHH at Z
 
+; CHECK:        {{.*}}Proc{{.*}}Sym {
+; CHECK:         FunctionType: operator<< ({{.*}})
+; CHECK:         DisplayName: S::operator<<
+; CHECK-NEXT:    LinkageName: ??6S@@QAEXH at Z
+
 ; CHECK:        {{.*}}Proc{{.*}}Sym {
 ; CHECK:         FunctionType: fn_tmpl ({{.*}})
 ; CHECK:         DisplayName: foo::fn_tmpl<int,&foo::bar>
@@ -27,8 +35,12 @@ source_filename = "t.cpp"
 target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
 target triple = "i386-pc-windows-msvc19.0.23918"
 
+%struct.S = type { i8 }
+
 $"\01??$fn_tmpl at H$1?bar at foo@@YAHH at Z@foo@@YAXXZ" = comdat any
 
+$"??6S@@QAEXH at Z" = comdat any
+
 ; Function Attrs: nounwind
 define i32 @"\01?bar at foo@@YAHH at Z"(i32 %x) #0 !dbg !6 {
 entry:
@@ -49,6 +61,17 @@ entry:
   ret void, !dbg !24
 }
 
+; Function Attrs: nounwind
+define linkonce_odr void @"??6S@@QAEXH at Z"(%struct.S* nonnull dereferenceable(1) %this, i32 %i) #0 !dbg !31 {
+entry:
+  %i.addr = alloca i32, align 4
+  %this.addr = alloca %struct.S*, align 4
+  store i32 %i, i32* %i.addr, align 4
+  store %struct.S* %this, %struct.S** %this.addr, align 4
+  %this1 = load %struct.S*, %struct.S** %this.addr, align 4
+  ret void, !dbg !32
+}
+
 attributes #0 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="all" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { nounwind readnone }
 
@@ -81,3 +104,11 @@ attributes #1 = { nounwind readnone }
 !22 = !DITemplateValueParameter(type: !23, value: i32 (i32)* @"\01?bar at foo@@YAHH at Z")
 !23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 32, align: 32)
 !24 = !DILocation(line: 4, column: 17, scope: !17)
+!25 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !1, line: 7, size: 8, flags: DIFlagTypePassByValue, elements: !26, identifier: ".?AUS@@")
+!26 = !{!27}
+!27 = !DISubprogram(name: "operator<<", linkageName: "??6S@@QAEXH at Z", scope: !25, file: !1, line: 8, type: !28, scopeLine: 8, flags: DIFlagPrototyped, spFlags: 0)
+!28 = !DISubroutineType(cc: DW_CC_BORLAND_thiscall, types: !29)
+!29 = !{null, !30, !10}
+!30 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !25, size: 32, flags: DIFlagArtificial | DIFlagObjectPointer)
+!31 = distinct !DISubprogram(name: "operator<<", linkageName: "??6S@@QAEXH at Z", scope: !25, file: !1, line: 8, type: !28, scopeLine: 8, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, declaration: !27, retainedNodes: !2)
+!32 = !DILocation(line: 8, column: 27, scope: !31)
\ No newline at end of file