[PATCH] D98799: [UniqueLinkageName] Use consistent checks when mangling symbo linkage name and debug linkage name.

Hongtao Yu via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Wed Mar 17 11:32:59 PDT 2021


hoy created this revision.
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hoy requested review of this revision.
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C functions may be declared and defined in different prototypes like below. This patch unifies the checks for mangling names in symbol linkage name emission and debug linkage name emission so that the two names are consistent.

static int go(int);

static int go(a) int a;
{

  return a;

}

Test Plan:


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98799

Files:
  clang/lib/AST/ItaniumMangle.cpp
  clang/lib/CodeGen/CGDebugInfo.cpp
  clang/test/CodeGen/unique-internal-linkage-names-dwarf.c


Index: clang/test/CodeGen/unique-internal-linkage-names-dwarf.c
===================================================================
--- clang/test/CodeGen/unique-internal-linkage-names-dwarf.c
+++ clang/test/CodeGen/unique-internal-linkage-names-dwarf.c
@@ -8,21 +8,48 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -dwarf-version=5 -funique-internal-linkage-names -emit-llvm -o -  %s | FileCheck %s --check-prefix=UNIQUE
 
 static int glob;
+// foo should be given a uniquefied name under -funique-internal-linkage-names.
 static int foo(void) {
   return glob;
 }
 
+// bar should not be given a uniquefied name under -funique-internal-linkage-names, 
+// since it doesn't come with valid prototype.
+static int bar(a) int a;
+{
+  return glob + a;
+}
+
+// go should be given a uniquefied name under -funique-internal-linkage-names, even 
+// if its definition doesn't come with a valid prototype, but the declaration here
+// has a prototype.
+static int go(int);
+
 void baz() {
   foo();
+  bar(1);
+  go(2);
 }
 
+static int go(a) int a;
+{
+  return glob + a;
+}
+
+
 // PLAIN: @glob = internal global i32
 // PLAIN: define internal i32 @foo()
+// PLAIN: define internal i32 @bar(i32 %a)
 // PLAIN: distinct !DIGlobalVariable(name: "glob"{{.*}})
 // PLAIN: distinct !DISubprogram(name: "foo"{{.*}})
+// PLAIN: distinct !DISubprogram(name: "bar"{{.*}})
+// PLAIN: distinct !DISubprogram(name: "go"{{.*}})
 // PLAIN-NOT: linkageName:
 //
 // UNIQUE: @glob = internal global i32
 // UNIQUE: define internal i32 @_ZL3foov.[[MODHASH:__uniq.[0-9]+]]()
+// UNIQUE: define internal i32 @bar(i32 %a)
+// UNIQUE: define internal i32 @_ZL2goi.[[MODHASH]](i32 %a)
 // UNIQUE: distinct !DIGlobalVariable(name: "glob"{{.*}})
 // UNIQUE: distinct !DISubprogram(name: "foo", linkageName: "_ZL3foov.[[MODHASH]]"{{.*}})
+// UNIQUE: distinct !DISubprogram(name: "go", linkageName: "_ZL2goi.[[MODHASH]]"{{.*}})
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3522,7 +3522,8 @@
                                            llvm::DIScope *&FDContext,
                                            llvm::DINodeArray &TParamsArray,
                                            llvm::DINode::DIFlags &Flags) {
-  const auto *FD = cast<FunctionDecl>(GD.getDecl());
+  GlobalDecl CanonicalGD = GD.getCanonicalDecl();
+  const auto *FD = cast<FunctionDecl>(CanonicalGD.getDecl());
   Name = getFunctionName(FD);
   // Use mangled name as linkage name for C/C++ functions.
   if (FD->hasPrototype()) {
Index: clang/lib/AST/ItaniumMangle.cpp
===================================================================
--- clang/lib/AST/ItaniumMangle.cpp
+++ clang/lib/AST/ItaniumMangle.cpp
@@ -640,7 +640,7 @@
 
   // For C functions without prototypes, return false as their
   // names should not be mangled.
-  if (!FD->getType()->getAs<FunctionProtoType>())
+  if (!FD->hasPrototype())
     return false;
 
   if (isInternalLinkageDecl(ND))


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