[clang] fc1812a - [UniqueLinkageName] Use consistent checks when mangling symbo linkage name and debug linkage name.

[Hongtao Yu via cfe-commits]

Author: Hongtao Yu
Date: 2021-03-18T22:11:16-07:00
New Revision: fc1812a0ad757838b66aab57e1df720ec205a16a

URL: https://github.com/llvm/llvm-project/commit/fc1812a0ad757838b66aab57e1df720ec205a16a
DIFF: https://github.com/llvm/llvm-project/commit/fc1812a0ad757838b66aab57e1df720ec205a16a.diff

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

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:

Differential Revision: https://reviews.llvm.org/D98799

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index ba96fda6cd57..3e6e29207f08 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -640,7 +640,7 @@ bool ItaniumMangleContextImpl::isUniqueInternalLinkageDecl(
 
   // 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))

diff  --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 468c2b78b488..c80249a9c9fc 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3522,7 +3522,7 @@ void CGDebugInfo::collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
                                            llvm::DIScope *&FDContext,
                                            llvm::DINodeArray &TParamsArray,
                                            llvm::DINode::DIFlags &Flags) {
-  const auto *FD = cast<FunctionDecl>(GD.getDecl());
+  const auto *FD = cast<FunctionDecl>(GD.getCanonicalDecl().getDecl());
   Name = getFunctionName(FD);
   // Use mangled name as linkage name for C/C++ functions.
   if (FD->hasPrototype()) {

diff  --git a/clang/test/CodeGen/unique-internal-linkage-names-dwarf.c b/clang/test/CodeGen/unique-internal-linkage-names-dwarf.c
index a3583426de79..e5d507e154ae 100644
--- a/clang/test/CodeGen/unique-internal-linkage-names-dwarf.c
+++ b/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]]"{{.*}})