Improve code generation for function template specializations:
- Track implicit instantiations vs. the not-yet-supported explicit
specializations
- Give implicit instantiations of function templates (and member
functions of class templates) linkonce_odr linkage.
- Improve name mangling for function template specializations,
including the template arguments of the instantiation and the return
type of the function.
Note that our name-mangling is improved, but not correct: we still
don't mangle substitutions, although the manglings we produce can be
demangled.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74466 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index acd90e2..7957a9f 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -243,12 +243,20 @@
static CodeGenModule::GVALinkage
GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD,
const LangOptions &Features) {
+ // The kind of external linkage this function will have, if it is not
+ // inline or static.
+ CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal;
+ if (Context.getLangOptions().CPlusPlus &&
+ (FD->getPrimaryTemplate() || FD->getInstantiatedFromMemberFunction()) &&
+ !FD->isExplicitSpecialization())
+ External = CodeGenModule::GVA_TemplateInstantiation;
+
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
// C++ member functions defined inside the class are always inline.
if (MD->isInline() || !MD->isOutOfLine())
return CodeGenModule::GVA_CXXInline;
- return CodeGenModule::GVA_StrongExternal;
+ return External;
}
// "static" functions get internal linkage.
@@ -256,7 +264,7 @@
return CodeGenModule::GVA_Internal;
if (!FD->isInline())
- return CodeGenModule::GVA_StrongExternal;
+ return External;
// If the inline function explicitly has the GNU inline attribute on it, or if
// this is C89 mode, we use to GNU semantics.
@@ -273,7 +281,7 @@
if (FD->isExternGNUInline(Context))
return CodeGenModule::GVA_C99Inline;
// Normal inline is a strong symbol.
- return CodeGenModule::GVA_StrongExternal;
+ return External;
}
// The definition of inline changes based on the language. Note that we
@@ -306,7 +314,7 @@
// In C99 mode, 'inline' functions are guaranteed to have a strong
// definition somewhere else, so we can use available_externally linkage.
GV->setLinkage(llvm::Function::AvailableExternallyLinkage);
- } else if (Linkage == GVA_CXXInline) {
+ } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) {
// In C++, the compiler has to emit a definition in every translation unit
// that references the function. We should use linkonce_odr because
// a) if all references in this translation unit are optimized away, we