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implement codegen support for __attribute((__gnuc_inline__)), 

pulling some attribute munging stuff into GetLinkageForFunction.

This should fix PR3986

llvm-svn: 69045
This commit is contained in:
Chris Lattner 2009-04-14 16:44:36 +00:00
parent eaad6b70a9
commit 02e987f3e8
3 changed files with 55 additions and 39 deletions
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81
clang/lib/CodeGen/CodeGenModule.cpp
View File

@ -221,19 +221,34 @@ void CodeGenModule::EmitAnnotations() {
gv->setSection("llvm.metadata");
}
static CodeGenModule::GVALinkage GetLinkageForFunction(const FunctionDecl *FD) {
static CodeGenModule::GVALinkage
GetLinkageForFunction(const FunctionDecl *FD, const LangOptions &Features) {
// "static" and attr(always_inline) functions get internal linkage.
if (FD->getStorageClass() == FunctionDecl::Static ||
FD->hasAttr<AlwaysInlineAttr>())
return CodeGenModule::GVA_Internal;
if (FD->isInline()) {
if (FD->getStorageClass() == FunctionDecl::Extern)
return CodeGenModule::GVA_ExternInline;
return CodeGenModule::GVA_Inline;
}
if (!FD->isInline())
return CodeGenModule::GVA_Normal;
if (FD->getStorageClass() == FunctionDecl::Extern)
return CodeGenModule::GVA_ExternInline;
return CodeGenModule::GVA_Normal;
// If the inline function explicitly has the GNU inline attribute on it, then
// force to GNUC semantics, regardless of language.
if (FD->hasAttr<GNUCInlineAttr>())
return CodeGenModule::GVA_GNUCInline;
// The definition of inline changes based on the language. Note that we
// have already handled "static inline" above, with the GVA_Internal case.
if (Features.CPlusPlus)
return CodeGenModule::GVA_CXXInline;
if (Features.C99)
return CodeGenModule::GVA_C99Inline;
// Otherwise, this is the GNU inline extension in K&R and GNU C89 mode.
return CodeGenModule::GVA_GNUCInline;
}
/// SetFunctionDefinitionAttributes - Set attributes for a global.
@ -243,7 +258,7 @@ static CodeGenModule::GVALinkage GetLinkageForFunction(const FunctionDecl *FD) {
/// EmitGlobalVarDefinition for variables).
void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
llvm::GlobalValue *GV) {
GVALinkage Linkage = GetLinkageForFunction(D);
GVALinkage Linkage = GetLinkageForFunction(D, Features);
if (Linkage == GVA_Internal) {
GV->setLinkage(llvm::Function::InternalLinkage);
@ -256,27 +271,23 @@ void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
// strongest linkage type we can give an inline function: we don't have to
// codegen the definition at all, yet we know that it is "ODR".
GV->setLinkage(llvm::Function::AvailableExternallyLinkage);
} else if (Linkage == GVA_Inline) {
// The definition of inline changes based on the language. Note that we
// have already handled "static inline" above, with the GVA_Internal case.
if (Features.CPlusPlus) {
// 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
// don't need to codegen it. b) if the function persists, it needs to be
// merged with other definitions. c) C++ has the ODR, so we know the
// definition is dependable.
GV->setLinkage(llvm::Function::LinkOnceODRLinkage);
} else if (Features.C99) {
// 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 {
// In C89 mode, an 'inline' function may only occur in one translation
// unit in the program, but may be extern'd in others. Give it strong
// external linkage.
GV->setLinkage(llvm::Function::ExternalLinkage);
}
} else if (Linkage == GVA_CXXInline) {
// 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
// don't need to codegen it. b) if the function persists, it needs to be
// merged with other definitions. c) C++ has the ODR, so we know the
// definition is dependable.
GV->setLinkage(llvm::Function::LinkOnceODRLinkage);
} else if (Linkage == GVA_C99Inline) {
// 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_GNUCInline) {
// In C89 mode, an 'inline' function may only occur in one translation
// unit in the program, but may be extern'd in others. Give it strong
// external linkage.
GV->setLinkage(llvm::Function::ExternalLinkage);
} else {
GV->setLinkage(llvm::Function::ExternalLinkage);
}
@ -466,17 +477,13 @@ bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
if (FD->hasAttr<ConstructorAttr>() || FD->hasAttr<DestructorAttr>())
return false;
GVALinkage Linkage = GetLinkageForFunction(FD);
GVALinkage Linkage = GetLinkageForFunction(FD, Features);
// static, static inline, always_inline, and extern inline functions can
// always be deferred.
if (Linkage == GVA_Internal || Linkage == GVA_ExternInline)
// always be deferred. Normal inline functions can be deferred in C99/C++.
if (Linkage == GVA_Internal || Linkage == GVA_ExternInline ||
Linkage == GVA_C99Inline || Linkage == GVA_CXXInline)
return true;
// inline functions can be deferred unless we're in C89 mode.
if (Linkage == GVA_Inline && (Features.C99 || Features.CPlusPlus))
return true;
return false;
}

4
clang/lib/CodeGen/CodeGenModule.h
View File

@ -314,8 +314,10 @@ public:
enum GVALinkage {
GVA_Internal,
GVA_Inline,
GVA_ExternInline,
GVA_GNUCInline,
GVA_C99Inline,
GVA_CXXInline,
GVA_Normal
};

9
clang/test/CodeGen/inline.c
View File

@ -1,21 +1,27 @@
// RUN: echo "C89 tests:" &&
// RUN: clang %s -emit-llvm -S -o %t -std=c89 &&
// RUN: grep "define available_externally i32 @ei()" %t &&
// RUN: grep "define i32 @foo()" %t &&
// RUN: grep "define i32 @bar()" %t &&
// RUN: grep "define void @unreferenced1()" %t &&
// RUN: not grep unreferenced2 %t &&
// RUN: grep "define void @gnu_inline()" %t &&
// RUN: echo "\nC99 tests:" &&
// RUN: clang %s -emit-llvm -S -o %t -std=c99 &&
// RUN: grep "define available_externally i32 @ei()" %t &&
// RUN: grep "define available_externally i32 @foo()" %t &&
// RUN: grep "define i32 @bar()" %t &&
// RUN: not grep unreferenced %t &&
// RUN: grep "define void @gnu_inline()" %t &&
// RUN: echo "\nC++ tests:" &&
// RUN: clang %s -emit-llvm -S -o %t -std=c++98 &&
// RUN: grep "define available_externally i32 @_Z2eiv()" %t &&
// RUN: grep "define linkonce_odr i32 @_Z3foov()" %t &&
// RUN: grep "define i32 @_Z3barv()" %t &&
// RUN: not grep unreferenced %t
// RUN: not grep unreferenced %t &&
// RUN: grep "define void @_Z10gnu_inlinev()" %t
extern inline int ei() { return 123; }
@ -29,3 +35,4 @@ int bar() { return foo(); }
inline void unreferenced1() {}
extern inline void unreferenced2() {}
__inline __attribute((__gnuc_inline__)) void gnu_inline() {}