llvm-project/clang/lib/AST/Mangle.cpp

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//===--- Mangle.cpp - Mangle C++ Names --------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implements generic name mangling support for blocks and Objective-C.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/Attr.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/Mangle.h"
#include "clang/Basic/ABI.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#define MANGLE_CHECKER 0
#if MANGLE_CHECKER
#include <cxxabi.h>
#endif
using namespace clang;
// FIXME: For blocks we currently mimic GCC's mangling scheme, which leaves
// much to be desired. Come up with a better mangling scheme.
static void mangleFunctionBlock(MangleContext &Context,
StringRef Outer,
const BlockDecl *BD,
raw_ostream &Out) {
unsigned discriminator = Context.getBlockId(BD, true);
if (discriminator == 0)
Out << "__" << Outer << "_block_invoke";
else
Out << "__" << Outer << "_block_invoke_" << discriminator+1;
}
void MangleContext::anchor() { }
enum CCMangling {
CCM_Other,
CCM_Fast,
CCM_Vector,
CCM_Std
};
static bool isExternC(const NamedDecl *ND) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
return FD->isExternC();
return cast<VarDecl>(ND)->isExternC();
}
static CCMangling getCallingConvMangling(const ASTContext &Context,
const NamedDecl *ND) {
const TargetInfo &TI = Context.getTargetInfo();
const llvm::Triple &Triple = TI.getTriple();
if (!Triple.isOSWindows() ||
!(Triple.getArch() == llvm::Triple::x86 ||
Triple.getArch() == llvm::Triple::x86_64))
return CCM_Other;
if (Context.getLangOpts().CPlusPlus && !isExternC(ND) &&
TI.getCXXABI() == TargetCXXABI::Microsoft)
return CCM_Other;
const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND);
if (!FD)
return CCM_Other;
QualType T = FD->getType();
const FunctionType *FT = T->castAs<FunctionType>();
CallingConv CC = FT->getCallConv();
switch (CC) {
default:
return CCM_Other;
case CC_X86FastCall:
return CCM_Fast;
case CC_X86StdCall:
return CCM_Std;
case CC_X86VectorCall:
return CCM_Vector;
}
}
bool MangleContext::shouldMangleDeclName(const NamedDecl *D) {
const ASTContext &ASTContext = getASTContext();
CCMangling CC = getCallingConvMangling(ASTContext, D);
if (CC != CCM_Other)
return true;
// In C, functions with no attributes never need to be mangled. Fastpath them.
if (!getASTContext().getLangOpts().CPlusPlus && !D->hasAttrs())
return false;
// Any decl can be declared with __asm("foo") on it, and this takes precedence
// over all other naming in the .o file.
if (D->hasAttr<AsmLabelAttr>())
return true;
return shouldMangleCXXName(D);
}
void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) {
// Any decl can be declared with __asm("foo") on it, and this takes precedence
// over all other naming in the .o file.
if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
// If we have an asm name, then we use it as the mangling.
// Adding the prefix can cause problems when one file has a "foo" and
// another has a "\01foo". That is known to happen on ELF with the
// tricks normally used for producing aliases (PR9177). Fortunately the
// llvm mangler on ELF is a nop, so we can just avoid adding the \01
// marker. We also avoid adding the marker if this is an alias for an
// LLVM intrinsic.
char GlobalPrefix =
getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix();
if (GlobalPrefix && !ALA->getLabel().startswith("llvm."))
Out << '\01'; // LLVM IR Marker for __asm("foo")
Out << ALA->getLabel();
return;
}
const ASTContext &ASTContext = getASTContext();
CCMangling CC = getCallingConvMangling(ASTContext, D);
bool MCXX = shouldMangleCXXName(D);
const TargetInfo &TI = Context.getTargetInfo();
if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) {
if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
mangleObjCMethodName(OMD, Out);
else
mangleCXXName(D, Out);
return;
}
Out << '\01';
if (CC == CCM_Std)
Out << '_';
else if (CC == CCM_Fast)
Out << '@';
if (!MCXX)
Out << D->getIdentifier()->getName();
else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
mangleObjCMethodName(OMD, Out);
else
mangleCXXName(D, Out);
const FunctionDecl *FD = cast<FunctionDecl>(D);
const FunctionType *FT = FD->getType()->castAs<FunctionType>();
const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT);
if (CC == CCM_Vector)
Out << '@';
Out << '@';
if (!Proto) {
Out << '0';
return;
}
assert(!Proto->isVariadic());
unsigned ArgWords = 0;
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD))
if (!MD->isStatic())
++ArgWords;
for (const auto &AT : Proto->param_types())
// Size should be aligned to pointer size.
ArgWords +=
llvm::alignTo(ASTContext.getTypeSize(AT), TI.getPointerWidth(0)) /
TI.getPointerWidth(0);
Out << ((TI.getPointerWidth(0) / 8) * ArgWords);
}
void MangleContext::mangleGlobalBlock(const BlockDecl *BD,
const NamedDecl *ID,
raw_ostream &Out) {
unsigned discriminator = getBlockId(BD, false);
if (ID) {
if (shouldMangleDeclName(ID))
mangleName(ID, Out);
else {
Out << ID->getIdentifier()->getName();
}
}
if (discriminator == 0)
Out << "_block_invoke";
else
Out << "_block_invoke_" << discriminator+1;
}
void MangleContext::mangleCtorBlock(const CXXConstructorDecl *CD,
CXXCtorType CT, const BlockDecl *BD,
raw_ostream &ResStream) {
SmallString<64> Buffer;
llvm::raw_svector_ostream Out(Buffer);
mangleCXXCtor(CD, CT, Out);
mangleFunctionBlock(*this, Buffer, BD, ResStream);
}
void MangleContext::mangleDtorBlock(const CXXDestructorDecl *DD,
CXXDtorType DT, const BlockDecl *BD,
raw_ostream &ResStream) {
SmallString<64> Buffer;
llvm::raw_svector_ostream Out(Buffer);
mangleCXXDtor(DD, DT, Out);
mangleFunctionBlock(*this, Buffer, BD, ResStream);
}
void MangleContext::mangleBlock(const DeclContext *DC, const BlockDecl *BD,
raw_ostream &Out) {
assert(!isa<CXXConstructorDecl>(DC) && !isa<CXXDestructorDecl>(DC));
SmallString<64> Buffer;
llvm::raw_svector_ostream Stream(Buffer);
if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
mangleObjCMethodName(Method, Stream);
} else {
assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) &&
"expected a NamedDecl or BlockDecl");
if (isa<BlockDecl>(DC))
for (; DC && isa<BlockDecl>(DC); DC = DC->getParent())
(void) getBlockId(cast<BlockDecl>(DC), true);
assert((isa<TranslationUnitDecl>(DC) || isa<NamedDecl>(DC)) &&
"expected a TranslationUnitDecl or a NamedDecl");
if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out);
else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out);
else if (auto ND = dyn_cast<NamedDecl>(DC)) {
if (!shouldMangleDeclName(ND) && ND->getIdentifier())
Stream << ND->getIdentifier()->getName();
else {
// FIXME: We were doing a mangleUnqualifiedName() before, but that's
// a private member of a class that will soon itself be private to the
// Itanium C++ ABI object. What should we do now? Right now, I'm just
// calling the mangleName() method on the MangleContext; is there a
// better way?
mangleName(ND, Stream);
}
}
}
mangleFunctionBlock(*this, Buffer, BD, Out);
}
void MangleContext::mangleObjCMethodNameWithoutSize(const ObjCMethodDecl *MD,
raw_ostream &OS) {
const ObjCContainerDecl *CD =
dyn_cast<ObjCContainerDecl>(MD->getDeclContext());
assert (CD && "Missing container decl in GetNameForMethod");
OS << (MD->isInstanceMethod() ? '-' : '+') << '[' << CD->getName();
if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(CD))
OS << '(' << *CID << ')';
OS << ' ';
MD->getSelector().print(OS);
OS << ']';
}
void MangleContext::mangleObjCMethodName(const ObjCMethodDecl *MD,
raw_ostream &Out) {
SmallString<64> Name;
llvm::raw_svector_ostream OS(Name);
mangleObjCMethodNameWithoutSize(MD, OS);
Out << OS.str().size() << OS.str();
}