1 //===--- Mangle.cpp - Mangle C++ Names --------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // Implements generic name mangling support for blocks and Objective-C.
11 //===----------------------------------------------------------------------===//
12 #include "clang/AST/Attr.h"
13 #include "clang/AST/ASTContext.h"
14 #include "clang/AST/Decl.h"
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/Mangle.h"
20 #include "clang/AST/VTableBuilder.h"
21 #include "clang/Basic/ABI.h"
22 #include "clang/Basic/SourceManager.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "llvm/ADT/StringExtras.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/Mangler.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/raw_ostream.h"
30 using namespace clang;
32 // FIXME: For blocks we currently mimic GCC's mangling scheme, which leaves
33 // much to be desired. Come up with a better mangling scheme.
35 static void mangleFunctionBlock(MangleContext &Context,
39 unsigned discriminator = Context.getBlockId(BD, true);
40 if (discriminator == 0)
41 Out << "__" << Outer << "_block_invoke";
43 Out << "__" << Outer << "_block_invoke_" << discriminator+1;
46 void MangleContext::anchor() { }
56 static bool isExternC(const NamedDecl *ND) {
57 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
58 return FD->isExternC();
59 return cast<VarDecl>(ND)->isExternC();
62 static CCMangling getCallingConvMangling(const ASTContext &Context,
63 const NamedDecl *ND) {
64 const TargetInfo &TI = Context.getTargetInfo();
65 const llvm::Triple &Triple = TI.getTriple();
66 if (!Triple.isOSWindows() ||
67 !(Triple.getArch() == llvm::Triple::x86 ||
68 Triple.getArch() == llvm::Triple::x86_64))
71 if (Context.getLangOpts().CPlusPlus && !isExternC(ND) &&
72 TI.getCXXABI() == TargetCXXABI::Microsoft)
75 const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND);
78 QualType T = FD->getType();
80 const FunctionType *FT = T->castAs<FunctionType>();
82 CallingConv CC = FT->getCallConv();
90 case CC_X86VectorCall:
95 bool MangleContext::shouldMangleDeclName(const NamedDecl *D) {
96 const ASTContext &ASTContext = getASTContext();
98 CCMangling CC = getCallingConvMangling(ASTContext, D);
102 // If the declaration has an owning module for linkage purposes that needs to
103 // be mangled, we must mangle its name.
104 if (!D->hasExternalFormalLinkage() && D->getOwningModuleForLinkage())
107 // In C, functions with no attributes never need to be mangled. Fastpath them.
108 if (!getASTContext().getLangOpts().CPlusPlus && !D->hasAttrs())
111 // Any decl can be declared with __asm("foo") on it, and this takes precedence
112 // over all other naming in the .o file.
113 if (D->hasAttr<AsmLabelAttr>())
116 return shouldMangleCXXName(D);
119 void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) {
120 // Any decl can be declared with __asm("foo") on it, and this takes precedence
121 // over all other naming in the .o file.
122 if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
123 // If we have an asm name, then we use it as the mangling.
125 // Adding the prefix can cause problems when one file has a "foo" and
126 // another has a "\01foo". That is known to happen on ELF with the
127 // tricks normally used for producing aliases (PR9177). Fortunately the
128 // llvm mangler on ELF is a nop, so we can just avoid adding the \01
129 // marker. We also avoid adding the marker if this is an alias for an
132 getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix();
133 if (GlobalPrefix && !ALA->getLabel().startswith("llvm."))
134 Out << '\01'; // LLVM IR Marker for __asm("foo")
136 Out << ALA->getLabel();
140 const ASTContext &ASTContext = getASTContext();
141 CCMangling CC = getCallingConvMangling(ASTContext, D);
142 bool MCXX = shouldMangleCXXName(D);
143 const TargetInfo &TI = Context.getTargetInfo();
144 if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) {
145 if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
146 mangleObjCMethodName(OMD, Out);
148 mangleCXXName(D, Out);
155 else if (CC == CCM_Fast)
157 else if (CC == CCM_RegCall)
158 Out << "__regcall3__";
161 Out << D->getIdentifier()->getName();
162 else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
163 mangleObjCMethodName(OMD, Out);
165 mangleCXXName(D, Out);
167 const FunctionDecl *FD = cast<FunctionDecl>(D);
168 const FunctionType *FT = FD->getType()->castAs<FunctionType>();
169 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT);
170 if (CC == CCM_Vector)
177 assert(!Proto->isVariadic());
178 unsigned ArgWords = 0;
179 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD))
182 for (const auto &AT : Proto->param_types())
183 // Size should be aligned to pointer size.
185 llvm::alignTo(ASTContext.getTypeSize(AT), TI.getPointerWidth(0)) /
186 TI.getPointerWidth(0);
187 Out << ((TI.getPointerWidth(0) / 8) * ArgWords);
190 void MangleContext::mangleGlobalBlock(const BlockDecl *BD,
193 unsigned discriminator = getBlockId(BD, false);
195 if (shouldMangleDeclName(ID))
198 Out << ID->getIdentifier()->getName();
201 if (discriminator == 0)
202 Out << "_block_invoke";
204 Out << "_block_invoke_" << discriminator+1;
207 void MangleContext::mangleCtorBlock(const CXXConstructorDecl *CD,
208 CXXCtorType CT, const BlockDecl *BD,
209 raw_ostream &ResStream) {
210 SmallString<64> Buffer;
211 llvm::raw_svector_ostream Out(Buffer);
212 mangleCXXCtor(CD, CT, Out);
213 mangleFunctionBlock(*this, Buffer, BD, ResStream);
216 void MangleContext::mangleDtorBlock(const CXXDestructorDecl *DD,
217 CXXDtorType DT, const BlockDecl *BD,
218 raw_ostream &ResStream) {
219 SmallString<64> Buffer;
220 llvm::raw_svector_ostream Out(Buffer);
221 mangleCXXDtor(DD, DT, Out);
222 mangleFunctionBlock(*this, Buffer, BD, ResStream);
225 void MangleContext::mangleBlock(const DeclContext *DC, const BlockDecl *BD,
227 assert(!isa<CXXConstructorDecl>(DC) && !isa<CXXDestructorDecl>(DC));
229 SmallString<64> Buffer;
230 llvm::raw_svector_ostream Stream(Buffer);
231 if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
232 mangleObjCMethodName(Method, Stream);
234 assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) &&
235 "expected a NamedDecl or BlockDecl");
236 if (isa<BlockDecl>(DC))
237 for (; DC && isa<BlockDecl>(DC); DC = DC->getParent())
238 (void) getBlockId(cast<BlockDecl>(DC), true);
239 assert((isa<TranslationUnitDecl>(DC) || isa<NamedDecl>(DC)) &&
240 "expected a TranslationUnitDecl or a NamedDecl");
241 if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
242 mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out);
243 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
244 mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out);
245 else if (auto ND = dyn_cast<NamedDecl>(DC)) {
246 if (!shouldMangleDeclName(ND) && ND->getIdentifier())
247 Stream << ND->getIdentifier()->getName();
249 // FIXME: We were doing a mangleUnqualifiedName() before, but that's
250 // a private member of a class that will soon itself be private to the
251 // Itanium C++ ABI object. What should we do now? Right now, I'm just
252 // calling the mangleName() method on the MangleContext; is there a
254 mangleName(ND, Stream);
258 mangleFunctionBlock(*this, Buffer, BD, Out);
261 void MangleContext::mangleObjCMethodNameWithoutSize(const ObjCMethodDecl *MD,
263 const ObjCContainerDecl *CD =
264 dyn_cast<ObjCContainerDecl>(MD->getDeclContext());
265 assert (CD && "Missing container decl in GetNameForMethod");
266 OS << (MD->isInstanceMethod() ? '-' : '+') << '[';
267 if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(CD)) {
268 OS << CID->getClassInterface()->getName();
269 OS << '(' << *CID << ')';
274 MD->getSelector().print(OS);
278 void MangleContext::mangleObjCMethodName(const ObjCMethodDecl *MD,
280 SmallString<64> Name;
281 llvm::raw_svector_ostream OS(Name);
283 mangleObjCMethodNameWithoutSize(MD, OS);
284 Out << OS.str().size() << OS.str();
287 class ASTNameGenerator::Implementation {
288 std::unique_ptr<MangleContext> MC;
292 explicit Implementation(ASTContext &Ctx)
293 : MC(Ctx.createMangleContext()), DL(Ctx.getTargetInfo().getDataLayout()) {
296 bool writeName(const Decl *D, raw_ostream &OS) {
297 // First apply frontend mangling.
298 SmallString<128> FrontendBuf;
299 llvm::raw_svector_ostream FrontendBufOS(FrontendBuf);
300 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
301 if (FD->isDependentContext())
303 if (writeFuncOrVarName(FD, FrontendBufOS))
305 } else if (auto *VD = dyn_cast<VarDecl>(D)) {
306 if (writeFuncOrVarName(VD, FrontendBufOS))
308 } else if (auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
309 MC->mangleObjCMethodNameWithoutSize(MD, OS);
311 } else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
312 writeObjCClassName(ID, FrontendBufOS);
317 // Now apply backend mangling.
318 llvm::Mangler::getNameWithPrefix(OS, FrontendBufOS.str(), DL);
322 std::string getName(const Decl *D) {
325 llvm::raw_string_ostream OS(Name);
336 static StringRef getClassSymbolPrefix(ObjCKind Kind,
337 const ASTContext &Context) {
338 if (Context.getLangOpts().ObjCRuntime.isGNUFamily())
339 return Kind == ObjCMetaclass ? "_OBJC_METACLASS_" : "_OBJC_CLASS_";
340 return Kind == ObjCMetaclass ? "OBJC_METACLASS_$_" : "OBJC_CLASS_$_";
343 std::vector<std::string> getAllManglings(const ObjCContainerDecl *OCD) {
345 if (const auto *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
346 ClassName = OID->getObjCRuntimeNameAsString();
347 else if (const auto *OID = dyn_cast<ObjCImplementationDecl>(OCD))
348 ClassName = OID->getObjCRuntimeNameAsString();
350 if (ClassName.empty())
353 auto Mangle = [&](ObjCKind Kind, StringRef ClassName) -> std::string {
354 SmallString<40> Mangled;
355 auto Prefix = getClassSymbolPrefix(Kind, OCD->getASTContext());
356 llvm::Mangler::getNameWithPrefix(Mangled, Prefix + ClassName, DL);
357 return Mangled.str();
361 Mangle(ObjCClass, ClassName),
362 Mangle(ObjCMetaclass, ClassName),
366 std::vector<std::string> getAllManglings(const Decl *D) {
367 if (const auto *OCD = dyn_cast<ObjCContainerDecl>(D))
368 return getAllManglings(OCD);
370 if (!(isa<CXXRecordDecl>(D) || isa<CXXMethodDecl>(D)))
373 const NamedDecl *ND = cast<NamedDecl>(D);
375 ASTContext &Ctx = ND->getASTContext();
376 std::unique_ptr<MangleContext> M(Ctx.createMangleContext());
378 std::vector<std::string> Manglings;
380 auto hasDefaultCXXMethodCC = [](ASTContext &C, const CXXMethodDecl *MD) {
381 auto DefaultCC = C.getDefaultCallingConvention(/*IsVariadic=*/false,
382 /*IsCXXMethod=*/true);
383 auto CC = MD->getType()->getAs<FunctionProtoType>()->getCallConv();
384 return CC == DefaultCC;
387 if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND)) {
388 Manglings.emplace_back(getMangledStructor(CD, Ctor_Base));
390 if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily())
391 if (!CD->getParent()->isAbstract())
392 Manglings.emplace_back(getMangledStructor(CD, Ctor_Complete));
394 if (Ctx.getTargetInfo().getCXXABI().isMicrosoft())
395 if (CD->hasAttr<DLLExportAttr>() && CD->isDefaultConstructor())
396 if (!(hasDefaultCXXMethodCC(Ctx, CD) && CD->getNumParams() == 0))
397 Manglings.emplace_back(getMangledStructor(CD, Ctor_DefaultClosure));
398 } else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND)) {
399 Manglings.emplace_back(getMangledStructor(DD, Dtor_Base));
400 if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily()) {
401 Manglings.emplace_back(getMangledStructor(DD, Dtor_Complete));
403 Manglings.emplace_back(getMangledStructor(DD, Dtor_Deleting));
405 } else if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(ND)) {
406 Manglings.emplace_back(getName(ND));
408 if (const auto *TIV = Ctx.getVTableContext()->getThunkInfo(MD))
409 for (const auto &T : *TIV)
410 Manglings.emplace_back(getMangledThunk(MD, T));
417 bool writeFuncOrVarName(const NamedDecl *D, raw_ostream &OS) {
418 if (MC->shouldMangleDeclName(D)) {
419 if (const auto *CtorD = dyn_cast<CXXConstructorDecl>(D))
420 MC->mangleCXXCtor(CtorD, Ctor_Complete, OS);
421 else if (const auto *DtorD = dyn_cast<CXXDestructorDecl>(D))
422 MC->mangleCXXDtor(DtorD, Dtor_Complete, OS);
424 MC->mangleName(D, OS);
427 IdentifierInfo *II = D->getIdentifier();
435 void writeObjCClassName(const ObjCInterfaceDecl *D, raw_ostream &OS) {
436 OS << getClassSymbolPrefix(ObjCClass, D->getASTContext());
437 OS << D->getObjCRuntimeNameAsString();
440 std::string getMangledStructor(const NamedDecl *ND, unsigned StructorType) {
441 std::string FrontendBuf;
442 llvm::raw_string_ostream FOS(FrontendBuf);
444 if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND))
445 MC->mangleCXXCtor(CD, static_cast<CXXCtorType>(StructorType), FOS);
446 else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND))
447 MC->mangleCXXDtor(DD, static_cast<CXXDtorType>(StructorType), FOS);
449 std::string BackendBuf;
450 llvm::raw_string_ostream BOS(BackendBuf);
452 llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
457 std::string getMangledThunk(const CXXMethodDecl *MD, const ThunkInfo &T) {
458 std::string FrontendBuf;
459 llvm::raw_string_ostream FOS(FrontendBuf);
461 MC->mangleThunk(MD, T, FOS);
463 std::string BackendBuf;
464 llvm::raw_string_ostream BOS(BackendBuf);
466 llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
472 ASTNameGenerator::ASTNameGenerator(ASTContext &Ctx)
473 : Impl(llvm::make_unique<Implementation>(Ctx)) {}
475 ASTNameGenerator::~ASTNameGenerator() {}
477 bool ASTNameGenerator::writeName(const Decl *D, raw_ostream &OS) {
478 return Impl->writeName(D, OS);
481 std::string ASTNameGenerator::getName(const Decl *D) {
482 return Impl->getName(D);
485 std::vector<std::string> ASTNameGenerator::getAllManglings(const Decl *D) {
486 return Impl->getAllManglings(D);