Mangle.cpp revision 327952
1//===--- Mangle.cpp - Mangle C++ Names --------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Implements generic name mangling support for blocks and Objective-C. 11// 12//===----------------------------------------------------------------------===// 13#include "clang/AST/Attr.h" 14#include "clang/AST/ASTContext.h" 15#include "clang/AST/Decl.h" 16#include "clang/AST/DeclCXX.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/DeclTemplate.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/AST/Mangle.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/Support/ErrorHandling.h" 26#include "llvm/Support/raw_ostream.h" 27 28#define MANGLE_CHECKER 0 29 30#if MANGLE_CHECKER 31#include <cxxabi.h> 32#endif 33 34using namespace clang; 35 36// FIXME: For blocks we currently mimic GCC's mangling scheme, which leaves 37// much to be desired. Come up with a better mangling scheme. 38 39static void mangleFunctionBlock(MangleContext &Context, 40 StringRef Outer, 41 const BlockDecl *BD, 42 raw_ostream &Out) { 43 unsigned discriminator = Context.getBlockId(BD, true); 44 if (discriminator == 0) 45 Out << "__" << Outer << "_block_invoke"; 46 else 47 Out << "__" << Outer << "_block_invoke_" << discriminator+1; 48} 49 50void MangleContext::anchor() { } 51 52enum CCMangling { 53 CCM_Other, 54 CCM_Fast, 55 CCM_RegCall, 56 CCM_Vector, 57 CCM_Std 58}; 59 60static bool isExternC(const NamedDecl *ND) { 61 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 62 return FD->isExternC(); 63 return cast<VarDecl>(ND)->isExternC(); 64} 65 66static CCMangling getCallingConvMangling(const ASTContext &Context, 67 const NamedDecl *ND) { 68 const TargetInfo &TI = Context.getTargetInfo(); 69 const llvm::Triple &Triple = TI.getTriple(); 70 if (!Triple.isOSWindows() || 71 !(Triple.getArch() == llvm::Triple::x86 || 72 Triple.getArch() == llvm::Triple::x86_64)) 73 return CCM_Other; 74 75 if (Context.getLangOpts().CPlusPlus && !isExternC(ND) && 76 TI.getCXXABI() == TargetCXXABI::Microsoft) 77 return CCM_Other; 78 79 const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND); 80 if (!FD) 81 return CCM_Other; 82 QualType T = FD->getType(); 83 84 const FunctionType *FT = T->castAs<FunctionType>(); 85 86 CallingConv CC = FT->getCallConv(); 87 switch (CC) { 88 default: 89 return CCM_Other; 90 case CC_X86FastCall: 91 return CCM_Fast; 92 case CC_X86StdCall: 93 return CCM_Std; 94 case CC_X86VectorCall: 95 return CCM_Vector; 96 } 97} 98 99bool MangleContext::shouldMangleDeclName(const NamedDecl *D) { 100 const ASTContext &ASTContext = getASTContext(); 101 102 CCMangling CC = getCallingConvMangling(ASTContext, D); 103 if (CC != CCM_Other) 104 return true; 105 106 // If the declaration has an owning module for linkage purposes that needs to 107 // be mangled, we must mangle its name. 108 if (!D->hasExternalFormalLinkage() && D->getOwningModuleForLinkage()) 109 return true; 110 111 // In C, functions with no attributes never need to be mangled. Fastpath them. 112 if (!getASTContext().getLangOpts().CPlusPlus && !D->hasAttrs()) 113 return false; 114 115 // Any decl can be declared with __asm("foo") on it, and this takes precedence 116 // over all other naming in the .o file. 117 if (D->hasAttr<AsmLabelAttr>()) 118 return true; 119 120 return shouldMangleCXXName(D); 121} 122 123void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) { 124 // Any decl can be declared with __asm("foo") on it, and this takes precedence 125 // over all other naming in the .o file. 126 if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) { 127 // If we have an asm name, then we use it as the mangling. 128 129 // Adding the prefix can cause problems when one file has a "foo" and 130 // another has a "\01foo". That is known to happen on ELF with the 131 // tricks normally used for producing aliases (PR9177). Fortunately the 132 // llvm mangler on ELF is a nop, so we can just avoid adding the \01 133 // marker. We also avoid adding the marker if this is an alias for an 134 // LLVM intrinsic. 135 char GlobalPrefix = 136 getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix(); 137 if (GlobalPrefix && !ALA->getLabel().startswith("llvm.")) 138 Out << '\01'; // LLVM IR Marker for __asm("foo") 139 140 Out << ALA->getLabel(); 141 return; 142 } 143 144 const ASTContext &ASTContext = getASTContext(); 145 CCMangling CC = getCallingConvMangling(ASTContext, D); 146 bool MCXX = shouldMangleCXXName(D); 147 const TargetInfo &TI = Context.getTargetInfo(); 148 if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) { 149 if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) 150 mangleObjCMethodName(OMD, Out); 151 else 152 mangleCXXName(D, Out); 153 return; 154 } 155 156 Out << '\01'; 157 if (CC == CCM_Std) 158 Out << '_'; 159 else if (CC == CCM_Fast) 160 Out << '@'; 161 else if (CC == CCM_RegCall) 162 Out << "__regcall3__"; 163 164 if (!MCXX) 165 Out << D->getIdentifier()->getName(); 166 else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) 167 mangleObjCMethodName(OMD, Out); 168 else 169 mangleCXXName(D, Out); 170 171 const FunctionDecl *FD = cast<FunctionDecl>(D); 172 const FunctionType *FT = FD->getType()->castAs<FunctionType>(); 173 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT); 174 if (CC == CCM_Vector) 175 Out << '@'; 176 Out << '@'; 177 if (!Proto) { 178 Out << '0'; 179 return; 180 } 181 assert(!Proto->isVariadic()); 182 unsigned ArgWords = 0; 183 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) 184 if (!MD->isStatic()) 185 ++ArgWords; 186 for (const auto &AT : Proto->param_types()) 187 // Size should be aligned to pointer size. 188 ArgWords += 189 llvm::alignTo(ASTContext.getTypeSize(AT), TI.getPointerWidth(0)) / 190 TI.getPointerWidth(0); 191 Out << ((TI.getPointerWidth(0) / 8) * ArgWords); 192} 193 194void MangleContext::mangleGlobalBlock(const BlockDecl *BD, 195 const NamedDecl *ID, 196 raw_ostream &Out) { 197 unsigned discriminator = getBlockId(BD, false); 198 if (ID) { 199 if (shouldMangleDeclName(ID)) 200 mangleName(ID, Out); 201 else { 202 Out << ID->getIdentifier()->getName(); 203 } 204 } 205 if (discriminator == 0) 206 Out << "_block_invoke"; 207 else 208 Out << "_block_invoke_" << discriminator+1; 209} 210 211void MangleContext::mangleCtorBlock(const CXXConstructorDecl *CD, 212 CXXCtorType CT, const BlockDecl *BD, 213 raw_ostream &ResStream) { 214 SmallString<64> Buffer; 215 llvm::raw_svector_ostream Out(Buffer); 216 mangleCXXCtor(CD, CT, Out); 217 mangleFunctionBlock(*this, Buffer, BD, ResStream); 218} 219 220void MangleContext::mangleDtorBlock(const CXXDestructorDecl *DD, 221 CXXDtorType DT, const BlockDecl *BD, 222 raw_ostream &ResStream) { 223 SmallString<64> Buffer; 224 llvm::raw_svector_ostream Out(Buffer); 225 mangleCXXDtor(DD, DT, Out); 226 mangleFunctionBlock(*this, Buffer, BD, ResStream); 227} 228 229void MangleContext::mangleBlock(const DeclContext *DC, const BlockDecl *BD, 230 raw_ostream &Out) { 231 assert(!isa<CXXConstructorDecl>(DC) && !isa<CXXDestructorDecl>(DC)); 232 233 SmallString<64> Buffer; 234 llvm::raw_svector_ostream Stream(Buffer); 235 if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) { 236 mangleObjCMethodName(Method, Stream); 237 } else { 238 assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) && 239 "expected a NamedDecl or BlockDecl"); 240 if (isa<BlockDecl>(DC)) 241 for (; DC && isa<BlockDecl>(DC); DC = DC->getParent()) 242 (void) getBlockId(cast<BlockDecl>(DC), true); 243 assert((isa<TranslationUnitDecl>(DC) || isa<NamedDecl>(DC)) && 244 "expected a TranslationUnitDecl or a NamedDecl"); 245 if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC)) 246 mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out); 247 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC)) 248 mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out); 249 else if (auto ND = dyn_cast<NamedDecl>(DC)) { 250 if (!shouldMangleDeclName(ND) && ND->getIdentifier()) 251 Stream << ND->getIdentifier()->getName(); 252 else { 253 // FIXME: We were doing a mangleUnqualifiedName() before, but that's 254 // a private member of a class that will soon itself be private to the 255 // Itanium C++ ABI object. What should we do now? Right now, I'm just 256 // calling the mangleName() method on the MangleContext; is there a 257 // better way? 258 mangleName(ND, Stream); 259 } 260 } 261 } 262 mangleFunctionBlock(*this, Buffer, BD, Out); 263} 264 265void MangleContext::mangleObjCMethodNameWithoutSize(const ObjCMethodDecl *MD, 266 raw_ostream &OS) { 267 const ObjCContainerDecl *CD = 268 dyn_cast<ObjCContainerDecl>(MD->getDeclContext()); 269 assert (CD && "Missing container decl in GetNameForMethod"); 270 OS << (MD->isInstanceMethod() ? '-' : '+') << '['; 271 if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(CD)) { 272 OS << CID->getClassInterface()->getName(); 273 OS << '(' << *CID << ')'; 274 } else { 275 OS << CD->getName(); 276 } 277 OS << ' '; 278 MD->getSelector().print(OS); 279 OS << ']'; 280} 281 282void MangleContext::mangleObjCMethodName(const ObjCMethodDecl *MD, 283 raw_ostream &Out) { 284 SmallString<64> Name; 285 llvm::raw_svector_ostream OS(Name); 286 287 mangleObjCMethodNameWithoutSize(MD, OS); 288 Out << OS.str().size() << OS.str(); 289} 290