external/bsd/llvm/dist/clang/lib/AST/Mangle.cpp

   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
  34 using 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
  39 static 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
  50 void MangleContext::anchor() { }
  51
  52 enum CCMangling {
  53   CCM_Other,
  54   CCM_Fast,
  55   CCM_Vector,
  56   CCM_Std
  57 };
  58
  59 static bool isExternC(const NamedDecl *ND) {
  60   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
  61     return FD->isExternC();
  62   return cast<VarDecl>(ND)->isExternC();
  63 }
  64
  65 static CCMangling getCallingConvMangling(const ASTContext &Context,
  66                                          const NamedDecl *ND) {
  67   const TargetInfo &TI = Context.getTargetInfo();
  68   const llvm::Triple &Triple = TI.getTriple();
  69   if (!Triple.isOSWindows() ||
  70       !(Triple.getArch() == llvm::Triple::x86 ||
  71         Triple.getArch() == llvm::Triple::x86_64))
  72     return CCM_Other;
  73
  74   if (Context.getLangOpts().CPlusPlus && !isExternC(ND) &&
  75       TI.getCXXABI() == TargetCXXABI::Microsoft)
  76     return CCM_Other;
  77
  78   const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND);
  79   if (!FD)
  80     return CCM_Other;
  81   QualType T = FD->getType();
  82
  83   const FunctionType *FT = T->castAs<FunctionType>();
  84
  85   CallingConv CC = FT->getCallConv();
  86   switch (CC) {
  87   default:
  88     return CCM_Other;
  89   case CC_X86FastCall:
  90     return CCM_Fast;
  91   case CC_X86StdCall:
  92     return CCM_Std;
  93   case CC_X86VectorCall:
  94     return CCM_Vector;
  95   }
  96 }
  97
  98 bool MangleContext::shouldMangleDeclName(const NamedDecl *D) {
  99   const ASTContext &ASTContext = getASTContext();
 100
 101   CCMangling CC = getCallingConvMangling(ASTContext, D);
 102   if (CC != CCM_Other)
 103     return true;
 104
 105   // In C, functions with no attributes never need to be mangled. Fastpath them.
 106   if (!getASTContext().getLangOpts().CPlusPlus && !D->hasAttrs())
 107     return false;
 108
 109   // Any decl can be declared with __asm("foo") on it, and this takes precedence
 110   // over all other naming in the .o file.
 111   if (D->hasAttr<AsmLabelAttr>())
 112     return true;
 113
 114   return shouldMangleCXXName(D);
 115 }
 116
 117 void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) {
 118   // Any decl can be declared with __asm("foo") on it, and this takes precedence
 119   // over all other naming in the .o file.
 120   if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
 121     // If we have an asm name, then we use it as the mangling.
 122
 123     // Adding the prefix can cause problems when one file has a "foo" and
 124     // another has a "\01foo". That is known to happen on ELF with the
 125     // tricks normally used for producing aliases (PR9177). Fortunately the
 126     // llvm mangler on ELF is a nop, so we can just avoid adding the \01
 127     // marker.  We also avoid adding the marker if this is an alias for an
 128     // LLVM intrinsic.
 129     StringRef UserLabelPrefix =
 130         getASTContext().getTargetInfo().getUserLabelPrefix();
 131     if (!UserLabelPrefix.empty() && !ALA->getLabel().startswith("llvm."))
 132       Out << '\01'; // LLVM IR Marker for __asm("foo")
 133
 134     Out << ALA->getLabel();
 135     return;
 136   }
 137
 138   const ASTContext &ASTContext = getASTContext();
 139   CCMangling CC = getCallingConvMangling(ASTContext, D);
 140   bool MCXX = shouldMangleCXXName(D);
 141   const TargetInfo &TI = Context.getTargetInfo();
 142   if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) {
 143     if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
 144       mangleObjCMethodName(OMD, Out);
 145     else
 146       mangleCXXName(D, Out);
 147     return;
 148   }
 149
 150   Out << '\01';
 151   if (CC == CCM_Std)
 152     Out << '_';
 153   else if (CC == CCM_Fast)
 154     Out << '@';
 155
 156   if (!MCXX)
 157     Out << D->getIdentifier()->getName();
 158   else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
 159     mangleObjCMethodName(OMD, Out);
 160   else
 161     mangleCXXName(D, Out);
 162
 163   const FunctionDecl *FD = cast<FunctionDecl>(D);
 164   const FunctionType *FT = FD->getType()->castAs<FunctionType>();
 165   const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT);
 166   if (CC == CCM_Vector)
 167     Out << '@';
 168   Out << '@';
 169   if (!Proto) {
 170     Out << '0';
 171     return;
 172   }
 173   assert(!Proto->isVariadic());
 174   unsigned ArgWords = 0;
 175   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD))
 176     if (!MD->isStatic())
 177       ++ArgWords;
 178   for (const auto &AT : Proto->param_types())
 179     // Size should be aligned to pointer size.
 180     ArgWords += llvm::RoundUpToAlignment(ASTContext.getTypeSize(AT),
 181                                          TI.getPointerWidth(0)) /
 182                 TI.getPointerWidth(0);
 183   Out << ((TI.getPointerWidth(0) / 8) * ArgWords);
 184 }
 185
 186 void MangleContext::mangleGlobalBlock(const BlockDecl *BD,
 187                                       const NamedDecl *ID,
 188                                       raw_ostream &Out) {
 189   unsigned discriminator = getBlockId(BD, false);
 190   if (ID) {
 191     if (shouldMangleDeclName(ID))
 192       mangleName(ID, Out);
 193     else {
 194       Out << ID->getIdentifier()->getName();
 195     }
 196   }
 197   if (discriminator == 0)
 198     Out << "_block_invoke";
 199   else
 200     Out << "_block_invoke_" << discriminator+1;
 201 }
 202
 203 void MangleContext::mangleCtorBlock(const CXXConstructorDecl *CD,
 204                                     CXXCtorType CT, const BlockDecl *BD,
 205                                     raw_ostream &ResStream) {
 206   SmallString<64> Buffer;
 207   llvm::raw_svector_ostream Out(Buffer);
 208   mangleCXXCtor(CD, CT, Out);
 209   Out.flush();
 210   mangleFunctionBlock(*this, Buffer, BD, ResStream);
 211 }
 212
 213 void MangleContext::mangleDtorBlock(const CXXDestructorDecl *DD,
 214                                     CXXDtorType DT, const BlockDecl *BD,
 215                                     raw_ostream &ResStream) {
 216   SmallString<64> Buffer;
 217   llvm::raw_svector_ostream Out(Buffer);
 218   mangleCXXDtor(DD, DT, Out);
 219   Out.flush();
 220   mangleFunctionBlock(*this, Buffer, BD, ResStream);
 221 }
 222
 223 void MangleContext::mangleBlock(const DeclContext *DC, const BlockDecl *BD,
 224                                 raw_ostream &Out) {
 225   assert(!isa<CXXConstructorDecl>(DC) && !isa<CXXDestructorDecl>(DC));
 226
 227   SmallString<64> Buffer;
 228   llvm::raw_svector_ostream Stream(Buffer);
 229   if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
 230     mangleObjCMethodName(Method, Stream);
 231   } else {
 232     assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) &&
 233            "expected a NamedDecl or BlockDecl");
 234     if (isa<BlockDecl>(DC))
 235       for (; DC && isa<BlockDecl>(DC); DC = DC->getParent())
 236         (void) getBlockId(cast<BlockDecl>(DC), true);
 237     assert((isa<TranslationUnitDecl>(DC) || isa<NamedDecl>(DC)) &&
 238            "expected a TranslationUnitDecl or a NamedDecl");
 239     if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
 240       mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out);
 241     else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
 242       mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out);
 243     else if (auto ND = dyn_cast<NamedDecl>(DC)) {
 244       if (!shouldMangleDeclName(ND) && ND->getIdentifier())
 245         Stream << ND->getIdentifier()->getName();
 246       else {
 247         // FIXME: We were doing a mangleUnqualifiedName() before, but that's
 248         // a private member of a class that will soon itself be private to the
 249         // Itanium C++ ABI object. What should we do now? Right now, I'm just
 250         // calling the mangleName() method on the MangleContext; is there a
 251         // better way?
 252         mangleName(ND, Stream);
 253       }
 254     }
 255   }
 256   Stream.flush();
 257   mangleFunctionBlock(*this, Buffer, BD, Out);
 258 }
 259
 260 void MangleContext::mangleObjCMethodName(const ObjCMethodDecl *MD,
 261                                          raw_ostream &Out) {
 262   SmallString<64> Name;
 263   llvm::raw_svector_ostream OS(Name);
 264
 265   const ObjCContainerDecl *CD =
 266   dyn_cast<ObjCContainerDecl>(MD->getDeclContext());
 267   assert (CD && "Missing container decl in GetNameForMethod");
 268   OS << (MD->isInstanceMethod() ? '-' : '+') << '[' << CD->getName();
 269   if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(CD))
 270     OS << '(' << *CID << ')';
 271   OS << ' ';
 272   MD->getSelector().print(OS);
 273   OS << ']';
 274
 275   Out << OS.str().size() << OS.str();
 276 }