1//===- CodegenNameGenerator.cpp - Codegen name generation -----------------===//
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// Determines the name that the symbol will get for code generation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Index/CodegenNameGenerator.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclCXX.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/Mangle.h"
19#include "clang/AST/VTableBuilder.h"
20#include "clang/Basic/TargetInfo.h"
21#include "llvm/IR/DataLayout.h"
22#include "llvm/IR/Mangler.h"
23#include "llvm/Support/raw_ostream.h"
24
25using namespace clang;
26using namespace clang::index;
27
28struct CodegenNameGenerator::Implementation {
29  std::unique_ptr<MangleContext> MC;
30  llvm::DataLayout DL;
31
32  Implementation(ASTContext &Ctx)
33    : MC(Ctx.createMangleContext()),
34      DL(Ctx.getTargetInfo().getDataLayout()) {}
35
36  bool writeName(const Decl *D, raw_ostream &OS) {
37    // First apply frontend mangling.
38    SmallString<128> FrontendBuf;
39    llvm::raw_svector_ostream FrontendBufOS(FrontendBuf);
40    if (auto *FD = dyn_cast<FunctionDecl>(D)) {
41      if (FD->isDependentContext())
42        return true;
43      if (writeFuncOrVarName(FD, FrontendBufOS))
44        return true;
45    } else if (auto *VD = dyn_cast<VarDecl>(D)) {
46      if (writeFuncOrVarName(VD, FrontendBufOS))
47        return true;
48    } else if (auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
49      MC->mangleObjCMethodNameWithoutSize(MD, OS);
50      return false;
51    } else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
52      writeObjCClassName(ID, FrontendBufOS);
53    } else {
54      return true;
55    }
56
57    // Now apply backend mangling.
58    llvm::Mangler::getNameWithPrefix(OS, FrontendBufOS.str(), DL);
59    return false;
60  }
61
62  std::string getName(const Decl *D) {
63    std::string Name;
64    {
65      llvm::raw_string_ostream OS(Name);
66      writeName(D, OS);
67    }
68    return Name;
69  }
70
71  std::vector<std::string> getAllManglings(const Decl *D) {
72    if (!(isa<CXXRecordDecl>(D) || isa<CXXMethodDecl>(D)))
73      return {};
74
75    const NamedDecl *ND = cast<NamedDecl>(D);
76
77    ASTContext &Ctx = ND->getASTContext();
78    std::unique_ptr<MangleContext> M(Ctx.createMangleContext());
79
80    std::vector<std::string> Manglings;
81
82    auto hasDefaultCXXMethodCC = [](ASTContext &C, const CXXMethodDecl *MD) {
83      auto DefaultCC = C.getDefaultCallingConvention(/*IsVariadic=*/false,
84                                                     /*IsCSSMethod=*/true);
85      auto CC = MD->getType()->getAs<FunctionProtoType>()->getCallConv();
86      return CC == DefaultCC;
87    };
88
89    if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND)) {
90      Manglings.emplace_back(getMangledStructor(CD, Ctor_Base));
91
92      if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily())
93        if (!CD->getParent()->isAbstract())
94          Manglings.emplace_back(getMangledStructor(CD, Ctor_Complete));
95
96      if (Ctx.getTargetInfo().getCXXABI().isMicrosoft())
97        if (CD->hasAttr<DLLExportAttr>() && CD->isDefaultConstructor())
98          if (!(hasDefaultCXXMethodCC(Ctx, CD) && CD->getNumParams() == 0))
99            Manglings.emplace_back(getMangledStructor(CD, Ctor_DefaultClosure));
100    } else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND)) {
101      Manglings.emplace_back(getMangledStructor(DD, Dtor_Base));
102      if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily()) {
103        Manglings.emplace_back(getMangledStructor(DD, Dtor_Complete));
104        if (DD->isVirtual())
105          Manglings.emplace_back(getMangledStructor(DD, Dtor_Deleting));
106      }
107    } else if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(ND)) {
108      Manglings.emplace_back(getName(ND));
109      if (MD->isVirtual())
110        if (const auto *TIV = Ctx.getVTableContext()->getThunkInfo(MD))
111          for (const auto &T : *TIV)
112            Manglings.emplace_back(getMangledThunk(MD, T));
113    }
114
115    return Manglings;
116  }
117
118private:
119  bool writeFuncOrVarName(const NamedDecl *D, raw_ostream &OS) {
120    if (MC->shouldMangleDeclName(D)) {
121      if (const auto *CtorD = dyn_cast<CXXConstructorDecl>(D))
122        MC->mangleCXXCtor(CtorD, Ctor_Complete, OS);
123      else if (const auto *DtorD = dyn_cast<CXXDestructorDecl>(D))
124        MC->mangleCXXDtor(DtorD, Dtor_Complete, OS);
125      else
126        MC->mangleName(D, OS);
127      return false;
128    } else {
129      IdentifierInfo *II = D->getIdentifier();
130      if (!II)
131        return true;
132      OS << II->getName();
133      return false;
134    }
135  }
136
137  void writeObjCClassName(const ObjCInterfaceDecl *D, raw_ostream &OS) {
138    OS << getClassSymbolPrefix();
139    OS << D->getObjCRuntimeNameAsString();
140  }
141
142  static StringRef getClassSymbolPrefix() {
143    return "OBJC_CLASS_$_";
144  }
145
146  std::string getMangledStructor(const NamedDecl *ND, unsigned StructorType) {
147    std::string FrontendBuf;
148    llvm::raw_string_ostream FOS(FrontendBuf);
149
150    if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND))
151      MC->mangleCXXCtor(CD, static_cast<CXXCtorType>(StructorType), FOS);
152    else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND))
153      MC->mangleCXXDtor(DD, static_cast<CXXDtorType>(StructorType), FOS);
154
155    std::string BackendBuf;
156    llvm::raw_string_ostream BOS(BackendBuf);
157
158    llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
159
160    return BOS.str();
161  }
162
163  std::string getMangledThunk(const CXXMethodDecl *MD, const ThunkInfo &T) {
164    std::string FrontendBuf;
165    llvm::raw_string_ostream FOS(FrontendBuf);
166
167    MC->mangleThunk(MD, T, FOS);
168
169    std::string BackendBuf;
170    llvm::raw_string_ostream BOS(BackendBuf);
171
172    llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
173
174    return BOS.str();
175  }
176};
177
178CodegenNameGenerator::CodegenNameGenerator(ASTContext &Ctx)
179  : Impl(new Implementation(Ctx)) {
180}
181
182CodegenNameGenerator::~CodegenNameGenerator() {
183}
184
185bool CodegenNameGenerator::writeName(const Decl *D, raw_ostream &OS) {
186  return Impl->writeName(D, OS);
187}
188
189std::string CodegenNameGenerator::getName(const Decl *D) {
190  return Impl->getName(D);
191}
192
193std::vector<std::string> CodegenNameGenerator::getAllManglings(const Decl *D) {
194  return Impl->getAllManglings(D);
195}
196