clang  5.0.0
Mangle.cpp
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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"
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 
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 {
58 };
59 
60 static 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 
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) &&
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 
101 
102  CCMangling CC = getCallingConvMangling(ASTContext, D);
103  if (CC != CCM_Other)
104  return true;
105 
106  // In C, functions with no attributes never need to be mangled. Fastpath them.
107  if (!getASTContext().getLangOpts().CPlusPlus && !D->hasAttrs())
108  return false;
109 
110  // Any decl can be declared with __asm("foo") on it, and this takes precedence
111  // over all other naming in the .o file.
112  if (D->hasAttr<AsmLabelAttr>())
113  return true;
114 
115  return shouldMangleCXXName(D);
116 }
117 
118 void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) {
119  // Any decl can be declared with __asm("foo") on it, and this takes precedence
120  // over all other naming in the .o file.
121  if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
122  // If we have an asm name, then we use it as the mangling.
123 
124  // Adding the prefix can cause problems when one file has a "foo" and
125  // another has a "\01foo". That is known to happen on ELF with the
126  // tricks normally used for producing aliases (PR9177). Fortunately the
127  // llvm mangler on ELF is a nop, so we can just avoid adding the \01
128  // marker. We also avoid adding the marker if this is an alias for an
129  // LLVM intrinsic.
130  char GlobalPrefix =
131  getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix();
132  if (GlobalPrefix && !ALA->getLabel().startswith("llvm."))
133  Out << '\01'; // LLVM IR Marker for __asm("foo")
134 
135  Out << ALA->getLabel();
136  return;
137  }
138 
140  CCMangling CC = getCallingConvMangling(ASTContext, D);
141  bool MCXX = shouldMangleCXXName(D);
142  const TargetInfo &TI = Context.getTargetInfo();
143  if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) {
144  if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
145  mangleObjCMethodName(OMD, Out);
146  else
147  mangleCXXName(D, Out);
148  return;
149  }
150 
151  Out << '\01';
152  if (CC == CCM_Std)
153  Out << '_';
154  else if (CC == CCM_Fast)
155  Out << '@';
156  else if (CC == CCM_RegCall)
157  Out << "__regcall3__";
158 
159  if (!MCXX)
160  Out << D->getIdentifier()->getName();
161  else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
162  mangleObjCMethodName(OMD, Out);
163  else
164  mangleCXXName(D, Out);
165 
166  const FunctionDecl *FD = cast<FunctionDecl>(D);
167  const FunctionType *FT = FD->getType()->castAs<FunctionType>();
168  const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT);
169  if (CC == CCM_Vector)
170  Out << '@';
171  Out << '@';
172  if (!Proto) {
173  Out << '0';
174  return;
175  }
176  assert(!Proto->isVariadic());
177  unsigned ArgWords = 0;
178  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD))
179  if (!MD->isStatic())
180  ++ArgWords;
181  for (const auto &AT : Proto->param_types())
182  // Size should be aligned to pointer size.
183  ArgWords +=
184  llvm::alignTo(ASTContext.getTypeSize(AT), TI.getPointerWidth(0)) /
185  TI.getPointerWidth(0);
186  Out << ((TI.getPointerWidth(0) / 8) * ArgWords);
187 }
188 
190  const NamedDecl *ID,
191  raw_ostream &Out) {
192  unsigned discriminator = getBlockId(BD, false);
193  if (ID) {
194  if (shouldMangleDeclName(ID))
195  mangleName(ID, Out);
196  else {
197  Out << ID->getIdentifier()->getName();
198  }
199  }
200  if (discriminator == 0)
201  Out << "_block_invoke";
202  else
203  Out << "_block_invoke_" << discriminator+1;
204 }
205 
207  CXXCtorType CT, const BlockDecl *BD,
208  raw_ostream &ResStream) {
210  llvm::raw_svector_ostream Out(Buffer);
211  mangleCXXCtor(CD, CT, Out);
212  mangleFunctionBlock(*this, Buffer, BD, ResStream);
213 }
214 
216  CXXDtorType DT, const BlockDecl *BD,
217  raw_ostream &ResStream) {
219  llvm::raw_svector_ostream Out(Buffer);
220  mangleCXXDtor(DD, DT, Out);
221  mangleFunctionBlock(*this, Buffer, BD, ResStream);
222 }
223 
225  raw_ostream &Out) {
226  assert(!isa<CXXConstructorDecl>(DC) && !isa<CXXDestructorDecl>(DC));
227 
229  llvm::raw_svector_ostream Stream(Buffer);
230  if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
231  mangleObjCMethodName(Method, Stream);
232  } else {
233  assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) &&
234  "expected a NamedDecl or BlockDecl");
235  if (isa<BlockDecl>(DC))
236  for (; DC && isa<BlockDecl>(DC); DC = DC->getParent())
237  (void) getBlockId(cast<BlockDecl>(DC), true);
238  assert((isa<TranslationUnitDecl>(DC) || isa<NamedDecl>(DC)) &&
239  "expected a TranslationUnitDecl or a NamedDecl");
240  if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
241  mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out);
242  else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
243  mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out);
244  else if (auto ND = dyn_cast<NamedDecl>(DC)) {
245  if (!shouldMangleDeclName(ND) && ND->getIdentifier())
246  Stream << ND->getIdentifier()->getName();
247  else {
248  // FIXME: We were doing a mangleUnqualifiedName() before, but that's
249  // a private member of a class that will soon itself be private to the
250  // Itanium C++ ABI object. What should we do now? Right now, I'm just
251  // calling the mangleName() method on the MangleContext; is there a
252  // better way?
253  mangleName(ND, Stream);
254  }
255  }
256  }
257  mangleFunctionBlock(*this, Buffer, BD, Out);
258 }
259 
261  raw_ostream &OS) {
262  const ObjCContainerDecl *CD =
263  dyn_cast<ObjCContainerDecl>(MD->getDeclContext());
264  assert (CD && "Missing container decl in GetNameForMethod");
265  OS << (MD->isInstanceMethod() ? '-' : '+') << '[';
266  if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(CD)) {
267  OS << CID->getClassInterface()->getName();
268  OS << '(' << *CID << ')';
269  } else {
270  OS << CD->getName();
271  }
272  OS << ' ';
273  MD->getSelector().print(OS);
274  OS << ']';
275 }
276 
278  raw_ostream &Out) {
280  llvm::raw_svector_ostream OS(Name);
281 
283  Out << OS.str().size() << OS.str();
284 }
Defines the clang::ASTContext interface.
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1618
StringRef getName() const
getName - Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:237
Complete object ctor.
Definition: ABI.h:26
A (possibly-)qualified type.
Definition: Type.h:616
IdentifierInfo * getIdentifier() const
getIdentifier - Get the identifier that names this declaration, if there is one.
Definition: Decl.h:232
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:2923
virtual void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type, raw_ostream &)=0
Defines the SourceManager interface.
virtual void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type, raw_ostream &)=0
Defines the C++ template declaration subclasses.
ASTContext & getASTContext() const
Definition: Mangle.h:70
std::unique_ptr< llvm::MemoryBuffer > Buffer
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2329
CallingConv getCallConv() const
Definition: Type.h:3073
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:1924
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:113
Defines the clang::Expr interface and subclasses for C++ expressions.
void mangleObjCMethodNameWithoutSize(const ObjCMethodDecl *MD, raw_ostream &)
Definition: Mangle.cpp:260
static CCMangling getCallingConvMangling(const ASTContext &Context, const NamedDecl *ND)
Definition: Mangle.cpp:66
bool hasAttr() const
Definition: DeclBase.h:521
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
bool shouldMangleDeclName(const NamedDecl *D)
Definition: Mangle.cpp:99
T * getAttr() const
Definition: DeclBase.h:518
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:643
ObjCContainerDecl - Represents a container for method declarations.
Definition: DeclObjC.h:919
const LangOptions & getLangOpts() const
Definition: ASTContext.h:659
The Microsoft ABI is the ABI used by Microsoft Visual Studio (and compatible compilers).
Definition: TargetCXXABI.h:113
Enums/classes describing ABI related information about constructors, destructors and thunks...
void print(llvm::raw_ostream &OS) const
Prints the full selector name (e.g. "foo:bar:").
QualType getType() const
Definition: Decl.h:589
void mangleName(const NamedDecl *D, raw_ostream &)
Definition: Mangle.cpp:118
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3129
ASTContext * Context
Exposes information about the current target.
Definition: TargetInfo.h:54
CXXDtorType
C++ destructor types.
Definition: ABI.h:34
BlockDecl - This represents a block literal declaration, which is like an unnamed FunctionDecl...
Definition: Decl.h:3557
StringRef getName() const
Return the actual identifier string.
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2551
DeclContext * getDeclContext()
Definition: DeclBase.h:416
bool isInstanceMethod() const
Definition: DeclObjC.h:416
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1294
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:232
unsigned getBlockId(const BlockDecl *BD, bool Local)
Definition: Mangle.h:76
const std::string ID
void mangleDtorBlock(const CXXDestructorDecl *CD, CXXDtorType DT, const BlockDecl *BD, raw_ostream &Out)
Definition: Mangle.cpp:215
virtual bool shouldMangleCXXName(const NamedDecl *D)=0
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1903
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:42
virtual void mangleCXXName(const NamedDecl *D, raw_ostream &)=0
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6105
Complete object dtor.
Definition: ABI.h:36
CXXCtorType
C++ constructor types.
Definition: ABI.h:25
void mangleGlobalBlock(const BlockDecl *BD, const NamedDecl *ID, raw_ostream &Out)
Definition: Mangle.cpp:189
void mangleBlock(const DeclContext *DC, const BlockDecl *BD, raw_ostream &Out)
Definition: Mangle.cpp:224
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1215
StringRef Name
Definition: USRFinder.cpp:123
void mangleObjCMethodName(const ObjCMethodDecl *MD, raw_ostream &)
Definition: Mangle.cpp:277
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:792
Selector getSelector() const
Definition: DeclObjC.h:328
bool hasAttrs() const
Definition: DeclBase.h:462
static void mangleFunctionBlock(MangleContext &Context, StringRef Outer, const BlockDecl *BD, raw_ostream &Out)
Definition: Mangle.cpp:39
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:307
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
TargetCXXABI getCXXABI() const
Get the C++ ABI currently in use.
Definition: TargetInfo.h:861
Defines the clang::TargetInfo interface.
NamedDecl - This represents a decl with a name.
Definition: Decl.h:213
CCMangling
Definition: Mangle.cpp:52
const llvm::DataLayout & getDataLayout() const
Definition: TargetInfo.h:796
void mangleCtorBlock(const CXXConstructorDecl *CD, CXXCtorType CT, const BlockDecl *BD, raw_ostream &Out)
Definition: Mangle.cpp:206
ObjCCategoryImplDecl - An object of this class encapsulates a category @implementation declaration...
Definition: DeclObjC.h:2396
static bool isExternC(const NamedDecl *ND)
Definition: Mangle.cpp:60