1 //===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Unified name mangler for assembly backends.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/Mangler.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/ADT/Twine.h"
17 #include "llvm/IR/DataLayout.h"
18 #include "llvm/IR/DerivedTypes.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/MC/MCAsmInfo.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/Target/TargetMachine.h"
23 #include "llvm/Support/raw_ostream.h"
26 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
27 /// and the specified name as the global variable name. GVName must not be
29 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
30 const Twine &GVName, ManglerPrefixTy PrefixTy) {
31 SmallString<256> TmpData;
32 StringRef Name = GVName.toStringRef(TmpData);
33 assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
35 const MCAsmInfo *MAI = TM->getMCAsmInfo();
37 // If the global name is not led with \1, add the appropriate prefixes.
38 if (Name[0] == '\1') {
39 Name = Name.substr(1);
41 if (PrefixTy == Mangler::Private) {
42 const char *Prefix = MAI->getPrivateGlobalPrefix();
43 OutName.append(Prefix, Prefix+strlen(Prefix));
44 } else if (PrefixTy == Mangler::LinkerPrivate) {
45 const char *Prefix = MAI->getLinkerPrivateGlobalPrefix();
46 OutName.append(Prefix, Prefix+strlen(Prefix));
50 char Prefix = MAI->getGlobalPrefix();
52 OutName.push_back(Prefix);
55 // If this is a simple string that doesn't need escaping, just append it.
56 OutName.append(Name.begin(), Name.end());
59 /// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require
60 /// a suffix on their name indicating the number of words of arguments they
62 static void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName,
63 const Function *F, const DataLayout &TD) {
64 // Calculate arguments size total.
65 unsigned ArgWords = 0;
66 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
68 Type *Ty = AI->getType();
69 // 'Dereference' type in case of byval parameter attribute
70 if (AI->hasByValAttr())
71 Ty = cast<PointerType>(Ty)->getElementType();
72 // Size should be aligned to DWORD boundary
73 ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4;
76 raw_svector_ostream(OutName) << '@' << ArgWords;
80 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
81 /// and the specified global variable's name. If the global variable doesn't
82 /// have a name, this fills in a unique name for the global.
83 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
84 const GlobalValue *GV,
85 bool isImplicitlyPrivate) {
86 ManglerPrefixTy PrefixTy = Mangler::Default;
87 if (GV->hasPrivateLinkage() || isImplicitlyPrivate)
88 PrefixTy = Mangler::Private;
89 else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
90 PrefixTy = Mangler::LinkerPrivate;
92 // If this global has a name, handle it simply.
94 StringRef Name = GV->getName();
95 getNameWithPrefix(OutName, Name, PrefixTy);
96 // No need to do anything else if the global has the special "do not mangle"
101 // Get the ID for the global, assigning a new one if we haven't got one
103 unsigned &ID = AnonGlobalIDs[GV];
104 if (ID == 0) ID = NextAnonGlobalID++;
106 // Must mangle the global into a unique ID.
107 getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
110 // If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
112 if (TM->getMCAsmInfo()->hasMicrosoftFastStdCallMangling()) {
113 if (const Function *F = dyn_cast<Function>(GV)) {
114 CallingConv::ID CC = F->getCallingConv();
116 // fastcall functions need to start with @.
117 // FIXME: This logic seems unlikely to be right.
118 if (CC == CallingConv::X86_FastCall) {
119 if (OutName[0] == '_')
122 OutName.insert(OutName.begin(), '@');
125 // fastcall and stdcall functions usually need @42 at the end to specify
126 // the argument info.
127 FunctionType *FT = F->getFunctionType();
128 if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
129 // "Pure" variadic functions do not receive @0 suffix.
130 (!FT->isVarArg() || FT->getNumParams() == 0 ||
131 (FT->getNumParams() == 1 && F->hasStructRetAttr())))
132 AddFastCallStdCallSuffix(OutName, F, *TM->getDataLayout());