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/IR/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/Support/raw_ostream.h"
23 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
24 /// and the specified name as the global variable name. GVName must not be
26 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
27 const Twine &GVName, ManglerPrefixTy PrefixTy) {
28 SmallString<256> TmpData;
29 StringRef Name = GVName.toStringRef(TmpData);
30 assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
32 // If the global name is not led with \1, add the appropriate prefixes.
33 if (Name[0] == '\1') {
34 Name = Name.substr(1);
36 if (PrefixTy == Mangler::Private) {
37 const char *Prefix = DL->getPrivateGlobalPrefix();
38 OutName.append(Prefix, Prefix+strlen(Prefix));
39 } else if (PrefixTy == Mangler::LinkerPrivate) {
40 const char *Prefix = DL->getLinkerPrivateGlobalPrefix();
41 OutName.append(Prefix, Prefix+strlen(Prefix));
44 char Prefix = DL->getGlobalPrefix();
46 OutName.push_back(Prefix);
49 // If this is a simple string that doesn't need escaping, just append it.
50 OutName.append(Name.begin(), Name.end());
53 /// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require
54 /// a suffix on their name indicating the number of words of arguments they
56 static void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName,
57 const Function *F, const DataLayout &TD) {
58 // Calculate arguments size total.
59 unsigned ArgWords = 0;
60 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
62 Type *Ty = AI->getType();
63 // 'Dereference' type in case of byval parameter attribute
64 if (AI->hasByValAttr())
65 Ty = cast<PointerType>(Ty)->getElementType();
66 // Size should be aligned to DWORD boundary
67 ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4;
70 raw_svector_ostream(OutName) << '@' << ArgWords;
74 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
75 /// and the specified global variable's name. If the global variable doesn't
76 /// have a name, this fills in a unique name for the global.
77 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
78 const GlobalValue *GV) {
79 ManglerPrefixTy PrefixTy = Mangler::Default;
80 if (GV->hasPrivateLinkage())
81 PrefixTy = Mangler::Private;
82 else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
83 PrefixTy = Mangler::LinkerPrivate;
85 size_t NameBegin = OutName.size();
87 // If this global has a name, handle it simply.
89 StringRef Name = GV->getName();
90 getNameWithPrefix(OutName, Name, PrefixTy);
91 // No need to do anything else if the global has the special "do not mangle"
96 // Get the ID for the global, assigning a new one if we haven't got one
98 unsigned &ID = AnonGlobalIDs[GV];
99 if (ID == 0) ID = NextAnonGlobalID++;
101 // Must mangle the global into a unique ID.
102 getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
105 // If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
107 if (DL->hasMicrosoftFastStdCallMangling()) {
108 if (const Function *F = dyn_cast<Function>(GV)) {
109 CallingConv::ID CC = F->getCallingConv();
111 // fastcall functions need to start with @ instead of _.
112 if (CC == CallingConv::X86_FastCall) {
113 assert(OutName[NameBegin] == '_' && DL->getGlobalPrefix() == '_');
114 OutName[NameBegin] = '@';
117 // fastcall and stdcall functions usually need @42 at the end to specify
118 // the argument info.
119 FunctionType *FT = F->getFunctionType();
120 if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
121 // "Pure" variadic functions do not receive @0 suffix.
122 (!FT->isVarArg() || FT->getNumParams() == 0 ||
123 (FT->getNumParams() == 1 && F->hasStructRetAttr())))
124 AddFastCallStdCallSuffix(OutName, F, *DL);