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/GlobalValue.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/Twine.h"
21 static bool isAcceptableChar(char C) {
22 if ((C < 'a' || C > 'z') &&
23 (C < 'A' || C > 'Z') &&
24 (C < '0' || C > '9') &&
25 C != '_' && C != '$' && C != '.' && C != '@')
30 static char HexDigit(int V) {
31 return V < 10 ? V+'0' : V+'A'-10;
34 static void MangleLetter(SmallVectorImpl<char> &OutName, unsigned char C) {
35 OutName.push_back('_');
36 OutName.push_back(HexDigit(C >> 4));
37 OutName.push_back(HexDigit(C & 15));
38 OutName.push_back('_');
41 /// NameNeedsEscaping - Return true if the identifier \arg Str needs quotes
42 /// for this assembler.
43 static bool NameNeedsEscaping(StringRef Str, const MCAsmInfo &MAI) {
44 assert(!Str.empty() && "Cannot create an empty MCSymbol");
46 // If the first character is a number and the target does not allow this, we
48 if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9')
51 // If any of the characters in the string is an unacceptable character, force
53 for (unsigned i = 0, e = Str.size(); i != e; ++i)
54 if (!isAcceptableChar(Str[i]))
59 /// appendMangledName - Add the specified string in mangled form if it uses
60 /// any unusual characters.
61 void Mangler::appendMangledName(SmallVectorImpl<char> &OutName, StringRef Str,
62 const MCAsmInfo *MAI) {
63 // The first character is not allowed to be a number unless the target
64 // explicitly allows it.
65 if ((MAI == 0 || !MAI->doesAllowNameToStartWithDigit()) &&
66 Str[0] >= '0' && Str[0] <= '9') {
67 MangleLetter(OutName, Str[0]);
71 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
72 if (!isAcceptableChar(Str[i]))
73 MangleLetter(OutName, Str[i]);
75 OutName.push_back(Str[i]);
80 /// appendMangledQuotedName - On systems that support quoted symbols, we still
81 /// have to escape some (obscure) characters like " and \n which would break the
82 /// assembler's lexing.
83 static void appendMangledQuotedName(SmallVectorImpl<char> &OutName,
85 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
86 if (Str[i] == '"' || Str[i] == '\n')
87 MangleLetter(OutName, Str[i]);
89 OutName.push_back(Str[i]);
94 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
95 /// and the specified name as the global variable name. GVName must not be
97 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
98 const Twine &GVName, ManglerPrefixTy PrefixTy) {
99 SmallString<256> TmpData;
100 StringRef Name = GVName.toStringRef(TmpData);
101 assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
103 // If the global name is not led with \1, add the appropriate prefixes.
104 if (Name[0] == '\1') {
105 Name = Name.substr(1);
107 if (PrefixTy == Mangler::Private) {
108 const char *Prefix = MAI.getPrivateGlobalPrefix();
109 OutName.append(Prefix, Prefix+strlen(Prefix));
110 } else if (PrefixTy == Mangler::LinkerPrivate) {
111 const char *Prefix = MAI.getLinkerPrivateGlobalPrefix();
112 OutName.append(Prefix, Prefix+strlen(Prefix));
115 const char *Prefix = MAI.getGlobalPrefix();
117 ; // Common noop, no prefix.
118 else if (Prefix[1] == 0)
119 OutName.push_back(Prefix[0]); // Common, one character prefix.
121 OutName.append(Prefix, Prefix+strlen(Prefix)); // Arbitrary length prefix.
124 // If this is a simple string that doesn't need escaping, just append it.
125 if (!NameNeedsEscaping(Name, MAI) ||
126 // If quotes are supported, they can be used unless the string contains
127 // a quote or newline.
128 (MAI.doesAllowQuotesInName() &&
129 Name.find_first_of("\n\"") == StringRef::npos)) {
130 OutName.append(Name.begin(), Name.end());
134 // On systems that do not allow quoted names, we need to mangle most
135 // strange characters.
136 if (!MAI.doesAllowQuotesInName())
137 return appendMangledName(OutName, Name, &MAI);
139 // Okay, the system allows quoted strings. We can quote most anything, the
140 // only characters that need escaping are " and \n.
141 assert(Name.find_first_of("\n\"") != StringRef::npos);
142 return appendMangledQuotedName(OutName, Name);
146 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
147 /// and the specified global variable's name. If the global variable doesn't
148 /// have a name, this fills in a unique name for the global.
149 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
150 const GlobalValue *GV,
151 bool isImplicitlyPrivate) {
152 ManglerPrefixTy PrefixTy = Mangler::Default;
153 if (GV->hasPrivateLinkage() || isImplicitlyPrivate)
154 PrefixTy = Mangler::Private;
155 else if (GV->hasLinkerPrivateLinkage())
156 PrefixTy = Mangler::LinkerPrivate;
158 // If this global has a name, handle it simply.
160 return getNameWithPrefix(OutName, GV->getName(), PrefixTy);
162 // Get the ID for the global, assigning a new one if we haven't got one
164 unsigned &ID = AnonGlobalIDs[GV];
165 if (ID == 0) ID = NextAnonGlobalID++;
167 // Must mangle the global into a unique ID.
168 getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
171 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
172 /// and the specified global variable's name. If the global variable doesn't
173 /// have a name, this fills in a unique name for the global.
174 std::string Mangler::getNameWithPrefix(const GlobalValue *GV,
175 bool isImplicitlyPrivate) {
177 getNameWithPrefix(Buf, GV, isImplicitlyPrivate);
178 return std::string(Buf.begin(), Buf.end());