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//===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// Unified name mangler for assembly backends.
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//===----------------------------------------------------------------------===//
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#include "llvm/Target/Mangler.h"
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#include "llvm/GlobalValue.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/Twine.h"
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static bool isAcceptableChar(char C) {
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if ((C < 'a' || C > 'z') &&
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(C < 'A' || C > 'Z') &&
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(C < '0' || C > '9') &&
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C != '_' && C != '$' && C != '.' && C != '@')
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static char HexDigit(int V) {
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return V < 10 ? V+'0' : V+'A'-10;
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static void MangleLetter(SmallVectorImpl<char> &OutName, unsigned char C) {
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OutName.push_back('_');
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OutName.push_back(HexDigit(C >> 4));
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OutName.push_back(HexDigit(C & 15));
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OutName.push_back('_');
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/// NameNeedsEscaping - Return true if the identifier \arg Str needs quotes
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/// for this assembler.
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static bool NameNeedsEscaping(StringRef Str, const MCAsmInfo &MAI) {
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assert(!Str.empty() && "Cannot create an empty MCSymbol");
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// If the first character is a number and the target does not allow this, we
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if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9')
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// If any of the characters in the string is an unacceptable character, force
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for (unsigned i = 0, e = Str.size(); i != e; ++i)
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if (!isAcceptableChar(Str[i]))
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/// appendMangledName - Add the specified string in mangled form if it uses
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/// any unusual characters.
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static void appendMangledName(SmallVectorImpl<char> &OutName, StringRef Str,
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const MCAsmInfo *MAI) {
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// The first character is not allowed to be a number unless the target
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// explicitly allows it.
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if ((MAI == 0 || !MAI->doesAllowNameToStartWithDigit()) &&
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Str[0] >= '0' && Str[0] <= '9') {
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MangleLetter(OutName, Str[0]);
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for (unsigned i = 0, e = Str.size(); i != e; ++i) {
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if (!isAcceptableChar(Str[i]))
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MangleLetter(OutName, Str[i]);
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OutName.push_back(Str[i]);
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/// appendMangledQuotedName - On systems that support quoted symbols, we still
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/// have to escape some (obscure) characters like " and \n which would break the
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/// assembler's lexing.
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static void appendMangledQuotedName(SmallVectorImpl<char> &OutName,
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for (unsigned i = 0, e = Str.size(); i != e; ++i) {
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if (Str[i] == '"' || Str[i] == '\n')
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MangleLetter(OutName, Str[i]);
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OutName.push_back(Str[i]);
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/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
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/// and the specified name as the global variable name. GVName must not be
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void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
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const Twine &GVName, ManglerPrefixTy PrefixTy) {
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SmallString<256> TmpData;
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StringRef Name = GVName.toStringRef(TmpData);
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assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
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// If the global name is not led with \1, add the appropriate prefixes.
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if (Name[0] == '\1') {
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Name = Name.substr(1);
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if (PrefixTy == Mangler::Private) {
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const char *Prefix = MAI.getPrivateGlobalPrefix();
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OutName.append(Prefix, Prefix+strlen(Prefix));
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} else if (PrefixTy == Mangler::LinkerPrivate) {
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const char *Prefix = MAI.getLinkerPrivateGlobalPrefix();
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OutName.append(Prefix, Prefix+strlen(Prefix));
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const char *Prefix = MAI.getGlobalPrefix();
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; // Common noop, no prefix.
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else if (Prefix[1] == 0)
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OutName.push_back(Prefix[0]); // Common, one character prefix.
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OutName.append(Prefix, Prefix+strlen(Prefix)); // Arbitrary length prefix.
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// If this is a simple string that doesn't need escaping, just append it.
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if (!NameNeedsEscaping(Name, MAI) ||
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// If quotes are supported, they can be used unless the string contains
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// a quote or newline.
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(MAI.doesAllowQuotesInName() &&
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Name.find_first_of("\n\"") == StringRef::npos)) {
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OutName.append(Name.begin(), Name.end());
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// On systems that do not allow quoted names, we need to mangle most
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// strange characters.
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if (!MAI.doesAllowQuotesInName())
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return appendMangledName(OutName, Name, &MAI);
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// Okay, the system allows quoted strings. We can quote most anything, the
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// only characters that need escaping are " and \n.
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assert(Name.find_first_of("\n\"") != StringRef::npos);
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return appendMangledQuotedName(OutName, Name);
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/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
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/// and the specified global variable's name. If the global variable doesn't
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/// have a name, this fills in a unique name for the global.
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void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
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const GlobalValue *GV,
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bool isImplicitlyPrivate) {
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ManglerPrefixTy PrefixTy = Mangler::Default;
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if (GV->hasPrivateLinkage() || isImplicitlyPrivate)
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PrefixTy = Mangler::Private;
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else if (GV->hasLinkerPrivateLinkage())
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PrefixTy = Mangler::LinkerPrivate;
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// If this global has a name, handle it simply.
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return getNameWithPrefix(OutName, GV->getName(), PrefixTy);
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// Get the ID for the global, assigning a new one if we haven't got one
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unsigned &ID = AnonGlobalIDs[GV];
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if (ID == 0) ID = NextAnonGlobalID++;
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// Must mangle the global into a unique ID.
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getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
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/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
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/// and the specified global variable's name. If the global variable doesn't
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/// have a name, this fills in a unique name for the global.
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std::string Mangler::getNameWithPrefix(const GlobalValue *GV,
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bool isImplicitlyPrivate) {
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getNameWithPrefix(Buf, GV, isImplicitlyPrivate);
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return std::string(Buf.begin(), Buf.end());