llvm/lib/VMCore/Mangler.cpp

217 lines
6.7 KiB
C++

//===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Unified name mangler for CWriter and assembly backends.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Mangler.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
using namespace llvm;
static char HexDigit(int V) {
return V < 10 ? V+'0' : V+'A'-10;
}
static std::string MangleLetter(unsigned char C) {
char Result[] = { '_', HexDigit(C >> 4), HexDigit(C & 15), '_', 0 };
return Result;
}
/// makeNameProper - We don't want identifier names non-C-identifier characters
/// in them, so mangle them as appropriate.
///
std::string Mangler::makeNameProper(const std::string &X, const char *Prefix) {
std::string Result;
if (X.empty()) return X; // Empty names are uniqued by the caller.
// If PreserveAsmNames is set, names with asm identifiers are not modified.
if (PreserveAsmNames && X[0] == 1)
return X;
if (!UseQuotes) {
// If X does not start with (char)1, add the prefix.
std::string::const_iterator I = X.begin();
if (*I != 1)
Result = Prefix;
else
++I; // Skip over the marker.
// Mangle the first letter specially, don't allow numbers.
if (*I >= '0' && *I <= '9')
Result += MangleLetter(*I++);
for (std::string::const_iterator E = X.end(); I != E; ++I) {
if (!isCharAcceptable(*I))
Result += MangleLetter(*I);
else
Result += *I;
}
} else {
bool NeedsQuotes = false;
std::string::const_iterator I = X.begin();
if (*I == 1)
++I; // Skip over the marker.
// If the first character is a number, we need quotes.
if (*I >= '0' && *I <= '9')
NeedsQuotes = true;
// Do an initial scan of the string, checking to see if we need quotes or
// to escape a '"' or not.
if (!NeedsQuotes)
for (std::string::const_iterator E = X.end(); I != E; ++I)
if (!isCharAcceptable(*I)) {
NeedsQuotes = true;
break;
}
// In the common case, we don't need quotes. Handle this quickly.
if (!NeedsQuotes) {
if (*X.begin() != 1)
return Prefix+X;
else
return X.substr(1);
}
// Otherwise, construct the string the expensive way.
I = X.begin();
// If X does not start with (char)1, add the prefix.
if (*I != 1)
Result = Prefix;
else
++I; // Skip the marker if present.
for (std::string::const_iterator E = X.end(); I != E; ++I) {
if (*I == '"')
Result += "_QQ_";
else if (*I == '\n')
Result += "_NL_";
else
Result += *I;
}
Result = '"' + Result + '"';
}
return Result;
}
/// getTypeID - Return a unique ID for the specified LLVM type.
///
unsigned Mangler::getTypeID(const Type *Ty) {
unsigned &E = TypeMap[Ty];
if (E == 0) E = ++TypeCounter;
return E;
}
std::string Mangler::getValueName(const Value *V) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
return getValueName(GV);
std::string &Name = Memo[V];
if (!Name.empty())
return Name; // Return the already-computed name for V.
// Always mangle local names.
Name = "ltmp_" + utostr(Count++) + "_" + utostr(getTypeID(V->getType()));
return Name;
}
std::string Mangler::getValueName(const GlobalValue *GV, const char * Suffix) {
// Check to see whether we've already named V.
std::string &Name = Memo[GV];
if (!Name.empty())
return Name; // Return the already-computed name for V.
// Name mangling occurs as follows:
// - If V is an intrinsic function, do not change name at all
// - Otherwise, mangling occurs if global collides with existing name.
if (isa<Function>(GV) && cast<Function>(GV)->isIntrinsic()) {
Name = GV->getName(); // Is an intrinsic function
} else if (!GV->hasName()) {
// Must mangle the global into a unique ID.
unsigned TypeUniqueID = getTypeID(GV->getType());
static unsigned GlobalID = 0;
Name = "__unnamed_" + utostr(TypeUniqueID) + "_" + utostr(GlobalID++);
} else if (!MangledGlobals.count(GV)) {
Name = makeNameProper(GV->getName() + Suffix, Prefix);
} else {
unsigned TypeUniqueID = getTypeID(GV->getType());
Name = "l" + utostr(TypeUniqueID) + "_" + makeNameProper(GV->getName());
}
return Name;
}
void Mangler::InsertName(GlobalValue *GV,
std::map<std::string, GlobalValue*> &Names) {
if (!GV->hasName()) // We must mangle unnamed globals.
return;
// Figure out if this is already used.
GlobalValue *&ExistingValue = Names[GV->getName()];
if (!ExistingValue) {
ExistingValue = GV;
} else {
// If GV is external but the existing one is static, mangle the existing one
if ((GV->hasExternalLinkage() || GV->hasDLLImportLinkage()) &&
!(ExistingValue->hasExternalLinkage()
|| ExistingValue->hasDLLImportLinkage())) {
MangledGlobals.insert(ExistingValue);
ExistingValue = GV;
} else if ((GV->hasExternalLinkage() ||
GV->hasDLLImportLinkage()) &&
(ExistingValue->hasExternalLinkage() ||
ExistingValue->hasDLLImportLinkage()) &&
GV->isDeclaration() &&
ExistingValue->isDeclaration()) {
// If the two globals both have external inkage, and are both external,
// don't mangle either of them, we just have some silly type mismatch.
} else {
// Otherwise, mangle GV
MangledGlobals.insert(GV);
}
}
}
Mangler::Mangler(Module &M, const char *prefix)
: Prefix(prefix), UseQuotes(false), PreserveAsmNames(false),
Count(0), TypeCounter(0) {
std::fill(AcceptableChars, array_endof(AcceptableChars), 0);
// Letters and numbers are acceptable.
for (unsigned char X = 'a'; X <= 'z'; ++X)
markCharAcceptable(X);
for (unsigned char X = 'A'; X <= 'Z'; ++X)
markCharAcceptable(X);
for (unsigned char X = '0'; X <= '9'; ++X)
markCharAcceptable(X);
// These chars are acceptable.
markCharAcceptable('_');
markCharAcceptable('$');
markCharAcceptable('.');
// Calculate which global values have names that will collide when we throw
// away type information.
std::map<std::string, GlobalValue*> Names;
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
InsertName(I, Names);
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E;
++I)
InsertName(I, Names);
}