llvm-6502/lib/IR/Mangler.cpp
Nico Rieck 1b1321f080 Fix fastcall mangling of dllimported symbols
fastcall requires @ as global prefix instead of _ but getNameWithPrefix
wrongly assumes the OutName buffer is empty and replaces at index 0.
For imported functions this buffer is pre-filled with "__imp_" resulting
in broken "@_imp_foo@0" mangling.

Instead replace at the proper index. We also never have to prepend the
@-prefix because this fastcall mangling is only used on 32-bit Windows
targets which have _ has global prefix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-14 11:53:26 +00:00

128 lines
4.7 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 assembly backends.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/Mangler.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
/// and the specified name as the global variable name. GVName must not be
/// empty.
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
const Twine &GVName, ManglerPrefixTy PrefixTy) {
SmallString<256> TmpData;
StringRef Name = GVName.toStringRef(TmpData);
assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
// If the global name is not led with \1, add the appropriate prefixes.
if (Name[0] == '\1') {
Name = Name.substr(1);
} else {
if (PrefixTy == Mangler::Private) {
const char *Prefix = DL->getPrivateGlobalPrefix();
OutName.append(Prefix, Prefix+strlen(Prefix));
} else if (PrefixTy == Mangler::LinkerPrivate) {
const char *Prefix = DL->getLinkerPrivateGlobalPrefix();
OutName.append(Prefix, Prefix+strlen(Prefix));
}
char Prefix = DL->getGlobalPrefix();
if (Prefix != '\0')
OutName.push_back(Prefix);
}
// If this is a simple string that doesn't need escaping, just append it.
OutName.append(Name.begin(), Name.end());
}
/// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require
/// a suffix on their name indicating the number of words of arguments they
/// take.
static void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName,
const Function *F, const DataLayout &TD) {
// Calculate arguments size total.
unsigned ArgWords = 0;
for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
AI != AE; ++AI) {
Type *Ty = AI->getType();
// 'Dereference' type in case of byval parameter attribute
if (AI->hasByValAttr())
Ty = cast<PointerType>(Ty)->getElementType();
// Size should be aligned to DWORD boundary
ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4;
}
raw_svector_ostream(OutName) << '@' << ArgWords;
}
/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
/// and the specified global variable's name. If the global variable doesn't
/// have a name, this fills in a unique name for the global.
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
const GlobalValue *GV) {
ManglerPrefixTy PrefixTy = Mangler::Default;
if (GV->hasPrivateLinkage())
PrefixTy = Mangler::Private;
else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
PrefixTy = Mangler::LinkerPrivate;
size_t NameBegin = OutName.size();
// If this global has a name, handle it simply.
if (GV->hasName()) {
StringRef Name = GV->getName();
getNameWithPrefix(OutName, Name, PrefixTy);
// No need to do anything else if the global has the special "do not mangle"
// flag in the name.
if (Name[0] == 1)
return;
} else {
// Get the ID for the global, assigning a new one if we haven't got one
// already.
unsigned &ID = AnonGlobalIDs[GV];
if (ID == 0) ID = NextAnonGlobalID++;
// Must mangle the global into a unique ID.
getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
}
// If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
// add it.
if (DL->hasMicrosoftFastStdCallMangling()) {
if (const Function *F = dyn_cast<Function>(GV)) {
CallingConv::ID CC = F->getCallingConv();
// fastcall functions need to start with @ instead of _.
if (CC == CallingConv::X86_FastCall) {
assert(OutName[NameBegin] == '_' && DL->getGlobalPrefix() == '_');
OutName[NameBegin] = '@';
}
// fastcall and stdcall functions usually need @42 at the end to specify
// the argument info.
FunctionType *FT = F->getFunctionType();
if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
// "Pure" variadic functions do not receive @0 suffix.
(!FT->isVarArg() || FT->getNumParams() == 0 ||
(FT->getNumParams() == 1 && F->hasStructRetAttr())))
AddFastCallStdCallSuffix(OutName, F, *DL);
}
}
}