llvm-6502/lib/IR/Mangler.cpp
Reid Kleckner 7963762fce Revert "Move dllimport name mangling to IR mangler."
This reverts commit r239437.

This broke clang-cl self-hosts. We'd end up calling the __imp_ symbol
directly instead of using it to do an indirect function call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239502 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 01:31:48 +00:00

159 lines
5.4 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;
static void getNameWithPrefixx(raw_ostream &OS, const Twine &GVName,
Mangler::ManglerPrefixTy PrefixTy,
const DataLayout &DL, char Prefix) {
SmallString<256> TmpData;
StringRef Name = GVName.toStringRef(TmpData);
assert(!Name.empty() && "getNameWithPrefix requires non-empty name");
// No need to do anything special if the global has the special "do not
// mangle" flag in the name.
if (Name[0] == '\1') {
OS << Name.substr(1);
return;
}
if (PrefixTy == Mangler::Private)
OS << DL.getPrivateGlobalPrefix();
else if (PrefixTy == Mangler::LinkerPrivate)
OS << DL.getLinkerPrivateGlobalPrefix();
if (Prefix != '\0')
OS << Prefix;
// If this is a simple string that doesn't need escaping, just append it.
OS << Name;
}
void Mangler::getNameWithPrefix(raw_ostream &OS, const Twine &GVName,
ManglerPrefixTy PrefixTy) const {
char Prefix = DL->getGlobalPrefix();
return getNameWithPrefixx(OS, GVName, PrefixTy, *DL, Prefix);
}
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
const Twine &GVName,
ManglerPrefixTy PrefixTy) const {
raw_svector_ostream OS(OutName);
return getNameWithPrefix(OS, GVName, PrefixTy);
}
static bool hasByteCountSuffix(CallingConv::ID CC) {
switch (CC) {
case CallingConv::X86_FastCall:
case CallingConv::X86_StdCall:
case CallingConv::X86_VectorCall:
return true;
default:
return false;
}
}
/// Microsoft fastcall and stdcall functions require a suffix on their name
/// indicating the number of words of arguments they take.
static void addByteCountSuffix(raw_ostream &OS, const Function *F,
const DataLayout &DL) {
// 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 or inalloca parameter attribute.
if (AI->hasByValOrInAllocaAttr())
Ty = cast<PointerType>(Ty)->getElementType();
// Size should be aligned to pointer size.
unsigned PtrSize = DL.getPointerSize();
ArgWords += RoundUpToAlignment(DL.getTypeAllocSize(Ty), PtrSize);
}
OS << '@' << ArgWords;
}
void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV,
bool CannotUsePrivateLabel) const {
ManglerPrefixTy PrefixTy = Mangler::Default;
if (GV->hasPrivateLinkage()) {
if (CannotUsePrivateLabel)
PrefixTy = Mangler::LinkerPrivate;
else
PrefixTy = Mangler::Private;
}
if (!GV->hasName()) {
// 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(OS, "__unnamed_" + Twine(ID), PrefixTy);
return;
}
StringRef Name = GV->getName();
char Prefix = DL->getGlobalPrefix();
// Mangle functions with Microsoft calling conventions specially. Only do
// this mangling for x86_64 vectorcall and 32-bit x86.
const Function *MSFunc = dyn_cast<Function>(GV);
if (Name.startswith("\01"))
MSFunc = nullptr; // Don't mangle when \01 is present.
CallingConv::ID CC =
MSFunc ? MSFunc->getCallingConv() : (unsigned)CallingConv::C;
if (!DL->hasMicrosoftFastStdCallMangling() &&
CC != CallingConv::X86_VectorCall)
MSFunc = nullptr;
if (MSFunc) {
if (CC == CallingConv::X86_FastCall)
Prefix = '@'; // fastcall functions have an @ prefix instead of _.
else if (CC == CallingConv::X86_VectorCall)
Prefix = '\0'; // vectorcall functions have no prefix.
}
getNameWithPrefixx(OS, Name, PrefixTy, *DL, Prefix);
if (!MSFunc)
return;
// If we are supposed to add a microsoft-style suffix for stdcall, fastcall,
// or vectorcall, add it. These functions have a suffix of @N where N is the
// cumulative byte size of all of the parameters to the function in decimal.
if (CC == CallingConv::X86_VectorCall)
OS << '@'; // vectorcall functions use a double @ suffix.
FunctionType *FT = MSFunc->getFunctionType();
if (hasByteCountSuffix(CC) &&
// "Pure" variadic functions do not receive @0 suffix.
(!FT->isVarArg() || FT->getNumParams() == 0 ||
(FT->getNumParams() == 1 && MSFunc->hasStructRetAttr())))
addByteCountSuffix(OS, MSFunc, *DL);
}
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
const GlobalValue *GV,
bool CannotUsePrivateLabel) const {
raw_svector_ostream OS(OutName);
getNameWithPrefix(OS, GV, CannotUsePrivateLabel);
}