Support programs that do not #include <malloc.h> or give a full prototype

for malloc and free.  Lots of crufty benchmarks are using stuff like:
char *malloc();
void free();

to forward declare malloc and free.  Now we recognize and raise these forms


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2740 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-05-24 20:29:18 +00:00
parent 7e9ee756a3
commit 47e0f3a8a0

View File

@ -71,6 +71,22 @@ bool RaiseAllocations::doInitialization(Module *M) {
MallocFunc = M->getFunction("malloc", MallocType);
FreeFunc = M->getFunction("free" , FreeType);
// Check to see if the prototype is missing, giving us sbyte*(...) * malloc
// This handles the common declaration of: 'char *malloc();'
if (MallocFunc == 0) {
MallocType = FunctionType::get(PointerType::get(Type::SByteTy),
std::vector<const Type*>(), true);
MallocFunc = M->getFunction("malloc", MallocType);
}
// Check to see if the prototype was forgotten, giving us void (...) * free
// This handles the common forward declaration of: 'void free();'
if (FreeFunc == 0) {
FreeType = FunctionType::get(Type::VoidTy, std::vector<const Type*>(),true);
FreeFunc = M->getFunction("free", FreeType);
}
// Don't mess with locally defined versions of these functions...
if (MallocFunc && !MallocFunc->isExternal()) MallocFunc = 0;
if (FreeFunc && !FreeFunc->isExternal()) FreeFunc = 0;
@ -89,15 +105,38 @@ bool RaiseAllocations::runOnBasicBlock(BasicBlock *BB) {
if (CallInst *CI = dyn_cast<CallInst>(I)) {
if (CI->getCalledValue() == MallocFunc) { // Replace call to malloc?
const Type *PtrSByte = PointerType::get(Type::SByteTy);
MallocInst *MallocI = new MallocInst(PtrSByte, CI->getOperand(1),
CI->getName());
Value *Source = CI->getOperand(1);
// If no prototype was provided for malloc, we may need to cast the
// source size.
if (Source->getType() != Type::UIntTy) {
CastInst *New = new CastInst(Source, Type::UIntTy, "MallocAmtCast");
BI = BIL.insert(BI, New)+1;
Source = New;
}
MallocInst *MallocI = new MallocInst(PtrSByte, Source, CI->getName());
CI->setName("");
ReplaceInstWithInst(BIL, BI, MallocI);
Changed = true;
++NumRaised;
continue; // Skip the ++BI
} else if (CI->getCalledValue() == FreeFunc) { // Replace call to free?
ReplaceInstWithInst(BIL, BI, new FreeInst(CI->getOperand(1)));
// If no prototype was provided for free, we may need to cast the
// source pointer. This should be really uncommon, but it's neccesary
// just in case we are dealing with wierd code like this:
// free((long)ptr);
//
Value *Source = CI->getOperand(1);
if (!isa<PointerType>(Source->getType())) {
CastInst *New = new CastInst(Source, PointerType::get(Type::SByteTy),
"FreePtrCast");
BI = BIL.insert(BI, New)+1;
Source = New;
}
ReplaceInstWithInst(BIL, BI, new FreeInst(Source));
Changed = true;
continue; // Skip the ++BI
++NumRaised;