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Keep track of memory allocated by alloca so that it is freed appropriately

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1776 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-02-19 18:50:09 +00:00
parent ae50560920
commit 9bffa73530
2 changed files with 37 additions and 5 deletions
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11
lib/ExecutionEngine/Interpreter/Execution.cpp
View File

@ -741,15 +741,16 @@ void Interpreter::executeAllocInst(AllocationInst *I, ExecutionContext &SF) {
}
// Allocate enough memory to hold the type...
GenericValue Result;
// FIXME: Don't use CALLOC, use a tainted malloc.
Result.PointerVal = (PointerTy)calloc(NumElements, TD.getTypeSize(Ty));
void *Memory = calloc(NumElements, TD.getTypeSize(Ty));
GenericValue Result;
Result.PointerVal = (PointerTy)Memory;
assert(Result.PointerVal != 0 && "Null pointer returned by malloc!");
SetValue(I, Result, SF);
if (I->getOpcode() == Instruction::Alloca) {
// TODO: FIXME: alloca should keep track of memory to free it later...
}
if (I->getOpcode() == Instruction::Alloca)
ECStack.back().Allocas.add(Memory);
}
static void executeFreeInst(FreeInst *I, ExecutionContext &SF) {

31
lib/ExecutionEngine/Interpreter/Interpreter.h
View File

@ -42,6 +42,36 @@ union GenericValue {
PointerTy PointerVal;
};
// AllocaHolder - Object to track all of the blocks of memory allocated by
// alloca. When the function returns, this object is poped off the execution
// stack, which causes the dtor to be run, which frees all the alloca'd memory.
//
class AllocaHolder {
friend class AllocaHolderHandle;
std::vector<void*> Allocations;
unsigned RefCnt;
public:
AllocaHolder() : RefCnt(0) {}
void add(void *mem) { Allocations.push_back(mem); }
~AllocaHolder() {
for (unsigned i = 0; i < Allocations.size(); ++i)
free(Allocations[i]);
}
};
// AllocaHolderHandle gives AllocaHolder value semantics so we can stick it into
// a vector...
//
class AllocaHolderHandle {
AllocaHolder *H;
public:
AllocaHolderHandle() : H(new AllocaHolder()) { H->RefCnt++; }
AllocaHolderHandle(const AllocaHolderHandle &AH) : H(AH.H) { H->RefCnt++; }
~AllocaHolderHandle() { if (--H->RefCnt == 0) delete H; }
void add(void *mem) { H->add(mem); }
};
typedef std::vector<GenericValue> ValuePlaneTy;
// ExecutionContext struct - This struct represents one stack frame currently
@ -57,6 +87,7 @@ struct ExecutionContext {
BasicBlock *PrevBB; // The previous BB or null if in first BB
CallInst *Caller; // Holds the call that called subframes.
// NULL if main func or debugger invoked fn
AllocaHolderHandle Allocas; // Track memory allocated by alloca
};
// Interpreter - This class represents the entirety of the interpreter.