llvm-project/clang/lib/AST/ByteCode/InterpStack.cpp
Timm Baeder 048bc67276
[clang][bytecode] Start implementing fixed point types (#110216)
Add the primitive type and implement to-bool casts.
2024-09-27 11:32:43 +02:00

137 lines
3.2 KiB
C++

//===--- InterpStack.cpp - Stack implementation for the VM ------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "InterpStack.h"
#include "Boolean.h"
#include "FixedPoint.h"
#include "Floating.h"
#include "Integral.h"
#include "MemberPointer.h"
#include "Pointer.h"
#include <cassert>
#include <cstdlib>
using namespace clang;
using namespace clang::interp;
InterpStack::~InterpStack() { clear(); }
void InterpStack::clear() {
if (Chunk && Chunk->Next)
std::free(Chunk->Next);
if (Chunk)
std::free(Chunk);
Chunk = nullptr;
StackSize = 0;
#ifndef NDEBUG
ItemTypes.clear();
#endif
}
void InterpStack::clearTo(size_t NewSize) {
assert(NewSize <= size());
size_t ToShrink = size() - NewSize;
if (ToShrink == 0)
return;
shrink(ToShrink);
assert(size() == NewSize);
}
void *InterpStack::grow(size_t Size) {
assert(Size < ChunkSize - sizeof(StackChunk) && "Object too large");
if (!Chunk || sizeof(StackChunk) + Chunk->size() + Size > ChunkSize) {
if (Chunk && Chunk->Next) {
Chunk = Chunk->Next;
} else {
StackChunk *Next = new (std::malloc(ChunkSize)) StackChunk(Chunk);
if (Chunk)
Chunk->Next = Next;
Chunk = Next;
}
}
auto *Object = reinterpret_cast<void *>(Chunk->End);
Chunk->End += Size;
StackSize += Size;
return Object;
}
void *InterpStack::peekData(size_t Size) const {
assert(Chunk && "Stack is empty!");
StackChunk *Ptr = Chunk;
while (Size > Ptr->size()) {
Size -= Ptr->size();
Ptr = Ptr->Prev;
assert(Ptr && "Offset too large");
}
return reinterpret_cast<void *>(Ptr->End - Size);
}
void InterpStack::shrink(size_t Size) {
assert(Chunk && "Chunk is empty!");
while (Size > Chunk->size()) {
Size -= Chunk->size();
if (Chunk->Next) {
std::free(Chunk->Next);
Chunk->Next = nullptr;
}
Chunk->End = Chunk->start();
Chunk = Chunk->Prev;
assert(Chunk && "Offset too large");
}
Chunk->End -= Size;
StackSize -= Size;
#ifndef NDEBUG
size_t TypesSize = 0;
for (PrimType T : ItemTypes)
TYPE_SWITCH(T, { TypesSize += aligned_size<T>(); });
size_t StackSize = size();
while (TypesSize > StackSize) {
TYPE_SWITCH(ItemTypes.back(), {
TypesSize -= aligned_size<T>();
ItemTypes.pop_back();
});
}
assert(TypesSize == StackSize);
#endif
}
void InterpStack::dump() const {
#ifndef NDEBUG
llvm::errs() << "Items: " << ItemTypes.size() << ". Size: " << size() << '\n';
if (ItemTypes.empty())
return;
size_t Index = 0;
size_t Offset = 0;
// The type of the item on the top of the stack is inserted to the back
// of the vector, so the iteration has to happen backwards.
for (auto TyIt = ItemTypes.rbegin(); TyIt != ItemTypes.rend(); ++TyIt) {
Offset += align(primSize(*TyIt));
llvm::errs() << Index << '/' << Offset << ": ";
TYPE_SWITCH(*TyIt, {
const T &V = peek<T>(Offset);
llvm::errs() << V;
});
llvm::errs() << '\n';
++Index;
}
#endif
}