llvm-6502/lib/Support/StreamableMemoryObject.cpp
Benjamin Kramer 49a6a8d8f2 Remove the Copied parameter from MemoryObject::readBytes.
There was exactly one caller using this API right, the others were relying on
specific behavior of the default implementation. Since it's too hard to use it
right just remove it and standardize on the default behavior.

Defines away PR16132.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182636 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 10:54:58 +00:00

142 lines
4.5 KiB
C++

//===- StreamableMemoryObject.cpp - Streamable data interface -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/StreamableMemoryObject.h"
#include "llvm/Support/Compiler.h"
#include <cassert>
#include <cstring>
using namespace llvm;
namespace {
class RawMemoryObject : public StreamableMemoryObject {
public:
RawMemoryObject(const unsigned char *Start, const unsigned char *End) :
FirstChar(Start), LastChar(End) {
assert(LastChar >= FirstChar && "Invalid start/end range");
}
virtual uint64_t getBase() const LLVM_OVERRIDE { return 0; }
virtual uint64_t getExtent() const LLVM_OVERRIDE {
return LastChar - FirstChar;
}
virtual int readByte(uint64_t address, uint8_t* ptr) const LLVM_OVERRIDE;
virtual int readBytes(uint64_t address,
uint64_t size,
uint8_t *buf) const LLVM_OVERRIDE;
virtual const uint8_t *getPointer(uint64_t address,
uint64_t size) const LLVM_OVERRIDE;
virtual bool isValidAddress(uint64_t address) const LLVM_OVERRIDE {
return validAddress(address);
}
virtual bool isObjectEnd(uint64_t address) const LLVM_OVERRIDE {
return objectEnd(address);
}
private:
const uint8_t* const FirstChar;
const uint8_t* const LastChar;
// These are implemented as inline functions here to avoid multiple virtual
// calls per public function
bool validAddress(uint64_t address) const {
return static_cast<ptrdiff_t>(address) < LastChar - FirstChar;
}
bool objectEnd(uint64_t address) const {
return static_cast<ptrdiff_t>(address) == LastChar - FirstChar;
}
RawMemoryObject(const RawMemoryObject&) LLVM_DELETED_FUNCTION;
void operator=(const RawMemoryObject&) LLVM_DELETED_FUNCTION;
};
int RawMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
if (!validAddress(address)) return -1;
*ptr = *((uint8_t *)(uintptr_t)(address + FirstChar));
return 0;
}
int RawMemoryObject::readBytes(uint64_t address,
uint64_t size,
uint8_t *buf) const {
if (!validAddress(address) || !validAddress(address + size - 1)) return -1;
memcpy(buf, (uint8_t *)(uintptr_t)(address + FirstChar), size);
return size;
}
const uint8_t *RawMemoryObject::getPointer(uint64_t address,
uint64_t size) const {
return FirstChar + address;
}
} // anonymous namespace
namespace llvm {
// If the bitcode has a header, then its size is known, and we don't have to
// block until we actually want to read it.
bool StreamingMemoryObject::isValidAddress(uint64_t address) const {
if (ObjectSize && address < ObjectSize) return true;
return fetchToPos(address);
}
bool StreamingMemoryObject::isObjectEnd(uint64_t address) const {
if (ObjectSize) return address == ObjectSize;
fetchToPos(address);
return address == ObjectSize && address != 0;
}
uint64_t StreamingMemoryObject::getExtent() const {
if (ObjectSize) return ObjectSize;
size_t pos = BytesRead + kChunkSize;
// keep fetching until we run out of bytes
while (fetchToPos(pos)) pos += kChunkSize;
return ObjectSize;
}
int StreamingMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
if (!fetchToPos(address)) return -1;
*ptr = Bytes[address + BytesSkipped];
return 0;
}
int StreamingMemoryObject::readBytes(uint64_t address,
uint64_t size,
uint8_t *buf) const {
if (!fetchToPos(address + size - 1)) return -1;
memcpy(buf, &Bytes[address + BytesSkipped], size);
return 0;
}
bool StreamingMemoryObject::dropLeadingBytes(size_t s) {
if (BytesRead < s) return true;
BytesSkipped = s;
BytesRead -= s;
return false;
}
void StreamingMemoryObject::setKnownObjectSize(size_t size) {
ObjectSize = size;
Bytes.reserve(size);
}
StreamableMemoryObject *getNonStreamedMemoryObject(
const unsigned char *Start, const unsigned char *End) {
return new RawMemoryObject(Start, End);
}
StreamableMemoryObject::~StreamableMemoryObject() { }
StreamingMemoryObject::StreamingMemoryObject(DataStreamer *streamer) :
Bytes(kChunkSize), Streamer(streamer), BytesRead(0), BytesSkipped(0),
ObjectSize(0), EOFReached(false) {
BytesRead = streamer->GetBytes(&Bytes[0], kChunkSize);
}
}