6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-15 21:24:00 +00:00
Code Issues Projects Releases Wiki Activity

Object/Mach-O: Add header and load command information.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120198 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Dunbar
2010-11-27 07:19:41 +00:00
parent bce55776af
commit a956d8b717
4 changed files with 228 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

83
lib/Object/MachOObject.cpp
View File

@ -10,13 +10,49 @@
#include "llvm/Object/MachOObject.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/System/Host.h"
#include "llvm/System/SwapByteOrder.h"
using namespace llvm;
using namespace object;
using namespace llvm::object;
template<typename T>
static void SwapValue(T &Value) {
Value = sys::SwapByteOrder(Value);
}
MachOObject::MachOObject(MemoryBuffer *Buffer_, bool IsLittleEndian_,
bool Is64Bit_)
: Buffer(Buffer_), IsLittleEndian(IsLittleEndian_), Is64Bit(Is64Bit_) {
: Buffer(Buffer_), IsLittleEndian(IsLittleEndian_), Is64Bit(Is64Bit_),
IsSwappedEndian(IsLittleEndian != sys::isLittleEndianHost()),
LoadCommands(0), NumLoadedCommands(0) {
// Load the common header.
memcpy(&Header, Buffer->getBuffer().data(), sizeof(Header));
if (IsSwappedEndian) {
SwapValue(Header.Magic);
SwapValue(Header.CPUType);
SwapValue(Header.CPUSubtype);
SwapValue(Header.FileType);
SwapValue(Header.NumLoadCommands);
SwapValue(Header.SizeOfLoadCommands);
SwapValue(Header.Flags);
}
if (is64Bit()) {
memcpy(&Header64Ext, Buffer->getBuffer().data() + sizeof(Header),
sizeof(Header64Ext));
if (IsSwappedEndian) {
SwapValue(Header64Ext.Reserved);
}
}
// Create the load command array if sane.
if (getHeader().NumLoadCommands < (1 << 20))
LoadCommands = new LoadCommandInfo[getHeader().NumLoadCommands];
}
MachOObject::~MachOObject() {
delete LoadCommands;
}
MachOObject *MachOObject::LoadFromBuffer(MemoryBuffer *Buffer,
@ -33,13 +69,54 @@ MachOObject *MachOObject::LoadFromBuffer(MemoryBuffer *Buffer,
IsLittleEndian = true;
Is64Bit = true;
} else {
*ErrorStr = "not a Mach object file";
if (ErrorStr) *ErrorStr = "not a Mach object file (invalid magic)";
return 0;
}
// Ensure that the at least the full header is present.
unsigned HeaderSize = Is64Bit ? macho::Header64Size : macho::Header32Size;
if (Buffer->getBufferSize() < HeaderSize) {
if (ErrorStr) *ErrorStr = "not a Mach object file (invalid header)";
return 0;
}
OwningPtr<MachOObject> Object(new MachOObject(Buffer, IsLittleEndian,
Is64Bit));
// Check for bogus number of load commands.
if (Object->getHeader().NumLoadCommands >= (1 << 20)) {
if (ErrorStr) *ErrorStr = "not a Mach object file (unreasonable header)";
return 0;
}
if (ErrorStr) *ErrorStr = "";
return Object.take();
}
const MachOObject::LoadCommandInfo &
MachOObject::getLoadCommandInfo(unsigned Index) const {
assert(Index < getHeader().NumLoadCommands && "Invalid index!");
// Load the command, if necessary.
if (Index >= NumLoadedCommands) {
uint64_t Offset;
if (Index == 0) {
Offset = getHeaderSize();
} else {
const LoadCommandInfo &Prev = getLoadCommandInfo(Index - 1);
Offset = Prev.Offset + Prev.Command.Size;
}
LoadCommandInfo &Info = LoadCommands[Index];
memcpy(&Info.Command, Buffer->getBuffer().data() + Offset,
sizeof(macho::LoadCommand));
if (IsSwappedEndian) {
SwapValue(Info.Command.Type);
SwapValue(Info.Command.Size);
}
Info.Offset = Offset;
NumLoadedCommands = Index + 1;
}
return LoadCommands[Index];
}