llvm-6502/tools/llvm-mc/Disassembler.cpp
Tim Northover 38c6ff6c11 Improve llvm-mc disassembler mode and refactor ARM tests to use it
This allows "llvm-mc -disassemble" to accept two new features:
  + Using comma as a byte separator
  + Grouping bytes with '[' and ']' pairs.

The behaviour outside a [...] group is unchanged. But within the group once
llvm-mc encounters a true error, it stops rather than trying to resynchronise
the stream at the next byte. This is more useful for disassembly tests, where
we have an almost-instruction in mind and don't care what the misaligned
interpretation would be. Particularly if it means llvm-mc won't actually see
the next intended almost-instruction.

As a side effect, this means llvm-mc can disassemble its own -show-encoding
output if copy-pasted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186661 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 10:05:04 +00:00

216 lines
6.4 KiB
C++

//===- Disassembler.cpp - Disassembler for hex strings --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements the disassembler of strings of bytes written in
// hexadecimal, from standard input or from a file.
//
//===----------------------------------------------------------------------===//
#include "Disassembler.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/Triple.h"
#include "llvm/MC/MCDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
typedef std::vector<std::pair<unsigned char, const char*> > ByteArrayTy;
namespace {
class VectorMemoryObject : public MemoryObject {
private:
const ByteArrayTy &Bytes;
public:
VectorMemoryObject(const ByteArrayTy &bytes) : Bytes(bytes) {}
uint64_t getBase() const { return 0; }
uint64_t getExtent() const { return Bytes.size(); }
int readByte(uint64_t Addr, uint8_t *Byte) const {
if (Addr >= getExtent())
return -1;
*Byte = Bytes[Addr].first;
return 0;
}
};
}
static bool PrintInsts(const MCDisassembler &DisAsm,
const ByteArrayTy &Bytes,
SourceMgr &SM, raw_ostream &Out,
MCStreamer &Streamer, bool InAtomicBlock) {
// Wrap the vector in a MemoryObject.
VectorMemoryObject memoryObject(Bytes);
// Disassemble it to strings.
uint64_t Size;
uint64_t Index;
for (Index = 0; Index < Bytes.size(); Index += Size) {
MCInst Inst;
MCDisassembler::DecodeStatus S;
S = DisAsm.getInstruction(Inst, Size, memoryObject, Index,
/*REMOVE*/ nulls(), nulls());
switch (S) {
case MCDisassembler::Fail:
SM.PrintMessage(SMLoc::getFromPointer(Bytes[Index].second),
SourceMgr::DK_Warning,
"invalid instruction encoding");
// Don't try to resynchronise the stream in a block
if (InAtomicBlock)
return true;
if (Size == 0)
Size = 1; // skip illegible bytes
break;
case MCDisassembler::SoftFail:
SM.PrintMessage(SMLoc::getFromPointer(Bytes[Index].second),
SourceMgr::DK_Warning,
"potentially undefined instruction encoding");
// Fall through
case MCDisassembler::Success:
Streamer.EmitInstruction(Inst);
break;
}
}
return false;
}
static bool SkipToToken(StringRef &Str) {
while (!Str.empty() && Str.find_first_not_of(" \t\r\n#,") != 0) {
// Strip horizontal whitespace and commas.
if (size_t Pos = Str.find_first_not_of(" \t\r,")) {
Str = Str.substr(Pos);
}
// If this is the end of a line or start of a comment, remove the rest of
// the line.
if (Str[0] == '\n' || Str[0] == '#') {
// Strip to the end of line if we already processed any bytes on this
// line. This strips the comment and/or the \n.
if (Str[0] == '\n') {
Str = Str.substr(1);
} else {
Str = Str.substr(Str.find_first_of('\n'));
if (!Str.empty())
Str = Str.substr(1);
}
continue;
}
}
return !Str.empty();
}
static bool ByteArrayFromString(ByteArrayTy &ByteArray,
StringRef &Str,
SourceMgr &SM) {
while (SkipToToken(Str)) {
// Handled by higher level
if (Str[0] == '[' || Str[0] == ']')
return false;
// Get the current token.
size_t Next = Str.find_first_of(" \t\n\r,#[]");
StringRef Value = Str.substr(0, Next);
// Convert to a byte and add to the byte vector.
unsigned ByteVal;
if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) {
// If we have an error, print it and skip to the end of line.
SM.PrintMessage(SMLoc::getFromPointer(Value.data()), SourceMgr::DK_Error,
"invalid input token");
Str = Str.substr(Str.find('\n'));
ByteArray.clear();
continue;
}
ByteArray.push_back(std::make_pair((unsigned char)ByteVal, Value.data()));
Str = Str.substr(Next);
}
return false;
}
int Disassembler::disassemble(const Target &T,
const std::string &Triple,
MCSubtargetInfo &STI,
MCStreamer &Streamer,
MemoryBuffer &Buffer,
SourceMgr &SM,
raw_ostream &Out) {
OwningPtr<const MCDisassembler> DisAsm(T.createMCDisassembler(STI));
if (!DisAsm) {
errs() << "error: no disassembler for target " << Triple << "\n";
return -1;
}
// Set up initial section manually here
Streamer.InitSections();
bool ErrorOccurred = false;
// Convert the input to a vector for disassembly.
ByteArrayTy ByteArray;
StringRef Str = Buffer.getBuffer();
bool InAtomicBlock = false;
while (SkipToToken(Str)) {
ByteArray.clear();
if (Str[0] == '[') {
if (InAtomicBlock) {
SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error,
"nested atomic blocks make no sense");
ErrorOccurred = true;
}
InAtomicBlock = true;
Str = Str.drop_front();
continue;
} else if (Str[0] == ']') {
if (!InAtomicBlock) {
SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error,
"attempt to close atomic block without opening");
ErrorOccurred = true;
}
InAtomicBlock = false;
Str = Str.drop_front();
continue;
}
// It's a real token, get the bytes and emit them
ErrorOccurred |= ByteArrayFromString(ByteArray, Str, SM);
if (!ByteArray.empty())
ErrorOccurred |= PrintInsts(*DisAsm, ByteArray, SM, Out, Streamer,
InAtomicBlock);
}
if (InAtomicBlock) {
SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error,
"unclosed atomic block");
ErrorOccurred = true;
}
return ErrorOccurred;
}