llvm-project/llvm/tools/llvm-objdump/llvm-objdump.cpp

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//===-- llvm-objdump.cpp - Object file dumping utility for llvm -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This program is a utility that works like binutils "objdump", that is, it
// dumps out a plethora of information about an object file depending on the
// flags.
//
//===----------------------------------------------------------------------===//
#include "MCFunction.h"
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#include "llvm/Object/ObjectFile.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/STLExtras.h"
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#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCInstrAnalysis.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
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#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/GraphWriter.h"
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#include "llvm/Support/Host.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
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#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/system_error.h"
#include <algorithm>
#include <cstring>
using namespace llvm;
using namespace object;
namespace {
cl::list<std::string>
InputFilenames(cl::Positional, cl::desc("<input object files>"),
cl::ZeroOrMore);
cl::opt<bool>
Disassemble("disassemble",
cl::desc("Display assembler mnemonics for the machine instructions"));
cl::alias
Disassembled("d", cl::desc("Alias for --disassemble"),
cl::aliasopt(Disassemble));
cl::opt<bool>
CFG("cfg", cl::desc("Create a CFG for every symbol in the object file and"
"write it to a graphviz file"));
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cl::opt<std::string>
TripleName("triple", cl::desc("Target triple to disassemble for, "
"see -version for available targets"));
cl::opt<std::string>
ArchName("arch", cl::desc("Target arch to disassemble for, "
"see -version for available targets"));
StringRef ToolName;
bool error(error_code ec) {
if (!ec) return false;
outs() << ToolName << ": error reading file: " << ec.message() << ".\n";
outs().flush();
return true;
}
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}
static const Target *GetTarget(const ObjectFile *Obj = NULL) {
// Figure out the target triple.
llvm::Triple TT("unknown-unknown-unknown");
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if (TripleName.empty()) {
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if (Obj)
TT.setArch(Triple::ArchType(Obj->getArch()));
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} else
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TT.setTriple(Triple::normalize(TripleName));
if (!ArchName.empty())
TT.setArchName(ArchName);
TripleName = TT.str();
// Get the target specific parser.
std::string Error;
const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
if (TheTarget)
return TheTarget;
errs() << ToolName << ": error: unable to get target for '" << TripleName
<< "', see --version and --triple.\n";
return 0;
}
namespace {
class StringRefMemoryObject : public MemoryObject {
private:
StringRef Bytes;
public:
StringRefMemoryObject(StringRef 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 {
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if (Addr >= getExtent())
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return -1;
*Byte = Bytes[Addr];
return 0;
}
};
}
static void DumpBytes(StringRef bytes) {
static char hex_rep[] = "0123456789abcdef";
// FIXME: The real way to do this is to figure out the longest instruction
// and align to that size before printing. I'll fix this when I get
// around to outputting relocations.
// 15 is the longest x86 instruction
// 3 is for the hex rep of a byte + a space.
// 1 is for the null terminator.
enum { OutputSize = (15 * 3) + 1 };
char output[OutputSize];
assert(bytes.size() <= 15
&& "DumpBytes only supports instructions of up to 15 bytes");
memset(output, ' ', sizeof(output));
unsigned index = 0;
for (StringRef::iterator i = bytes.begin(),
e = bytes.end(); i != e; ++i) {
output[index] = hex_rep[(*i & 0xF0) >> 4];
output[index + 1] = hex_rep[*i & 0xF];
index += 3;
}
output[sizeof(output) - 1] = 0;
outs() << output;
}
static void DisassembleInput(const StringRef &Filename) {
OwningPtr<MemoryBuffer> Buff;
if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
errs() << ToolName << ": " << Filename << ": " << ec.message() << "\n";
return;
}
OwningPtr<ObjectFile> Obj(ObjectFile::createObjectFile(Buff.take()));
const Target *TheTarget = GetTarget(Obj.get());
if (!TheTarget) {
// GetTarget prints out stuff.
return;
}
const MCInstrInfo *InstrInfo = TheTarget->createMCInstrInfo();
OwningPtr<MCInstrAnalysis>
InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo));
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outs() << '\n';
outs() << Filename
<< ":\tfile format " << Obj->getFileFormatName() << "\n\n";
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error_code ec;
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for (ObjectFile::section_iterator i = Obj->begin_sections(),
e = Obj->end_sections();
i != e; i.increment(ec)) {
if (error(ec)) break;
bool text;
if (error(i->isText(text))) break;
if (!text) continue;
// Make a list of all the symbols in this section.
std::vector<std::pair<uint64_t, StringRef> > Symbols;
for (ObjectFile::symbol_iterator si = Obj->begin_symbols(),
se = Obj->end_symbols();
si != se; si.increment(ec)) {
bool contains;
if (!error(i->containsSymbol(*si, contains)) && contains) {
uint64_t Address;
if (error(si->getAddress(Address))) break;
StringRef Name;
if (error(si->getName(Name))) break;
Symbols.push_back(std::make_pair(Address, Name));
}
}
// Sort the symbols by address, just in case they didn't come in that way.
array_pod_sort(Symbols.begin(), Symbols.end());
StringRef name;
if (error(i->getName(name))) break;
outs() << "Disassembly of section " << name << ':';
// If the section has no symbols just insert a dummy one and disassemble
// the whole section.
if (Symbols.empty())
Symbols.push_back(std::make_pair(0, name));
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// Set up disassembler.
OwningPtr<const MCAsmInfo> AsmInfo(TheTarget->createMCAsmInfo(TripleName));
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if (!AsmInfo) {
errs() << "error: no assembly info for target " << TripleName << "\n";
return;
}
OwningPtr<const MCSubtargetInfo> STI(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
if (!STI) {
errs() << "error: no subtarget info for target " << TripleName << "\n";
return;
}
OwningPtr<const MCDisassembler> DisAsm(TheTarget->createMCDisassembler(*STI));
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if (!DisAsm) {
errs() << "error: no disassembler for target " << TripleName << "\n";
return;
}
int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
OwningPtr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
AsmPrinterVariant, *AsmInfo, *STI));
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if (!IP) {
errs() << "error: no instruction printer for target " << TripleName << '\n';
return;
}
StringRef Bytes;
if (error(i->getContents(Bytes))) break;
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StringRefMemoryObject memoryObject(Bytes);
uint64_t Size;
uint64_t Index;
uint64_t SectSize;
if (error(i->getSize(SectSize))) break;
// Disassemble symbol by symbol.
for (unsigned si = 0, se = Symbols.size(); si != se; ++si) {
uint64_t Start = Symbols[si].first;
uint64_t End = si == se-1 ? SectSize : Symbols[si + 1].first - 1;
outs() << '\n' << Symbols[si].second << ":\n";
#ifndef NDEBUG
raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls();
#else
raw_ostream &DebugOut = nulls();
#endif
if (!CFG) {
for (Index = Start; Index < End; Index += Size) {
MCInst Inst;
if (DisAsm->getInstruction(Inst, Size, memoryObject, Index,
DebugOut)) {
uint64_t addr;
if (error(i->getAddress(addr))) break;
outs() << format("%8x:\t", addr + Index);
DumpBytes(StringRef(Bytes.data() + Index, Size));
IP->printInst(&Inst, outs());
outs() << "\n";
} else {
errs() << ToolName << ": warning: invalid instruction encoding\n";
if (Size == 0)
Size = 1; // skip illegible bytes
}
}
} else {
// Create CFG and use it for disassembly.
MCFunction f =
MCFunction::createFunctionFromMC(Symbols[si].second, DisAsm.get(),
memoryObject, Start, End,
InstrAnalysis.get(), DebugOut);
for (MCFunction::iterator fi = f.begin(), fe = f.end(); fi != fe; ++fi){
bool hasPreds = false;
// Only print blocks that have predecessors.
// FIXME: Slow.
for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
++pi)
if (pi->second.contains(&fi->second)) {
hasPreds = true;
break;
}
// Data block.
if (!hasPreds && fi != f.begin()) {
uint64_t End = llvm::next(fi) == fe ? SectSize :
llvm::next(fi)->first;
uint64_t addr;
if (error(i->getAddress(addr))) break;
outs() << "# " << End-fi->first << " bytes of data:\n";
for (unsigned pos = fi->first; pos != End; ++pos) {
outs() << format("%8x:\t", addr + pos);
DumpBytes(StringRef(Bytes.data() + pos, 1));
outs() << format("\t.byte 0x%02x\n", (uint8_t)Bytes[pos]);
}
continue;
}
if (fi->second.contains(&fi->second))
outs() << "# Loop begin:\n";
for (unsigned ii = 0, ie = fi->second.getInsts().size(); ii != ie;
++ii) {
uint64_t addr;
if (error(i->getAddress(addr))) break;
const MCDecodedInst &Inst = fi->second.getInsts()[ii];
outs() << format("%8x:\t", addr + Inst.Address);
DumpBytes(StringRef(Bytes.data() + Inst.Address, Inst.Size));
// Simple loops.
if (fi->second.contains(&fi->second))
outs() << '\t';
IP->printInst(&Inst.Inst, outs());
outs() << '\n';
}
}
// Start a new dot file.
std::string Error;
raw_fd_ostream Out((f.getName().str() + ".dot").c_str(), Error);
if (!Error.empty()) {
errs() << ToolName << ": warning: " << Error << '\n';
continue;
}
Out << "digraph " << f.getName() << " {\n";
Out << "graph [ rankdir = \"LR\" ];\n";
for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i) {
bool hasPreds = false;
// Only print blocks that have predecessors.
// FIXME: Slow.
for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
++pi)
if (pi->second.contains(&i->second)) {
hasPreds = true;
break;
}
if (!hasPreds && i != f.begin())
continue;
Out << '"' << (uintptr_t)&i->second << "\" [ label=\"<a>";
// Print instructions.
for (unsigned ii = 0, ie = i->second.getInsts().size(); ii != ie;
++ii) {
// Escape special chars and print the instruction in mnemonic form.
std::string Str;
raw_string_ostream OS(Str);
IP->printInst(&i->second.getInsts()[ii].Inst, OS);
Out << DOT::EscapeString(OS.str()) << '|';
}
Out << "<o>\" shape=\"record\" ];\n";
// Add edges.
for (MCBasicBlock::succ_iterator si = i->second.succ_begin(),
se = i->second.succ_end(); si != se; ++si)
Out << (uintptr_t)&i->second << ":o -> " << (uintptr_t)*si <<":a\n";
}
Out << "}\n";
}
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}
}
}
int main(int argc, char **argv) {
// Print a stack trace if we signal out.
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
// Initialize targets and assembly printers/parsers.
llvm::InitializeAllTargetInfos();
llvm::InitializeAllTargetMCs();
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llvm::InitializeAllAsmParsers();
llvm::InitializeAllDisassemblers();
cl::ParseCommandLineOptions(argc, argv, "llvm object file dumper\n");
TripleName = Triple::normalize(TripleName);
ToolName = argv[0];
// Defaults to a.out if no filenames specified.
if (InputFilenames.size() == 0)
InputFilenames.push_back("a.out");
// -d is the only flag that is currently implemented, so just print help if
// it is not set.
if (!Disassemble) {
cl::PrintHelpMessage();
return 2;
}
std::for_each(InputFilenames.begin(), InputFilenames.end(),
DisassembleInput);
return 0;
}