llvm-elfabi.cpp
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//===- llvm-elfabi.cpp ----------------------------------------------------===//
//
// 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 "ErrorCollector.h"
#include "llvm/InterfaceStub/ELFObjHandler.h"
#include "llvm/InterfaceStub/TBEHandler.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/FileOutputBuffer.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
#include <string>
namespace llvm {
namespace elfabi {
enum class FileFormat {
TBE,
ELF
};
} // end namespace elfabi
} // end namespace llvm
using namespace llvm;
using namespace llvm::elfabi;
// Command line flags:
cl::opt<FileFormat> InputFileFormat(
cl::desc("Force input file format:"),
cl::values(clEnumValN(FileFormat::TBE,
"tbe", "Read `input` as text-based ELF stub"),
clEnumValN(FileFormat::ELF,
"elf", "Read `input` as ELF binary")));
cl::opt<std::string> InputFilePath(cl::Positional, cl::desc("input"),
cl::Required);
cl::opt<std::string>
EmitTBE("emit-tbe",
cl::desc("Emit a text-based ELF stub (.tbe) from the input file"),
cl::value_desc("path"));
cl::opt<std::string> SOName(
"soname",
cl::desc("Manually set the DT_SONAME entry of any emitted files"),
cl::value_desc("name"));
/// writeTBE() writes a Text-Based ELF stub to a file using the latest version
/// of the YAML parser.
static Error writeTBE(StringRef FilePath, ELFStub &Stub) {
std::error_code SysErr;
// Open file for writing.
raw_fd_ostream Out(FilePath, SysErr);
if (SysErr)
return createStringError(SysErr, "Couldn't open `%s` for writing",
FilePath.data());
// Write file.
Error YAMLErr = writeTBEToOutputStream(Out, Stub);
if (YAMLErr)
return YAMLErr;
return Error::success();
}
/// readInputFile populates an ELFStub by attempting to read the
/// input file using both the TBE and binary ELF parsers.
static Expected<std::unique_ptr<ELFStub>> readInputFile(StringRef FilePath) {
// Read in file.
ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrError =
MemoryBuffer::getFile(FilePath);
if (!BufOrError) {
return createStringError(BufOrError.getError(), "Could not open `%s`",
FilePath.data());
}
std::unique_ptr<MemoryBuffer> FileReadBuffer = std::move(*BufOrError);
ErrorCollector EC(/*UseFatalErrors=*/false);
// First try to read as a binary (fails fast if not binary).
if (InputFileFormat.getNumOccurrences() == 0 ||
InputFileFormat == FileFormat::ELF) {
Expected<std::unique_ptr<ELFStub>> StubFromELF =
readELFFile(FileReadBuffer->getMemBufferRef());
if (StubFromELF) {
return std::move(*StubFromELF);
}
EC.addError(StubFromELF.takeError(), "BinaryRead");
}
// Fall back to reading as a tbe.
if (InputFileFormat.getNumOccurrences() == 0 ||
InputFileFormat == FileFormat::TBE) {
Expected<std::unique_ptr<ELFStub>> StubFromTBE =
readTBEFromBuffer(FileReadBuffer->getBuffer());
if (StubFromTBE) {
return std::move(*StubFromTBE);
}
EC.addError(StubFromTBE.takeError(), "YamlParse");
}
// If both readers fail, build a new error that includes all information.
EC.addError(createStringError(errc::not_supported,
"No file readers succeeded reading `%s` "
"(unsupported/malformed file?)",
FilePath.data()),
"ReadInputFile");
EC.escalateToFatal();
return EC.makeError();
}
int main(int argc, char *argv[]) {
// Parse arguments.
cl::ParseCommandLineOptions(argc, argv);
Expected<std::unique_ptr<ELFStub>> StubOrErr = readInputFile(InputFilePath);
if (!StubOrErr) {
Error ReadError = StubOrErr.takeError();
WithColor::error() << ReadError << "\n";
exit(1);
}
std::unique_ptr<ELFStub> TargetStub = std::move(StubOrErr.get());
// Write out .tbe file.
if (EmitTBE.getNumOccurrences() == 1) {
TargetStub->TbeVersion = TBEVersionCurrent;
if (SOName.getNumOccurrences() == 1) {
TargetStub->SoName = SOName;
}
Error TBEWriteError = writeTBE(EmitTBE, *TargetStub);
if (TBEWriteError) {
WithColor::error() << TBEWriteError << "\n";
exit(1);
}
}
}