llvm/lib/Object/Binary.cpp
Kevin Enderby c6bf9be16d Thread Expected<...> up from createMachOObjectFile() to allow llvm-objdump to produce a real error message
Produce the first specific error message for a malformed Mach-O file describing
the problem instead of the generic message for object_error::parse_failed of
"Invalid data was encountered while parsing the file”.  Many more good error
messages will follow after this first one.

This is built on Lang Hames’ great work of adding the ’Error' class for
structured error handling and threading Error through MachOObjectFile
construction.  And making createMachOObjectFile return Expected<...> .

So to to get the error to the llvm-obdump tool, I changed the stack of
these methods to also return Expected<...> :

  object::ObjectFile::createObjectFile()
  object::SymbolicFile::createSymbolicFile()
  object::createBinary()

Then finally in ParseInputMachO() in MachODump.cpp the error can
be reported and the specific error message can be printed in llvm-objdump
and can be seen in the existing test case for the existing malformed binary
but with the updated error message.

Converting these interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. To contain the changes for now use of
errorToErrorCode() and errorOrToExpected() are used where the callers
are yet to be converted.

Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values.  So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
“// TODO: Actually report errors helpfully” and a call something like
consumeError(ObjOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.

Note there is one fix also needed to lld/COFF/InputFiles.cpp that goes along
with this that I will commit right after this.  So expect lld not to built
after this commit and before the next one.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265606 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-06 22:14:09 +00:00

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3.4 KiB
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//===- Binary.cpp - A generic binary file -----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the Binary class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/Binary.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
// Include headers for createBinary.
#include "llvm/Object/Archive.h"
#include "llvm/Object/MachOUniversal.h"
#include "llvm/Object/ObjectFile.h"
using namespace llvm;
using namespace object;
Binary::~Binary() {}
Binary::Binary(unsigned int Type, MemoryBufferRef Source)
: TypeID(Type), Data(Source) {}
StringRef Binary::getData() const { return Data.getBuffer(); }
StringRef Binary::getFileName() const { return Data.getBufferIdentifier(); }
MemoryBufferRef Binary::getMemoryBufferRef() const { return Data; }
Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
LLVMContext *Context) {
sys::fs::file_magic Type = sys::fs::identify_magic(Buffer.getBuffer());
switch (Type) {
case sys::fs::file_magic::archive:
return errorOrToExpected(Archive::create(Buffer));
case sys::fs::file_magic::elf:
case sys::fs::file_magic::elf_relocatable:
case sys::fs::file_magic::elf_executable:
case sys::fs::file_magic::elf_shared_object:
case sys::fs::file_magic::elf_core:
case sys::fs::file_magic::macho_object:
case sys::fs::file_magic::macho_executable:
case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
case sys::fs::file_magic::macho_core:
case sys::fs::file_magic::macho_preload_executable:
case sys::fs::file_magic::macho_dynamically_linked_shared_lib:
case sys::fs::file_magic::macho_dynamic_linker:
case sys::fs::file_magic::macho_bundle:
case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
case sys::fs::file_magic::macho_dsym_companion:
case sys::fs::file_magic::macho_kext_bundle:
case sys::fs::file_magic::coff_object:
case sys::fs::file_magic::coff_import_library:
case sys::fs::file_magic::pecoff_executable:
case sys::fs::file_magic::bitcode:
return ObjectFile::createSymbolicFile(Buffer, Type, Context);
case sys::fs::file_magic::macho_universal_binary:
return errorOrToExpected(MachOUniversalBinary::create(Buffer));
case sys::fs::file_magic::unknown:
case sys::fs::file_magic::windows_resource:
// Unrecognized object file format.
return errorCodeToError(object_error::invalid_file_type);
}
llvm_unreachable("Unexpected Binary File Type");
}
Expected<OwningBinary<Binary>> object::createBinary(StringRef Path) {
ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
MemoryBuffer::getFileOrSTDIN(Path);
if (std::error_code EC = FileOrErr.getError())
return errorCodeToError(EC);
std::unique_ptr<MemoryBuffer> &Buffer = FileOrErr.get();
Expected<std::unique_ptr<Binary>> BinOrErr =
createBinary(Buffer->getMemBufferRef());
if (!BinOrErr)
return BinOrErr.takeError();
std::unique_ptr<Binary> &Bin = BinOrErr.get();
return OwningBinary<Binary>(std::move(Bin), std::move(Buffer));
}