2aa020f49b
In a PR last month I changed the ObjectFile CreateInstance etc methods to accept an optional DataExtractorSP instead of a DataBufferSP, and retain the extractor in a shared pointer internally in all of the ObjectFile subclasses. This is laying the groundwork for using a VirtualDataExtractor for some Mach-O binaries on macOS, where the segments of the binary are out-of-order in actual memory, and we add a lookup table to make it appear that the TEXT segment is at offset 0 in the Extractor, etc. Working on the actual implementation, I realized we were still using DataBufferSP's in ModuleSpec and Module, as well as in ObjectFile::GetModuleSpecifications. I originally was making a much larger NFC change where I had all ObjectFile subclasses operating on DataExtractors throughout their implementation, as well as in the DWARF parser. It was a very large patchset. Many subclasses start with their DataExtractor, then create smaller DataExtractors for parts of the binary image - the string table, the symbol table, etc., for processing. After consideration and discussion with Jonas, we agreed that a segment/section of a binary will never require a lookup table to access the bytes within it, so I changed VirtualDataExtractor::GetSubsetExtractorSP to (1) require that the Subset be contained within a single lookup table entry, and (2) return a simple DataExtractor bounded on that byte range. By doing this, I was able to remove all of my very-invasive changes to the ObjectFile subclass internals; it's only when they are operating on the entire binary image that care is needed. One pattern that subclasses like ObjectFileBreakpad use is to take an ArrayRef of the DataBuffer for a binary, then create a StringRef of that, then look for strings in it. With a VirtualDataExtractor and out-of-order binary segments, with gaps between them, this allows us to search the entire buffer looking for a string, and segfault when it gets to an unmapped region of the buffer. I added a VirtualDataExtractor::GetSubsetExtractorSP(0) which gets the largest contiguous memory region starting at offset 0 for this use case, and I added a comment about what was being done there because I know it is not obvious, and people not working on macOS wouldn't be familiar with the requirement. (when we have a ModuleSpec with a DataExtractor, any of the ObjectFile subclasses get a shot at Creating, so they all have to be able to iterate on these) rdar://148939795
68 lines
2.8 KiB
C++
68 lines
2.8 KiB
C++
//===-- ObjectFileMinidump.h ---------------------------------- -*- C++ -*-===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
/// \file
|
|
/// Placeholder plugin for the save core functionality.
|
|
///
|
|
/// ObjectFileMinidump is created only to be able to save minidump core files
|
|
/// from existing processes with the ObjectFileMinidump::SaveCore function.
|
|
/// Minidump files are not ObjectFile objects, but they are core files and
|
|
/// currently LLDB's ObjectFile plug-ins handle emitting core files. If the
|
|
/// core file saving ever moves into a new plug-in type within LLDB, this code
|
|
/// should move as well, but for now this is the best place architecturally.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLDB_SOURCE_PLUGINS_OBJECTFILE_MINIDUMP_OBJECTFILEMINIDUMP_H
|
|
#define LLDB_SOURCE_PLUGINS_OBJECTFILE_MINIDUMP_OBJECTFILEMINIDUMP_H
|
|
|
|
#include "lldb/Symbol/ObjectFile.h"
|
|
#include "lldb/Symbol/SaveCoreOptions.h"
|
|
#include "lldb/Utility/ArchSpec.h"
|
|
|
|
class ObjectFileMinidump : public lldb_private::PluginInterface {
|
|
public:
|
|
// Static Functions
|
|
static void Initialize();
|
|
static void Terminate();
|
|
|
|
static llvm::StringRef GetPluginNameStatic() { return "minidump"; }
|
|
static const char *GetPluginDescriptionStatic() {
|
|
return "Minidump object file.";
|
|
}
|
|
|
|
// PluginInterface protocol
|
|
llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
|
|
|
|
static lldb_private::ObjectFile *
|
|
CreateInstance(const lldb::ModuleSP &module_sp,
|
|
lldb::DataExtractorSP extractor_sp, lldb::offset_t data_offset,
|
|
const lldb_private::FileSpec *file, lldb::offset_t offset,
|
|
lldb::offset_t length);
|
|
|
|
static lldb_private::ObjectFile *CreateMemoryInstance(
|
|
const lldb::ModuleSP &module_sp, lldb::WritableDataBufferSP data_sp,
|
|
const lldb::ProcessSP &process_sp, lldb::addr_t header_addr);
|
|
|
|
static size_t GetModuleSpecifications(const lldb_private::FileSpec &file,
|
|
lldb::DataExtractorSP &extractor_sp,
|
|
lldb::offset_t data_offset,
|
|
lldb::offset_t file_offset,
|
|
lldb::offset_t length,
|
|
lldb_private::ModuleSpecList &specs);
|
|
|
|
// Saves dump in Minidump file format
|
|
static bool SaveCore(const lldb::ProcessSP &process_sp,
|
|
lldb_private::SaveCoreOptions &options,
|
|
lldb_private::Status &error);
|
|
|
|
private:
|
|
ObjectFileMinidump() = default;
|
|
};
|
|
|
|
#endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_MINIDUMP_OBJECTFILEMINIDUMP_H
|