From 9b3254dbf9f6624c772db7cfa7a3c29a0b94be8e Mon Sep 17 00:00:00 2001 From: Paolo Severini Date: Thu, 16 Jan 2020 08:36:45 -0800 Subject: [PATCH] [LLDB] Add SymbolVendorWasm plugin for WebAssembly debugging Add plugin class SymbolVendorWasm, with the logic to manage debug symbols for Wasm modules. Reviewers: clayborg, labath, aprantl, sbc100, teemperor Reviewed By: labath Tags: #lldb Differential Revision: https://reviews.llvm.org/D72650 --- lldb/source/API/SystemInitializerFull.cpp | 3 + .../Plugins/ObjectFile/wasm/ObjectFileWasm.cpp | 23 ++++ .../Plugins/ObjectFile/wasm/ObjectFileWasm.h | 15 +++ lldb/source/Plugins/SymbolVendor/CMakeLists.txt | 1 + .../Plugins/SymbolVendor/wasm/CMakeLists.txt | 9 ++ .../Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp | 145 +++++++++++++++++++++ .../Plugins/SymbolVendor/wasm/SymbolVendorWasm.h | 44 +++++++ .../ObjectFile/wasm/unified-debug-sections.yaml | 85 ++++++++++++ lldb/tools/lldb-test/SystemInitializerTest.cpp | 3 + 9 files changed, 328 insertions(+) create mode 100644 lldb/source/Plugins/SymbolVendor/wasm/CMakeLists.txt create mode 100644 lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp create mode 100644 lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.h create mode 100644 lldb/test/Shell/ObjectFile/wasm/unified-debug-sections.yaml diff --git a/lldb/source/API/SystemInitializerFull.cpp b/lldb/source/API/SystemInitializerFull.cpp index 2c56797..2bc53af 100644 --- a/lldb/source/API/SystemInitializerFull.cpp +++ b/lldb/source/API/SystemInitializerFull.cpp @@ -95,6 +95,7 @@ #include "Plugins/SymbolFile/PDB/SymbolFilePDB.h" #include "Plugins/SymbolFile/Symtab/SymbolFileSymtab.h" #include "Plugins/SymbolVendor/ELF/SymbolVendorELF.h" +#include "Plugins/SymbolVendor/wasm/SymbolVendorWasm.h" #include "Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.h" #include "Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.h" #include "Plugins/UnwindAssembly/x86/UnwindAssembly-x86.h" @@ -242,6 +243,7 @@ llvm::Error SystemInitializerFull::Initialize() { SymbolFileDWARF::Initialize(); SymbolFilePDB::Initialize(); SymbolFileSymtab::Initialize(); + wasm::SymbolVendorWasm::Initialize(); UnwindAssemblyInstEmulation::Initialize(); UnwindAssembly_x86::Initialize(); @@ -334,6 +336,7 @@ void SystemInitializerFull::Terminate() { ThreadSanitizerRuntime::Terminate(); UndefinedBehaviorSanitizerRuntime::Terminate(); MainThreadCheckerRuntime::Terminate(); + wasm::SymbolVendorWasm::Terminate(); SymbolVendorELF::Terminate(); breakpad::SymbolFileBreakpad::Terminate(); SymbolFileDWARF::Terminate(); diff --git a/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.cpp b/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.cpp index 2c918a8..bd4c359 100644 --- a/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.cpp +++ b/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.cpp @@ -72,6 +72,8 @@ GetWasmString(llvm::DataExtractor &data, llvm::DataExtractor::Cursor &c) { return ConstString(str); } +char ObjectFileWasm::ID; + void ObjectFileWasm::Initialize() { PluginManager::RegisterPlugin(GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance, @@ -177,6 +179,9 @@ bool ObjectFileWasm::DecodeNextSection(lldb::offset_t *offset_ptr) { return false; if (section_id == llvm::wasm::WASM_SEC_CUSTOM) { + // Custom sections have the id 0. Their contents consist of a name + // identifying the custom section, followed by an uninterpreted sequence + // of bytes. lldb::offset_t prev_offset = c.tell(); llvm::Optional sect_name = GetWasmString(data, c); if (!sect_name) @@ -389,6 +394,24 @@ DataExtractor ObjectFileWasm::ReadImageData(uint64_t offset, size_t size) { return data; } +llvm::Optional ObjectFileWasm::GetExternalDebugInfoFileSpec() { + static ConstString g_sect_name_external_debug_info("external_debug_info"); + + for (const section_info §_info : m_sect_infos) { + if (g_sect_name_external_debug_info == sect_info.name) { + const uint32_t kBufferSize = 1024; + DataExtractor section_header_data = + ReadImageData(sect_info.offset, kBufferSize); + llvm::DataExtractor data = section_header_data.GetAsLLVM(); + llvm::DataExtractor::Cursor c(0); + llvm::Optional symbols_url = GetWasmString(data, c); + if (symbols_url) + return FileSpec(symbols_url->GetStringRef()); + } + } + return llvm::None; +} + void ObjectFileWasm::Dump(Stream *s) { ModuleSP module_sp(GetModule()); if (!module_sp) diff --git a/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.h b/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.h index 986f7f9..65d237e 100644 --- a/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.h +++ b/lldb/source/Plugins/ObjectFile/wasm/ObjectFileWasm.h @@ -52,6 +52,15 @@ public: uint32_t GetPluginVersion() override { return 1; } /// \} + /// LLVM RTTI support + /// \{ + static char ID; + bool isA(const void *ClassID) const override { + return ClassID == &ID || ObjectFile::isA(ClassID); + } + static bool classof(const ObjectFile *obj) { return obj->isA(&ID); } + /// \} + /// ObjectFile Protocol. /// \{ bool ParseHeader() override; @@ -97,6 +106,12 @@ public: } /// \} + /// A Wasm module that has external DWARF debug information should contain a + /// custom section named "external_debug_info", whose payload is an UTF-8 + /// encoded string that points to a Wasm module that contains the debug + /// information for this module. + llvm::Optional GetExternalDebugInfoFileSpec(); + private: ObjectFileWasm(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp, lldb::offset_t data_offset, const FileSpec *file, diff --git a/lldb/source/Plugins/SymbolVendor/CMakeLists.txt b/lldb/source/Plugins/SymbolVendor/CMakeLists.txt index 94862d5..695b9a0 100644 --- a/lldb/source/Plugins/SymbolVendor/CMakeLists.txt +++ b/lldb/source/Plugins/SymbolVendor/CMakeLists.txt @@ -3,3 +3,4 @@ if (CMAKE_SYSTEM_NAME MATCHES "Darwin") endif() add_subdirectory(ELF) +add_subdirectory(wasm) diff --git a/lldb/source/Plugins/SymbolVendor/wasm/CMakeLists.txt b/lldb/source/Plugins/SymbolVendor/wasm/CMakeLists.txt new file mode 100644 index 0000000..49f6012 --- /dev/null +++ b/lldb/source/Plugins/SymbolVendor/wasm/CMakeLists.txt @@ -0,0 +1,9 @@ +add_lldb_library(lldbPluginSymbolVendorWasm PLUGIN + SymbolVendorWasm.cpp + + LINK_LIBS + lldbCore + lldbHost + lldbSymbol + lldbPluginObjectFileWasm + ) diff --git a/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp b/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp new file mode 100644 index 0000000..bd59bd5 --- /dev/null +++ b/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp @@ -0,0 +1,145 @@ +//===-- SymbolVendorWasm.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 "SymbolVendorWasm.h" + +#include + +#include "Plugins/ObjectFile/wasm/ObjectFileWasm.h" +#include "lldb/Core/Module.h" +#include "lldb/Core/ModuleSpec.h" +#include "lldb/Core/PluginManager.h" +#include "lldb/Core/Section.h" +#include "lldb/Host/Host.h" +#include "lldb/Symbol/LocateSymbolFile.h" +#include "lldb/Symbol/ObjectFile.h" +#include "lldb/Target/Target.h" +#include "lldb/Utility/StreamString.h" +#include "lldb/Utility/Timer.h" + +using namespace lldb; +using namespace lldb_private; +using namespace lldb_private::wasm; + +// SymbolVendorWasm constructor +SymbolVendorWasm::SymbolVendorWasm(const lldb::ModuleSP &module_sp) + : SymbolVendor(module_sp) {} + +void SymbolVendorWasm::Initialize() { + PluginManager::RegisterPlugin(GetPluginNameStatic(), + GetPluginDescriptionStatic(), CreateInstance); +} + +void SymbolVendorWasm::Terminate() { + PluginManager::UnregisterPlugin(CreateInstance); +} + +lldb_private::ConstString SymbolVendorWasm::GetPluginNameStatic() { + static ConstString g_name("WASM"); + return g_name; +} + +const char *SymbolVendorWasm::GetPluginDescriptionStatic() { + return "Symbol vendor for WASM that looks for dwo files that match " + "executables."; +} + +// CreateInstance +// +// Platforms can register a callback to use when creating symbol vendors to +// allow for complex debug information file setups, and to also allow for +// finding separate debug information files. +SymbolVendor * +SymbolVendorWasm::CreateInstance(const lldb::ModuleSP &module_sp, + lldb_private::Stream *feedback_strm) { + if (!module_sp) + return nullptr; + + ObjectFileWasm *obj_file = + llvm::dyn_cast_or_null(module_sp->GetObjectFile()); + if (!obj_file) + return nullptr; + + // If the main object file already contains debug info, then we are done. + if (obj_file->GetSectionList()->FindSectionByType( + lldb::eSectionTypeDWARFDebugInfo, true)) + return nullptr; + + static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); + Timer scoped_timer(func_cat, "SymbolVendorWasm::CreateInstance (module = %s)", + module_sp->GetFileSpec().GetPath().c_str()); + + ModuleSpec module_spec; + module_spec.GetFileSpec() = obj_file->GetFileSpec(); + FileSystem::Instance().Resolve(module_spec.GetFileSpec()); + module_spec.GetUUID() = obj_file->GetUUID(); + + // A Wasm module may have a custom section named "external_debug_info" whose + // content is the absolute or relative path of the Wasm module that contains + // debug symbols for this module. + llvm::Optional symbol_file_spec = + obj_file->GetExternalDebugInfoFileSpec(); + if (!symbol_file_spec) + return nullptr; + module_spec.GetSymbolFileSpec() = *symbol_file_spec; + + FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths(); + FileSpec sym_fspec = + Symbols::LocateExecutableSymbolFile(module_spec, search_paths); + if (!sym_fspec) + return nullptr; + + DataBufferSP sym_file_data_sp; + lldb::offset_t sym_file_data_offset = 0; + ObjectFileSP sym_objfile_sp = ObjectFile::FindPlugin( + module_sp, &sym_fspec, 0, FileSystem::Instance().GetByteSize(sym_fspec), + sym_file_data_sp, sym_file_data_offset); + if (!sym_objfile_sp) + return nullptr; + + // This objfile is for debugging purposes. + sym_objfile_sp->SetType(ObjectFile::eTypeDebugInfo); + + SymbolVendorWasm *symbol_vendor = new SymbolVendorWasm(module_sp); + + // Get the module unified section list and add our debug sections to + // that. + SectionList *module_section_list = module_sp->GetSectionList(); + SectionList *objfile_section_list = sym_objfile_sp->GetSectionList(); + + static const SectionType g_sections[] = { + eSectionTypeDWARFDebugAbbrev, eSectionTypeDWARFDebugAddr, + eSectionTypeDWARFDebugAranges, eSectionTypeDWARFDebugCuIndex, + eSectionTypeDWARFDebugFrame, eSectionTypeDWARFDebugInfo, + eSectionTypeDWARFDebugLine, eSectionTypeDWARFDebugLineStr, + eSectionTypeDWARFDebugLoc, eSectionTypeDWARFDebugLocLists, + eSectionTypeDWARFDebugMacInfo, eSectionTypeDWARFDebugMacro, + eSectionTypeDWARFDebugPubNames, eSectionTypeDWARFDebugPubTypes, + eSectionTypeDWARFDebugRanges, eSectionTypeDWARFDebugRngLists, + eSectionTypeDWARFDebugStr, eSectionTypeDWARFDebugStrOffsets, + eSectionTypeDWARFDebugTypes}; + for (SectionType section_type : g_sections) { + if (SectionSP section_sp = + objfile_section_list->FindSectionByType(section_type, true)) { + if (SectionSP module_section_sp = + module_section_list->FindSectionByType(section_type, true)) + module_section_list->ReplaceSection(module_section_sp->GetID(), + section_sp); + else + module_section_list->AddSection(section_sp); + } + } + + symbol_vendor->AddSymbolFileRepresentation(sym_objfile_sp); + return symbol_vendor; +} + +// PluginInterface protocol +ConstString SymbolVendorWasm::GetPluginName() { return GetPluginNameStatic(); } + +uint32_t SymbolVendorWasm::GetPluginVersion() { return 1; } diff --git a/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.h b/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.h new file mode 100644 index 0000000..7a688ab --- /dev/null +++ b/lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.h @@ -0,0 +1,44 @@ +//===-- SymbolVendorWasm.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 +// +//===----------------------------------------------------------------------===// + +#ifndef liblldb_SymbolVendorWasm_h_ +#define liblldb_SymbolVendorWasm_h_ + +#include "lldb/Symbol/SymbolVendor.h" +#include "lldb/lldb-private.h" + +namespace lldb_private { +namespace wasm { + +class SymbolVendorWasm : public lldb_private::SymbolVendor { +public: + SymbolVendorWasm(const lldb::ModuleSP &module_sp); + + static void Initialize(); + static void Terminate(); + static lldb_private::ConstString GetPluginNameStatic(); + static const char *GetPluginDescriptionStatic(); + + static lldb_private::SymbolVendor * + CreateInstance(const lldb::ModuleSP &module_sp, + lldb_private::Stream *feedback_strm); + + /// PluginInterface protocol. + /// \{ + lldb_private::ConstString GetPluginName() override; + uint32_t GetPluginVersion() override; + /// \} + +private: + DISALLOW_COPY_AND_ASSIGN(SymbolVendorWasm); +}; + +} // namespace wasm +} // namespace lldb_private + +#endif // liblldb_SymbolVendorWasm_h_ diff --git a/lldb/test/Shell/ObjectFile/wasm/unified-debug-sections.yaml b/lldb/test/Shell/ObjectFile/wasm/unified-debug-sections.yaml new file mode 100644 index 0000000..d72080f --- /dev/null +++ b/lldb/test/Shell/ObjectFile/wasm/unified-debug-sections.yaml @@ -0,0 +1,85 @@ +# RUN: yaml2obj -docnum=1 %s > test.wasm +# RUN: yaml2obj -docnum=2 %s > test_sym.wasm +# RUN: lldb-test object-file test.wasm | FileCheck %s + +# This test checks that SymbolVendorWasm correctly loads DWARF debug sections +# that have been stripped out into a separated Wasm module. The original Wasm +# module contains a "external_debug_info" custom section with the absolute or +# relative path of the debug module. + +# CHECK: Plugin name: wasm +# CHECK: Architecture: wasm32-unknown-unknown-wasm +# CHECK: UUID: +# CHECK: Executable: true +# CHECK: Stripped: true +# CHECK: Type: executable +# CHECK: Strata: user +# CHECK: Base VM address: 0xa + +# CHECK: Name: code +# CHECK: Type: code +# CHECK: VM address: 0x0 +# CHECK: VM size: 56 +# CHECK: File size: 56 + +# CHECK: Name: .debug_info +# CHECK: Type: dwarf-info +# CHECK: VM address: 0x0 +# CHECK: VM size: 0 +# CHECK: File size: 2 + +# CHECK: Name: .debug_abbrev +# CHECK: Type: dwarf-abbrev +# CHECK: VM address: 0x0 +# CHECK: VM size: 0 +# CHECK: File size: 2 + +# CHECK: Name: .debug_line +# CHECK: Type: dwarf-line +# CHECK: VM address: 0x0 +# CHECK: VM size: 0 +# CHECK: File size: 2 + +# CHECK: Name: .debug_str +# CHECK: Type: dwarf-str +# CHECK: VM address: 0x0 +# CHECK: VM size: 0 +# CHECK: File size: 3 + +--- !WASM +FileHeader: + Version: 0x00000001 +Sections: + - Type: CODE + Functions: + - Index: 0 + Locals: + - Type: I32 + Count: 6 + Body: 238080808000210141102102200120026B21032003200036020C200328020C2104200328020C2105200420056C210620060F0B + - Type: CUSTOM + Name: external_debug_info + Payload: 0D746573745F73796D2E7761736D # test_sym.wasm + +... + + +--- !WASM +FileHeader: + Version: 0x00000001 +Sections: + + - Type: CUSTOM + Name: .debug_info + Payload: 4C00 + - Type: CUSTOM + Name: .debug_abbrev + Payload: 0111 + - Type: CUSTOM + Name: .debug_line + Payload: 5100 + - Type: CUSTOM + Name: .debug_str + Payload: 636CFF + +... diff --git a/lldb/tools/lldb-test/SystemInitializerTest.cpp b/lldb/tools/lldb-test/SystemInitializerTest.cpp index ab8a92e..db0a9d4 100644 --- a/lldb/tools/lldb-test/SystemInitializerTest.cpp +++ b/lldb/tools/lldb-test/SystemInitializerTest.cpp @@ -76,6 +76,7 @@ #include "Plugins/SymbolFile/PDB/SymbolFilePDB.h" #include "Plugins/SymbolFile/Symtab/SymbolFileSymtab.h" #include "Plugins/SymbolVendor/ELF/SymbolVendorELF.h" +#include "Plugins/SymbolVendor/wasm/SymbolVendorWasm.h" #include "Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.h" #include "Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.h" #include "Plugins/UnwindAssembly/x86/UnwindAssembly-x86.h" @@ -201,6 +202,7 @@ llvm::Error SystemInitializerTest::Initialize() { SymbolFileDWARF::Initialize(); SymbolFilePDB::Initialize(); SymbolFileSymtab::Initialize(); + wasm::SymbolVendorWasm::Initialize(); UnwindAssemblyInstEmulation::Initialize(); UnwindAssembly_x86::Initialize(); EmulateInstructionARM64::Initialize(); @@ -288,6 +290,7 @@ void SystemInitializerTest::Terminate() { SymbolFileDWARF::Terminate(); SymbolFilePDB::Terminate(); SymbolFileSymtab::Terminate(); + wasm::SymbolVendorWasm::Terminate(); UnwindAssembly_x86::Terminate(); UnwindAssemblyInstEmulation::Terminate(); EmulateInstructionARM64::Terminate(); -- 2.7.4