lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp

   1 //===-- SymbolVendorWasm.cpp ----------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "SymbolVendorWasm.h"
  10
  11 #include <cstring>
  12 #include <optional>
  13
  14 #include "Plugins/ObjectFile/wasm/ObjectFileWasm.h"
  15 #include "lldb/Core/Module.h"
  16 #include "lldb/Core/ModuleSpec.h"
  17 #include "lldb/Core/PluginManager.h"
  18 #include "lldb/Core/Section.h"
  19 #include "lldb/Host/Host.h"
  20 #include "lldb/Symbol/LocateSymbolFile.h"
  21 #include "lldb/Symbol/ObjectFile.h"
  22 #include "lldb/Target/Target.h"
  23 #include "lldb/Utility/StreamString.h"
  24 #include "lldb/Utility/Timer.h"
  25
  26 using namespace lldb;
  27 using namespace lldb_private;
  28 using namespace lldb_private::wasm;
  29
  30 LLDB_PLUGIN_DEFINE(SymbolVendorWasm)
  31
  32 // SymbolVendorWasm constructor
  33 SymbolVendorWasm::SymbolVendorWasm(const lldb::ModuleSP &module_sp)
  34     : SymbolVendor(module_sp) {}
  35
  36 void SymbolVendorWasm::Initialize() {
  37   PluginManager::RegisterPlugin(GetPluginNameStatic(),
  38                                 GetPluginDescriptionStatic(), CreateInstance);
  39 }
  40
  41 void SymbolVendorWasm::Terminate() {
  42   PluginManager::UnregisterPlugin(CreateInstance);
  43 }
  44
  45 llvm::StringRef SymbolVendorWasm::GetPluginDescriptionStatic() {
  46   return "Symbol vendor for WASM that looks for dwo files that match "
  47          "executables.";
  48 }
  49
  50 // CreateInstance
  51 //
  52 // Platforms can register a callback to use when creating symbol vendors to
  53 // allow for complex debug information file setups, and to also allow for
  54 // finding separate debug information files.
  55 SymbolVendor *
  56 SymbolVendorWasm::CreateInstance(const lldb::ModuleSP &module_sp,
  57                                  lldb_private::Stream *feedback_strm) {
  58   if (!module_sp)
  59     return nullptr;
  60
  61   ObjectFileWasm *obj_file =
  62       llvm::dyn_cast_or_null<ObjectFileWasm>(module_sp->GetObjectFile());
  63   if (!obj_file)
  64     return nullptr;
  65
  66   // If the main object file already contains debug info, then we are done.
  67   if (obj_file->GetSectionList()->FindSectionByType(
  68           lldb::eSectionTypeDWARFDebugInfo, true))
  69     return nullptr;
  70
  71   LLDB_SCOPED_TIMERF("SymbolVendorWasm::CreateInstance (module = %s)",
  72                      module_sp->GetFileSpec().GetPath().c_str());
  73
  74   ModuleSpec module_spec;
  75   module_spec.GetFileSpec() = obj_file->GetFileSpec();
  76   FileSystem::Instance().Resolve(module_spec.GetFileSpec());
  77   module_spec.GetUUID() = obj_file->GetUUID();
  78
  79   // A Wasm module may have a custom section named "external_debug_info" whose
  80   // content is the absolute or relative path of the Wasm module that contains
  81   // debug symbols for this module.
  82   std::optional<FileSpec> symbol_file_spec =
  83       obj_file->GetExternalDebugInfoFileSpec();
  84   if (!symbol_file_spec)
  85     return nullptr;
  86   module_spec.GetSymbolFileSpec() = *symbol_file_spec;
  87
  88   FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
  89   FileSpec sym_fspec =
  90       Symbols::LocateExecutableSymbolFile(module_spec, search_paths);
  91   if (!sym_fspec)
  92     return nullptr;
  93
  94   DataBufferSP sym_file_data_sp;
  95   lldb::offset_t sym_file_data_offset = 0;
  96   ObjectFileSP sym_objfile_sp = ObjectFile::FindPlugin(
  97       module_sp, &sym_fspec, 0, FileSystem::Instance().GetByteSize(sym_fspec),
  98       sym_file_data_sp, sym_file_data_offset);
  99   if (!sym_objfile_sp)
 100     return nullptr;
 101
 102   // This objfile is for debugging purposes.
 103   sym_objfile_sp->SetType(ObjectFile::eTypeDebugInfo);
 104
 105   SymbolVendorWasm *symbol_vendor = new SymbolVendorWasm(module_sp);
 106
 107   // Get the module unified section list and add our debug sections to
 108   // that.
 109   SectionList *module_section_list = module_sp->GetSectionList();
 110   SectionList *objfile_section_list = sym_objfile_sp->GetSectionList();
 111
 112   if (!module_section_list || !objfile_section_list)
 113     return nullptr;
 114
 115   static const SectionType g_sections[] = {
 116       eSectionTypeDWARFDebugAbbrev,   eSectionTypeDWARFDebugAddr,
 117       eSectionTypeDWARFDebugAranges,  eSectionTypeDWARFDebugCuIndex,
 118       eSectionTypeDWARFDebugFrame,    eSectionTypeDWARFDebugInfo,
 119       eSectionTypeDWARFDebugLine,     eSectionTypeDWARFDebugLineStr,
 120       eSectionTypeDWARFDebugLoc,      eSectionTypeDWARFDebugLocLists,
 121       eSectionTypeDWARFDebugMacInfo,  eSectionTypeDWARFDebugMacro,
 122       eSectionTypeDWARFDebugPubNames, eSectionTypeDWARFDebugPubTypes,
 123       eSectionTypeDWARFDebugRanges,   eSectionTypeDWARFDebugRngLists,
 124       eSectionTypeDWARFDebugStr,      eSectionTypeDWARFDebugStrOffsets,
 125       eSectionTypeDWARFDebugTypes};
 126   for (SectionType section_type : g_sections) {
 127     if (SectionSP section_sp =
 128             objfile_section_list->FindSectionByType(section_type, true)) {
 129       if (SectionSP module_section_sp =
 130               module_section_list->FindSectionByType(section_type, true))
 131         module_section_list->ReplaceSection(module_section_sp->GetID(),
 132                                             section_sp);
 133       else
 134         module_section_list->AddSection(section_sp);
 135     }
 136   }
 137
 138   symbol_vendor->AddSymbolFileRepresentation(sym_objfile_sp);
 139   return symbol_vendor;
 140 }