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 <string.h>
12 
13 #include "Plugins/ObjectFile/wasm/ObjectFileWasm.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/ModuleSpec.h"
16 #include "lldb/Core/PluginManager.h"
17 #include "lldb/Core/Section.h"
18 #include "lldb/Host/Host.h"
19 #include "lldb/Symbol/LocateSymbolFile.h"
20 #include "lldb/Symbol/ObjectFile.h"
21 #include "lldb/Target/Target.h"
22 #include "lldb/Utility/StreamString.h"
23 #include "lldb/Utility/Timer.h"
24 
25 using namespace lldb;
26 using namespace lldb_private;
27 using namespace lldb_private::wasm;
28 
29 LLDB_PLUGIN_DEFINE(SymbolVendorWasm)
30 
31 // SymbolVendorWasm constructor
32 SymbolVendorWasm::SymbolVendorWasm(const lldb::ModuleSP &module_sp)
33     : SymbolVendor(module_sp) {}
34 
35 void SymbolVendorWasm::Initialize() {
36   PluginManager::RegisterPlugin(GetPluginNameStatic(),
37                                 GetPluginDescriptionStatic(), CreateInstance);
38 }
39 
40 void SymbolVendorWasm::Terminate() {
41   PluginManager::UnregisterPlugin(CreateInstance);
42 }
43 
44 lldb_private::ConstString SymbolVendorWasm::GetPluginNameStatic() {
45   static ConstString g_name("WASM");
46   return g_name;
47 }
48 
49 const char *SymbolVendorWasm::GetPluginDescriptionStatic() {
50   return "Symbol vendor for WASM that looks for dwo files that match "
51          "executables.";
52 }
53 
54 // CreateInstance
55 //
56 // Platforms can register a callback to use when creating symbol vendors to
57 // allow for complex debug information file setups, and to also allow for
58 // finding separate debug information files.
59 SymbolVendor *
60 SymbolVendorWasm::CreateInstance(const lldb::ModuleSP &module_sp,
61                                  lldb_private::Stream *feedback_strm) {
62   if (!module_sp)
63     return nullptr;
64 
65   ObjectFileWasm *obj_file =
66       llvm::dyn_cast_or_null<ObjectFileWasm>(module_sp->GetObjectFile());
67   if (!obj_file)
68     return nullptr;
69 
70   // If the main object file already contains debug info, then we are done.
71   if (obj_file->GetSectionList()->FindSectionByType(
72           lldb::eSectionTypeDWARFDebugInfo, true))
73     return nullptr;
74 
75   LLDB_SCOPED_TIMERF("SymbolVendorWasm::CreateInstance (module = %s)",
76                      module_sp->GetFileSpec().GetPath().c_str());
77 
78   ModuleSpec module_spec;
79   module_spec.GetFileSpec() = obj_file->GetFileSpec();
80   FileSystem::Instance().Resolve(module_spec.GetFileSpec());
81   module_spec.GetUUID() = obj_file->GetUUID();
82 
83   // A Wasm module may have a custom section named "external_debug_info" whose
84   // content is the absolute or relative path of the Wasm module that contains
85   // debug symbols for this module.
86   llvm::Optional<FileSpec> symbol_file_spec =
87       obj_file->GetExternalDebugInfoFileSpec();
88   if (!symbol_file_spec)
89     return nullptr;
90   module_spec.GetSymbolFileSpec() = *symbol_file_spec;
91 
92   FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
93   FileSpec sym_fspec =
94       Symbols::LocateExecutableSymbolFile(module_spec, search_paths);
95   if (!sym_fspec)
96     return nullptr;
97 
98   DataBufferSP sym_file_data_sp;
99   lldb::offset_t sym_file_data_offset = 0;
100   ObjectFileSP sym_objfile_sp = ObjectFile::FindPlugin(
101       module_sp, &sym_fspec, 0, FileSystem::Instance().GetByteSize(sym_fspec),
102       sym_file_data_sp, sym_file_data_offset);
103   if (!sym_objfile_sp)
104     return nullptr;
105 
106   // This objfile is for debugging purposes.
107   sym_objfile_sp->SetType(ObjectFile::eTypeDebugInfo);
108 
109   SymbolVendorWasm *symbol_vendor = new SymbolVendorWasm(module_sp);
110 
111   // Get the module unified section list and add our debug sections to
112   // that.
113   SectionList *module_section_list = module_sp->GetSectionList();
114   SectionList *objfile_section_list = sym_objfile_sp->GetSectionList();
115 
116   static const SectionType g_sections[] = {
117       eSectionTypeDWARFDebugAbbrev,   eSectionTypeDWARFDebugAddr,
118       eSectionTypeDWARFDebugAranges,  eSectionTypeDWARFDebugCuIndex,
119       eSectionTypeDWARFDebugFrame,    eSectionTypeDWARFDebugInfo,
120       eSectionTypeDWARFDebugLine,     eSectionTypeDWARFDebugLineStr,
121       eSectionTypeDWARFDebugLoc,      eSectionTypeDWARFDebugLocLists,
122       eSectionTypeDWARFDebugMacInfo,  eSectionTypeDWARFDebugMacro,
123       eSectionTypeDWARFDebugPubNames, eSectionTypeDWARFDebugPubTypes,
124       eSectionTypeDWARFDebugRanges,   eSectionTypeDWARFDebugRngLists,
125       eSectionTypeDWARFDebugStr,      eSectionTypeDWARFDebugStrOffsets,
126       eSectionTypeDWARFDebugTypes};
127   for (SectionType section_type : g_sections) {
128     if (SectionSP section_sp =
129             objfile_section_list->FindSectionByType(section_type, true)) {
130       if (SectionSP module_section_sp =
131               module_section_list->FindSectionByType(section_type, true))
132         module_section_list->ReplaceSection(module_section_sp->GetID(),
133                                             section_sp);
134       else
135         module_section_list->AddSection(section_sp);
136     }
137   }
138 
139   symbol_vendor->AddSymbolFileRepresentation(sym_objfile_sp);
140   return symbol_vendor;
141 }
142 
143 // PluginInterface protocol
144 ConstString SymbolVendorWasm::GetPluginName() { return GetPluginNameStatic(); }
145 
146 uint32_t SymbolVendorWasm::GetPluginVersion() { return 1; }
147