1 //===-- ObjectFileWasm.h ----------------------------------------*- C++ -*-===//
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 #ifndef LLDB_SOURCE_PLUGINS_OBJECTFILE_WASM_OBJECTFILEWASM_H
10 #define LLDB_SOURCE_PLUGINS_OBJECTFILE_WASM_OBJECTFILEWASM_H
11 
12 #include "lldb/Symbol/ObjectFile.h"
13 #include "lldb/Utility/ArchSpec.h"
14 #include <optional>
15 
16 namespace lldb_private {
17 namespace wasm {
18 
19 /// Generic Wasm object file reader.
20 ///
21 /// This class provides a generic wasm32 reader plugin implementing the
22 /// ObjectFile protocol.
23 class ObjectFileWasm : public ObjectFile {
24 public:
25   static void Initialize();
26   static void Terminate();
27 
28   static llvm::StringRef GetPluginNameStatic() { return "wasm"; }
29   static const char *GetPluginDescriptionStatic() {
30     return "WebAssembly object file reader.";
31   }
32 
33   static ObjectFile *
34   CreateInstance(const lldb::ModuleSP &module_sp, lldb::DataBufferSP data_sp,
35                  lldb::offset_t data_offset, const FileSpec *file,
36                  lldb::offset_t file_offset, lldb::offset_t length);
37 
38   static ObjectFile *CreateMemoryInstance(const lldb::ModuleSP &module_sp,
39                                           lldb::WritableDataBufferSP data_sp,
40                                           const lldb::ProcessSP &process_sp,
41                                           lldb::addr_t header_addr);
42 
43   static size_t GetModuleSpecifications(const FileSpec &file,
44                                         lldb::DataBufferSP &data_sp,
45                                         lldb::offset_t data_offset,
46                                         lldb::offset_t file_offset,
47                                         lldb::offset_t length,
48                                         ModuleSpecList &specs);
49 
50   /// PluginInterface protocol.
51   /// \{
52   llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
53   /// \}
54 
55   /// LLVM RTTI support
56   /// \{
57   static char ID;
58   bool isA(const void *ClassID) const override {
59     return ClassID == &ID || ObjectFile::isA(ClassID);
60   }
61   static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
62   /// \}
63 
64   /// ObjectFile Protocol.
65   /// \{
66   bool ParseHeader() override;
67 
68   lldb::ByteOrder GetByteOrder() const override {
69     return m_arch.GetByteOrder();
70   }
71 
72   bool IsExecutable() const override { return false; }
73 
74   uint32_t GetAddressByteSize() const override {
75     return m_arch.GetAddressByteSize();
76   }
77 
78   AddressClass GetAddressClass(lldb::addr_t file_addr) override {
79     return AddressClass::eInvalid;
80   }
81 
82   void ParseSymtab(lldb_private::Symtab &symtab) override;
83 
84   bool IsStripped() override { return !!GetExternalDebugInfoFileSpec(); }
85 
86   void CreateSections(SectionList &unified_section_list) override;
87 
88   void Dump(Stream *s) override;
89 
90   ArchSpec GetArchitecture() override { return m_arch; }
91 
92   UUID GetUUID() override { return m_uuid; }
93 
94   uint32_t GetDependentModules(FileSpecList &files) override { return 0; }
95 
96   Type CalculateType() override { return eTypeSharedLibrary; }
97 
98   Strata CalculateStrata() override { return eStrataUser; }
99 
100   bool SetLoadAddress(lldb_private::Target &target, lldb::addr_t value,
101                       bool value_is_offset) override;
102 
103   lldb_private::Address GetBaseAddress() override {
104     return IsInMemory() ? Address(m_memory_addr) : Address(0);
105   }
106   /// \}
107 
108   /// A Wasm module that has external DWARF debug information should contain a
109   /// custom section named "external_debug_info", whose payload is an UTF-8
110   /// encoded string that points to a Wasm module that contains the debug
111   /// information for this module.
112   std::optional<FileSpec> GetExternalDebugInfoFileSpec();
113 
114 private:
115   ObjectFileWasm(const lldb::ModuleSP &module_sp, lldb::DataBufferSP data_sp,
116                  lldb::offset_t data_offset, const FileSpec *file,
117                  lldb::offset_t offset, lldb::offset_t length);
118   ObjectFileWasm(const lldb::ModuleSP &module_sp,
119                  lldb::WritableDataBufferSP header_data_sp,
120                  const lldb::ProcessSP &process_sp, lldb::addr_t header_addr);
121 
122   /// Wasm section decoding routines.
123   /// \{
124   bool DecodeNextSection(lldb::offset_t *offset_ptr);
125   bool DecodeSections();
126   /// \}
127 
128   /// Read a range of bytes from the Wasm module.
129   DataExtractor ReadImageData(lldb::offset_t offset, uint32_t size);
130 
131   typedef struct section_info {
132     lldb::offset_t offset;
133     uint32_t size;
134     uint32_t id;
135     ConstString name;
136   } section_info_t;
137 
138   /// Wasm section header dump routines.
139   /// \{
140   void DumpSectionHeader(llvm::raw_ostream &ostream, const section_info_t &sh);
141   void DumpSectionHeaders(llvm::raw_ostream &ostream);
142   /// \}
143 
144   std::vector<section_info_t> m_sect_infos;
145   ArchSpec m_arch;
146   UUID m_uuid;
147 };
148 
149 } // namespace wasm
150 } // namespace lldb_private
151 #endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_WASM_OBJECTFILEWASM_H
152