1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
#define V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
#include <map>
#include <memory>
#include "src/debug/wasm/gdb-server/gdb-server-thread.h"
#include "src/debug/wasm/gdb-server/wasm-module-debug.h"
namespace v8 {
namespace internal {
namespace wasm {
namespace gdb_server {
class TaskRunner;
// class GdbServer acts as a manager for the GDB-remote stub. It is instantiated
// as soon as the first Wasm module is loaded in the Wasm engine and spawns a
// separate thread to accept connections and exchange messages with a debugger.
// It will contain the logic to serve debugger queries and access the state of
// the Wasm engine.
class GdbServer {
public:
// Factory method: creates and returns a GdbServer. Spawns a "GDB-remote"
// thread that will be used to communicate with the debugger.
// May return null on failure.
// This should be called once, the first time a Wasm module is loaded in the
// Wasm engine.
static std::unique_ptr<GdbServer> Create();
// Stops the "GDB-remote" thread and waits for it to complete. This should be
// called once, when the Wasm engine shuts down.
~GdbServer();
// Queries the set of the Wasm modules currently loaded. Each module is
// identified by a unique integer module id.
struct WasmModuleInfo {
uint32_t module_id;
std::string module_name;
};
std::vector<WasmModuleInfo> GetLoadedModules();
// Queries the value of the {index} global value in the Wasm module identified
// by {frame_index}.
//
bool GetWasmGlobal(uint32_t frame_index, uint32_t index, uint8_t* buffer,
uint32_t buffer_size, uint32_t* size);
// Queries the value of the {index} local value in the {frame_index}th stack
// frame in the Wasm module identified by {frame_index}.
//
bool GetWasmLocal(uint32_t frame_index, uint32_t index, uint8_t* buffer,
uint32_t buffer_size, uint32_t* size);
// Queries the value of the {index} value in the operand stack.
//
bool GetWasmStackValue(uint32_t frame_index, uint32_t index, uint8_t* buffer,
uint32_t buffer_size, uint32_t* size);
// Reads {size} bytes, starting from {offset}, from the Memory instance
// associated to the Wasm module identified by {frame_index}.
// Returns the number of bytes copied to {buffer}, or 0 is case of error.
// Note: only one Memory for Module is currently supported.
//
uint32_t GetWasmMemory(uint32_t frame_index, uint32_t offset, uint8_t* buffer,
uint32_t size);
// Reads {size} bytes, starting from the low dword of {address}, from the Code
// space of th Wasm module identified by high dword of {address}.
// Returns the number of bytes copied to {buffer}, or 0 is case of error.
uint32_t GetWasmModuleBytes(wasm_addr_t address, uint8_t* buffer,
uint32_t size);
// Inserts a breakpoint at the offset {offset} of the Wasm module identified
// by {wasm_module_id}.
// Returns true if the breakpoint was successfully added.
bool AddBreakpoint(uint32_t wasm_module_id, uint32_t offset);
// Removes a breakpoint at the offset {offset} of the Wasm module identified
// by {wasm_module_id}.
// Returns true if the breakpoint was successfully removed.
bool RemoveBreakpoint(uint32_t wasm_module_id, uint32_t offset);
// Returns the current call stack as a vector of program counters.
std::vector<wasm_addr_t> GetWasmCallStack() const;
// Manage the set of Isolates for this GdbServer.
void AddIsolate(Isolate* isolate);
void RemoveIsolate(Isolate* isolate);
// Requests that the thread suspend execution at the next Wasm instruction.
void Suspend();
// Handle stepping in wasm functions via the wasm interpreter.
void PrepareStep();
// Called when the target debuggee can resume execution (for example after
// having been suspended on a breakpoint). Terminates the task runner leaving
// all pending tasks in the queue.
void QuitMessageLoopOnPause();
private:
GdbServer();
// When the target debuggee is suspended for a breakpoint or exception, blocks
// the main (isolate) thread and enters in a message loop. Here it waits on a
// queue of Task objects that are posted by the GDB-stub thread and that
// represent queries received from the debugger via the GDB-remote protocol.
void RunMessageLoopOnPause();
// Post a task to run a callback in the isolate thread.
template <typename Callback>
auto RunSyncTask(Callback&& callback) const;
void AddWasmModule(uint32_t module_id, Local<debug::WasmScript> wasm_script);
// Given a Wasm module id, retrieves the corresponding debugging WasmScript
// object.
bool GetModuleDebugHandler(uint32_t module_id,
WasmModuleDebug** wasm_module_debug);
// Returns the debugging target.
Target& GetTarget() const;
// Class DebugDelegate implements the debug::DebugDelegate interface to
// receive notifications when debug events happen in a given isolate, like a
// script being loaded, a breakpoint being hit, an exception being thrown.
class DebugDelegate : public debug::DebugDelegate {
public:
DebugDelegate(Isolate* isolate, GdbServer* gdb_server);
~DebugDelegate();
// debug::DebugDelegate
void ScriptCompiled(Local<debug::Script> script, bool is_live_edited,
bool has_compile_error) override;
void BreakProgramRequested(Local<v8::Context> paused_context,
const std::vector<debug::BreakpointId>&
inspector_break_points_hit) override;
void ExceptionThrown(Local<v8::Context> paused_context,
Local<Value> exception, Local<Value> promise,
bool is_uncaught,
debug::ExceptionType exception_type) override;
bool IsFunctionBlackboxed(Local<debug::Script> script,
const debug::Location& start,
const debug::Location& end) override;
private:
// Calculates module_id as:
// +--------------------+------------------- +
// | DebugDelegate::id_ | Script::Id() |
// +--------------------+------------------- +
// <----- 16 bit -----> <----- 16 bit ----->
uint32_t GetModuleId(uint32_t script_id) const {
DCHECK_LT(script_id, 0x10000);
DCHECK_LT(id_, 0x10000);
return id_ << 16 | script_id;
}
Isolate* isolate_;
uint32_t id_;
GdbServer* gdb_server_;
static std::atomic<uint32_t> id_s;
};
// The GDB-stub thread where all the communication with the debugger happens.
std::unique_ptr<GdbServerThread> thread_;
// Used to transform the queries that arrive in the GDB-stub thread into
// tasks executed in the main (isolate) thread.
std::unique_ptr<TaskRunner> task_runner_;
//////////////////////////////////////////////////////////////////////////////
// Always accessed in the isolate thread.
// Set of breakpoints currently defines in Wasm code.
typedef std::map<uint64_t, int> BreakpointsMap;
BreakpointsMap breakpoints_;
typedef std::map<uint32_t, WasmModuleDebug> ScriptsMap;
ScriptsMap scripts_;
typedef std::map<Isolate*, std::unique_ptr<DebugDelegate>>
IsolateDebugDelegateMap;
IsolateDebugDelegateMap isolate_delegates_;
// End of fields always accessed in the isolate thread.
//////////////////////////////////////////////////////////////////////////////
DISALLOW_COPY_AND_ASSIGN(GdbServer);
};
} // namespace gdb_server
} // namespace wasm
} // namespace internal
} // namespace v8
#endif // V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
|
