1 //===-- LLVMUserExpression.cpp ----------------------------------*- 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
10 #include "lldb/Expression/LLVMUserExpression.h"
11 #include "lldb/Core/Module.h"
12 #include "lldb/Core/StreamFile.h"
13 #include "lldb/Core/ValueObjectConstResult.h"
14 #include "lldb/Expression/DiagnosticManager.h"
15 #include "lldb/Expression/ExpressionVariable.h"
16 #include "lldb/Expression/IRExecutionUnit.h"
17 #include "lldb/Expression/IRInterpreter.h"
18 #include "lldb/Expression/Materializer.h"
19 #include "lldb/Host/HostInfo.h"
20 #include "lldb/Symbol/Block.h"
21 #include "lldb/Symbol/Function.h"
22 #include "lldb/Symbol/ObjectFile.h"
23 #include "lldb/Symbol/SymbolVendor.h"
24 #include "lldb/Symbol/Type.h"
25 #include "lldb/Symbol/VariableList.h"
26 #include "lldb/Target/ExecutionContext.h"
27 #include "lldb/Target/Process.h"
28 #include "lldb/Target/StackFrame.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/ThreadPlan.h"
31 #include "lldb/Target/ThreadPlanCallUserExpression.h"
32 #include "lldb/Utility/ConstString.h"
33 #include "lldb/Utility/Log.h"
34 #include "lldb/Utility/StreamString.h"
35
36 using namespace lldb_private;
37
38 char LLVMUserExpression::ID;
39
LLVMUserExpression(ExecutionContextScope & exe_scope,llvm::StringRef expr,llvm::StringRef prefix,lldb::LanguageType language,ResultType desired_type,const EvaluateExpressionOptions & options)40 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope,
41 llvm::StringRef expr,
42 llvm::StringRef prefix,
43 lldb::LanguageType language,
44 ResultType desired_type,
45 const EvaluateExpressionOptions &options)
46 : UserExpression(exe_scope, expr, prefix, language, desired_type, options),
47 m_stack_frame_bottom(LLDB_INVALID_ADDRESS),
48 m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false),
49 m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(),
50 m_materializer_up(), m_jit_module_wp(), m_can_interpret(false),
51 m_materialized_address(LLDB_INVALID_ADDRESS) {}
52
~LLVMUserExpression()53 LLVMUserExpression::~LLVMUserExpression() {
54 if (m_target) {
55 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
56 if (jit_module_sp)
57 m_target->GetImages().Remove(jit_module_sp);
58 }
59 }
60
61 lldb::ExpressionResults
DoExecute(DiagnosticManager & diagnostic_manager,ExecutionContext & exe_ctx,const EvaluateExpressionOptions & options,lldb::UserExpressionSP & shared_ptr_to_me,lldb::ExpressionVariableSP & result)62 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager,
63 ExecutionContext &exe_ctx,
64 const EvaluateExpressionOptions &options,
65 lldb::UserExpressionSP &shared_ptr_to_me,
66 lldb::ExpressionVariableSP &result) {
67 // The expression log is quite verbose, and if you're just tracking the
68 // execution of the expression, it's quite convenient to have these logs come
69 // out with the STEP log as well.
70 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
71 LIBLLDB_LOG_STEP));
72
73 if (m_jit_start_addr == LLDB_INVALID_ADDRESS && !m_can_interpret) {
74 diagnostic_manager.PutString(
75 eDiagnosticSeverityError,
76 "Expression can't be run, because there is no JIT compiled function");
77 return lldb::eExpressionSetupError;
78 }
79
80 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS;
81
82 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx,
83 struct_address)) {
84 diagnostic_manager.Printf(
85 eDiagnosticSeverityError,
86 "errored out in %s, couldn't PrepareToExecuteJITExpression",
87 __FUNCTION__);
88 return lldb::eExpressionSetupError;
89 }
90
91 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS;
92 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS;
93
94 if (m_can_interpret) {
95 llvm::Module *module = m_execution_unit_sp->GetModule();
96 llvm::Function *function = m_execution_unit_sp->GetFunction();
97
98 if (!module || !function) {
99 diagnostic_manager.PutString(
100 eDiagnosticSeverityError,
101 "supposed to interpret, but nothing is there");
102 return lldb::eExpressionSetupError;
103 }
104
105 Status interpreter_error;
106
107 std::vector<lldb::addr_t> args;
108
109 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
110 diagnostic_manager.Printf(eDiagnosticSeverityError,
111 "errored out in %s, couldn't AddArguments",
112 __FUNCTION__);
113 return lldb::eExpressionSetupError;
114 }
115
116 function_stack_bottom = m_stack_frame_bottom;
117 function_stack_top = m_stack_frame_top;
118
119 IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp,
120 interpreter_error, function_stack_bottom,
121 function_stack_top, exe_ctx);
122
123 if (!interpreter_error.Success()) {
124 diagnostic_manager.Printf(eDiagnosticSeverityError,
125 "supposed to interpret, but failed: %s",
126 interpreter_error.AsCString());
127 return lldb::eExpressionDiscarded;
128 }
129 } else {
130 if (!exe_ctx.HasThreadScope()) {
131 diagnostic_manager.Printf(eDiagnosticSeverityError,
132 "%s called with no thread selected",
133 __FUNCTION__);
134 return lldb::eExpressionSetupError;
135 }
136
137 Address wrapper_address(m_jit_start_addr);
138
139 std::vector<lldb::addr_t> args;
140
141 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
142 diagnostic_manager.Printf(eDiagnosticSeverityError,
143 "errored out in %s, couldn't AddArguments",
144 __FUNCTION__);
145 return lldb::eExpressionSetupError;
146 }
147
148 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression(
149 exe_ctx.GetThreadRef(), wrapper_address, args, options,
150 shared_ptr_to_me));
151
152 StreamString ss;
153 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) {
154 diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString());
155 return lldb::eExpressionSetupError;
156 }
157
158 ThreadPlanCallUserExpression *user_expression_plan =
159 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get());
160
161 lldb::addr_t function_stack_pointer =
162 user_expression_plan->GetFunctionStackPointer();
163
164 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize();
165 function_stack_top = function_stack_pointer;
166
167 LLDB_LOGF(log,
168 "-- [UserExpression::Execute] Execution of expression begins --");
169
170 if (exe_ctx.GetProcessPtr())
171 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
172
173 lldb::ExpressionResults execution_result =
174 exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options,
175 diagnostic_manager);
176
177 if (exe_ctx.GetProcessPtr())
178 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
179
180 LLDB_LOGF(log, "-- [UserExpression::Execute] Execution of expression "
181 "completed --");
182
183 if (execution_result == lldb::eExpressionInterrupted ||
184 execution_result == lldb::eExpressionHitBreakpoint) {
185 const char *error_desc = nullptr;
186
187 if (call_plan_sp) {
188 lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo();
189 if (real_stop_info_sp)
190 error_desc = real_stop_info_sp->GetDescription();
191 }
192 if (error_desc)
193 diagnostic_manager.Printf(eDiagnosticSeverityError,
194 "Execution was interrupted, reason: %s.",
195 error_desc);
196 else
197 diagnostic_manager.PutString(eDiagnosticSeverityError,
198 "Execution was interrupted.");
199
200 if ((execution_result == lldb::eExpressionInterrupted &&
201 options.DoesUnwindOnError()) ||
202 (execution_result == lldb::eExpressionHitBreakpoint &&
203 options.DoesIgnoreBreakpoints()))
204 diagnostic_manager.AppendMessageToDiagnostic(
205 "The process has been returned to the state before expression "
206 "evaluation.");
207 else {
208 if (execution_result == lldb::eExpressionHitBreakpoint)
209 user_expression_plan->TransferExpressionOwnership();
210 diagnostic_manager.AppendMessageToDiagnostic(
211 "The process has been left at the point where it was "
212 "interrupted, "
213 "use \"thread return -x\" to return to the state before "
214 "expression evaluation.");
215 }
216
217 return execution_result;
218 } else if (execution_result == lldb::eExpressionStoppedForDebug) {
219 diagnostic_manager.PutString(
220 eDiagnosticSeverityRemark,
221 "Execution was halted at the first instruction of the expression "
222 "function because \"debug\" was requested.\n"
223 "Use \"thread return -x\" to return to the state before expression "
224 "evaluation.");
225 return execution_result;
226 } else if (execution_result != lldb::eExpressionCompleted) {
227 diagnostic_manager.Printf(
228 eDiagnosticSeverityError, "Couldn't execute function; result was %s",
229 Process::ExecutionResultAsCString(execution_result));
230 return execution_result;
231 }
232 }
233
234 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result,
235 function_stack_bottom, function_stack_top)) {
236 return lldb::eExpressionCompleted;
237 } else {
238 return lldb::eExpressionResultUnavailable;
239 }
240 }
241
FinalizeJITExecution(DiagnosticManager & diagnostic_manager,ExecutionContext & exe_ctx,lldb::ExpressionVariableSP & result,lldb::addr_t function_stack_bottom,lldb::addr_t function_stack_top)242 bool LLVMUserExpression::FinalizeJITExecution(
243 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
244 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom,
245 lldb::addr_t function_stack_top) {
246 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
247
248 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing "
249 "after execution --");
250
251 if (!m_dematerializer_sp) {
252 diagnostic_manager.Printf(eDiagnosticSeverityError,
253 "Couldn't apply expression side effects : no "
254 "dematerializer is present");
255 return false;
256 }
257
258 Status dematerialize_error;
259
260 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom,
261 function_stack_top);
262
263 if (!dematerialize_error.Success()) {
264 diagnostic_manager.Printf(eDiagnosticSeverityError,
265 "Couldn't apply expression side effects : %s",
266 dematerialize_error.AsCString("unknown error"));
267 return false;
268 }
269
270 result =
271 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope());
272
273 if (result)
274 result->TransferAddress();
275
276 m_dematerializer_sp.reset();
277
278 return true;
279 }
280
PrepareToExecuteJITExpression(DiagnosticManager & diagnostic_manager,ExecutionContext & exe_ctx,lldb::addr_t & struct_address)281 bool LLVMUserExpression::PrepareToExecuteJITExpression(
282 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
283 lldb::addr_t &struct_address) {
284 lldb::TargetSP target;
285 lldb::ProcessSP process;
286 lldb::StackFrameSP frame;
287
288 if (!LockAndCheckContext(exe_ctx, target, process, frame)) {
289 diagnostic_manager.PutString(
290 eDiagnosticSeverityError,
291 "The context has changed before we could JIT the expression!");
292 return false;
293 }
294
295 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) {
296 if (m_materialized_address == LLDB_INVALID_ADDRESS) {
297 Status alloc_error;
298
299 IRMemoryMap::AllocationPolicy policy =
300 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly
301 : IRMemoryMap::eAllocationPolicyMirror;
302
303 const bool zero_memory = false;
304
305 m_materialized_address = m_execution_unit_sp->Malloc(
306 m_materializer_up->GetStructByteSize(),
307 m_materializer_up->GetStructAlignment(),
308 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy,
309 zero_memory, alloc_error);
310
311 if (!alloc_error.Success()) {
312 diagnostic_manager.Printf(
313 eDiagnosticSeverityError,
314 "Couldn't allocate space for materialized struct: %s",
315 alloc_error.AsCString());
316 return false;
317 }
318 }
319
320 struct_address = m_materialized_address;
321
322 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) {
323 Status alloc_error;
324
325 const size_t stack_frame_size = 512 * 1024;
326
327 const bool zero_memory = false;
328
329 m_stack_frame_bottom = m_execution_unit_sp->Malloc(
330 stack_frame_size, 8,
331 lldb::ePermissionsReadable | lldb::ePermissionsWritable,
332 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error);
333
334 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size;
335
336 if (!alloc_error.Success()) {
337 diagnostic_manager.Printf(
338 eDiagnosticSeverityError,
339 "Couldn't allocate space for the stack frame: %s",
340 alloc_error.AsCString());
341 return false;
342 }
343 }
344
345 Status materialize_error;
346
347 m_dematerializer_sp = m_materializer_up->Materialize(
348 frame, *m_execution_unit_sp, struct_address, materialize_error);
349
350 if (!materialize_error.Success()) {
351 diagnostic_manager.Printf(eDiagnosticSeverityError,
352 "Couldn't materialize: %s",
353 materialize_error.AsCString());
354 return false;
355 }
356 }
357 return true;
358 }
359
GetJITModule()360 lldb::ModuleSP LLVMUserExpression::GetJITModule() {
361 if (m_execution_unit_sp)
362 return m_execution_unit_sp->GetJITModule();
363 return lldb::ModuleSP();
364 }
365