1 | //===-- FunctionCaller.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 "lldb/Expression/FunctionCaller.h" |
10 | #include "lldb/Core/Module.h" |
11 | #include "lldb/Core/Progress.h" |
12 | #include "lldb/Expression/DiagnosticManager.h" |
13 | #include "lldb/Expression/IRExecutionUnit.h" |
14 | #include "lldb/Interpreter/CommandReturnObject.h" |
15 | #include "lldb/Symbol/Function.h" |
16 | #include "lldb/Symbol/Type.h" |
17 | #include "lldb/Target/ExecutionContext.h" |
18 | #include "lldb/Target/Process.h" |
19 | #include "lldb/Target/RegisterContext.h" |
20 | #include "lldb/Target/Target.h" |
21 | #include "lldb/Target/Thread.h" |
22 | #include "lldb/Target/ThreadPlan.h" |
23 | #include "lldb/Target/ThreadPlanCallFunction.h" |
24 | #include "lldb/Utility/DataExtractor.h" |
25 | #include "lldb/Utility/ErrorMessages.h" |
26 | #include "lldb/Utility/LLDBLog.h" |
27 | #include "lldb/Utility/Log.h" |
28 | #include "lldb/Utility/State.h" |
29 | #include "lldb/ValueObject/ValueObject.h" |
30 | #include "lldb/ValueObject/ValueObjectList.h" |
31 | |
32 | using namespace lldb_private; |
33 | |
34 | char FunctionCaller::ID; |
35 | |
36 | // FunctionCaller constructor |
37 | FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope, |
38 | const CompilerType &return_type, |
39 | const Address &functionAddress, |
40 | const ValueList &arg_value_list, |
41 | const char *name) |
42 | : Expression(exe_scope), m_execution_unit_sp(), m_parser(), |
43 | m_jit_module_wp(), m_name(name ? name : "<unknown>" ), |
44 | m_function_ptr(nullptr), m_function_addr(functionAddress), |
45 | m_function_return_type(return_type), |
46 | m_wrapper_function_name("__lldb_caller_function" ), |
47 | m_wrapper_struct_name("__lldb_caller_struct" ), m_wrapper_args_addrs(), |
48 | m_struct_valid(false), m_struct_size(0), m_return_size(0), |
49 | m_return_offset(0), m_arg_values(arg_value_list), m_compiled(false), |
50 | m_JITted(false) { |
51 | m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess()); |
52 | // Can't make a FunctionCaller without a process. |
53 | assert(m_jit_process_wp.lock()); |
54 | } |
55 | |
56 | // Destructor |
57 | FunctionCaller::~FunctionCaller() { |
58 | lldb::ProcessSP process_sp(m_jit_process_wp.lock()); |
59 | if (process_sp) { |
60 | lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); |
61 | if (jit_module_sp) |
62 | process_sp->GetTarget().GetImages().Remove(module_sp: jit_module_sp); |
63 | } |
64 | } |
65 | |
66 | bool FunctionCaller::WriteFunctionWrapper( |
67 | ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) { |
68 | Process *process = exe_ctx.GetProcessPtr(); |
69 | |
70 | if (!process) { |
71 | diagnostic_manager.Printf(severity: lldb::eSeverityError, format: "no process." ); |
72 | return false; |
73 | } |
74 | |
75 | lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); |
76 | |
77 | if (process != jit_process_sp.get()) { |
78 | diagnostic_manager.Printf(severity: lldb::eSeverityError, |
79 | format: "process does not match the stored process." ); |
80 | return false; |
81 | } |
82 | |
83 | if (process->GetState() != lldb::eStateStopped) { |
84 | diagnostic_manager.Printf(severity: lldb::eSeverityError, format: "process is not stopped" ); |
85 | return false; |
86 | } |
87 | |
88 | if (!m_compiled) { |
89 | diagnostic_manager.Printf(severity: lldb::eSeverityError, format: "function not compiled" ); |
90 | return false; |
91 | } |
92 | |
93 | if (m_JITted) |
94 | return true; |
95 | |
96 | bool can_interpret = false; // should stay that way |
97 | |
98 | Status jit_error(m_parser->PrepareForExecution( |
99 | func_addr&: m_jit_start_addr, func_end&: m_jit_end_addr, execution_unit_sp&: m_execution_unit_sp, exe_ctx, |
100 | can_interpret, execution_policy: eExecutionPolicyAlways)); |
101 | |
102 | if (!jit_error.Success()) { |
103 | diagnostic_manager.Printf(severity: lldb::eSeverityError, |
104 | format: "Error in PrepareForExecution: %s." , |
105 | jit_error.AsCString()); |
106 | return false; |
107 | } |
108 | |
109 | if (m_parser->GetGenerateDebugInfo()) { |
110 | lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule()); |
111 | |
112 | if (jit_module_sp) { |
113 | ConstString const_func_name(FunctionName()); |
114 | FileSpec jit_file; |
115 | jit_file.SetFilename(const_func_name); |
116 | jit_module_sp->SetFileSpecAndObjectName(file: jit_file, object_name: ConstString()); |
117 | m_jit_module_wp = jit_module_sp; |
118 | process->GetTarget().GetImages().Append(module_sp: jit_module_sp, |
119 | notify: true /* notify */); |
120 | } |
121 | } |
122 | if (process && m_jit_start_addr) |
123 | m_jit_process_wp = process->shared_from_this(); |
124 | |
125 | m_JITted = true; |
126 | |
127 | return true; |
128 | } |
129 | |
130 | bool FunctionCaller::WriteFunctionArguments( |
131 | ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, |
132 | DiagnosticManager &diagnostic_manager) { |
133 | return WriteFunctionArguments(exe_ctx, args_addr_ref, arg_values&: m_arg_values, |
134 | diagnostic_manager); |
135 | } |
136 | |
137 | // FIXME: Assure that the ValueList we were passed in is consistent with the one |
138 | // that defined this function. |
139 | |
140 | bool FunctionCaller::WriteFunctionArguments( |
141 | ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, |
142 | ValueList &arg_values, DiagnosticManager &diagnostic_manager) { |
143 | // All the information to reconstruct the struct is provided by the |
144 | // StructExtractor. |
145 | if (!m_struct_valid) { |
146 | diagnostic_manager.PutString(severity: lldb::eSeverityError, |
147 | str: "Argument information was not correctly " |
148 | "parsed, so the function cannot be called." ); |
149 | return false; |
150 | } |
151 | |
152 | Status error; |
153 | lldb::ExpressionResults return_value = lldb::eExpressionSetupError; |
154 | |
155 | Process *process = exe_ctx.GetProcessPtr(); |
156 | |
157 | if (process == nullptr) |
158 | return return_value; |
159 | |
160 | lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); |
161 | |
162 | if (process != jit_process_sp.get()) |
163 | return false; |
164 | |
165 | if (args_addr_ref == LLDB_INVALID_ADDRESS) { |
166 | args_addr_ref = process->AllocateMemory( |
167 | size: m_struct_size, permissions: lldb::ePermissionsReadable | lldb::ePermissionsWritable, |
168 | error); |
169 | if (args_addr_ref == LLDB_INVALID_ADDRESS) |
170 | return false; |
171 | m_wrapper_args_addrs.push_back(x: args_addr_ref); |
172 | } else { |
173 | // Make sure this is an address that we've already handed out. |
174 | if (!llvm::is_contained(Range&: m_wrapper_args_addrs, Element: args_addr_ref)) |
175 | return false; |
176 | } |
177 | |
178 | // TODO: verify fun_addr needs to be a callable address |
179 | Scalar fun_addr( |
180 | m_function_addr.GetCallableLoadAddress(target: exe_ctx.GetTargetPtr())); |
181 | uint64_t first_offset = m_member_offsets[0]; |
182 | process->WriteScalarToMemory(vm_addr: args_addr_ref + first_offset, scalar: fun_addr, |
183 | size: process->GetAddressByteSize(), error); |
184 | |
185 | // FIXME: We will need to extend this for Variadic functions. |
186 | |
187 | Status value_error; |
188 | |
189 | size_t num_args = arg_values.GetSize(); |
190 | if (num_args != m_arg_values.GetSize()) { |
191 | diagnostic_manager.Printf( |
192 | severity: lldb::eSeverityError, |
193 | format: "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "" , |
194 | (uint64_t)num_args, (uint64_t)m_arg_values.GetSize()); |
195 | return false; |
196 | } |
197 | |
198 | for (size_t i = 0; i < num_args; i++) { |
199 | // FIXME: We should sanity check sizes. |
200 | |
201 | uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes. |
202 | Value *arg_value = arg_values.GetValueAtIndex(idx: i); |
203 | |
204 | // FIXME: For now just do scalars: |
205 | |
206 | // Special case: if it's a pointer, don't do anything (the ABI supports |
207 | // passing cstrings) |
208 | |
209 | if (arg_value->GetValueType() == Value::ValueType::HostAddress && |
210 | arg_value->GetContextType() == Value::ContextType::Invalid && |
211 | arg_value->GetCompilerType().IsPointerType()) |
212 | continue; |
213 | |
214 | const Scalar &arg_scalar = arg_value->ResolveValue(exe_ctx: &exe_ctx); |
215 | |
216 | if (!process->WriteScalarToMemory(vm_addr: args_addr_ref + offset, scalar: arg_scalar, |
217 | size: arg_scalar.GetByteSize(), error)) |
218 | return false; |
219 | } |
220 | |
221 | return true; |
222 | } |
223 | |
224 | bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx, |
225 | lldb::addr_t &args_addr_ref, |
226 | DiagnosticManager &diagnostic_manager) { |
227 | // Since we might need to call allocate memory and maybe call code to make |
228 | // the caller, we need to be stopped. |
229 | Process *process = exe_ctx.GetProcessPtr(); |
230 | if (!process) { |
231 | diagnostic_manager.PutString(severity: lldb::eSeverityError, str: "no process" ); |
232 | return false; |
233 | } |
234 | if (process->GetState() != lldb::eStateStopped) { |
235 | diagnostic_manager.PutString(severity: lldb::eSeverityError, str: "process running" ); |
236 | return false; |
237 | } |
238 | if (CompileFunction(thread_to_use_sp: exe_ctx.GetThreadSP(), diagnostic_manager) != 0) |
239 | return false; |
240 | if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager)) |
241 | return false; |
242 | if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager)) |
243 | return false; |
244 | |
245 | Log *log = GetLog(mask: LLDBLog::Step); |
246 | LLDB_LOGF(log, "Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n" , |
247 | m_jit_start_addr, args_addr_ref); |
248 | |
249 | return true; |
250 | } |
251 | |
252 | lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction( |
253 | ExecutionContext &exe_ctx, lldb::addr_t args_addr, |
254 | const EvaluateExpressionOptions &options, |
255 | DiagnosticManager &diagnostic_manager) { |
256 | Log *log(GetLog(mask: LLDBLog::Expressions | LLDBLog::Step)); |
257 | |
258 | LLDB_LOGF(log, |
259 | "-- [FunctionCaller::GetThreadPlanToCallFunction] Creating " |
260 | "thread plan to call function \"%s\" --" , |
261 | m_name.c_str()); |
262 | |
263 | // FIXME: Use the errors Stream for better error reporting. |
264 | Thread *thread = exe_ctx.GetThreadPtr(); |
265 | if (thread == nullptr) { |
266 | diagnostic_manager.PutString( |
267 | severity: lldb::eSeverityError, str: "Can't call a function without a valid thread." ); |
268 | return nullptr; |
269 | } |
270 | |
271 | // Okay, now run the function: |
272 | |
273 | Address wrapper_address(m_jit_start_addr); |
274 | |
275 | lldb::addr_t args = {args_addr}; |
276 | |
277 | lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction( |
278 | *thread, wrapper_address, CompilerType(), args, options)); |
279 | new_plan_sp->SetIsControllingPlan(true); |
280 | new_plan_sp->SetOkayToDiscard(false); |
281 | return new_plan_sp; |
282 | } |
283 | |
284 | bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx, |
285 | lldb::addr_t args_addr, |
286 | Value &ret_value) { |
287 | // Read the return value - it is the last field in the struct: |
288 | // FIXME: How does clang tell us there's no return value? We need to handle |
289 | // that case. |
290 | // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and |
291 | // then use GetReturnValueObject |
292 | // to fetch the value. That way we can fetch any values we need. |
293 | |
294 | Log *log(GetLog(mask: LLDBLog::Expressions | LLDBLog::Step)); |
295 | |
296 | LLDB_LOGF(log, |
297 | "-- [FunctionCaller::FetchFunctionResults] Fetching function " |
298 | "results for \"%s\"--" , |
299 | m_name.c_str()); |
300 | |
301 | Process *process = exe_ctx.GetProcessPtr(); |
302 | |
303 | if (process == nullptr) |
304 | return false; |
305 | |
306 | lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); |
307 | |
308 | if (process != jit_process_sp.get()) |
309 | return false; |
310 | |
311 | Status error; |
312 | ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory( |
313 | load_addr: args_addr + m_return_offset, byte_size: m_return_size, fail_value: 0, error); |
314 | |
315 | if (error.Fail()) |
316 | return false; |
317 | |
318 | ret_value.SetCompilerType(m_function_return_type); |
319 | ret_value.SetValueType(Value::ValueType::Scalar); |
320 | return true; |
321 | } |
322 | |
323 | void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx, |
324 | lldb::addr_t args_addr) { |
325 | std::list<lldb::addr_t>::iterator pos; |
326 | pos = llvm::find(Range&: m_wrapper_args_addrs, Val: args_addr); |
327 | if (pos != m_wrapper_args_addrs.end()) |
328 | m_wrapper_args_addrs.erase(position: pos); |
329 | |
330 | exe_ctx.GetProcessRef().DeallocateMemory(ptr: args_addr); |
331 | } |
332 | |
333 | lldb::ExpressionResults FunctionCaller::ExecuteFunction( |
334 | ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, |
335 | const EvaluateExpressionOptions &options, |
336 | DiagnosticManager &diagnostic_manager, Value &results) { |
337 | lldb::ExpressionResults return_value = lldb::eExpressionSetupError; |
338 | |
339 | Debugger *debugger = |
340 | exe_ctx.GetTargetPtr() ? &exe_ctx.GetTargetPtr()->GetDebugger() : nullptr; |
341 | Progress progress("Calling function" , FunctionName(), {}, debugger); |
342 | |
343 | // FunctionCaller::ExecuteFunction execution is always just to get the |
344 | // result. Unless explicitly asked for, ignore breakpoints and unwind on |
345 | // error. |
346 | const bool enable_debugging = |
347 | exe_ctx.GetTargetPtr() && |
348 | exe_ctx.GetTargetPtr()->GetDebugUtilityExpression(); |
349 | EvaluateExpressionOptions real_options = options; |
350 | real_options.SetDebug(false); // This halts the expression for debugging. |
351 | real_options.SetGenerateDebugInfo(enable_debugging); |
352 | real_options.SetUnwindOnError(!enable_debugging); |
353 | real_options.SetIgnoreBreakpoints(!enable_debugging); |
354 | |
355 | lldb::addr_t args_addr; |
356 | |
357 | if (args_addr_ptr != nullptr) |
358 | args_addr = *args_addr_ptr; |
359 | else |
360 | args_addr = LLDB_INVALID_ADDRESS; |
361 | |
362 | if (CompileFunction(thread_to_use_sp: exe_ctx.GetThreadSP(), diagnostic_manager) != 0) |
363 | return lldb::eExpressionSetupError; |
364 | |
365 | if (args_addr == LLDB_INVALID_ADDRESS) { |
366 | if (!InsertFunction(exe_ctx, args_addr_ref&: args_addr, diagnostic_manager)) |
367 | return lldb::eExpressionSetupError; |
368 | } |
369 | |
370 | Log *log(GetLog(mask: LLDBLog::Expressions | LLDBLog::Step)); |
371 | |
372 | LLDB_LOGF(log, |
373 | "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==" , |
374 | m_name.c_str()); |
375 | |
376 | lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction( |
377 | exe_ctx, args_addr, options: real_options, diagnostic_manager); |
378 | if (!call_plan_sp) |
379 | return lldb::eExpressionSetupError; |
380 | |
381 | // We need to make sure we record the fact that we are running an expression |
382 | // here otherwise this fact will fail to be recorded when fetching an |
383 | // Objective-C object description |
384 | if (exe_ctx.GetProcessPtr()) |
385 | exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); |
386 | |
387 | return_value = exe_ctx.GetProcessRef().RunThreadPlan( |
388 | exe_ctx, thread_plan_sp&: call_plan_sp, options: real_options, diagnostic_manager); |
389 | |
390 | if (log) { |
391 | if (return_value != lldb::eExpressionCompleted) { |
392 | LLDB_LOGF(log, |
393 | "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" " |
394 | "completed abnormally: %s ==" , |
395 | m_name.c_str(), toString(return_value).c_str()); |
396 | } else { |
397 | LLDB_LOGF(log, |
398 | "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" " |
399 | "completed normally ==" , |
400 | m_name.c_str()); |
401 | } |
402 | } |
403 | |
404 | if (exe_ctx.GetProcessPtr()) |
405 | exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); |
406 | |
407 | if (args_addr_ptr != nullptr) |
408 | *args_addr_ptr = args_addr; |
409 | |
410 | if (return_value != lldb::eExpressionCompleted) |
411 | return return_value; |
412 | |
413 | FetchFunctionResults(exe_ctx, args_addr, ret_value&: results); |
414 | |
415 | if (args_addr_ptr == nullptr) |
416 | DeallocateFunctionResults(exe_ctx, args_addr); |
417 | |
418 | return lldb::eExpressionCompleted; |
419 | } |
420 | |