1 //===-- FunctionCaller.cpp ---------------------------------------*- C++-*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10
11 #include "lldb/Expression/FunctionCaller.h"
12 #include "lldb/Core/Module.h"
13 #include "lldb/Core/ValueObject.h"
14 #include "lldb/Core/ValueObjectList.h"
15 #include "lldb/Expression/DiagnosticManager.h"
16 #include "lldb/Expression/IRExecutionUnit.h"
17 #include "lldb/Interpreter/CommandReturnObject.h"
18 #include "lldb/Symbol/Function.h"
19 #include "lldb/Symbol/Type.h"
20 #include "lldb/Target/ExecutionContext.h"
21 #include "lldb/Target/Process.h"
22 #include "lldb/Target/RegisterContext.h"
23 #include "lldb/Target/Target.h"
24 #include "lldb/Target/Thread.h"
25 #include "lldb/Target/ThreadPlan.h"
26 #include "lldb/Target/ThreadPlanCallFunction.h"
27 #include "lldb/Utility/DataExtractor.h"
28 #include "lldb/Utility/Log.h"
29 #include "lldb/Utility/State.h"
30
31 using namespace lldb_private;
32
33 //----------------------------------------------------------------------
34 // FunctionCaller constructor
35 //----------------------------------------------------------------------
FunctionCaller(ExecutionContextScope & exe_scope,const CompilerType & return_type,const Address & functionAddress,const ValueList & arg_value_list,const char * name)36 FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope,
37 const CompilerType &return_type,
38 const Address &functionAddress,
39 const ValueList &arg_value_list,
40 const char *name)
41 : Expression(exe_scope), m_execution_unit_sp(), m_parser(),
42 m_jit_module_wp(), m_name(name ? name : "<unknown>"),
43 m_function_ptr(NULL), m_function_addr(functionAddress),
44 m_function_return_type(return_type),
45 m_wrapper_function_name("__lldb_caller_function"),
46 m_wrapper_struct_name("__lldb_caller_struct"), m_wrapper_args_addrs(),
47 m_struct_valid(false), m_arg_values(arg_value_list), m_compiled(false),
48 m_JITted(false) {
49 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
50 // Can't make a FunctionCaller without a process.
51 assert(m_jit_process_wp.lock());
52 }
53
54 //----------------------------------------------------------------------
55 // Destructor
56 //----------------------------------------------------------------------
~FunctionCaller()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(jit_module_sp);
63 }
64 }
65
WriteFunctionWrapper(ExecutionContext & exe_ctx,DiagnosticManager & diagnostic_manager)66 bool FunctionCaller::WriteFunctionWrapper(
67 ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) {
68 Process *process = exe_ctx.GetProcessPtr();
69
70 if (!process)
71 return false;
72
73 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
74
75 if (process != jit_process_sp.get())
76 return false;
77
78 if (!m_compiled)
79 return false;
80
81 if (m_JITted)
82 return true;
83
84 bool can_interpret = false; // should stay that way
85
86 Status jit_error(m_parser->PrepareForExecution(
87 m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
88 can_interpret, eExecutionPolicyAlways));
89
90 if (!jit_error.Success()) {
91 diagnostic_manager.Printf(eDiagnosticSeverityError,
92 "Error in PrepareForExecution: %s.",
93 jit_error.AsCString());
94 return false;
95 }
96
97 if (m_parser->GetGenerateDebugInfo()) {
98 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
99
100 if (jit_module_sp) {
101 ConstString const_func_name(FunctionName());
102 FileSpec jit_file;
103 jit_file.GetFilename() = const_func_name;
104 jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
105 m_jit_module_wp = jit_module_sp;
106 process->GetTarget().GetImages().Append(jit_module_sp);
107 }
108 }
109 if (process && m_jit_start_addr)
110 m_jit_process_wp = process->shared_from_this();
111
112 m_JITted = true;
113
114 return true;
115 }
116
WriteFunctionArguments(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,DiagnosticManager & diagnostic_manager)117 bool FunctionCaller::WriteFunctionArguments(
118 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
119 DiagnosticManager &diagnostic_manager) {
120 return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values,
121 diagnostic_manager);
122 }
123
124 // FIXME: Assure that the ValueList we were passed in is consistent with the one
125 // that defined this function.
126
WriteFunctionArguments(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,ValueList & arg_values,DiagnosticManager & diagnostic_manager)127 bool FunctionCaller::WriteFunctionArguments(
128 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
129 ValueList &arg_values, DiagnosticManager &diagnostic_manager) {
130 // All the information to reconstruct the struct is provided by the
131 // StructExtractor.
132 if (!m_struct_valid) {
133 diagnostic_manager.PutString(eDiagnosticSeverityError,
134 "Argument information was not correctly "
135 "parsed, so the function cannot be called.");
136 return false;
137 }
138
139 Status error;
140 lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
141
142 Process *process = exe_ctx.GetProcessPtr();
143
144 if (process == NULL)
145 return return_value;
146
147 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
148
149 if (process != jit_process_sp.get())
150 return false;
151
152 if (args_addr_ref == LLDB_INVALID_ADDRESS) {
153 args_addr_ref = process->AllocateMemory(
154 m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable,
155 error);
156 if (args_addr_ref == LLDB_INVALID_ADDRESS)
157 return false;
158 m_wrapper_args_addrs.push_back(args_addr_ref);
159 } else {
160 // Make sure this is an address that we've already handed out.
161 if (find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
162 args_addr_ref) == m_wrapper_args_addrs.end()) {
163 return false;
164 }
165 }
166
167 // TODO: verify fun_addr needs to be a callable address
168 Scalar fun_addr(
169 m_function_addr.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));
170 uint64_t first_offset = m_member_offsets[0];
171 process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr,
172 process->GetAddressByteSize(), error);
173
174 // FIXME: We will need to extend this for Variadic functions.
175
176 Status value_error;
177
178 size_t num_args = arg_values.GetSize();
179 if (num_args != m_arg_values.GetSize()) {
180 diagnostic_manager.Printf(
181 eDiagnosticSeverityError,
182 "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "",
183 (uint64_t)num_args, (uint64_t)m_arg_values.GetSize());
184 return false;
185 }
186
187 for (size_t i = 0; i < num_args; i++) {
188 // FIXME: We should sanity check sizes.
189
190 uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes.
191 Value *arg_value = arg_values.GetValueAtIndex(i);
192
193 // FIXME: For now just do scalars:
194
195 // Special case: if it's a pointer, don't do anything (the ABI supports
196 // passing cstrings)
197
198 if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
199 arg_value->GetContextType() == Value::eContextTypeInvalid &&
200 arg_value->GetCompilerType().IsPointerType())
201 continue;
202
203 const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);
204
205 if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar,
206 arg_scalar.GetByteSize(), error))
207 return false;
208 }
209
210 return true;
211 }
212
InsertFunction(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,DiagnosticManager & diagnostic_manager)213 bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx,
214 lldb::addr_t &args_addr_ref,
215 DiagnosticManager &diagnostic_manager) {
216 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
217 return false;
218 if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager))
219 return false;
220 if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager))
221 return false;
222
223 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
224 if (log)
225 log->Printf("Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n",
226 m_jit_start_addr, args_addr_ref);
227
228 return true;
229 }
230
GetThreadPlanToCallFunction(ExecutionContext & exe_ctx,lldb::addr_t args_addr,const EvaluateExpressionOptions & options,DiagnosticManager & diagnostic_manager)231 lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction(
232 ExecutionContext &exe_ctx, lldb::addr_t args_addr,
233 const EvaluateExpressionOptions &options,
234 DiagnosticManager &diagnostic_manager) {
235 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
236 LIBLLDB_LOG_STEP));
237
238 if (log)
239 log->Printf("-- [FunctionCaller::GetThreadPlanToCallFunction] Creating "
240 "thread plan to call function \"%s\" --",
241 m_name.c_str());
242
243 // FIXME: Use the errors Stream for better error reporting.
244 Thread *thread = exe_ctx.GetThreadPtr();
245 if (thread == NULL) {
246 diagnostic_manager.PutString(
247 eDiagnosticSeverityError,
248 "Can't call a function without a valid thread.");
249 return NULL;
250 }
251
252 // Okay, now run the function:
253
254 Address wrapper_address(m_jit_start_addr);
255
256 lldb::addr_t args = {args_addr};
257
258 lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction(
259 *thread, wrapper_address, CompilerType(), args, options));
260 new_plan_sp->SetIsMasterPlan(true);
261 new_plan_sp->SetOkayToDiscard(false);
262 return new_plan_sp;
263 }
264
FetchFunctionResults(ExecutionContext & exe_ctx,lldb::addr_t args_addr,Value & ret_value)265 bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx,
266 lldb::addr_t args_addr,
267 Value &ret_value) {
268 // Read the return value - it is the last field in the struct:
269 // FIXME: How does clang tell us there's no return value? We need to handle
270 // that case.
271 // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and
272 // then use GetReturnValueObject
273 // to fetch the value. That way we can fetch any values we need.
274
275 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
276 LIBLLDB_LOG_STEP));
277
278 if (log)
279 log->Printf("-- [FunctionCaller::FetchFunctionResults] Fetching function "
280 "results for \"%s\"--",
281 m_name.c_str());
282
283 Process *process = exe_ctx.GetProcessPtr();
284
285 if (process == NULL)
286 return false;
287
288 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
289
290 if (process != jit_process_sp.get())
291 return false;
292
293 Status error;
294 ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory(
295 args_addr + m_return_offset, m_return_size, 0, error);
296
297 if (error.Fail())
298 return false;
299
300 ret_value.SetCompilerType(m_function_return_type);
301 ret_value.SetValueType(Value::eValueTypeScalar);
302 return true;
303 }
304
DeallocateFunctionResults(ExecutionContext & exe_ctx,lldb::addr_t args_addr)305 void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx,
306 lldb::addr_t args_addr) {
307 std::list<lldb::addr_t>::iterator pos;
308 pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
309 args_addr);
310 if (pos != m_wrapper_args_addrs.end())
311 m_wrapper_args_addrs.erase(pos);
312
313 exe_ctx.GetProcessRef().DeallocateMemory(args_addr);
314 }
315
ExecuteFunction(ExecutionContext & exe_ctx,lldb::addr_t * args_addr_ptr,const EvaluateExpressionOptions & options,DiagnosticManager & diagnostic_manager,Value & results)316 lldb::ExpressionResults FunctionCaller::ExecuteFunction(
317 ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr,
318 const EvaluateExpressionOptions &options,
319 DiagnosticManager &diagnostic_manager, Value &results) {
320 lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
321
322 // FunctionCaller::ExecuteFunction execution is always just to get the
323 // result. Do make sure we ignore breakpoints, unwind on error, and don't try
324 // to debug it.
325 EvaluateExpressionOptions real_options = options;
326 real_options.SetDebug(false);
327 real_options.SetUnwindOnError(true);
328 real_options.SetIgnoreBreakpoints(true);
329
330 lldb::addr_t args_addr;
331
332 if (args_addr_ptr != NULL)
333 args_addr = *args_addr_ptr;
334 else
335 args_addr = LLDB_INVALID_ADDRESS;
336
337 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
338 return lldb::eExpressionSetupError;
339
340 if (args_addr == LLDB_INVALID_ADDRESS) {
341 if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager))
342 return lldb::eExpressionSetupError;
343 }
344
345 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
346 LIBLLDB_LOG_STEP));
347
348 if (log)
349 log->Printf(
350 "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==",
351 m_name.c_str());
352
353 lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction(
354 exe_ctx, args_addr, real_options, diagnostic_manager);
355 if (!call_plan_sp)
356 return lldb::eExpressionSetupError;
357
358 // We need to make sure we record the fact that we are running an expression
359 // here otherwise this fact will fail to be recorded when fetching an
360 // Objective-C object description
361 if (exe_ctx.GetProcessPtr())
362 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
363
364 return_value = exe_ctx.GetProcessRef().RunThreadPlan(
365 exe_ctx, call_plan_sp, real_options, diagnostic_manager);
366
367 if (log) {
368 if (return_value != lldb::eExpressionCompleted) {
369 log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
370 "completed abnormally ==",
371 m_name.c_str());
372 } else {
373 log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
374 "completed normally ==",
375 m_name.c_str());
376 }
377 }
378
379 if (exe_ctx.GetProcessPtr())
380 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
381
382 if (args_addr_ptr != NULL)
383 *args_addr_ptr = args_addr;
384
385 if (return_value != lldb::eExpressionCompleted)
386 return return_value;
387
388 FetchFunctionResults(exe_ctx, args_addr, results);
389
390 if (args_addr_ptr == NULL)
391 DeallocateFunctionResults(exe_ctx, args_addr);
392
393 return lldb::eExpressionCompleted;
394 }
395