1 //===-- ClangFunction.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 // C Includes
12 // C++ Includes
13 // Other libraries and framework includes
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/RecordLayout.h"
16 #include "clang/CodeGen/CodeGenAction.h"
17 #include "clang/CodeGen/ModuleBuilder.h"
18 #include "clang/Frontend/CompilerInstance.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ExecutionEngine/ExecutionEngine.h"
22 #include "llvm/IR/Module.h"
23
24 // Project includes
25 #include "lldb/Expression/ASTStructExtractor.h"
26 #include "lldb/Expression/ClangExpressionParser.h"
27 #include "lldb/Expression/ClangFunction.h"
28 #include "lldb/Expression/IRExecutionUnit.h"
29 #include "lldb/Symbol/Type.h"
30 #include "lldb/Core/DataExtractor.h"
31 #include "lldb/Core/State.h"
32 #include "lldb/Core/ValueObject.h"
33 #include "lldb/Core/ValueObjectList.h"
34 #include "lldb/Interpreter/CommandReturnObject.h"
35 #include "lldb/Symbol/ClangASTContext.h"
36 #include "lldb/Symbol/Function.h"
37 #include "lldb/Target/ExecutionContext.h"
38 #include "lldb/Target/Process.h"
39 #include "lldb/Target/RegisterContext.h"
40 #include "lldb/Target/Target.h"
41 #include "lldb/Target/Thread.h"
42 #include "lldb/Target/ThreadPlan.h"
43 #include "lldb/Target/ThreadPlanCallFunction.h"
44 #include "lldb/Core/Log.h"
45
46 using namespace lldb_private;
47
48 //----------------------------------------------------------------------
49 // ClangFunction constructor
50 //----------------------------------------------------------------------
ClangFunction(ExecutionContextScope & exe_scope,const ClangASTType & return_type,const Address & functionAddress,const ValueList & arg_value_list)51 ClangFunction::ClangFunction
52 (
53 ExecutionContextScope &exe_scope,
54 const ClangASTType &return_type,
55 const Address& functionAddress,
56 const ValueList &arg_value_list
57 ) :
58 m_function_ptr (NULL),
59 m_function_addr (functionAddress),
60 m_function_return_type(return_type),
61 m_wrapper_function_name ("__lldb_caller_function"),
62 m_wrapper_struct_name ("__lldb_caller_struct"),
63 m_wrapper_args_addrs (),
64 m_arg_values (arg_value_list),
65 m_compiled (false),
66 m_JITted (false)
67 {
68 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
69 // Can't make a ClangFunction without a process.
70 assert (m_jit_process_wp.lock());
71 }
72
ClangFunction(ExecutionContextScope & exe_scope,Function & function,ClangASTContext * ast_context,const ValueList & arg_value_list)73 ClangFunction::ClangFunction
74 (
75 ExecutionContextScope &exe_scope,
76 Function &function,
77 ClangASTContext *ast_context,
78 const ValueList &arg_value_list
79 ) :
80 m_function_ptr (&function),
81 m_function_addr (),
82 m_function_return_type (),
83 m_wrapper_function_name ("__lldb_function_caller"),
84 m_wrapper_struct_name ("__lldb_caller_struct"),
85 m_wrapper_args_addrs (),
86 m_arg_values (arg_value_list),
87 m_compiled (false),
88 m_JITted (false)
89 {
90 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
91 // Can't make a ClangFunction without a process.
92 assert (m_jit_process_wp.lock());
93
94 m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress();
95 m_function_return_type = m_function_ptr->GetClangType().GetFunctionReturnType();
96 }
97
98 //----------------------------------------------------------------------
99 // Destructor
100 //----------------------------------------------------------------------
~ClangFunction()101 ClangFunction::~ClangFunction()
102 {
103 }
104
105 unsigned
CompileFunction(Stream & errors)106 ClangFunction::CompileFunction (Stream &errors)
107 {
108 if (m_compiled)
109 return 0;
110
111 // FIXME: How does clang tell us there's no return value? We need to handle that case.
112 unsigned num_errors = 0;
113
114 std::string return_type_str (m_function_return_type.GetTypeName().AsCString(""));
115
116 // Cons up the function we're going to wrap our call in, then compile it...
117 // We declare the function "extern "C"" because the compiler might be in C++
118 // mode which would mangle the name and then we couldn't find it again...
119 m_wrapper_function_text.clear();
120 m_wrapper_function_text.append ("extern \"C\" void ");
121 m_wrapper_function_text.append (m_wrapper_function_name);
122 m_wrapper_function_text.append (" (void *input)\n{\n struct ");
123 m_wrapper_function_text.append (m_wrapper_struct_name);
124 m_wrapper_function_text.append (" \n {\n");
125 m_wrapper_function_text.append (" ");
126 m_wrapper_function_text.append (return_type_str);
127 m_wrapper_function_text.append (" (*fn_ptr) (");
128
129 // Get the number of arguments. If we have a function type and it is prototyped,
130 // trust that, otherwise use the values we were given.
131
132 // FIXME: This will need to be extended to handle Variadic functions. We'll need
133 // to pull the defined arguments out of the function, then add the types from the
134 // arguments list for the variable arguments.
135
136 uint32_t num_args = UINT32_MAX;
137 bool trust_function = false;
138 // GetArgumentCount returns -1 for an unprototyped function.
139 ClangASTType function_clang_type;
140 if (m_function_ptr)
141 {
142 function_clang_type = m_function_ptr->GetClangType();
143 if (function_clang_type)
144 {
145 int num_func_args = function_clang_type.GetFunctionArgumentCount();
146 if (num_func_args >= 0)
147 {
148 trust_function = true;
149 num_args = num_func_args;
150 }
151 }
152 }
153
154 if (num_args == UINT32_MAX)
155 num_args = m_arg_values.GetSize();
156
157 std::string args_buffer; // This one stores the definition of all the args in "struct caller".
158 std::string args_list_buffer; // This one stores the argument list called from the structure.
159 for (size_t i = 0; i < num_args; i++)
160 {
161 std::string type_name;
162
163 if (trust_function)
164 {
165 type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i).GetTypeName().AsCString("");
166 }
167 else
168 {
169 ClangASTType clang_qual_type = m_arg_values.GetValueAtIndex(i)->GetClangType ();
170 if (clang_qual_type)
171 {
172 type_name = clang_qual_type.GetTypeName().AsCString("");
173 }
174 else
175 {
176 errors.Printf("Could not determine type of input value %zu.", i);
177 return 1;
178 }
179 }
180
181 m_wrapper_function_text.append (type_name);
182 if (i < num_args - 1)
183 m_wrapper_function_text.append (", ");
184
185 char arg_buf[32];
186 args_buffer.append (" ");
187 args_buffer.append (type_name);
188 snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
189 args_buffer.push_back (' ');
190 args_buffer.append (arg_buf);
191 args_buffer.append (";\n");
192
193 args_list_buffer.append ("__lldb_fn_data->");
194 args_list_buffer.append (arg_buf);
195 if (i < num_args - 1)
196 args_list_buffer.append (", ");
197
198 }
199 m_wrapper_function_text.append (");\n"); // Close off the function calling prototype.
200
201 m_wrapper_function_text.append (args_buffer);
202
203 m_wrapper_function_text.append (" ");
204 m_wrapper_function_text.append (return_type_str);
205 m_wrapper_function_text.append (" return_value;");
206 m_wrapper_function_text.append ("\n };\n struct ");
207 m_wrapper_function_text.append (m_wrapper_struct_name);
208 m_wrapper_function_text.append ("* __lldb_fn_data = (struct ");
209 m_wrapper_function_text.append (m_wrapper_struct_name);
210 m_wrapper_function_text.append (" *) input;\n");
211
212 m_wrapper_function_text.append (" __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
213 m_wrapper_function_text.append (args_list_buffer);
214 m_wrapper_function_text.append (");\n}\n");
215
216 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
217 if (log)
218 log->Printf ("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
219
220 // Okay, now compile this expression
221
222 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
223 if (jit_process_sp)
224 {
225 m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this));
226
227 num_errors = m_parser->Parse (errors);
228 }
229 else
230 {
231 errors.Printf("no process - unable to inject function");
232 num_errors = 1;
233 }
234
235 m_compiled = (num_errors == 0);
236
237 if (!m_compiled)
238 return num_errors;
239
240 return num_errors;
241 }
242
243 bool
WriteFunctionWrapper(ExecutionContext & exe_ctx,Stream & errors)244 ClangFunction::WriteFunctionWrapper (ExecutionContext &exe_ctx, Stream &errors)
245 {
246 Process *process = exe_ctx.GetProcessPtr();
247
248 if (!process)
249 return false;
250
251 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
252
253 if (process != jit_process_sp.get())
254 return false;
255
256 if (!m_compiled)
257 return false;
258
259 if (m_JITted)
260 return true;
261
262 bool can_interpret = false; // should stay that way
263
264 Error jit_error (m_parser->PrepareForExecution (m_jit_start_addr,
265 m_jit_end_addr,
266 m_execution_unit_ap,
267 exe_ctx,
268 can_interpret,
269 eExecutionPolicyAlways));
270
271 if (!jit_error.Success())
272 return false;
273
274 if (process && m_jit_start_addr)
275 m_jit_process_wp = lldb::ProcessWP(process->shared_from_this());
276
277 m_JITted = true;
278
279 return true;
280 }
281
282 bool
WriteFunctionArguments(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,Stream & errors)283 ClangFunction::WriteFunctionArguments (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors)
284 {
285 return WriteFunctionArguments(exe_ctx, args_addr_ref, m_function_addr, m_arg_values, errors);
286 }
287
288 // FIXME: Assure that the ValueList we were passed in is consistent with the one that defined this function.
289
290 bool
WriteFunctionArguments(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,Address function_address,ValueList & arg_values,Stream & errors)291 ClangFunction::WriteFunctionArguments (ExecutionContext &exe_ctx,
292 lldb::addr_t &args_addr_ref,
293 Address function_address,
294 ValueList &arg_values,
295 Stream &errors)
296 {
297 // All the information to reconstruct the struct is provided by the
298 // StructExtractor.
299 if (!m_struct_valid)
300 {
301 errors.Printf("Argument information was not correctly parsed, so the function cannot be called.");
302 return false;
303 }
304
305 Error error;
306 using namespace clang;
307 ExecutionResults return_value = eExecutionSetupError;
308
309 Process *process = exe_ctx.GetProcessPtr();
310
311 if (process == NULL)
312 return return_value;
313
314 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
315
316 if (process != jit_process_sp.get())
317 return false;
318
319 if (args_addr_ref == LLDB_INVALID_ADDRESS)
320 {
321 args_addr_ref = process->AllocateMemory(m_struct_size, lldb::ePermissionsReadable|lldb::ePermissionsWritable, error);
322 if (args_addr_ref == LLDB_INVALID_ADDRESS)
323 return false;
324 m_wrapper_args_addrs.push_back (args_addr_ref);
325 }
326 else
327 {
328 // Make sure this is an address that we've already handed out.
329 if (find (m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), args_addr_ref) == m_wrapper_args_addrs.end())
330 {
331 return false;
332 }
333 }
334
335 // TODO: verify fun_addr needs to be a callable address
336 Scalar fun_addr (function_address.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));
337 uint64_t first_offset = m_member_offsets[0];
338 process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr, process->GetAddressByteSize(), error);
339
340 // FIXME: We will need to extend this for Variadic functions.
341
342 Error value_error;
343
344 size_t num_args = arg_values.GetSize();
345 if (num_args != m_arg_values.GetSize())
346 {
347 errors.Printf ("Wrong number of arguments - was: %zu should be: %zu", num_args, m_arg_values.GetSize());
348 return false;
349 }
350
351 for (size_t i = 0; i < num_args; i++)
352 {
353 // FIXME: We should sanity check sizes.
354
355 uint64_t offset = m_member_offsets[i+1]; // Clang sizes are in bytes.
356 Value *arg_value = arg_values.GetValueAtIndex(i);
357
358 // FIXME: For now just do scalars:
359
360 // Special case: if it's a pointer, don't do anything (the ABI supports passing cstrings)
361
362 if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
363 arg_value->GetContextType() == Value::eContextTypeInvalid &&
364 arg_value->GetClangType().IsPointerType())
365 continue;
366
367 const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);
368
369 if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar, arg_scalar.GetByteSize(), error))
370 return false;
371 }
372
373 return true;
374 }
375
376 bool
InsertFunction(ExecutionContext & exe_ctx,lldb::addr_t & args_addr_ref,Stream & errors)377 ClangFunction::InsertFunction (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors)
378 {
379 using namespace clang;
380
381 if (CompileFunction(errors) != 0)
382 return false;
383 if (!WriteFunctionWrapper(exe_ctx, errors))
384 return false;
385 if (!WriteFunctionArguments(exe_ctx, args_addr_ref, errors))
386 return false;
387
388 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
389 if (log)
390 log->Printf ("Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n", m_jit_start_addr, args_addr_ref);
391
392 return true;
393 }
394
395 ThreadPlan *
GetThreadPlanToCallFunction(ExecutionContext & exe_ctx,lldb::addr_t args_addr,const EvaluateExpressionOptions & options,Stream & errors)396 ClangFunction::GetThreadPlanToCallFunction (ExecutionContext &exe_ctx,
397 lldb::addr_t args_addr,
398 const EvaluateExpressionOptions &options,
399 Stream &errors)
400 {
401 Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
402
403 if (log)
404 log->Printf("-- [ClangFunction::GetThreadPlanToCallFunction] Creating thread plan to call function --");
405
406 // FIXME: Use the errors Stream for better error reporting.
407 Thread *thread = exe_ctx.GetThreadPtr();
408 if (thread == NULL)
409 {
410 errors.Printf("Can't call a function without a valid thread.");
411 return NULL;
412 }
413
414 // Okay, now run the function:
415
416 Address wrapper_address (m_jit_start_addr);
417
418 lldb::addr_t args = { args_addr };
419
420 ThreadPlan *new_plan = new ThreadPlanCallFunction (*thread,
421 wrapper_address,
422 ClangASTType(),
423 args,
424 options);
425 new_plan->SetIsMasterPlan(true);
426 new_plan->SetOkayToDiscard (false);
427 return new_plan;
428 }
429
430 bool
FetchFunctionResults(ExecutionContext & exe_ctx,lldb::addr_t args_addr,Value & ret_value)431 ClangFunction::FetchFunctionResults (ExecutionContext &exe_ctx, lldb::addr_t args_addr, Value &ret_value)
432 {
433 // Read the return value - it is the last field in the struct:
434 // FIXME: How does clang tell us there's no return value? We need to handle that case.
435 // FIXME: Create our ThreadPlanCallFunction with the return ClangASTType, and then use GetReturnValueObject
436 // to fetch the value. That way we can fetch any values we need.
437
438 Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
439
440 if (log)
441 log->Printf("-- [ClangFunction::FetchFunctionResults] Fetching function results --");
442
443 Process *process = exe_ctx.GetProcessPtr();
444
445 if (process == NULL)
446 return false;
447
448 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
449
450 if (process != jit_process_sp.get())
451 return false;
452
453 Error error;
454 ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory (args_addr + m_return_offset, m_return_size, 0, error);
455
456 if (error.Fail())
457 return false;
458
459 ret_value.SetClangType(m_function_return_type);
460 ret_value.SetValueType(Value::eValueTypeScalar);
461 return true;
462 }
463
464 void
DeallocateFunctionResults(ExecutionContext & exe_ctx,lldb::addr_t args_addr)465 ClangFunction::DeallocateFunctionResults (ExecutionContext &exe_ctx, lldb::addr_t args_addr)
466 {
467 std::list<lldb::addr_t>::iterator pos;
468 pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), args_addr);
469 if (pos != m_wrapper_args_addrs.end())
470 m_wrapper_args_addrs.erase(pos);
471
472 exe_ctx.GetProcessRef().DeallocateMemory(args_addr);
473 }
474
475 ExecutionResults
ExecuteFunction(ExecutionContext & exe_ctx,lldb::addr_t * args_addr_ptr,const EvaluateExpressionOptions & options,Stream & errors,Value & results)476 ClangFunction::ExecuteFunction(
477 ExecutionContext &exe_ctx,
478 lldb::addr_t *args_addr_ptr,
479 const EvaluateExpressionOptions &options,
480 Stream &errors,
481 Value &results)
482 {
483 using namespace clang;
484 ExecutionResults return_value = eExecutionSetupError;
485
486 // ClangFunction::ExecuteFunction execution is always just to get the result. Do make sure we ignore
487 // breakpoints, unwind on error, and don't try to debug it.
488 EvaluateExpressionOptions real_options = options;
489 real_options.SetDebug(false);
490 real_options.SetUnwindOnError(true);
491 real_options.SetIgnoreBreakpoints(true);
492
493 lldb::addr_t args_addr;
494
495 if (args_addr_ptr != NULL)
496 args_addr = *args_addr_ptr;
497 else
498 args_addr = LLDB_INVALID_ADDRESS;
499
500 if (CompileFunction(errors) != 0)
501 return eExecutionSetupError;
502
503 if (args_addr == LLDB_INVALID_ADDRESS)
504 {
505 if (!InsertFunction(exe_ctx, args_addr, errors))
506 return eExecutionSetupError;
507 }
508
509 Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
510
511 if (log)
512 log->Printf("== [ClangFunction::ExecuteFunction] Executing function ==");
513
514 lldb::ThreadPlanSP call_plan_sp (GetThreadPlanToCallFunction (exe_ctx,
515 args_addr,
516 real_options,
517 errors));
518 if (!call_plan_sp)
519 return eExecutionSetupError;
520
521 // <rdar://problem/12027563> we need to make sure we record the fact that we are running an expression here
522 // otherwise this fact will fail to be recorded when fetching an Objective-C object description
523 if (exe_ctx.GetProcessPtr())
524 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
525
526 return_value = exe_ctx.GetProcessRef().RunThreadPlan (exe_ctx,
527 call_plan_sp,
528 real_options,
529 errors);
530
531 if (log)
532 {
533 if (return_value != eExecutionCompleted)
534 {
535 log->Printf("== [ClangFunction::ExecuteFunction] Execution completed abnormally ==");
536 }
537 else
538 {
539 log->Printf("== [ClangFunction::ExecuteFunction] Execution completed normally ==");
540 }
541 }
542
543 if (exe_ctx.GetProcessPtr())
544 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
545
546 if (args_addr_ptr != NULL)
547 *args_addr_ptr = args_addr;
548
549 if (return_value != eExecutionCompleted)
550 return return_value;
551
552 FetchFunctionResults(exe_ctx, args_addr, results);
553
554 if (args_addr_ptr == NULL)
555 DeallocateFunctionResults(exe_ctx, args_addr);
556
557 return eExecutionCompleted;
558 }
559
560 clang::ASTConsumer *
ASTTransformer(clang::ASTConsumer * passthrough)561 ClangFunction::ASTTransformer (clang::ASTConsumer *passthrough)
562 {
563 m_struct_extractor.reset(new ASTStructExtractor(passthrough, m_wrapper_struct_name.c_str(), *this));
564
565 return m_struct_extractor.get();
566 }
567