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