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FunctionCaller.cpp
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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
11#include "lldb/Core/Module.h"
18#include "lldb/Symbol/Type.h"
20#include "lldb/Target/Process.h"
22#include "lldb/Target/Target.h"
23#include "lldb/Target/Thread.h"
28#include "lldb/Utility/Log.h"
29#include "lldb/Utility/State.h"
30
31using namespace lldb_private;
32
34
35// FunctionCaller constructor
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(nullptr), 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_struct_size(0), m_return_size(0),
48 m_return_offset(0), m_arg_values(arg_value_list), m_compiled(false),
49 m_JITted(false) {
51 // Can't make a FunctionCaller without a process.
52 assert(m_jit_process_wp.lock());
53}
54
55// Destructor
57 lldb::ProcessSP process_sp(m_jit_process_wp.lock());
58 if (process_sp) {
59 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
60 if (jit_module_sp)
61 process_sp->GetTarget().GetImages().Remove(jit_module_sp);
62 }
63}
64
66 ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) {
67 Process *process = exe_ctx.GetProcessPtr();
68
69 if (!process) {
70 diagnostic_manager.Printf(lldb::eSeverityError, "no process.");
71 return false;
72 }
73
74 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
75
76 if (process != jit_process_sp.get()) {
77 diagnostic_manager.Printf(lldb::eSeverityError,
78 "process does not match the stored process.");
79 return false;
80 }
81
82 if (process->GetState() != lldb::eStateStopped) {
83 diagnostic_manager.Printf(lldb::eSeverityError, "process is not stopped");
84 return false;
85 }
86
87 if (!m_compiled) {
88 diagnostic_manager.Printf(lldb::eSeverityError, "function not compiled");
89 return false;
90 }
91
92 if (m_JITted)
93 return true;
94
95 bool can_interpret = false; // should stay that way
96
97 Status jit_error(m_parser->PrepareForExecution(
99 can_interpret, eExecutionPolicyAlways));
100
101 if (!jit_error.Success()) {
102 diagnostic_manager.Printf(lldb::eSeverityError,
103 "Error in PrepareForExecution: %s.",
104 jit_error.AsCString());
105 return false;
106 }
107
108 if (m_parser->GetGenerateDebugInfo()) {
109 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
110
111 if (jit_module_sp) {
112 ConstString const_func_name(FunctionName());
113 FileSpec jit_file;
114 jit_file.SetFilename(const_func_name);
115 jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
116 m_jit_module_wp = jit_module_sp;
117 process->GetTarget().GetImages().Append(jit_module_sp,
118 true /* notify */);
119 }
120 }
121 if (process && m_jit_start_addr)
122 m_jit_process_wp = process->shared_from_this();
123
124 m_JITted = true;
125
126 return true;
127}
128
130 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
131 DiagnosticManager &diagnostic_manager) {
132 return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values,
133 diagnostic_manager);
134}
135
136// FIXME: Assure that the ValueList we were passed in is consistent with the one
137// that defined this function.
138
140 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
141 ValueList &arg_values, DiagnosticManager &diagnostic_manager) {
142 // All the information to reconstruct the struct is provided by the
143 // StructExtractor.
144 if (!m_struct_valid) {
145 diagnostic_manager.PutString(lldb::eSeverityError,
146 "Argument information was not correctly "
147 "parsed, so the function cannot be called.");
148 return false;
149 }
150
153
154 Process *process = exe_ctx.GetProcessPtr();
155
156 if (process == nullptr)
157 return return_value;
158
159 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
160
161 if (process != jit_process_sp.get())
162 return false;
163
164 if (args_addr_ref == LLDB_INVALID_ADDRESS) {
165 args_addr_ref = process->AllocateMemory(
166 m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable,
167 error);
168 if (args_addr_ref == LLDB_INVALID_ADDRESS)
169 return false;
170 m_wrapper_args_addrs.push_back(args_addr_ref);
171 } else {
172 // Make sure this is an address that we've already handed out.
173 if (find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
174 args_addr_ref) == m_wrapper_args_addrs.end()) {
175 return false;
176 }
177 }
178
179 // TODO: verify fun_addr needs to be a callable address
180 Scalar fun_addr(
182 uint64_t first_offset = m_member_offsets[0];
183 process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr,
184 process->GetAddressByteSize(), error);
185
186 // FIXME: We will need to extend this for Variadic functions.
187
188 Status value_error;
189
190 size_t num_args = arg_values.GetSize();
191 if (num_args != m_arg_values.GetSize()) {
192 diagnostic_manager.Printf(
194 "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "",
195 (uint64_t)num_args, (uint64_t)m_arg_values.GetSize());
196 return false;
197 }
198
199 for (size_t i = 0; i < num_args; i++) {
200 // FIXME: We should sanity check sizes.
201
202 uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes.
203 Value *arg_value = arg_values.GetValueAtIndex(i);
204
205 // FIXME: For now just do scalars:
206
207 // Special case: if it's a pointer, don't do anything (the ABI supports
208 // passing cstrings)
209
210 if (arg_value->GetValueType() == Value::ValueType::HostAddress &&
212 arg_value->GetCompilerType().IsPointerType())
213 continue;
214
215 const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);
216
217 if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar,
218 arg_scalar.GetByteSize(), error))
219 return false;
220 }
221
222 return true;
223}
224
226 lldb::addr_t &args_addr_ref,
227 DiagnosticManager &diagnostic_manager) {
228 // Since we might need to call allocate memory and maybe call code to make
229 // the caller, we need to be stopped.
230 Process *process = exe_ctx.GetProcessPtr();
231 if (!process) {
232 diagnostic_manager.PutString(lldb::eSeverityError, "no process");
233 return false;
234 }
235 if (process->GetState() != lldb::eStateStopped) {
236 diagnostic_manager.PutString(lldb::eSeverityError, "process running");
237 return false;
238 }
239 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
240 return false;
241 if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager))
242 return false;
243 if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager))
244 return false;
245
246 Log *log = GetLog(LLDBLog::Step);
247 LLDB_LOGF(log, "Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n",
248 m_jit_start_addr, args_addr_ref);
249
250 return true;
251}
252
254 ExecutionContext &exe_ctx, lldb::addr_t args_addr,
255 const EvaluateExpressionOptions &options,
256 DiagnosticManager &diagnostic_manager) {
258
259 LLDB_LOGF(log,
260 "-- [FunctionCaller::GetThreadPlanToCallFunction] Creating "
261 "thread plan to call function \"%s\" --",
262 m_name.c_str());
263
264 // FIXME: Use the errors Stream for better error reporting.
265 Thread *thread = exe_ctx.GetThreadPtr();
266 if (thread == nullptr) {
267 diagnostic_manager.PutString(
268 lldb::eSeverityError, "Can't call a function without a valid thread.");
269 return nullptr;
270 }
271
272 // Okay, now run the function:
273
274 Address wrapper_address(m_jit_start_addr);
275
276 lldb::addr_t args = {args_addr};
277
279 *thread, wrapper_address, CompilerType(), args, options));
280 new_plan_sp->SetIsControllingPlan(true);
281 new_plan_sp->SetOkayToDiscard(false);
282 return new_plan_sp;
283}
284
286 lldb::addr_t args_addr,
287 Value &ret_value) {
288 // Read the return value - it is the last field in the struct:
289 // FIXME: How does clang tell us there's no return value? We need to handle
290 // that case.
291 // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and
292 // then use GetReturnValueObject
293 // to fetch the value. That way we can fetch any values we need.
294
296
297 LLDB_LOGF(log,
298 "-- [FunctionCaller::FetchFunctionResults] Fetching function "
299 "results for \"%s\"--",
300 m_name.c_str());
301
302 Process *process = exe_ctx.GetProcessPtr();
303
304 if (process == nullptr)
305 return false;
306
307 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
308
309 if (process != jit_process_sp.get())
310 return false;
311
313 ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory(
314 args_addr + m_return_offset, m_return_size, 0, error);
315
316 if (error.Fail())
317 return false;
318
321 return true;
322}
323
325 lldb::addr_t args_addr) {
326 std::list<lldb::addr_t>::iterator pos;
327 pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
328 args_addr);
329 if (pos != m_wrapper_args_addrs.end())
330 m_wrapper_args_addrs.erase(pos);
331
332 exe_ctx.GetProcessRef().DeallocateMemory(args_addr);
333}
334
336 ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr,
337 const EvaluateExpressionOptions &options,
338 DiagnosticManager &diagnostic_manager, Value &results) {
340
341 // FunctionCaller::ExecuteFunction execution is always just to get the
342 // result. Unless explicitly asked for, ignore breakpoints and unwind on
343 // error.
344 const bool enable_debugging =
345 exe_ctx.GetTargetPtr() &&
347 EvaluateExpressionOptions real_options = options;
348 real_options.SetDebug(false); // This halts the expression for debugging.
349 real_options.SetGenerateDebugInfo(enable_debugging);
350 real_options.SetUnwindOnError(!enable_debugging);
351 real_options.SetIgnoreBreakpoints(!enable_debugging);
352
353 lldb::addr_t args_addr;
354
355 if (args_addr_ptr != nullptr)
356 args_addr = *args_addr_ptr;
357 else
358 args_addr = LLDB_INVALID_ADDRESS;
359
360 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
362
363 if (args_addr == LLDB_INVALID_ADDRESS) {
364 if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager))
366 }
367
369
370 LLDB_LOGF(log,
371 "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==",
372 m_name.c_str());
373
375 exe_ctx, args_addr, real_options, diagnostic_manager);
376 if (!call_plan_sp)
378
379 // We need to make sure we record the fact that we are running an expression
380 // here otherwise this fact will fail to be recorded when fetching an
381 // Objective-C object description
382 if (exe_ctx.GetProcessPtr())
384
385 return_value = exe_ctx.GetProcessRef().RunThreadPlan(
386 exe_ctx, call_plan_sp, real_options, diagnostic_manager);
387
388 if (log) {
389 if (return_value != lldb::eExpressionCompleted) {
390 LLDB_LOGF(log,
391 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
392 "completed abnormally: %s ==",
393 m_name.c_str(),
395 } else {
396 LLDB_LOGF(log,
397 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
398 "completed normally ==",
399 m_name.c_str());
400 }
401 }
402
403 if (exe_ctx.GetProcessPtr())
404 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
405
406 if (args_addr_ptr != nullptr)
407 *args_addr_ptr = args_addr;
408
409 if (return_value != lldb::eExpressionCompleted)
410 return return_value;
411
412 FetchFunctionResults(exe_ctx, args_addr, results);
413
414 if (args_addr_ptr == nullptr)
415 DeallocateFunctionResults(exe_ctx, args_addr);
416
418}
static llvm::raw_ostream & error(Stream &strm)
#define LLDB_LOGF(log,...)
Definition: Log.h:366
A section + offset based address class.
Definition: Address.h:62
lldb::addr_t GetCallableLoadAddress(Target *target, bool is_indirect=false) const
Get the load address as a callable code load address.
Definition: Address.cpp:338
Generic representation of a type in a programming language.
Definition: CompilerType.h:36
bool IsPointerType(CompilerType *pointee_type=nullptr) const
A uniqued constant string class.
Definition: ConstString.h:40
size_t void PutString(lldb::Severity severity, llvm::StringRef str)
size_t Printf(lldb::Severity severity, const char *format,...) __attribute__((format(printf
void SetUnwindOnError(bool unwind=false)
Definition: Target.h:343
void SetIgnoreBreakpoints(bool ignore=false)
Definition: Target.h:347
"lldb/Target/ExecutionContextScope.h" Inherit from this if your object can reconstruct its execution ...
virtual lldb::ProcessSP CalculateProcess()=0
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
Process & GetProcessRef() const
Returns a reference to the process object.
Target * GetTargetPtr() const
Returns a pointer to the target object.
const lldb::ThreadSP & GetThreadSP() const
Get accessor to get the thread shared pointer.
Process * GetProcessPtr() const
Returns a pointer to the process object.
Thread * GetThreadPtr() const
Returns a pointer to the thread object.
Encapsulates a single expression for use in lldb.
Definition: Expression.h:31
lldb::addr_t m_jit_end_addr
The address of the JITted function within the JIT allocation.
Definition: Expression.h:94
lldb::ProcessWP m_jit_process_wp
Expression's always have to have a target...
Definition: Expression.h:88
lldb::addr_t m_jit_start_addr
An expression might have a process, but it doesn't need to (e.g.
Definition: Expression.h:91
A file utility class.
Definition: FileSpec.h:56
void SetFilename(ConstString filename)
Filename string set accessor.
Definition: FileSpec.cpp:345
std::list< lldb::addr_t > m_wrapper_args_addrs
The addresses of the arguments to the wrapper function.
FunctionCaller(ExecutionContextScope &exe_scope, const CompilerType &return_type, const Address &function_address, const ValueList &arg_value_list, const char *name)
Constructor.
~FunctionCaller() override
Destructor.
Address m_function_addr
If we don't have the FunctionSP, we at least need the address & return type.
size_t m_struct_size
These values are populated by the ASTStructExtractor.
void DeallocateFunctionResults(ExecutionContext &exe_ctx, lldb::addr_t args_addr)
Deallocate the arguments structure.
uint64_t m_return_offset
The offset of the result variable in the struct, in bytes.
bool m_struct_valid
True if the ASTStructExtractor has populated the variables below.
bool InsertFunction(ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, DiagnosticManager &diagnostic_manager)
Insert the default function wrapper and its default argument struct.
ValueList m_arg_values
The default values of the arguments.
lldb::ExpressionResults ExecuteFunction(ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, const EvaluateExpressionOptions &options, DiagnosticManager &diagnostic_manager, Value &results)
Run the function this FunctionCaller was created with.
lldb::ThreadPlanSP GetThreadPlanToCallFunction(ExecutionContext &exe_ctx, lldb::addr_t args_addr, const EvaluateExpressionOptions &options, DiagnosticManager &diagnostic_manager)
Get a thread plan to run the function this FunctionCaller was created with.
virtual unsigned CompileFunction(lldb::ThreadSP thread_to_use_sp, DiagnosticManager &diagnostic_manager)=0
Compile the wrapper function.
bool FetchFunctionResults(ExecutionContext &exe_ctx, lldb::addr_t args_addr, Value &ret_value)
Get the result of the function from its struct.
CompilerType m_function_return_type
The opaque clang qual type for the function return type.
bool WriteFunctionArguments(ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, DiagnosticManager &diagnostic_manager)
Insert the default function argument struct.
uint64_t m_return_size
The size of the result variable, in bytes.
bool m_compiled
True if the wrapper function has already been parsed.
std::string m_name
The name of this clang function - for debugging purposes.
bool m_JITted
True if the wrapper function has already been JIT-compiled.
std::shared_ptr< IRExecutionUnit > m_execution_unit_sp
std::unique_ptr< ExpressionParser > m_parser
The parser responsible for compiling the function.
const char * FunctionName() override
Return the function name that should be used for executing the expression.
std::vector< uint64_t > m_member_offsets
The offset of each member in the struct, in bytes.
bool WriteFunctionWrapper(ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager)
Insert the default function wrapper (using the JIT)
void Append(const lldb::ModuleSP &module_sp, bool notify=true)
Append a module to the module list.
Definition: ModuleList.cpp:247
A plug-in interface definition class for debugging a process.
Definition: Process.h:341
lldb::ExpressionResults RunThreadPlan(ExecutionContext &exe_ctx, lldb::ThreadPlanSP &thread_plan_sp, const EvaluateExpressionOptions &options, DiagnosticManager &diagnostic_manager)
Definition: Process.cpp:4785
lldb::addr_t AllocateMemory(size_t size, uint32_t permissions, Status &error)
The public interface to allocating memory in the process.
Definition: Process.cpp:2307
lldb::StateType GetState()
Get accessor for the current process state.
Definition: Process.cpp:1328
void SetRunningUserExpression(bool on)
Definition: Process.cpp:1514
uint64_t ReadUnsignedIntegerFromMemory(lldb::addr_t load_addr, size_t byte_size, uint64_t fail_value, Status &error)
Reads an unsigned integer of the specified byte size from process memory.
Definition: Process.cpp:2107
static const char * ExecutionResultAsCString(lldb::ExpressionResults result)
Definition: Process.cpp:5575
Status DeallocateMemory(lldb::addr_t ptr)
The public interface to deallocating memory in the process.
Definition: Process.cpp:2378
uint32_t GetAddressByteSize() const
Definition: Process.cpp:3458
size_t WriteScalarToMemory(lldb::addr_t vm_addr, const Scalar &scalar, size_t size, Status &error)
Write all or part of a scalar value to memory.
Definition: Process.cpp:2247
Target & GetTarget()
Get the target object pointer for this module.
Definition: Process.h:1277
size_t GetByteSize() const
Definition: Scalar.cpp:132
An error handling class.
Definition: Status.h:44
const char * AsCString(const char *default_error_str="unknown error") const
Get the error string associated with the current error.
Definition: Status.cpp:129
bool Success() const
Test for success condition.
Definition: Status.cpp:278
bool GetDebugUtilityExpression() const
Definition: Target.cpp:4875
const ModuleList & GetImages() const
Get accessor for the images for this process.
Definition: Target.h:981
Value * GetValueAtIndex(size_t idx)
Definition: Value.cpp:686
const Scalar & GetScalar() const
Definition: Value.h:112
@ HostAddress
A host address value (for memory in the process that < A is using liblldb).
@ Scalar
A raw scalar value.
ValueType GetValueType() const
Definition: Value.cpp:109
void SetCompilerType(const CompilerType &compiler_type)
Definition: Value.cpp:268
Scalar & ResolveValue(ExecutionContext *exe_ctx, Module *module=nullptr)
Definition: Value.cpp:577
void SetValueType(ValueType value_type)
Definition: Value.h:89
ContextType GetContextType() const
Definition: Value.h:87
const CompilerType & GetCompilerType()
Definition: Value.cpp:239
#define LLDB_INVALID_ADDRESS
Definition: lldb-defines.h:82
A class that represents a running process on the host machine.
Log * GetLog(Cat mask)
Retrieve the Log object for the channel associated with the given log enum.
Definition: Log.h:331
std::shared_ptr< lldb_private::ThreadPlan > ThreadPlanSP
Definition: lldb-forward.h:444
@ eStateStopped
Process or thread is stopped and can be examined.
ExpressionResults
The results of expression evaluation.
@ eExpressionCompleted
@ eExpressionSetupError
std::shared_ptr< lldb_private::Process > ProcessSP
Definition: lldb-forward.h:384
std::weak_ptr< lldb_private::Process > ProcessWP
Definition: lldb-forward.h:387
uint64_t addr_t
Definition: lldb-types.h:80
std::shared_ptr< lldb_private::Module > ModuleSP
Definition: lldb-forward.h:368