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lldb_private::ClangFunctionCaller Class Reference

#include <ClangFunctionCaller.h>

Inheritance diagram for lldb_private::ClangFunctionCaller:
Inheritance graph
Collaboration diagram for lldb_private::ClangFunctionCaller:
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class  ClangFunctionCallerHelper

Public Member Functions

bool isA (const void *ClassID) const override
 ClangFunctionCaller (ExecutionContextScope &exe_scope, const CompilerType &return_type, const Address &function_address, const ValueList &arg_value_list, const char *name)
 Constructor. More...
 ~ClangFunctionCaller () override
unsigned CompileFunction (lldb::ThreadSP thread_to_use_sp, DiagnosticManager &diagnostic_manager) override
 Compile the wrapper function. More...
ExpressionTypeSystemHelperGetTypeSystemHelper () override
- Public Member Functions inherited from lldb_private::FunctionCaller
 FunctionCaller (ExecutionContextScope &exe_scope, const CompilerType &return_type, const Address &function_address, const ValueList &arg_value_list, const char *name)
 Constructor. More...
 ~FunctionCaller () override
 Destructor. More...
bool InsertFunction (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, DiagnosticManager &diagnostic_manager)
 Insert the default function wrapper and its default argument struct. More...
bool WriteFunctionWrapper (ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager)
 Insert the default function wrapper (using the JIT) More...
bool WriteFunctionArguments (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, DiagnosticManager &diagnostic_manager)
 Insert the default function argument struct. More...
bool WriteFunctionArguments (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, ValueList &arg_values, DiagnosticManager &diagnostic_manager)
 Insert an argument struct with a non-default function address and non- default argument values. More...
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. More...
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. More...
bool FetchFunctionResults (ExecutionContext &exe_ctx, lldb::addr_t args_addr, Value &ret_value)
 Get the result of the function from its struct. More...
void DeallocateFunctionResults (ExecutionContext &exe_ctx, lldb::addr_t args_addr)
 Deallocate the arguments structure. More...
const char * Text () override
 Interface for ClangExpression. More...
const char * FunctionName () override
 Return the function name that should be used for executing the expression. More...
ExpressionVariableListLocalVariables ()
 Return the object that the parser should use when registering local variables. More...
bool NeedsValidation () override
 Return true if validation code should be inserted into the expression. More...
bool NeedsVariableResolution () override
 Return true if external variables in the expression should be resolved. More...
ValueList GetArgumentValues () const
- Public Member Functions inherited from lldb_private::Expression
 Expression (Target &target)
 Expression (ExecutionContextScope &exe_scope)
virtual ~Expression ()=default
 Destructor. More...
virtual lldb::LanguageType Language () const
 Return the language that should be used when parsing. More...
virtual MaterializerGetMaterializer ()
 Return the Materializer that the parser should use when registering external values. More...
virtual ResultType DesiredResultType ()
 Return the desired result type of the function, or eResultTypeAny if indifferent. More...
virtual EvaluateExpressionOptionsGetOptions ()
lldb::addr_t StartAddress ()
 Return the address of the function's JIT-compiled code, or LLDB_INVALID_ADDRESS if the function is not JIT compiled. More...
virtual void WillStartExecuting ()
 Called to notify the expression that it is about to be executed. More...
virtual void DidFinishExecuting ()
 Called to notify the expression that its execution has finished. More...

Static Public Member Functions

static bool classof (const Expression *obj)
- Static Public Member Functions inherited from lldb_private::FunctionCaller
static bool classof (const Expression *obj)

Protected Member Functions

const char * GetWrapperStructName ()

Private Attributes

ClangFunctionCallerHelper m_type_system_helper

Static Private Attributes

static char ID


class ASTStructExtractor

Additional Inherited Members

- Public Types inherited from lldb_private::Expression
enum  ResultType { eResultTypeAny, eResultTypeId }
- Protected Attributes inherited from lldb_private::FunctionCaller
std::shared_ptr< IRExecutionUnitm_execution_unit_sp
std::unique_ptr< ExpressionParserm_parser
 The parser responsible for compiling the function. More...
lldb::ModuleWP m_jit_module_wp
std::string m_name
 The name of this clang function - for debugging purposes. More...
 The function we're going to call. More...
Address m_function_addr
 If we don't have the FunctionSP, we at least need the address & return type. More...
CompilerType m_function_return_type
 The opaque clang qual type for the function return type. More...
std::string m_wrapper_function_name
 The name of the wrapper function. More...
std::string m_wrapper_function_text
 The contents of the wrapper function. More...
std::string m_wrapper_struct_name
 The name of the struct that contains the target function address, arguments, and result. More...
std::list< lldb::addr_tm_wrapper_args_addrs
 The addresses of the arguments to the wrapper function. More...
bool m_struct_valid
 True if the ASTStructExtractor has populated the variables below. More...
size_t m_struct_size
 These values are populated by the ASTStructExtractor. More...
std::vector< uint64_t > m_member_offsets
 The offset of each member in the struct, in bytes. More...
uint64_t m_return_size
 The size of the result variable, in bytes. More...
uint64_t m_return_offset
 The offset of the result variable in the struct, in bytes. More...
ValueList m_arg_values
 The default values of the arguments. More...
bool m_compiled
 True if the wrapper function has already been parsed. More...
bool m_JITted
 True if the wrapper function has already been JIT-compiled. More...
- Protected Attributes inherited from lldb_private::Expression
lldb::TargetWP m_target_wp
lldb::ProcessWP m_jit_process_wp
 Expression's always have to have a target... More...
lldb::addr_t m_jit_start_addr
 An expression might have a process, but it doesn't need to (e.g. More...
lldb::addr_t m_jit_end_addr
 The address of the JITted function within the JIT allocation. More...

Detailed Description

"lldb/Expression/ClangFunctionCaller.h" Encapsulates a function that can be called.

A given ClangFunctionCaller object can handle a single function signature. Once constructed, it can set up any number of concurrent calls to functions with that signature.

It performs the call by synthesizing a structure that contains the pointer to the function and the arguments that should be passed to that function, and producing a special-purpose JIT-compiled function that accepts a void* pointing to this struct as its only argument and calls the function in the struct with the written arguments. This method lets Clang handle the vagaries of function calling conventions.

The simplest use of the ClangFunctionCaller is to construct it with a function representative of the signature you want to use, then call ExecuteFunction(ExecutionContext &, Stream &, Value &).

If you need to reuse the arguments for several calls, you can call InsertFunction() followed by WriteFunctionArguments(), which will return the location of the args struct for the wrapper function in args_addr_ref.

If you need to call the function on the thread plan stack, you can also call InsertFunction() followed by GetThreadPlanToCallFunction().

Any of the methods that take arg_addr_ptr or arg_addr_ref can be passed a pointer set to LLDB_INVALID_ADDRESS and new structure will be allocated and its address returned in that variable.

Any of the methods that take arg_addr_ptr can be passed NULL, and the argument space will be managed for you.

Definition at line 57 of file ClangFunctionCaller.h.

Constructor & Destructor Documentation

◆ ClangFunctionCaller()

ClangFunctionCaller::ClangFunctionCaller ( ExecutionContextScope exe_scope,
const CompilerType return_type,
const Address function_address,
const ValueList arg_value_list,
const char *  name 


[in]exe_scopeAn execution context scope that gets us at least a target and process.
[in]return_typeA compiler type for the function result. Should be defined in ast_context.
[in]function_addressThe address of the function to call.
[in]arg_value_listThe default values to use when calling this function. Can be overridden using WriteFunctionArguments().

Definition at line 49 of file ClangFunctionCaller.cpp.

References lldb_private::ExecutionContextScope::CalculateProcess(), and lldb_private::Expression::m_jit_process_wp.

◆ ~ClangFunctionCaller()

ClangFunctionCaller::~ClangFunctionCaller ( )

Member Function Documentation

◆ classof()

static bool lldb_private::ClangFunctionCaller::classof ( const Expression obj)

Definition at line 94 of file ClangFunctionCaller.h.

References ID, and lldb_private::Expression::isA().

◆ CompileFunction()

unsigned ClangFunctionCaller::CompileFunction ( lldb::ThreadSP  thread_to_use_sp,
DiagnosticManager diagnostic_manager 

◆ GetTypeSystemHelper()

ExpressionTypeSystemHelper* lldb_private::ClangFunctionCaller::GetTypeSystemHelper ( )

Reimplemented from lldb_private::Expression.

Definition at line 134 of file ClangFunctionCaller.h.

References m_type_system_helper.

◆ GetWrapperStructName()

const char* lldb_private::ClangFunctionCaller::GetWrapperStructName ( )

◆ isA()

bool lldb_private::ClangFunctionCaller::isA ( const void *  ClassID) const

Reimplemented from lldb_private::FunctionCaller.

Definition at line 91 of file ClangFunctionCaller.h.

References ID, and lldb_private::FunctionCaller::isA().

Friends And Related Function Documentation

◆ ASTStructExtractor

friend class ASTStructExtractor

Definition at line 58 of file ClangFunctionCaller.h.

Member Data Documentation

◆ ID

char ClangFunctionCaller::ID

Definition at line 88 of file ClangFunctionCaller.h.

Referenced by classof(), and isA().

◆ m_type_system_helper

ClangFunctionCallerHelper lldb_private::ClangFunctionCaller::m_type_system_helper

Definition at line 146 of file ClangFunctionCaller.h.

Referenced by GetTypeSystemHelper().

The documentation for this class was generated from the following files: