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Diffstat (limited to 'include/lldb/Expression/FunctionCaller.h')
| -rw-r--r-- | include/lldb/Expression/FunctionCaller.h | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/include/lldb/Expression/FunctionCaller.h b/include/lldb/Expression/FunctionCaller.h new file mode 100644 index 000000000000..c9a45811670f --- /dev/null +++ b/include/lldb/Expression/FunctionCaller.h @@ -0,0 +1,395 @@ +//===-- FunctionCaller.h ----------------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef liblldb_FunctionCaller_h_ +#define liblldb_FunctionCaller_h_ + +// C Includes +// C++ Includes +#include <list> +#include <memory> +#include <string> +#include <vector> + +// Other libraries and framework includes +// Project includes +#include "lldb/Core/Address.h" +#include "lldb/Core/Value.h" +#include "lldb/Expression/Expression.h" +#include "lldb/Expression/ExpressionParser.h" +#include "lldb/Symbol/CompilerType.h" + +namespace lldb_private +{ + +//---------------------------------------------------------------------- +/// @class FunctionCaller FunctionCaller.h "lldb/Expression/FunctionCaller.h" +/// @brief Encapsulates a function that can be called. +/// +/// A given FunctionCaller 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 FunctionCaller 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 nullptr, and the +/// argument space will be managed for you. +//---------------------------------------------------------------------- +class FunctionCaller : public Expression +{ +public: + //------------------------------------------------------------------ + /// Constructor + /// + /// @param[in] exe_scope + /// An execution context scope that gets us at least a target and + /// process. + /// + /// @param[in] ast_context + /// The AST context to evaluate argument types in. + /// + /// @param[in] return_qualtype + /// An opaque Clang QualType for the function result. Should be + /// defined in ast_context. + /// + /// @param[in] function_address + /// The address of the function to call. + /// + /// @param[in] arg_value_list + /// The default values to use when calling this function. Can + /// be overridden using WriteFunctionArguments(). + //------------------------------------------------------------------ + FunctionCaller (ExecutionContextScope &exe_scope, + const CompilerType &return_type, + const Address& function_address, + const ValueList &arg_value_list, + const char *name); + + //------------------------------------------------------------------ + /// Destructor + //------------------------------------------------------------------ + ~FunctionCaller() override; + + //------------------------------------------------------------------ + /// Compile the wrapper function + /// + /// @param[in] errors + /// The stream to print parser errors to. + /// + /// @return + /// The number of errors. + //------------------------------------------------------------------ + virtual unsigned + CompileFunction (Stream &errors) = 0; + + //------------------------------------------------------------------ + /// Insert the default function wrapper and its default argument struct + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in,out] args_addr_ref + /// The address of the structure to write the arguments into. May + /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated + /// and args_addr_ref is pointed to it. + /// + /// @param[in] errors + /// The stream to write errors to. + /// + /// @return + /// True on success; false otherwise. + //------------------------------------------------------------------ + bool + InsertFunction (ExecutionContext &exe_ctx, + lldb::addr_t &args_addr_ref, + Stream &errors); + + //------------------------------------------------------------------ + /// Insert the default function wrapper (using the JIT) + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in] errors + /// The stream to write errors to. + /// + /// @return + /// True on success; false otherwise. + //------------------------------------------------------------------ + bool WriteFunctionWrapper (ExecutionContext &exe_ctx, + Stream &errors); + + //------------------------------------------------------------------ + /// Insert the default function argument struct + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in,out] args_addr_ref + /// The address of the structure to write the arguments into. May + /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated + /// and args_addr_ref is pointed to it. + /// + /// @param[in] errors + /// The stream to write errors to. + /// + /// @return + /// True on success; false otherwise. + //------------------------------------------------------------------ + bool WriteFunctionArguments (ExecutionContext &exe_ctx, + lldb::addr_t &args_addr_ref, + Stream &errors); + + //------------------------------------------------------------------ + /// Insert an argument struct with a non-default function address and + /// non-default argument values + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in,out] args_addr_ref + /// The address of the structure to write the arguments into. May + /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated + /// and args_addr_ref is pointed at it. + /// + /// @param[in] arg_values + /// The values of the function's arguments. + /// + /// @param[in] errors + /// The stream to write errors to. + /// + /// @return + /// True on success; false otherwise. + //------------------------------------------------------------------ + bool WriteFunctionArguments (ExecutionContext &exe_ctx, + lldb::addr_t &args_addr_ref, + ValueList &arg_values, + Stream &errors); + + //------------------------------------------------------------------ + /// Run the function this FunctionCaller was created with. + /// + /// This is the full version. + /// + /// @param[in] exe_ctx + /// The thread & process in which this function will run. + /// + /// @param[in] args_addr_ptr + /// If nullptr, the function will take care of allocating & deallocating the wrapper + /// args structure. Otherwise, if set to LLDB_INVALID_ADDRESS, a new structure + /// will be allocated, filled and the address returned to you. You are responsible + /// for deallocating it. And if passed in with a value other than LLDB_INVALID_ADDRESS, + /// this should point to an already allocated structure with the values already written. + /// + /// @param[in] errors + /// Errors will be written here if there are any. + /// + /// @param[in] options + /// The options for this expression execution. + /// + /// @param[out] results + /// The result value will be put here after running the function. + /// + /// @return + /// Returns one of the ExpressionResults enum indicating function call status. + //------------------------------------------------------------------ + lldb::ExpressionResults + ExecuteFunction(ExecutionContext &exe_ctx, + lldb::addr_t *args_addr_ptr, + const EvaluateExpressionOptions &options, + Stream &errors, + Value &results); + + //------------------------------------------------------------------ + /// Get a thread plan to run the function this FunctionCaller was created with. + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in] func_addr + /// The address of the function in the target process. + /// + /// @param[in] args_addr + /// The address of the argument struct. + /// + /// @param[in] errors + /// The stream to write errors to. + /// + /// @param[in] stop_others + /// True if other threads should pause during execution. + /// + /// @param[in] unwind_on_error + /// True if the thread plan may simply be discarded if an error occurs. + /// + /// @return + /// A ThreadPlan shared pointer for executing the function. + //------------------------------------------------------------------ + lldb::ThreadPlanSP + GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, + lldb::addr_t args_addr, + const EvaluateExpressionOptions &options, + Stream &errors); + + //------------------------------------------------------------------ + /// Get the result of the function from its struct + /// + /// @param[in] exe_ctx + /// The execution context to retrieve the result from. + /// + /// @param[in] args_addr + /// The address of the argument struct. + /// + /// @param[out] ret_value + /// The value returned by the function. + /// + /// @return + /// True on success; false otherwise. + //------------------------------------------------------------------ + bool FetchFunctionResults (ExecutionContext &exe_ctx, + lldb::addr_t args_addr, + Value &ret_value); + + //------------------------------------------------------------------ + /// Deallocate the arguments structure + /// + /// @param[in] exe_ctx + /// The execution context to insert the function and its arguments + /// into. + /// + /// @param[in] args_addr + /// The address of the argument struct. + //------------------------------------------------------------------ + void DeallocateFunctionResults (ExecutionContext &exe_ctx, + lldb::addr_t args_addr); + + //------------------------------------------------------------------ + /// Interface for ClangExpression + //------------------------------------------------------------------ + + //------------------------------------------------------------------ + /// Return the string that the parser should parse. Must be a full + /// translation unit. + //------------------------------------------------------------------ + const char * + Text() override + { + return m_wrapper_function_text.c_str(); + } + + //------------------------------------------------------------------ + /// Return the function name that should be used for executing the + /// expression. Text() should contain the definition of this + /// function. + //------------------------------------------------------------------ + const char * + FunctionName() override + { + return m_wrapper_function_name.c_str(); + } + + //------------------------------------------------------------------ + /// Return the object that the parser should use when registering + /// local variables. May be nullptr if the Expression doesn't care. + //------------------------------------------------------------------ + ExpressionVariableList * + LocalVariables () + { + return nullptr; + } + + //------------------------------------------------------------------ + /// Return true if validation code should be inserted into the + /// expression. + //------------------------------------------------------------------ + bool + NeedsValidation() override + { + return false; + } + + //------------------------------------------------------------------ + /// Return true if external variables in the expression should be + /// resolved. + //------------------------------------------------------------------ + bool + NeedsVariableResolution() override + { + return false; + } + + ValueList + GetArgumentValues () const + { + return m_arg_values; + } + +protected: + // Note: the parser needs to be destructed before the execution unit, so + // declare the execution unit first. + std::shared_ptr<IRExecutionUnit> m_execution_unit_sp; + std::unique_ptr<ExpressionParser> m_parser; ///< The parser responsible for compiling the function. + ///< This will get made in CompileFunction, so it is + ///< safe to access it after that. + + lldb::ModuleWP m_jit_module_wp; + std::string m_name; ///< The name of this clang function - for debugging purposes. + + Function *m_function_ptr; ///< The function we're going to call. May be nullptr if we don't have debug info for the function. + Address m_function_addr; ///< If we don't have the FunctionSP, we at least need the address & return type. + CompilerType m_function_return_type; ///< The opaque clang qual type for the function return type. + + std::string m_wrapper_function_name; ///< The name of the wrapper function. + std::string m_wrapper_function_text; ///< The contents of the wrapper function. + std::string m_wrapper_struct_name; ///< The name of the struct that contains the target function address, arguments, and result. + std::list<lldb::addr_t> m_wrapper_args_addrs; ///< The addresses of the arguments to the wrapper function. + + bool m_struct_valid; ///< True if the ASTStructExtractor has populated the variables below. + + //------------------------------------------------------------------ + /// These values are populated by the ASTStructExtractor + size_t m_struct_size; ///< The size of the argument struct, in bytes. + std::vector<uint64_t> m_member_offsets; ///< The offset of each member in the struct, in bytes. + uint64_t m_return_size; ///< The size of the result variable, in bytes. + uint64_t m_return_offset; ///< The offset of the result variable in the struct, in bytes. + //------------------------------------------------------------------ + + ValueList m_arg_values; ///< The default values of the arguments. + + bool m_compiled; ///< True if the wrapper function has already been parsed. + bool m_JITted; ///< True if the wrapper function has already been JIT-compiled. +}; + +} // namespace lldb_private + +#endif // liblldb_FunctionCaller_h_ |