llvm-project/lldb/source/Expression/FunctionCaller.cpp

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//===-- FunctionCaller.cpp ---------------------------------------*- C++-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Expression/FunctionCaller.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/State.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectList.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Expression/IRExecutionUnit.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/ThreadPlanCallFunction.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Log.h"
using namespace lldb_private;
This is a major refactoring of the expression parser. The goal is to separate the parser's data from the data belonging to the parser's clients. This allows clients to use the parser to obtain (for example) a JIT compiled function or some DWARF code, and then discard the parser state. Previously, parser state was held in ClangExpression and used liberally by ClangFunction, which inherited from ClangExpression. The main effects of this refactoring are: - reducing ClangExpression to an abstract class that declares methods that any client must expose to the expression parser, - moving the code specific to implementing the "expr" command from ClangExpression and CommandObjectExpression into ClangUserExpression, a new class, - moving the common parser interaction code from ClangExpression into ClangExpressionParser, a new class, and - making ClangFunction rely only on ClangExpressionParser and not depend on the internal implementation of ClangExpression. Side effects include: - the compiler interaction code has been factored out of ClangFunction and is now in an AST pass (ASTStructExtractor), - the header file for ClangFunction is now fully documented, - several bugs that only popped up when Clang was deallocated (which never happened, since the lifetime of the compiler was essentially infinite) are now fixed, and - the developer-only "call" command has been disabled. I have tested the expr command and the Objective-C step-into code, which use ClangUserExpression and ClangFunction, respectively, and verified that they work. Please let me know if you encounter bugs or poor documentation. llvm-svn: 112249
2010-08-27 09:01:44 +08:00
//----------------------------------------------------------------------
This patch makes Clang-independent base classes for all the expression types that lldb currently vends. Before we had: ClangFunction ClangUtilityFunction ClangUserExpression and code all over in lldb that explicitly made Clang-based expressions. This patch adds an Expression base class, and three pure virtual implementations for the Expression kinds: FunctionCaller UtilityFunction UserExpression You can request one of these expression types from the Target using the Get<ExpressionType>ForLanguage. The Target will then consult all the registered TypeSystem plugins, and if the type system that matches the language can make an expression of that kind, it will do so and return it. Because all of the real expression types need to communicate with their ExpressionParser in a uniform way, I also added a ExpressionTypeSystemHelper class that expressions generically can vend, and a ClangExpressionHelper that encapsulates the operations that the ClangExpressionParser needs to perform on the ClangExpression types. Then each of the Clang* expression kinds constructs the appropriate helper to do what it needs. The patch also fixes a wart in the UtilityFunction that to use it you had to create a parallel FunctionCaller to actually call the function made by the UtilityFunction. Now the UtilityFunction can be asked to vend a FunctionCaller that will run its function. This cleaned up a lot of boiler plate code using UtilityFunctions. Note, in this patch all the expression types explicitly depend on the LLVM JIT and IR, and all the common JIT running code is in the FunctionCaller etc base classes. At some point we could also abstract that dependency but I don't see us adding another back end in the near term, so I'll leave that exercise till it is actually necessary. llvm-svn: 247720
2015-09-16 05:13:50 +08:00
// FunctionCaller constructor
//----------------------------------------------------------------------
FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope,
const CompilerType &return_type,
const Address &functionAddress,
const ValueList &arg_value_list,
const char *name)
: Expression(exe_scope), m_execution_unit_sp(), m_parser(),
m_jit_module_wp(), m_name(name ? name : "<unknown>"),
m_function_ptr(NULL), m_function_addr(functionAddress),
m_function_return_type(return_type),
m_wrapper_function_name("__lldb_caller_function"),
m_wrapper_struct_name("__lldb_caller_struct"), m_wrapper_args_addrs(),
m_struct_valid(false), m_arg_values(arg_value_list), m_compiled(false),
m_JITted(false) {
m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
// Can't make a FunctionCaller without a process.
assert(m_jit_process_wp.lock());
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
FunctionCaller::~FunctionCaller() {
lldb::ProcessSP process_sp(m_jit_process_wp.lock());
if (process_sp) {
lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
if (jit_module_sp)
process_sp->GetTarget().GetImages().Remove(jit_module_sp);
}
}
bool FunctionCaller::WriteFunctionWrapper(
ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) {
Process *process = exe_ctx.GetProcessPtr();
if (!process)
return false;
lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
if (process != jit_process_sp.get())
return false;
if (!m_compiled)
return false;
if (m_JITted)
return true;
bool can_interpret = false; // should stay that way
Status jit_error(m_parser->PrepareForExecution(
m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
can_interpret, eExecutionPolicyAlways));
if (!jit_error.Success())
return false;
if (m_parser->GetGenerateDebugInfo()) {
lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
if (jit_module_sp) {
ConstString const_func_name(FunctionName());
FileSpec jit_file;
jit_file.GetFilename() = const_func_name;
jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
m_jit_module_wp = jit_module_sp;
process->GetTarget().GetImages().Append(jit_module_sp);
}
}
if (process && m_jit_start_addr)
m_jit_process_wp = process->shared_from_this();
m_JITted = true;
return true;
}
bool FunctionCaller::WriteFunctionArguments(
ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
DiagnosticManager &diagnostic_manager) {
return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values,
diagnostic_manager);
}
// FIXME: Assure that the ValueList we were passed in is consistent with the one
// that defined this function.
bool FunctionCaller::WriteFunctionArguments(
ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
ValueList &arg_values, DiagnosticManager &diagnostic_manager) {
// All the information to reconstruct the struct is provided by the
// StructExtractor.
if (!m_struct_valid) {
diagnostic_manager.PutString(eDiagnosticSeverityError,
"Argument information was not correctly "
"parsed, so the function cannot be called.");
return false;
}
Status error;
lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
Process *process = exe_ctx.GetProcessPtr();
if (process == NULL)
return return_value;
lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
if (process != jit_process_sp.get())
return false;
if (args_addr_ref == LLDB_INVALID_ADDRESS) {
args_addr_ref = process->AllocateMemory(
m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable,
error);
if (args_addr_ref == LLDB_INVALID_ADDRESS)
return false;
m_wrapper_args_addrs.push_back(args_addr_ref);
} else {
// Make sure this is an address that we've already handed out.
if (find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
args_addr_ref) == m_wrapper_args_addrs.end()) {
return false;
}
}
// TODO: verify fun_addr needs to be a callable address
Scalar fun_addr(
m_function_addr.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));
uint64_t first_offset = m_member_offsets[0];
process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr,
process->GetAddressByteSize(), error);
// FIXME: We will need to extend this for Variadic functions.
Status value_error;
size_t num_args = arg_values.GetSize();
if (num_args != m_arg_values.GetSize()) {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "",
(uint64_t)num_args, (uint64_t)m_arg_values.GetSize());
return false;
}
for (size_t i = 0; i < num_args; i++) {
// FIXME: We should sanity check sizes.
uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes.
Value *arg_value = arg_values.GetValueAtIndex(i);
// FIXME: For now just do scalars:
// Special case: if it's a pointer, don't do anything (the ABI supports
// passing cstrings)
if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
arg_value->GetContextType() == Value::eContextTypeInvalid &&
arg_value->GetCompilerType().IsPointerType())
continue;
const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);
if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar,
arg_scalar.GetByteSize(), error))
return false;
}
return true;
}
bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx,
lldb::addr_t &args_addr_ref,
DiagnosticManager &diagnostic_manager) {
if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
return false;
if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager))
return false;
if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager))
return false;
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log)
log->Printf("Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n",
m_jit_start_addr, args_addr_ref);
return true;
}
lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction(
ExecutionContext &exe_ctx, lldb::addr_t args_addr,
const EvaluateExpressionOptions &options,
DiagnosticManager &diagnostic_manager) {
Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
LIBLLDB_LOG_STEP));
if (log)
log->Printf("-- [FunctionCaller::GetThreadPlanToCallFunction] Creating "
"thread plan to call function \"%s\" --",
m_name.c_str());
// FIXME: Use the errors Stream for better error reporting.
Thread *thread = exe_ctx.GetThreadPtr();
if (thread == NULL) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"Can't call a function without a valid thread.");
return NULL;
}
// Okay, now run the function:
Address wrapper_address(m_jit_start_addr);
lldb::addr_t args = {args_addr};
lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction(
*thread, wrapper_address, CompilerType(), args, options));
new_plan_sp->SetIsMasterPlan(true);
new_plan_sp->SetOkayToDiscard(false);
return new_plan_sp;
}
bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx,
lldb::addr_t args_addr,
Value &ret_value) {
// Read the return value - it is the last field in the struct:
// FIXME: How does clang tell us there's no return value? We need to handle
// that case.
// FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and
// then use GetReturnValueObject
// to fetch the value. That way we can fetch any values we need.
Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
LIBLLDB_LOG_STEP));
if (log)
log->Printf("-- [FunctionCaller::FetchFunctionResults] Fetching function "
"results for \"%s\"--",
m_name.c_str());
Process *process = exe_ctx.GetProcessPtr();
if (process == NULL)
return false;
lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
if (process != jit_process_sp.get())
return false;
Status error;
ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory(
args_addr + m_return_offset, m_return_size, 0, error);
if (error.Fail())
return false;
ret_value.SetCompilerType(m_function_return_type);
ret_value.SetValueType(Value::eValueTypeScalar);
return true;
}
void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx,
lldb::addr_t args_addr) {
std::list<lldb::addr_t>::iterator pos;
pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
args_addr);
if (pos != m_wrapper_args_addrs.end())
m_wrapper_args_addrs.erase(pos);
exe_ctx.GetProcessRef().DeallocateMemory(args_addr);
}
lldb::ExpressionResults FunctionCaller::ExecuteFunction(
ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr,
const EvaluateExpressionOptions &options,
DiagnosticManager &diagnostic_manager, Value &results) {
lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
// FunctionCaller::ExecuteFunction execution is always just to get the
// result. Do make sure we ignore breakpoints, unwind on error, and don't try
// to debug it.
EvaluateExpressionOptions real_options = options;
real_options.SetDebug(false);
real_options.SetUnwindOnError(true);
real_options.SetIgnoreBreakpoints(true);
lldb::addr_t args_addr;
if (args_addr_ptr != NULL)
args_addr = *args_addr_ptr;
else
args_addr = LLDB_INVALID_ADDRESS;
if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
return lldb::eExpressionSetupError;
if (args_addr == LLDB_INVALID_ADDRESS) {
if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager))
return lldb::eExpressionSetupError;
}
Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
LIBLLDB_LOG_STEP));
if (log)
log->Printf(
"== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==",
m_name.c_str());
lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction(
exe_ctx, args_addr, real_options, diagnostic_manager);
if (!call_plan_sp)
return lldb::eExpressionSetupError;
// We need to make sure we record the fact that we are running an expression
// here otherwise this fact will fail to be recorded when fetching an
// Objective-C object description
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
return_value = exe_ctx.GetProcessRef().RunThreadPlan(
exe_ctx, call_plan_sp, real_options, diagnostic_manager);
if (log) {
if (return_value != lldb::eExpressionCompleted) {
log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
"completed abnormally ==",
m_name.c_str());
} else {
log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
"completed normally ==",
m_name.c_str());
}
}
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
if (args_addr_ptr != NULL)
*args_addr_ptr = args_addr;
if (return_value != lldb::eExpressionCompleted)
return return_value;
FetchFunctionResults(exe_ctx, args_addr, results);
if (args_addr_ptr == NULL)
DeallocateFunctionResults(exe_ctx, args_addr);
return lldb::eExpressionCompleted;
}