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//===-- FunctionCaller.cpp ------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Expression/FunctionCaller.h"
#include "lldb/Core/Module.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"
#include "lldb/Utility/State.h"
using namespace lldb_private;
char FunctionCaller::ID;
// 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(nullptr), 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()) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"Error in PrepareForExecution: %s.",
jit_error.AsCString());
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,
true /* notify */);
}
}
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 == nullptr)
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));
LLDB_LOGF(log, "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));
LLDB_LOGF(log,
"-- [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 == nullptr) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"Can't call a function without a valid thread.");
return nullptr;
}
// 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));
LLDB_LOGF(log,
"-- [FunctionCaller::FetchFunctionResults] Fetching function "
"results for \"%s\"--",
m_name.c_str());
Process *process = exe_ctx.GetProcessPtr();
if (process == nullptr)
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 != nullptr)
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));
LLDB_LOGF(log,
"== [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) {
LLDB_LOGF(log,
"== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
"completed abnormally: %s ==",
m_name.c_str(),
Process::ExecutionResultAsCString(return_value));
} else {
LLDB_LOGF(log,
"== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
"completed normally ==",
m_name.c_str());
}
}
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
if (args_addr_ptr != nullptr)
*args_addr_ptr = args_addr;
if (return_value != lldb::eExpressionCompleted)
return return_value;
FetchFunctionResults(exe_ctx, args_addr, results);
if (args_addr_ptr == nullptr)
DeallocateFunctionResults(exe_ctx, args_addr);
return lldb::eExpressionCompleted;
}