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

583 lines
21 KiB
C++

//===-- ClangFunction.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
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecordLayout.h"
#include "clang/CodeGen/CodeGenAction.h"
#include "clang/CodeGen/ModuleBuilder.h"
#include "clang/Frontend/CompilerInstance.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/Module.h"
// Project includes
#include "lldb/Expression/ASTStructExtractor.h"
#include "lldb/Expression/ClangExpressionParser.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/State.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectList.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/Function.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/Core/Log.h"
using namespace lldb_private;
//----------------------------------------------------------------------
// ClangFunction constructor
//----------------------------------------------------------------------
ClangFunction::ClangFunction
(
ExecutionContextScope &exe_scope,
ClangASTContext *ast_context,
void *return_qualtype,
const Address& functionAddress,
const ValueList &arg_value_list
) :
m_function_ptr (NULL),
m_function_addr (functionAddress),
m_function_return_qual_type(return_qualtype),
m_clang_ast_context (ast_context),
m_wrapper_function_name ("__lldb_caller_function"),
m_wrapper_struct_name ("__lldb_caller_struct"),
m_wrapper_args_addrs (),
m_arg_values (arg_value_list),
m_compiled (false),
m_JITted (false)
{
m_jit_process_sp = exe_scope.CalculateProcess();
// Can't make a ClangFunction without a process.
assert (m_jit_process_sp);
}
ClangFunction::ClangFunction
(
ExecutionContextScope &exe_scope,
Function &function,
ClangASTContext *ast_context,
const ValueList &arg_value_list
) :
m_function_ptr (&function),
m_function_addr (),
m_function_return_qual_type (),
m_clang_ast_context (ast_context),
m_wrapper_function_name ("__lldb_function_caller"),
m_wrapper_struct_name ("__lldb_caller_struct"),
m_wrapper_args_addrs (),
m_arg_values (arg_value_list),
m_compiled (false),
m_JITted (false)
{
m_jit_process_sp = exe_scope.CalculateProcess();
// Can't make a ClangFunction without a process.
assert (m_jit_process_sp);
m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress();
m_function_return_qual_type = m_function_ptr->GetReturnClangType();
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
ClangFunction::~ClangFunction()
{
}
unsigned
ClangFunction::CompileFunction (Stream &errors)
{
if (m_compiled)
return 0;
// FIXME: How does clang tell us there's no return value? We need to handle that case.
unsigned num_errors = 0;
std::string return_type_str (ClangASTType::GetTypeNameForOpaqueQualType (m_clang_ast_context->getASTContext(),
m_function_return_qual_type));
// Cons up the function we're going to wrap our call in, then compile it...
// We declare the function "extern "C"" because the compiler might be in C++
// mode which would mangle the name and then we couldn't find it again...
m_wrapper_function_text.clear();
m_wrapper_function_text.append ("extern \"C\" void ");
m_wrapper_function_text.append (m_wrapper_function_name);
m_wrapper_function_text.append (" (void *input)\n{\n struct ");
m_wrapper_function_text.append (m_wrapper_struct_name);
m_wrapper_function_text.append (" \n {\n");
m_wrapper_function_text.append (" ");
m_wrapper_function_text.append (return_type_str);
m_wrapper_function_text.append (" (*fn_ptr) (");
// Get the number of arguments. If we have a function type and it is prototyped,
// trust that, otherwise use the values we were given.
// FIXME: This will need to be extended to handle Variadic functions. We'll need
// to pull the defined arguments out of the function, then add the types from the
// arguments list for the variable arguments.
uint32_t num_args = UINT32_MAX;
bool trust_function = false;
// GetArgumentCount returns -1 for an unprototyped function.
if (m_function_ptr)
{
int num_func_args = m_function_ptr->GetArgumentCount();
if (num_func_args >= 0)
trust_function = true;
else
num_args = num_func_args;
}
if (num_args == UINT32_MAX)
num_args = m_arg_values.GetSize();
std::string args_buffer; // This one stores the definition of all the args in "struct caller".
std::string args_list_buffer; // This one stores the argument list called from the structure.
for (size_t i = 0; i < num_args; i++)
{
std::string type_name;
if (trust_function)
{
lldb::clang_type_t arg_clang_type = m_function_ptr->GetArgumentTypeAtIndex(i);
type_name = ClangASTType::GetTypeNameForOpaqueQualType (m_clang_ast_context->getASTContext(),
arg_clang_type);
}
else
{
Value *arg_value = m_arg_values.GetValueAtIndex(i);
lldb::clang_type_t clang_qual_type = arg_value->GetClangType ();
if (clang_qual_type != NULL)
{
type_name = ClangASTType::GetTypeNameForOpaqueQualType (m_clang_ast_context->getASTContext(),
clang_qual_type);
}
else
{
errors.Printf("Could not determine type of input value %lu.", i);
return 1;
}
}
m_wrapper_function_text.append (type_name);
if (i < num_args - 1)
m_wrapper_function_text.append (", ");
char arg_buf[32];
args_buffer.append (" ");
args_buffer.append (type_name);
snprintf(arg_buf, 31, "arg_%zd", i);
args_buffer.push_back (' ');
args_buffer.append (arg_buf);
args_buffer.append (";\n");
args_list_buffer.append ("__lldb_fn_data->");
args_list_buffer.append (arg_buf);
if (i < num_args - 1)
args_list_buffer.append (", ");
}
m_wrapper_function_text.append (");\n"); // Close off the function calling prototype.
m_wrapper_function_text.append (args_buffer);
m_wrapper_function_text.append (" ");
m_wrapper_function_text.append (return_type_str);
m_wrapper_function_text.append (" return_value;");
m_wrapper_function_text.append ("\n };\n struct ");
m_wrapper_function_text.append (m_wrapper_struct_name);
m_wrapper_function_text.append ("* __lldb_fn_data = (struct ");
m_wrapper_function_text.append (m_wrapper_struct_name);
m_wrapper_function_text.append (" *) input;\n");
m_wrapper_function_text.append (" __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
m_wrapper_function_text.append (args_list_buffer);
m_wrapper_function_text.append (");\n}\n");
lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (log)
log->Printf ("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
// Okay, now compile this expression
m_parser.reset(new ClangExpressionParser(m_jit_process_sp.get(), *this));
num_errors = m_parser->Parse (errors);
m_compiled = (num_errors == 0);
if (!m_compiled)
return num_errors;
return num_errors;
}
bool
ClangFunction::WriteFunctionWrapper (ExecutionContext &exe_ctx, Stream &errors)
{
Process *process = exe_ctx.GetProcessPtr();
if (!process)
return false;
if (process != m_jit_process_sp.get())
return false;
if (!m_compiled)
return false;
if (m_JITted)
return true;
lldb::ClangExpressionVariableSP const_result;
bool evaluated_statically = false; // should stay that way
Error jit_error (m_parser->PrepareForExecution (m_jit_alloc,
m_jit_start_addr,
m_jit_end_addr,
exe_ctx,
NULL,
evaluated_statically,
const_result,
eExecutionPolicyAlways));
if (!jit_error.Success())
return false;
if (process && m_jit_alloc != LLDB_INVALID_ADDRESS)
m_jit_process_sp = process->shared_from_this();
return true;
}
bool
ClangFunction::WriteFunctionArguments (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors)
{
return WriteFunctionArguments(exe_ctx, args_addr_ref, m_function_addr, m_arg_values, errors);
}
// FIXME: Assure that the ValueList we were passed in is consistent with the one that defined this function.
bool
ClangFunction::WriteFunctionArguments (ExecutionContext &exe_ctx,
lldb::addr_t &args_addr_ref,
Address function_address,
ValueList &arg_values,
Stream &errors)
{
// All the information to reconstruct the struct is provided by the
// StructExtractor.
if (!m_struct_valid)
{
errors.Printf("Argument information was not correctly parsed, so the function cannot be called.");
return false;
}
Error error;
using namespace clang;
ExecutionResults return_value = eExecutionSetupError;
Process *process = exe_ctx.GetProcessPtr();
if (process == NULL)
return return_value;
if (process != m_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 (function_address.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));
int 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.
Error value_error;
size_t num_args = arg_values.GetSize();
if (num_args != m_arg_values.GetSize())
{
errors.Printf ("Wrong number of arguments - was: %lu should be: %lu", num_args, m_arg_values.GetSize());
return false;
}
for (size_t i = 0; i < num_args; i++)
{
// FIXME: We should sanity check sizes.
int 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::eContextTypeClangType &&
ClangASTContext::IsPointerType(arg_value->GetClangType()))
continue;
const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx, m_clang_ast_context->getASTContext());
if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar, arg_scalar.GetByteSize(), error))
return false;
}
return true;
}
bool
ClangFunction::InsertFunction (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors)
{
using namespace clang;
if (CompileFunction(errors) != 0)
return false;
if (!WriteFunctionWrapper(exe_ctx, errors))
return false;
if (!WriteFunctionArguments(exe_ctx, args_addr_ref, errors))
return false;
lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
if (log)
log->Printf ("Call Address: 0x%llx Struct Address: 0x%llx.\n", m_jit_start_addr, args_addr_ref);
return true;
}
ThreadPlan *
ClangFunction::GetThreadPlanToCallFunction (ExecutionContext &exe_ctx,
lldb::addr_t func_addr,
lldb::addr_t &args_addr,
Stream &errors,
bool stop_others,
bool discard_on_error,
lldb::addr_t *this_arg,
lldb::addr_t *cmd_arg)
{
// FIXME: Use the errors Stream for better error reporting.
Thread *thread = exe_ctx.GetThreadPtr();
if (thread == NULL)
{
errors.Printf("Can't call a function without a valid thread.");
return NULL;
}
// Okay, now run the function:
Address wrapper_address (func_addr);
ThreadPlan *new_plan = new ThreadPlanCallFunction (*thread,
wrapper_address,
ClangASTType(),
args_addr,
stop_others,
discard_on_error,
this_arg,
cmd_arg);
new_plan->SetIsMasterPlan(true);
new_plan->SetOkayToDiscard (false);
return new_plan;
}
bool
ClangFunction::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 ClangASTType, and then use GetReturnValueObject
// to fetch the value. That way we can fetch any values we need.
Process *process = exe_ctx.GetProcessPtr();
if (process == NULL)
return false;
if (process != m_jit_process_sp.get())
return false;
Error error;
ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory (args_addr + m_return_offset, m_return_size, 0, error);
if (error.Fail())
return false;
ret_value.SetContext (Value::eContextTypeClangType, m_function_return_qual_type);
ret_value.SetValueType(Value::eValueTypeScalar);
return true;
}
void
ClangFunction::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);
}
ExecutionResults
ClangFunction::ExecuteFunction(ExecutionContext &exe_ctx, Stream &errors, Value &results)
{
return ExecuteFunction (exe_ctx, errors, 1000, true, results);
}
ExecutionResults
ClangFunction::ExecuteFunction(ExecutionContext &exe_ctx, Stream &errors, bool stop_others, Value &results)
{
const bool try_all_threads = false;
const bool discard_on_error = true;
return ExecuteFunction (exe_ctx, NULL, errors, stop_others, NULL, try_all_threads, discard_on_error, results);
}
ExecutionResults
ClangFunction::ExecuteFunction(
ExecutionContext &exe_ctx,
Stream &errors,
uint32_t single_thread_timeout_usec,
bool try_all_threads,
Value &results)
{
const bool stop_others = true;
const bool discard_on_error = true;
return ExecuteFunction (exe_ctx, NULL, errors, stop_others, single_thread_timeout_usec,
try_all_threads, discard_on_error, results);
}
// This is the static function
ExecutionResults
ClangFunction::ExecuteFunction (
ExecutionContext &exe_ctx,
lldb::addr_t function_address,
lldb::addr_t &void_arg,
bool stop_others,
bool try_all_threads,
bool discard_on_error,
uint32_t single_thread_timeout_usec,
Stream &errors,
lldb::addr_t *this_arg)
{
lldb::ThreadPlanSP call_plan_sp (ClangFunction::GetThreadPlanToCallFunction (exe_ctx,
function_address,
void_arg,
errors,
stop_others,
discard_on_error,
this_arg));
if (!call_plan_sp)
return eExecutionSetupError;
call_plan_sp->SetPrivate(true);
// <rdar://problem/12027563> 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);
ExecutionResults results = exe_ctx.GetProcessRef().RunThreadPlan (exe_ctx, call_plan_sp,
stop_others,
try_all_threads,
discard_on_error,
single_thread_timeout_usec,
errors);
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
return results;
}
ExecutionResults
ClangFunction::ExecuteFunction(
ExecutionContext &exe_ctx,
lldb::addr_t *args_addr_ptr,
Stream &errors,
bool stop_others,
uint32_t single_thread_timeout_usec,
bool try_all_threads,
bool discard_on_error,
Value &results)
{
using namespace clang;
ExecutionResults return_value = eExecutionSetupError;
lldb::addr_t args_addr;
if (args_addr_ptr != NULL)
args_addr = *args_addr_ptr;
else
args_addr = LLDB_INVALID_ADDRESS;
if (CompileFunction(errors) != 0)
return eExecutionSetupError;
if (args_addr == LLDB_INVALID_ADDRESS)
{
if (!InsertFunction(exe_ctx, args_addr, errors))
return eExecutionSetupError;
}
return_value = ClangFunction::ExecuteFunction (exe_ctx,
m_jit_start_addr,
args_addr,
stop_others,
try_all_threads,
discard_on_error,
single_thread_timeout_usec,
errors);
if (args_addr_ptr != NULL)
*args_addr_ptr = args_addr;
if (return_value != eExecutionCompleted)
return return_value;
FetchFunctionResults(exe_ctx, args_addr, results);
if (args_addr_ptr == NULL)
DeallocateFunctionResults(exe_ctx, args_addr);
return eExecutionCompleted;
}
clang::ASTConsumer *
ClangFunction::ASTTransformer (clang::ASTConsumer *passthrough)
{
return new ASTStructExtractor(passthrough, m_wrapper_struct_name.c_str(), *this);
}