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//===-- ClangFunctionCaller.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 "ClangFunctionCaller.h"
#include "ASTStructExtractor.h"
#include "ClangExpressionParser.h"
#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/IR/Module.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectList.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 ClangFunctionCaller::ID;
// ClangFunctionCaller constructor
ClangFunctionCaller::ClangFunctionCaller(ExecutionContextScope &exe_scope,
const CompilerType &return_type,
const Address &functionAddress,
const ValueList &arg_value_list,
const char *name)
: FunctionCaller(exe_scope, return_type, functionAddress, arg_value_list,
name),
m_type_system_helper(*this) {
m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
// Can't make a ClangFunctionCaller without a process.
assert(m_jit_process_wp.lock());
}
// Destructor
ClangFunctionCaller::~ClangFunctionCaller() {}
unsigned
ClangFunctionCaller::CompileFunction(lldb::ThreadSP thread_to_use_sp,
DiagnosticManager &diagnostic_manager) {
if (m_compiled)
return 0;
// Compilation might call code, make sure to keep on the thread the caller
// indicated.
ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
thread_to_use_sp);
// 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(
m_function_return_type.GetTypeName().AsCString(""));
// 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.
CompilerType function_clang_type;
if (m_function_ptr) {
function_clang_type = m_function_ptr->GetCompilerType();
if (function_clang_type) {
int num_func_args = function_clang_type.GetFunctionArgumentCount();
if (num_func_args >= 0) {
trust_function = true;
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) {
type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i)
.GetTypeName()
.AsCString("");
} else {
CompilerType clang_qual_type =
m_arg_values.GetValueAtIndex(i)->GetCompilerType();
if (clang_qual_type) {
type_name = clang_qual_type.GetTypeName().AsCString("");
} else {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"Could not determine type of input value %" PRIu64 ".",
(uint64_t)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_%" PRIu64, (uint64_t)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");
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
LLDB_LOGF(log, "Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
// Okay, now compile this expression
lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
if (jit_process_sp) {
const bool generate_debug_info = true;
auto *clang_parser = new ClangExpressionParser(jit_process_sp.get(), *this,
generate_debug_info);
num_errors = clang_parser->Parse(diagnostic_manager);
m_parser.reset(clang_parser);
} else {
diagnostic_manager.PutString(eDiagnosticSeverityError,
"no process - unable to inject function");
num_errors = 1;
}
m_compiled = (num_errors == 0);
if (!m_compiled)
return num_errors;
return num_errors;
}
clang::ASTConsumer *
ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer(
clang::ASTConsumer *passthrough) {
m_struct_extractor = std::make_unique<ASTStructExtractor>(
passthrough, m_owner.GetWrapperStructName(), m_owner);
return m_struct_extractor.get();
}