1 //===-- ClangFunctionCaller.cpp ---------------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "ClangFunctionCaller.h"
11 #include "ASTStructExtractor.h"
12 #include "ClangExpressionParser.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/RecordLayout.h"
16 #include "clang/CodeGen/CodeGenAction.h"
17 #include "clang/CodeGen/ModuleBuilder.h"
18 #include "clang/Frontend/CompilerInstance.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ExecutionEngine/ExecutionEngine.h"
22 #include "llvm/IR/Module.h"
24 #include "lldb/Core/Module.h"
25 #include "lldb/Core/ValueObject.h"
26 #include "lldb/Core/ValueObjectList.h"
27 #include "lldb/Expression/IRExecutionUnit.h"
28 #include "lldb/Interpreter/CommandReturnObject.h"
29 #include "lldb/Symbol/ClangASTContext.h"
30 #include "lldb/Symbol/Function.h"
31 #include "lldb/Symbol/Type.h"
32 #include "lldb/Target/ExecutionContext.h"
33 #include "lldb/Target/Process.h"
34 #include "lldb/Target/RegisterContext.h"
35 #include "lldb/Target/Target.h"
36 #include "lldb/Target/Thread.h"
37 #include "lldb/Target/ThreadPlan.h"
38 #include "lldb/Target/ThreadPlanCallFunction.h"
39 #include "lldb/Utility/DataExtractor.h"
40 #include "lldb/Utility/Log.h"
41 #include "lldb/Utility/State.h"
43 using namespace lldb_private;
45 // ClangFunctionCaller constructor
46 ClangFunctionCaller::ClangFunctionCaller(ExecutionContextScope &exe_scope,
47 const CompilerType &return_type,
48 const Address &functionAddress,
49 const ValueList &arg_value_list,
51 : FunctionCaller(exe_scope, return_type, functionAddress, arg_value_list,
53 m_type_system_helper(*this) {
54 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
55 // Can't make a ClangFunctionCaller without a process.
56 assert(m_jit_process_wp.lock());
60 ClangFunctionCaller::~ClangFunctionCaller() {}
64 ClangFunctionCaller::CompileFunction(lldb::ThreadSP thread_to_use_sp,
65 DiagnosticManager &diagnostic_manager) {
69 // Compilation might call code, make sure to keep on the thread the caller
71 ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
74 // FIXME: How does clang tell us there's no return value? We need to handle
76 unsigned num_errors = 0;
78 std::string return_type_str(
79 m_function_return_type.GetTypeName().AsCString(""));
81 // Cons up the function we're going to wrap our call in, then compile it...
82 // We declare the function "extern "C"" because the compiler might be in C++
83 // mode which would mangle the name and then we couldn't find it again...
84 m_wrapper_function_text.clear();
85 m_wrapper_function_text.append("extern \"C\" void ");
86 m_wrapper_function_text.append(m_wrapper_function_name);
87 m_wrapper_function_text.append(" (void *input)\n{\n struct ");
88 m_wrapper_function_text.append(m_wrapper_struct_name);
89 m_wrapper_function_text.append(" \n {\n");
90 m_wrapper_function_text.append(" ");
91 m_wrapper_function_text.append(return_type_str);
92 m_wrapper_function_text.append(" (*fn_ptr) (");
94 // Get the number of arguments. If we have a function type and it is
95 // prototyped, trust that, otherwise use the values we were given.
97 // FIXME: This will need to be extended to handle Variadic functions. We'll
99 // to pull the defined arguments out of the function, then add the types from
100 // the arguments list for the variable arguments.
102 uint32_t num_args = UINT32_MAX;
103 bool trust_function = false;
104 // GetArgumentCount returns -1 for an unprototyped function.
105 CompilerType function_clang_type;
106 if (m_function_ptr) {
107 function_clang_type = m_function_ptr->GetCompilerType();
108 if (function_clang_type) {
109 int num_func_args = function_clang_type.GetFunctionArgumentCount();
110 if (num_func_args >= 0) {
111 trust_function = true;
112 num_args = num_func_args;
117 if (num_args == UINT32_MAX)
118 num_args = m_arg_values.GetSize();
120 std::string args_buffer; // This one stores the definition of all the args in
122 std::string args_list_buffer; // This one stores the argument list called from
124 for (size_t i = 0; i < num_args; i++) {
125 std::string type_name;
127 if (trust_function) {
128 type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i)
132 CompilerType clang_qual_type =
133 m_arg_values.GetValueAtIndex(i)->GetCompilerType();
134 if (clang_qual_type) {
135 type_name = clang_qual_type.GetTypeName().AsCString("");
137 diagnostic_manager.Printf(
138 eDiagnosticSeverityError,
139 "Could not determine type of input value %" PRIu64 ".",
145 m_wrapper_function_text.append(type_name);
146 if (i < num_args - 1)
147 m_wrapper_function_text.append(", ");
150 args_buffer.append(" ");
151 args_buffer.append(type_name);
152 snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
153 args_buffer.push_back(' ');
154 args_buffer.append(arg_buf);
155 args_buffer.append(";\n");
157 args_list_buffer.append("__lldb_fn_data->");
158 args_list_buffer.append(arg_buf);
159 if (i < num_args - 1)
160 args_list_buffer.append(", ");
162 m_wrapper_function_text.append(
163 ");\n"); // Close off the function calling prototype.
165 m_wrapper_function_text.append(args_buffer);
167 m_wrapper_function_text.append(" ");
168 m_wrapper_function_text.append(return_type_str);
169 m_wrapper_function_text.append(" return_value;");
170 m_wrapper_function_text.append("\n };\n struct ");
171 m_wrapper_function_text.append(m_wrapper_struct_name);
172 m_wrapper_function_text.append("* __lldb_fn_data = (struct ");
173 m_wrapper_function_text.append(m_wrapper_struct_name);
174 m_wrapper_function_text.append(" *) input;\n");
176 m_wrapper_function_text.append(
177 " __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
178 m_wrapper_function_text.append(args_list_buffer);
179 m_wrapper_function_text.append(");\n}\n");
181 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
183 log->Printf("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
185 // Okay, now compile this expression
187 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
188 if (jit_process_sp) {
189 const bool generate_debug_info = true;
190 m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this,
191 generate_debug_info));
193 num_errors = m_parser->Parse(diagnostic_manager);
195 diagnostic_manager.PutString(eDiagnosticSeverityError,
196 "no process - unable to inject function");
200 m_compiled = (num_errors == 0);
209 ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer(
210 clang::ASTConsumer *passthrough) {
211 m_struct_extractor.reset(new ASTStructExtractor(
212 passthrough, m_owner.GetWrapperStructName(), m_owner));
214 return m_struct_extractor.get();