1 //===-- ClangFunctionCallerCaller.cpp ---------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "ClangFunctionCaller.h"
11 
12 #include "ASTStructExtractor.h"
13 #include "ClangExpressionParser.h"
14 
15 // C Includes
16 // C++ Includes
17 // Other libraries and framework includes
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/RecordLayout.h"
20 #include "clang/CodeGen/CodeGenAction.h"
21 #include "clang/CodeGen/ModuleBuilder.h"
22 #include "clang/Frontend/CompilerInstance.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/ExecutionEngine/ExecutionEngine.h"
26 #include "llvm/IR/Module.h"
27 
28 // Project includes
29 #include "lldb/Core/DataExtractor.h"
30 #include "lldb/Core/Log.h"
31 #include "lldb/Core/Module.h"
32 #include "lldb/Core/State.h"
33 #include "lldb/Core/ValueObject.h"
34 #include "lldb/Core/ValueObjectList.h"
35 #include "lldb/Expression/IRExecutionUnit.h"
36 #include "lldb/Interpreter/CommandReturnObject.h"
37 #include "lldb/Symbol/ClangASTContext.h"
38 #include "lldb/Symbol/Function.h"
39 #include "lldb/Symbol/Type.h"
40 #include "lldb/Target/ExecutionContext.h"
41 #include "lldb/Target/Process.h"
42 #include "lldb/Target/RegisterContext.h"
43 #include "lldb/Target/Target.h"
44 #include "lldb/Target/Thread.h"
45 #include "lldb/Target/ThreadPlan.h"
46 #include "lldb/Target/ThreadPlanCallFunction.h"
47 
48 using namespace lldb_private;
49 
50 //----------------------------------------------------------------------
51 // ClangFunctionCaller constructor
52 //----------------------------------------------------------------------
53 ClangFunctionCaller::ClangFunctionCaller
54 (
55     ExecutionContextScope &exe_scope,
56     const CompilerType &return_type,
57     const Address& functionAddress,
58     const ValueList &arg_value_list,
59     const char *name
60 ) :
61     FunctionCaller(exe_scope, return_type, functionAddress, arg_value_list, name),
62     m_type_system_helper (*this)
63 {
64     m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
65     // Can't make a ClangFunctionCaller without a process.
66     assert (m_jit_process_wp.lock());
67 }
68 
69 //----------------------------------------------------------------------
70 // Destructor
71 //----------------------------------------------------------------------
72 ClangFunctionCaller::~ClangFunctionCaller()
73 {
74 }
75 
76 unsigned
77 
78 ClangFunctionCaller::CompileFunction (lldb::ThreadSP thread_to_use_sp,
79                                       DiagnosticManager &diagnostic_manager)
80 {
81     if (m_compiled)
82         return 0;
83 
84     // Compilation might call code, make sure to keep on the thread the caller indicated.
85     ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(thread_to_use_sp);
86 
87     // FIXME: How does clang tell us there's no return value?  We need to handle that case.
88     unsigned num_errors = 0;
89 
90     std::string return_type_str (m_function_return_type.GetTypeName().AsCString(""));
91 
92     // Cons up the function we're going to wrap our call in, then compile it...
93     // We declare the function "extern "C"" because the compiler might be in C++
94     // mode which would mangle the name and then we couldn't find it again...
95     m_wrapper_function_text.clear();
96     m_wrapper_function_text.append ("extern \"C\" void ");
97     m_wrapper_function_text.append (m_wrapper_function_name);
98     m_wrapper_function_text.append (" (void *input)\n{\n    struct ");
99     m_wrapper_function_text.append (m_wrapper_struct_name);
100     m_wrapper_function_text.append (" \n  {\n");
101     m_wrapper_function_text.append ("    ");
102     m_wrapper_function_text.append (return_type_str);
103     m_wrapper_function_text.append (" (*fn_ptr) (");
104 
105     // Get the number of arguments.  If we have a function type and it is prototyped,
106     // trust that, otherwise use the values we were given.
107 
108     // FIXME: This will need to be extended to handle Variadic functions.  We'll need
109     // to pull the defined arguments out of the function, then add the types from the
110     // arguments list for the variable arguments.
111 
112     uint32_t num_args = UINT32_MAX;
113     bool trust_function = false;
114     // GetArgumentCount returns -1 for an unprototyped function.
115     CompilerType function_clang_type;
116     if (m_function_ptr)
117     {
118         function_clang_type = m_function_ptr->GetCompilerType();
119         if (function_clang_type)
120         {
121             int num_func_args = function_clang_type.GetFunctionArgumentCount();
122             if (num_func_args >= 0)
123             {
124                 trust_function = true;
125                 num_args = num_func_args;
126             }
127         }
128     }
129 
130     if (num_args == UINT32_MAX)
131         num_args = m_arg_values.GetSize();
132 
133     std::string args_buffer;  // This one stores the definition of all the args in "struct caller".
134     std::string args_list_buffer;  // This one stores the argument list called from the structure.
135     for (size_t i = 0; i < num_args; i++)
136     {
137         std::string type_name;
138 
139         if (trust_function)
140         {
141             type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i).GetTypeName().AsCString("");
142         }
143         else
144         {
145             CompilerType clang_qual_type = m_arg_values.GetValueAtIndex(i)->GetCompilerType ();
146             if (clang_qual_type)
147             {
148                 type_name = clang_qual_type.GetTypeName().AsCString("");
149             }
150             else
151             {
152                 diagnostic_manager.Printf(eDiagnosticSeverityError,
153                                           "Could not determine type of input value %" PRIu64 ".", (uint64_t)i);
154                 return 1;
155             }
156         }
157 
158         m_wrapper_function_text.append (type_name);
159         if (i < num_args - 1)
160             m_wrapper_function_text.append (", ");
161 
162         char arg_buf[32];
163         args_buffer.append ("    ");
164         args_buffer.append (type_name);
165         snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
166         args_buffer.push_back (' ');
167         args_buffer.append (arg_buf);
168         args_buffer.append (";\n");
169 
170         args_list_buffer.append ("__lldb_fn_data->");
171         args_list_buffer.append (arg_buf);
172         if (i < num_args - 1)
173             args_list_buffer.append (", ");
174 
175     }
176     m_wrapper_function_text.append (");\n"); // Close off the function calling prototype.
177 
178     m_wrapper_function_text.append (args_buffer);
179 
180     m_wrapper_function_text.append ("    ");
181     m_wrapper_function_text.append (return_type_str);
182     m_wrapper_function_text.append (" return_value;");
183     m_wrapper_function_text.append ("\n  };\n  struct ");
184     m_wrapper_function_text.append (m_wrapper_struct_name);
185     m_wrapper_function_text.append ("* __lldb_fn_data = (struct ");
186     m_wrapper_function_text.append (m_wrapper_struct_name);
187     m_wrapper_function_text.append (" *) input;\n");
188 
189     m_wrapper_function_text.append ("  __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
190     m_wrapper_function_text.append (args_list_buffer);
191     m_wrapper_function_text.append (");\n}\n");
192 
193     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
194     if (log)
195         log->Printf ("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
196 
197     // Okay, now compile this expression
198 
199     lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
200     if (jit_process_sp)
201     {
202         const bool generate_debug_info = true;
203         m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this, generate_debug_info));
204 
205         num_errors = m_parser->Parse(diagnostic_manager);
206     }
207     else
208     {
209         diagnostic_manager.PutCString(eDiagnosticSeverityError, "no process - unable to inject function");
210         num_errors = 1;
211     }
212 
213     m_compiled = (num_errors == 0);
214 
215     if (!m_compiled)
216         return num_errors;
217 
218     return num_errors;
219 }
220 
221 clang::ASTConsumer *
222 ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer (clang::ASTConsumer *passthrough)
223 {
224     m_struct_extractor.reset(new ASTStructExtractor(passthrough, m_owner.GetWrapperStructName(), m_owner));
225 
226     return m_struct_extractor.get();
227 }
228