ClangFunctionCaller.cpp revision 341825 
1//===-- ClangFunctionCaller.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/Module.h"
30#include "lldb/Core/State.h"
31#include "lldb/Core/ValueObject.h"
32#include "lldb/Core/ValueObjectList.h"
33#include "lldb/Expression/IRExecutionUnit.h"
34#include "lldb/Interpreter/CommandReturnObject.h"
35#include "lldb/Symbol/ClangASTContext.h"
36#include "lldb/Symbol/Function.h"
37#include "lldb/Symbol/Type.h"
38#include "lldb/Target/ExecutionContext.h"
39#include "lldb/Target/Process.h"
40#include "lldb/Target/RegisterContext.h"
41#include "lldb/Target/Target.h"
42#include "lldb/Target/Thread.h"
43#include "lldb/Target/ThreadPlan.h"
44#include "lldb/Target/ThreadPlanCallFunction.h"
45#include "lldb/Utility/DataExtractor.h"
46#include "lldb/Utility/Log.h"
47
48using namespace lldb_private;
49
50//----------------------------------------------------------------------
51// ClangFunctionCaller constructor
52//----------------------------------------------------------------------
53ClangFunctionCaller::ClangFunctionCaller(ExecutionContextScope &exe_scope,
54                                         const CompilerType &return_type,
55                                         const Address &functionAddress,
56                                         const ValueList &arg_value_list,
57                                         const char *name)
58    : FunctionCaller(exe_scope, return_type, functionAddress, arg_value_list,
59                     name),
60      m_type_system_helper(*this) {
61  m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
62  // Can't make a ClangFunctionCaller without a process.
63  assert(m_jit_process_wp.lock());
64}
65
66//----------------------------------------------------------------------
67// Destructor
68//----------------------------------------------------------------------
69ClangFunctionCaller::~ClangFunctionCaller() {}
70
71unsigned
72
73ClangFunctionCaller::CompileFunction(lldb::ThreadSP thread_to_use_sp,
74                                     DiagnosticManager &diagnostic_manager) {
75  if (m_compiled)
76    return 0;
77
78  // Compilation might call code, make sure to keep on the thread the caller
79  // indicated.
80  ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
81      thread_to_use_sp);
82
83  // FIXME: How does clang tell us there's no return value?  We need to handle
84  // that case.
85  unsigned num_errors = 0;
86
87  std::string return_type_str(
88      m_function_return_type.GetTypeName().AsCString(""));
89
90  // Cons up the function we're going to wrap our call in, then compile it...
91  // We declare the function "extern "C"" because the compiler might be in C++
92  // mode which would mangle the name and then we couldn't find it again...
93  m_wrapper_function_text.clear();
94  m_wrapper_function_text.append("extern \"C\" void ");
95  m_wrapper_function_text.append(m_wrapper_function_name);
96  m_wrapper_function_text.append(" (void *input)\n{\n    struct ");
97  m_wrapper_function_text.append(m_wrapper_struct_name);
98  m_wrapper_function_text.append(" \n  {\n");
99  m_wrapper_function_text.append("    ");
100  m_wrapper_function_text.append(return_type_str);
101  m_wrapper_function_text.append(" (*fn_ptr) (");
102
103  // Get the number of arguments.  If we have a function type and it is
104  // prototyped, trust that, otherwise use the values we were given.
105
106  // FIXME: This will need to be extended to handle Variadic functions.  We'll
107  // need
108  // to pull the defined arguments out of the function, then add the types from
109  // the arguments list for the variable arguments.
110
111  uint32_t num_args = UINT32_MAX;
112  bool trust_function = false;
113  // GetArgumentCount returns -1 for an unprototyped function.
114  CompilerType function_clang_type;
115  if (m_function_ptr) {
116    function_clang_type = m_function_ptr->GetCompilerType();
117    if (function_clang_type) {
118      int num_func_args = function_clang_type.GetFunctionArgumentCount();
119      if (num_func_args >= 0) {
120        trust_function = true;
121        num_args = num_func_args;
122      }
123    }
124  }
125
126  if (num_args == UINT32_MAX)
127    num_args = m_arg_values.GetSize();
128
129  std::string args_buffer; // This one stores the definition of all the args in
130                           // "struct caller".
131  std::string args_list_buffer; // This one stores the argument list called from
132                                // the structure.
133  for (size_t i = 0; i < num_args; i++) {
134    std::string type_name;
135
136    if (trust_function) {
137      type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i)
138                      .GetTypeName()
139                      .AsCString("");
140    } else {
141      CompilerType clang_qual_type =
142          m_arg_values.GetValueAtIndex(i)->GetCompilerType();
143      if (clang_qual_type) {
144        type_name = clang_qual_type.GetTypeName().AsCString("");
145      } else {
146        diagnostic_manager.Printf(
147            eDiagnosticSeverityError,
148            "Could not determine type of input value %" PRIu64 ".",
149            (uint64_t)i);
150        return 1;
151      }
152    }
153
154    m_wrapper_function_text.append(type_name);
155    if (i < num_args - 1)
156      m_wrapper_function_text.append(", ");
157
158    char arg_buf[32];
159    args_buffer.append("    ");
160    args_buffer.append(type_name);
161    snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
162    args_buffer.push_back(' ');
163    args_buffer.append(arg_buf);
164    args_buffer.append(";\n");
165
166    args_list_buffer.append("__lldb_fn_data->");
167    args_list_buffer.append(arg_buf);
168    if (i < num_args - 1)
169      args_list_buffer.append(", ");
170  }
171  m_wrapper_function_text.append(
172      ");\n"); // Close off the function calling prototype.
173
174  m_wrapper_function_text.append(args_buffer);
175
176  m_wrapper_function_text.append("    ");
177  m_wrapper_function_text.append(return_type_str);
178  m_wrapper_function_text.append(" return_value;");
179  m_wrapper_function_text.append("\n  };\n  struct ");
180  m_wrapper_function_text.append(m_wrapper_struct_name);
181  m_wrapper_function_text.append("* __lldb_fn_data = (struct ");
182  m_wrapper_function_text.append(m_wrapper_struct_name);
183  m_wrapper_function_text.append(" *) input;\n");
184
185  m_wrapper_function_text.append(
186      "  __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
187  m_wrapper_function_text.append(args_list_buffer);
188  m_wrapper_function_text.append(");\n}\n");
189
190  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
191  if (log)
192    log->Printf("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
193
194  // Okay, now compile this expression
195
196  lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
197  if (jit_process_sp) {
198    const bool generate_debug_info = true;
199    m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this,
200                                             generate_debug_info));
201
202    num_errors = m_parser->Parse(diagnostic_manager);
203  } else {
204    diagnostic_manager.PutString(eDiagnosticSeverityError,
205                                 "no process - unable to inject function");
206    num_errors = 1;
207  }
208
209  m_compiled = (num_errors == 0);
210
211  if (!m_compiled)
212    return num_errors;
213
214  return num_errors;
215}
216
217clang::ASTConsumer *
218ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer(
219    clang::ASTConsumer *passthrough) {
220  m_struct_extractor.reset(new ASTStructExtractor(
221      passthrough, m_owner.GetWrapperStructName(), m_owner));
222
223  return m_struct_extractor.get();
224}
225