ClangFunctionCaller.cpp revision 321369 
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,
105  // trust that, otherwise use the values we were given.
106
107  // FIXME: This will need to be extended to handle Variadic functions.  We'll
108  // need
109  // to pull the defined arguments out of the function, then add the types from
110  // the
111  // arguments list for the variable arguments.
112
113  uint32_t num_args = UINT32_MAX;
114  bool trust_function = false;
115  // GetArgumentCount returns -1 for an unprototyped function.
116  CompilerType function_clang_type;
117  if (m_function_ptr) {
118    function_clang_type = m_function_ptr->GetCompilerType();
119    if (function_clang_type) {
120      int num_func_args = function_clang_type.GetFunctionArgumentCount();
121      if (num_func_args >= 0) {
122        trust_function = true;
123        num_args = num_func_args;
124      }
125    }
126  }
127
128  if (num_args == UINT32_MAX)
129    num_args = m_arg_values.GetSize();
130
131  std::string args_buffer; // This one stores the definition of all the args in
132                           // "struct caller".
133  std::string args_list_buffer; // This one stores the argument list called from
134                                // the structure.
135  for (size_t i = 0; i < num_args; i++) {
136    std::string type_name;
137
138    if (trust_function) {
139      type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i)
140                      .GetTypeName()
141                      .AsCString("");
142    } else {
143      CompilerType clang_qual_type =
144          m_arg_values.GetValueAtIndex(i)->GetCompilerType();
145      if (clang_qual_type) {
146        type_name = clang_qual_type.GetTypeName().AsCString("");
147      } else {
148        diagnostic_manager.Printf(
149            eDiagnosticSeverityError,
150            "Could not determine type of input value %" PRIu64 ".",
151            (uint64_t)i);
152        return 1;
153      }
154    }
155
156    m_wrapper_function_text.append(type_name);
157    if (i < num_args - 1)
158      m_wrapper_function_text.append(", ");
159
160    char arg_buf[32];
161    args_buffer.append("    ");
162    args_buffer.append(type_name);
163    snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
164    args_buffer.push_back(' ');
165    args_buffer.append(arg_buf);
166    args_buffer.append(";\n");
167
168    args_list_buffer.append("__lldb_fn_data->");
169    args_list_buffer.append(arg_buf);
170    if (i < num_args - 1)
171      args_list_buffer.append(", ");
172  }
173  m_wrapper_function_text.append(
174      ");\n"); // Close off the function calling prototype.
175
176  m_wrapper_function_text.append(args_buffer);
177
178  m_wrapper_function_text.append("    ");
179  m_wrapper_function_text.append(return_type_str);
180  m_wrapper_function_text.append(" return_value;");
181  m_wrapper_function_text.append("\n  };\n  struct ");
182  m_wrapper_function_text.append(m_wrapper_struct_name);
183  m_wrapper_function_text.append("* __lldb_fn_data = (struct ");
184  m_wrapper_function_text.append(m_wrapper_struct_name);
185  m_wrapper_function_text.append(" *) input;\n");
186
187  m_wrapper_function_text.append(
188      "  __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
189  m_wrapper_function_text.append(args_list_buffer);
190  m_wrapper_function_text.append(");\n}\n");
191
192  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
193  if (log)
194    log->Printf("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
195
196  // Okay, now compile this expression
197
198  lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
199  if (jit_process_sp) {
200    const bool generate_debug_info = true;
201    m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this,
202                                             generate_debug_info));
203
204    num_errors = m_parser->Parse(diagnostic_manager);
205  } else {
206    diagnostic_manager.PutString(eDiagnosticSeverityError,
207                                 "no process - unable to inject function");
208    num_errors = 1;
209  }
210
211  m_compiled = (num_errors == 0);
212
213  if (!m_compiled)
214    return num_errors;
215
216  return num_errors;
217}
218
219clang::ASTConsumer *
220ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer(
221    clang::ASTConsumer *passthrough) {
222  m_struct_extractor.reset(new ASTStructExtractor(
223      passthrough, m_owner.GetWrapperStructName(), m_owner));
224
225  return m_struct_extractor.get();
226}
227