ClangFunctionCaller.cpp revision 344779 
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#include "clang/AST/ASTContext.h"
16#include "clang/AST/RecordLayout.h"
17#include "clang/CodeGen/CodeGenAction.h"
18#include "clang/CodeGen/ModuleBuilder.h"
19#include "clang/Frontend/CompilerInstance.h"
20#include "llvm/ADT/StringRef.h"
21#include "llvm/ADT/Triple.h"
22#include "llvm/ExecutionEngine/ExecutionEngine.h"
23#include "llvm/IR/Module.h"
24
25#include "lldb/Core/Module.h"
26#include "lldb/Core/ValueObject.h"
27#include "lldb/Core/ValueObjectList.h"
28#include "lldb/Expression/IRExecutionUnit.h"
29#include "lldb/Interpreter/CommandReturnObject.h"
30#include "lldb/Symbol/ClangASTContext.h"
31#include "lldb/Symbol/Function.h"
32#include "lldb/Symbol/Type.h"
33#include "lldb/Target/ExecutionContext.h"
34#include "lldb/Target/Process.h"
35#include "lldb/Target/RegisterContext.h"
36#include "lldb/Target/Target.h"
37#include "lldb/Target/Thread.h"
38#include "lldb/Target/ThreadPlan.h"
39#include "lldb/Target/ThreadPlanCallFunction.h"
40#include "lldb/Utility/DataExtractor.h"
41#include "lldb/Utility/Log.h"
42#include "lldb/Utility/State.h"
43
44using namespace lldb_private;
45
46//----------------------------------------------------------------------
47// ClangFunctionCaller constructor
48//----------------------------------------------------------------------
49ClangFunctionCaller::ClangFunctionCaller(ExecutionContextScope &exe_scope,
50                                         const CompilerType &return_type,
51                                         const Address &functionAddress,
52                                         const ValueList &arg_value_list,
53                                         const char *name)
54    : FunctionCaller(exe_scope, return_type, functionAddress, arg_value_list,
55                     name),
56      m_type_system_helper(*this) {
57  m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
58  // Can't make a ClangFunctionCaller without a process.
59  assert(m_jit_process_wp.lock());
60}
61
62//----------------------------------------------------------------------
63// Destructor
64//----------------------------------------------------------------------
65ClangFunctionCaller::~ClangFunctionCaller() {}
66
67unsigned
68
69ClangFunctionCaller::CompileFunction(lldb::ThreadSP thread_to_use_sp,
70                                     DiagnosticManager &diagnostic_manager) {
71  if (m_compiled)
72    return 0;
73
74  // Compilation might call code, make sure to keep on the thread the caller
75  // indicated.
76  ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
77      thread_to_use_sp);
78
79  // FIXME: How does clang tell us there's no return value?  We need to handle
80  // that case.
81  unsigned num_errors = 0;
82
83  std::string return_type_str(
84      m_function_return_type.GetTypeName().AsCString(""));
85
86  // Cons up the function we're going to wrap our call in, then compile it...
87  // We declare the function "extern "C"" because the compiler might be in C++
88  // mode which would mangle the name and then we couldn't find it again...
89  m_wrapper_function_text.clear();
90  m_wrapper_function_text.append("extern \"C\" void ");
91  m_wrapper_function_text.append(m_wrapper_function_name);
92  m_wrapper_function_text.append(" (void *input)\n{\n    struct ");
93  m_wrapper_function_text.append(m_wrapper_struct_name);
94  m_wrapper_function_text.append(" \n  {\n");
95  m_wrapper_function_text.append("    ");
96  m_wrapper_function_text.append(return_type_str);
97  m_wrapper_function_text.append(" (*fn_ptr) (");
98
99  // Get the number of arguments.  If we have a function type and it is
100  // prototyped, trust that, otherwise use the values we were given.
101
102  // FIXME: This will need to be extended to handle Variadic functions.  We'll
103  // need
104  // to pull the defined arguments out of the function, then add the types from
105  // the arguments list for the variable arguments.
106
107  uint32_t num_args = UINT32_MAX;
108  bool trust_function = false;
109  // GetArgumentCount returns -1 for an unprototyped function.
110  CompilerType function_clang_type;
111  if (m_function_ptr) {
112    function_clang_type = m_function_ptr->GetCompilerType();
113    if (function_clang_type) {
114      int num_func_args = function_clang_type.GetFunctionArgumentCount();
115      if (num_func_args >= 0) {
116        trust_function = true;
117        num_args = num_func_args;
118      }
119    }
120  }
121
122  if (num_args == UINT32_MAX)
123    num_args = m_arg_values.GetSize();
124
125  std::string args_buffer; // This one stores the definition of all the args in
126                           // "struct caller".
127  std::string args_list_buffer; // This one stores the argument list called from
128                                // the structure.
129  for (size_t i = 0; i < num_args; i++) {
130    std::string type_name;
131
132    if (trust_function) {
133      type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i)
134                      .GetTypeName()
135                      .AsCString("");
136    } else {
137      CompilerType clang_qual_type =
138          m_arg_values.GetValueAtIndex(i)->GetCompilerType();
139      if (clang_qual_type) {
140        type_name = clang_qual_type.GetTypeName().AsCString("");
141      } else {
142        diagnostic_manager.Printf(
143            eDiagnosticSeverityError,
144            "Could not determine type of input value %" PRIu64 ".",
145            (uint64_t)i);
146        return 1;
147      }
148    }
149
150    m_wrapper_function_text.append(type_name);
151    if (i < num_args - 1)
152      m_wrapper_function_text.append(", ");
153
154    char arg_buf[32];
155    args_buffer.append("    ");
156    args_buffer.append(type_name);
157    snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)i);
158    args_buffer.push_back(' ');
159    args_buffer.append(arg_buf);
160    args_buffer.append(";\n");
161
162    args_list_buffer.append("__lldb_fn_data->");
163    args_list_buffer.append(arg_buf);
164    if (i < num_args - 1)
165      args_list_buffer.append(", ");
166  }
167  m_wrapper_function_text.append(
168      ");\n"); // Close off the function calling prototype.
169
170  m_wrapper_function_text.append(args_buffer);
171
172  m_wrapper_function_text.append("    ");
173  m_wrapper_function_text.append(return_type_str);
174  m_wrapper_function_text.append(" return_value;");
175  m_wrapper_function_text.append("\n  };\n  struct ");
176  m_wrapper_function_text.append(m_wrapper_struct_name);
177  m_wrapper_function_text.append("* __lldb_fn_data = (struct ");
178  m_wrapper_function_text.append(m_wrapper_struct_name);
179  m_wrapper_function_text.append(" *) input;\n");
180
181  m_wrapper_function_text.append(
182      "  __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
183  m_wrapper_function_text.append(args_list_buffer);
184  m_wrapper_function_text.append(");\n}\n");
185
186  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
187  if (log)
188    log->Printf("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str());
189
190  // Okay, now compile this expression
191
192  lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
193  if (jit_process_sp) {
194    const bool generate_debug_info = true;
195    m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this,
196                                             generate_debug_info));
197
198    num_errors = m_parser->Parse(diagnostic_manager);
199  } else {
200    diagnostic_manager.PutString(eDiagnosticSeverityError,
201                                 "no process - unable to inject function");
202    num_errors = 1;
203  }
204
205  m_compiled = (num_errors == 0);
206
207  if (!m_compiled)
208    return num_errors;
209
210  return num_errors;
211}
212
213clang::ASTConsumer *
214ClangFunctionCaller::ClangFunctionCallerHelper::ASTTransformer(
215    clang::ASTConsumer *passthrough) {
216  m_struct_extractor.reset(new ASTStructExtractor(
217      passthrough, m_owner.GetWrapperStructName(), m_owner));
218
219  return m_struct_extractor.get();
220}
221