1 //===-- ClangUtilityFunction.cpp ------------------------------------------===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Host/Config.h"
10 
11 #include "ClangUtilityFunction.h"
12 #include "ClangExpressionDeclMap.h"
13 #include "ClangExpressionParser.h"
14 #include "ClangExpressionSourceCode.h"
15 #include "ClangPersistentVariables.h"
16 
17 #include <stdio.h>
18 #if HAVE_SYS_TYPES_H
19 #include <sys/types.h>
20 #endif
21 
22 
23 #include "lldb/Core/Module.h"
24 #include "lldb/Core/StreamFile.h"
25 #include "lldb/Expression/IRExecutionUnit.h"
26 #include "lldb/Host/Host.h"
27 #include "lldb/Target/ExecutionContext.h"
28 #include "lldb/Target/Target.h"
29 #include "lldb/Utility/ConstString.h"
30 #include "lldb/Utility/Log.h"
31 #include "lldb/Utility/Stream.h"
32 
33 using namespace lldb_private;
34 
35 char ClangUtilityFunction::ID;
36 
37 /// Constructor
38 ///
39 /// \param[in] text
40 ///     The text of the function.  Must be a full translation unit.
41 ///
42 /// \param[in] name
43 ///     The name of the function, as used in the text.
ClangUtilityFunction(ExecutionContextScope & exe_scope,std::string text,std::string name)44 ClangUtilityFunction::ClangUtilityFunction(ExecutionContextScope &exe_scope,
45                                            std::string text, std::string name)
46     : UtilityFunction(
47           exe_scope,
48           std::string(ClangExpressionSourceCode::g_expression_prefix) + text,
49           std::move(name)) {}
50 
~ClangUtilityFunction()51 ClangUtilityFunction::~ClangUtilityFunction() {}
52 
53 /// Install the utility function into a process
54 ///
55 /// \param[in] diagnostic_manager
56 ///     A diagnostic manager to report errors and warnings to.
57 ///
58 /// \param[in] exe_ctx
59 ///     The execution context to install the utility function to.
60 ///
61 /// \return
62 ///     True on success (no errors); false otherwise.
Install(DiagnosticManager & diagnostic_manager,ExecutionContext & exe_ctx)63 bool ClangUtilityFunction::Install(DiagnosticManager &diagnostic_manager,
64                                    ExecutionContext &exe_ctx) {
65   if (m_jit_start_addr != LLDB_INVALID_ADDRESS) {
66     diagnostic_manager.PutString(eDiagnosticSeverityWarning,
67                                  "already installed");
68     return false;
69   }
70 
71   ////////////////////////////////////
72   // Set up the target and compiler
73   //
74 
75   Target *target = exe_ctx.GetTargetPtr();
76 
77   if (!target) {
78     diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid target");
79     return false;
80   }
81 
82   Process *process = exe_ctx.GetProcessPtr();
83 
84   if (!process) {
85     diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid process");
86     return false;
87   }
88 
89   //////////////////////////
90   // Parse the expression
91   //
92 
93   bool keep_result_in_memory = false;
94 
95   ResetDeclMap(exe_ctx, keep_result_in_memory);
96 
97   if (!DeclMap()->WillParse(exe_ctx, nullptr)) {
98     diagnostic_manager.PutString(
99         eDiagnosticSeverityError,
100         "current process state is unsuitable for expression parsing");
101     return false;
102   }
103 
104   const bool generate_debug_info = true;
105   ClangExpressionParser parser(exe_ctx.GetBestExecutionContextScope(), *this,
106                                generate_debug_info);
107 
108   unsigned num_errors = parser.Parse(diagnostic_manager);
109 
110   if (num_errors) {
111     ResetDeclMap();
112 
113     return false;
114   }
115 
116   //////////////////////////////////
117   // JIT the output of the parser
118   //
119 
120   bool can_interpret = false; // should stay that way
121 
122   Status jit_error = parser.PrepareForExecution(
123       m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
124       can_interpret, eExecutionPolicyAlways);
125 
126   if (m_jit_start_addr != LLDB_INVALID_ADDRESS) {
127     m_jit_process_wp = process->shared_from_this();
128     if (parser.GetGenerateDebugInfo()) {
129       lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
130 
131       if (jit_module_sp) {
132         ConstString const_func_name(FunctionName());
133         FileSpec jit_file;
134         jit_file.GetFilename() = const_func_name;
135         jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
136         m_jit_module_wp = jit_module_sp;
137         target->GetImages().Append(jit_module_sp);
138       }
139     }
140   }
141 
142   DeclMap()->DidParse();
143 
144   ResetDeclMap();
145 
146   if (jit_error.Success()) {
147     return true;
148   } else {
149     const char *error_cstr = jit_error.AsCString();
150     if (error_cstr && error_cstr[0]) {
151       diagnostic_manager.Printf(eDiagnosticSeverityError, "%s", error_cstr);
152     } else {
153       diagnostic_manager.PutString(eDiagnosticSeverityError,
154                                    "expression can't be interpreted or run");
155     }
156     return false;
157   }
158 }
159 
ResetDeclMap(ExecutionContext & exe_ctx,bool keep_result_in_memory)160 void ClangUtilityFunction::ClangUtilityFunctionHelper::ResetDeclMap(
161     ExecutionContext &exe_ctx, bool keep_result_in_memory) {
162   std::shared_ptr<ClangASTImporter> ast_importer;
163   auto *state = exe_ctx.GetTargetSP()->GetPersistentExpressionStateForLanguage(
164       lldb::eLanguageTypeC);
165   if (state) {
166     auto *persistent_vars = llvm::cast<ClangPersistentVariables>(state);
167     ast_importer = persistent_vars->GetClangASTImporter();
168   }
169   m_expr_decl_map_up = std::make_unique<ClangExpressionDeclMap>(
170       keep_result_in_memory, nullptr, exe_ctx.GetTargetSP(), ast_importer,
171       nullptr);
172 }
173