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 "ClangUtilityFunction.h"
10 #include "ClangExpressionDeclMap.h"
11 #include "ClangExpressionParser.h"
12 #include "ClangExpressionSourceCode.h"
13 #include "ClangPersistentVariables.h"
14
15 #include <cstdio>
16 #include <sys/types.h>
17
18
19 #include "lldb/Core/Module.h"
20 #include "lldb/Core/StreamFile.h"
21 #include "lldb/Expression/IRExecutionUnit.h"
22 #include "lldb/Host/Host.h"
23 #include "lldb/Target/ExecutionContext.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/ConstString.h"
26 #include "lldb/Utility/Log.h"
27 #include "lldb/Utility/Stream.h"
28
29 using namespace lldb_private;
30
31 char ClangUtilityFunction::ID;
32
ClangUtilityFunction(ExecutionContextScope & exe_scope,std::string text,std::string name,bool enable_debugging)33 ClangUtilityFunction::ClangUtilityFunction(ExecutionContextScope &exe_scope,
34 std::string text, std::string name,
35 bool enable_debugging)
36 : UtilityFunction(
37 exe_scope,
38 std::string(ClangExpressionSourceCode::g_expression_prefix) + text +
39 std::string(ClangExpressionSourceCode::g_expression_suffix),
40 std::move(name), enable_debugging) {
41 // Write the source code to a file so that LLDB's source manager can display
42 // it when debugging the code.
43 if (enable_debugging) {
44 int temp_fd = -1;
45 llvm::SmallString<128> result_path;
46 llvm::sys::fs::createTemporaryFile("lldb", "expr", temp_fd, result_path);
47 if (temp_fd != -1) {
48 lldb_private::NativeFile file(temp_fd, File::eOpenOptionWriteOnly, true);
49 text = "#line 1 \"" + std::string(result_path) + "\"\n" + text;
50 size_t bytes_written = text.size();
51 file.Write(text.c_str(), bytes_written);
52 if (bytes_written == text.size()) {
53 // If we successfully wrote the source to a temporary file, replace the
54 // function text with the next text containing the line directive.
55 m_function_text =
56 std::string(ClangExpressionSourceCode::g_expression_prefix) + text +
57 std::string(ClangExpressionSourceCode::g_expression_suffix);
58 }
59 file.Close();
60 }
61 }
62 }
63
64 ClangUtilityFunction::~ClangUtilityFunction() = default;
65
66 /// Install the utility function into a process
67 ///
68 /// \param[in] diagnostic_manager
69 /// A diagnostic manager to report errors and warnings to.
70 ///
71 /// \param[in] exe_ctx
72 /// The execution context to install the utility function to.
73 ///
74 /// \return
75 /// True on success (no errors); false otherwise.
Install(DiagnosticManager & diagnostic_manager,ExecutionContext & exe_ctx)76 bool ClangUtilityFunction::Install(DiagnosticManager &diagnostic_manager,
77 ExecutionContext &exe_ctx) {
78 if (m_jit_start_addr != LLDB_INVALID_ADDRESS) {
79 diagnostic_manager.PutString(eDiagnosticSeverityWarning,
80 "already installed");
81 return false;
82 }
83
84 ////////////////////////////////////
85 // Set up the target and compiler
86 //
87
88 Target *target = exe_ctx.GetTargetPtr();
89
90 if (!target) {
91 diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid target");
92 return false;
93 }
94
95 Process *process = exe_ctx.GetProcessPtr();
96
97 if (!process) {
98 diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid process");
99 return false;
100 }
101
102 // Since we might need to call allocate memory and maybe call code to make
103 // the caller, we need to be stopped.
104 if (process->GetState() != lldb::eStateStopped) {
105 diagnostic_manager.PutString(eDiagnosticSeverityError, "process running");
106 return false;
107 }
108 //////////////////////////
109 // Parse the expression
110 //
111
112 bool keep_result_in_memory = false;
113
114 ResetDeclMap(exe_ctx, keep_result_in_memory);
115
116 if (!DeclMap()->WillParse(exe_ctx, nullptr)) {
117 diagnostic_manager.PutString(
118 eDiagnosticSeverityError,
119 "current process state is unsuitable for expression parsing");
120 return false;
121 }
122
123 const bool generate_debug_info = true;
124 ClangExpressionParser parser(exe_ctx.GetBestExecutionContextScope(), *this,
125 generate_debug_info);
126
127 unsigned num_errors = parser.Parse(diagnostic_manager);
128
129 if (num_errors) {
130 ResetDeclMap();
131
132 return false;
133 }
134
135 //////////////////////////////////
136 // JIT the output of the parser
137 //
138
139 bool can_interpret = false; // should stay that way
140
141 Status jit_error = parser.PrepareForExecution(
142 m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
143 can_interpret, eExecutionPolicyAlways);
144
145 if (m_jit_start_addr != LLDB_INVALID_ADDRESS) {
146 m_jit_process_wp = process->shared_from_this();
147 if (parser.GetGenerateDebugInfo()) {
148 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
149
150 if (jit_module_sp) {
151 ConstString const_func_name(FunctionName());
152 FileSpec jit_file;
153 jit_file.SetFilename(const_func_name);
154 jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
155 m_jit_module_wp = jit_module_sp;
156 target->GetImages().Append(jit_module_sp);
157 }
158 }
159 }
160
161 DeclMap()->DidParse();
162
163 ResetDeclMap();
164
165 if (jit_error.Success()) {
166 return true;
167 } else {
168 const char *error_cstr = jit_error.AsCString();
169 if (error_cstr && error_cstr[0]) {
170 diagnostic_manager.Printf(eDiagnosticSeverityError, "%s", error_cstr);
171 } else {
172 diagnostic_manager.PutString(eDiagnosticSeverityError,
173 "expression can't be interpreted or run");
174 }
175 return false;
176 }
177 }
178
ResetDeclMap(ExecutionContext & exe_ctx,bool keep_result_in_memory)179 void ClangUtilityFunction::ClangUtilityFunctionHelper::ResetDeclMap(
180 ExecutionContext &exe_ctx, bool keep_result_in_memory) {
181 std::shared_ptr<ClangASTImporter> ast_importer;
182 auto *state = exe_ctx.GetTargetSP()->GetPersistentExpressionStateForLanguage(
183 lldb::eLanguageTypeC);
184 if (state) {
185 auto *persistent_vars = llvm::cast<ClangPersistentVariables>(state);
186 ast_importer = persistent_vars->GetClangASTImporter();
187 }
188 m_expr_decl_map_up = std::make_unique<ClangExpressionDeclMap>(
189 keep_result_in_memory, nullptr, exe_ctx.GetTargetSP(), ast_importer,
190 nullptr);
191 }
192