xref: /llvm-project/lldb/source/Commands/CommandObjectDWIMPrint.cpp (revision 061a839033dc5f11c4e43fb64ed49cc85e1e5f32)
1 //===-- CommandObjectDWIMPrint.cpp ------------------------------*- C++ -*-===//
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 "CommandObjectDWIMPrint.h"
10 
11 #include "lldb/Core/ValueObject.h"
12 #include "lldb/DataFormatters/DumpValueObjectOptions.h"
13 #include "lldb/Expression/ExpressionVariable.h"
14 #include "lldb/Expression/UserExpression.h"
15 #include "lldb/Interpreter/CommandInterpreter.h"
16 #include "lldb/Interpreter/CommandObject.h"
17 #include "lldb/Interpreter/CommandReturnObject.h"
18 #include "lldb/Interpreter/OptionGroupFormat.h"
19 #include "lldb/Interpreter/OptionGroupValueObjectDisplay.h"
20 #include "lldb/Target/StackFrame.h"
21 #include "lldb/Utility/ConstString.h"
22 #include "lldb/lldb-defines.h"
23 #include "lldb/lldb-enumerations.h"
24 #include "lldb/lldb-forward.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/Support/FormatVariadic.h"
27 
28 using namespace llvm;
29 using namespace lldb;
30 using namespace lldb_private;
31 
32 CommandObjectDWIMPrint::CommandObjectDWIMPrint(CommandInterpreter &interpreter)
33     : CommandObjectRaw(interpreter, "dwim-print",
34                        "Print a variable or expression.",
35                        "dwim-print [<variable-name> | <expression>]",
36                        eCommandProcessMustBePaused | eCommandTryTargetAPILock) {
37 
38   CommandArgumentData var_name_arg(eArgTypeVarName, eArgRepeatPlain);
39   m_arguments.push_back({var_name_arg});
40 
41   m_option_group.Append(&m_format_options,
42                         OptionGroupFormat::OPTION_GROUP_FORMAT |
43                             OptionGroupFormat::OPTION_GROUP_GDB_FMT,
44                         LLDB_OPT_SET_1);
45   StringRef exclude_expr_options[] = {"debug", "top-level"};
46   m_option_group.Append(&m_expr_options, exclude_expr_options);
47   m_option_group.Append(&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1);
48   m_option_group.Finalize();
49 }
50 
51 Options *CommandObjectDWIMPrint::GetOptions() { return &m_option_group; }
52 
53 void CommandObjectDWIMPrint::HandleArgumentCompletion(
54     CompletionRequest &request, OptionElementVector &opt_element_vector) {
55   CommandCompletions::InvokeCommonCompletionCallbacks(
56       GetCommandInterpreter(), CommandCompletions::eVariablePathCompletion,
57       request, nullptr);
58 }
59 
60 bool CommandObjectDWIMPrint::DoExecute(StringRef command,
61                                        CommandReturnObject &result) {
62   m_option_group.NotifyOptionParsingStarting(&m_exe_ctx);
63   OptionsWithRaw args{command};
64   StringRef expr = args.GetRawPart();
65 
66   if (expr.empty()) {
67     result.AppendErrorWithFormatv("'{0}' takes a variable or expression",
68                                   m_cmd_name);
69     return false;
70   }
71 
72   if (args.HasArgs()) {
73     if (!ParseOptionsAndNotify(args.GetArgs(), result, m_option_group,
74                                m_exe_ctx))
75       return false;
76   }
77 
78   // If the user has not specified, default to disabling persistent results.
79   if (m_expr_options.suppress_persistent_result == eLazyBoolCalculate)
80     m_expr_options.suppress_persistent_result = eLazyBoolYes;
81   bool suppress_result = m_expr_options.ShouldSuppressResult(m_varobj_options);
82 
83   auto verbosity = GetDebugger().GetDWIMPrintVerbosity();
84 
85   Target *target_ptr = m_exe_ctx.GetTargetPtr();
86   // Fallback to the dummy target, which can allow for expression evaluation.
87   Target &target = target_ptr ? *target_ptr : GetDummyTarget();
88 
89   EvaluateExpressionOptions eval_options =
90       m_expr_options.GetEvaluateExpressionOptions(target, m_varobj_options);
91   // This command manually removes the result variable, make sure expression
92   // evaluation doesn't do it first.
93   eval_options.SetSuppressPersistentResult(false);
94 
95   DumpValueObjectOptions dump_options = m_varobj_options.GetAsDumpOptions(
96       m_expr_options.m_verbosity, m_format_options.GetFormat());
97   dump_options.SetHideRootName(suppress_result);
98 
99   StackFrame *frame = m_exe_ctx.GetFramePtr();
100 
101   // First, try `expr` as the name of a frame variable.
102   if (frame) {
103     auto valobj_sp = frame->FindVariable(ConstString(expr));
104     if (valobj_sp && valobj_sp->GetError().Success()) {
105       if (!suppress_result) {
106         if (auto persisted_valobj = valobj_sp->Persist())
107           valobj_sp = persisted_valobj;
108       }
109 
110       if (verbosity == eDWIMPrintVerbosityFull) {
111         StringRef flags;
112         if (args.HasArgs())
113           flags = args.GetArgString();
114         result.AppendMessageWithFormatv("note: ran `frame variable {0}{1}`",
115                                         flags, expr);
116       }
117 
118       valobj_sp->Dump(result.GetOutputStream(), dump_options);
119       result.SetStatus(eReturnStatusSuccessFinishResult);
120       return true;
121     }
122   }
123 
124   // Second, also lastly, try `expr` as a source expression to evaluate.
125   {
126     auto *exe_scope = m_exe_ctx.GetBestExecutionContextScope();
127     ValueObjectSP valobj_sp;
128     ExpressionResults expr_result =
129         target.EvaluateExpression(expr, exe_scope, valobj_sp, eval_options);
130     if (expr_result == eExpressionCompleted) {
131       if (verbosity != eDWIMPrintVerbosityNone) {
132         StringRef flags;
133         if (args.HasArgs())
134           flags = args.GetArgStringWithDelimiter();
135         result.AppendMessageWithFormatv("note: ran `expression {0}{1}`", flags,
136                                         expr);
137       }
138 
139       if (valobj_sp->GetError().GetError() != UserExpression::kNoResult)
140         valobj_sp->Dump(result.GetOutputStream(), dump_options);
141 
142       if (suppress_result)
143         if (auto result_var_sp =
144                 target.GetPersistentVariable(valobj_sp->GetName())) {
145           auto language = valobj_sp->GetPreferredDisplayLanguage();
146           if (auto *persistent_state =
147                   target.GetPersistentExpressionStateForLanguage(language))
148             persistent_state->RemovePersistentVariable(result_var_sp);
149         }
150 
151       result.SetStatus(eReturnStatusSuccessFinishResult);
152       return true;
153     } else {
154       if (valobj_sp)
155         result.SetError(valobj_sp->GetError());
156       else
157         result.AppendErrorWithFormatv(
158             "unknown error evaluating expression `{0}`", expr);
159       return false;
160     }
161   }
162 }
163