xref: /llvm-project/lldb/source/Commands/CommandObjectExpression.cpp (revision 1d1806641146f60f10e6269c7ec66f9ed1e5e88a)
1 //===-- CommandObjectExpression.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 "CommandObjectExpression.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Interpreter/Args.h"
17 #include "lldb/Core/Value.h"
18 #include "lldb/Core/InputReader.h"
19 #include "lldb/Expression/ClangExpression.h"
20 #include "lldb/Expression/ClangExpressionDeclMap.h"
21 #include "lldb/Expression/ClangExpressionVariable.h"
22 #include "lldb/Expression/DWARFExpression.h"
23 #include "lldb/Host/Host.h"
24 #include "lldb/Core/Debugger.h"
25 #include "lldb/Interpreter/CommandInterpreter.h"
26 #include "lldb/Interpreter/CommandReturnObject.h"
27 #include "lldb/Symbol/ObjectFile.h"
28 #include "lldb/Symbol/Variable.h"
29 #include "lldb/Target/Process.h"
30 #include "lldb/Target/StackFrame.h"
31 #include "lldb/Target/Target.h"
32 #include "llvm/ADT/StringRef.h"
33 
34 using namespace lldb;
35 using namespace lldb_private;
36 
37 CommandObjectExpression::CommandOptions::CommandOptions () :
38     Options()
39 {
40     // Keep only one place to reset the values to their defaults
41     ResetOptionValues();
42 }
43 
44 
45 CommandObjectExpression::CommandOptions::~CommandOptions ()
46 {
47 }
48 
49 Error
50 CommandObjectExpression::CommandOptions::SetOptionValue (int option_idx, const char *option_arg)
51 {
52     Error error;
53 
54     char short_option = (char) m_getopt_table[option_idx].val;
55 
56     switch (short_option)
57     {
58     case 'l':
59         if (language.SetLanguageFromCString (option_arg) == false)
60         {
61             error.SetErrorStringWithFormat("Invalid language option argument '%s'.\n", option_arg);
62         }
63         break;
64 
65     case 'g':
66         debug = true;
67         break;
68 
69     case 'f':
70         error = Args::StringToFormat(option_arg, format);
71         break;
72 
73     case 'i':
74         use_ir = true;
75         break;
76 
77     default:
78         error.SetErrorStringWithFormat("Invalid short option character '%c'.\n", short_option);
79         break;
80     }
81 
82     return error;
83 }
84 
85 void
86 CommandObjectExpression::CommandOptions::ResetOptionValues ()
87 {
88     Options::ResetOptionValues();
89     language.Clear();
90     debug = false;
91     format = eFormatDefault;
92     show_types = true;
93     show_summary = true;
94     use_ir = false;
95 }
96 
97 const lldb::OptionDefinition*
98 CommandObjectExpression::CommandOptions::GetDefinitions ()
99 {
100     return g_option_table;
101 }
102 
103 CommandObjectExpression::CommandObjectExpression () :
104     CommandObject (
105             "expression",
106             "Evaluate a C expression in the current program context, using variables currently in scope.",
107             "expression [<cmd-options>] <expr>"),
108     m_expr_line_count (0),
109     m_expr_lines ()
110 {
111   SetHelpLong(
112 "Examples: \n\
113 \n\
114    expr my_struct->a = my_array[3] \n\
115    expr -f bin -- (index * 8) + 5 \n\
116    expr char c[] = \"foo\"; c[0]\n");
117 }
118 
119 CommandObjectExpression::~CommandObjectExpression ()
120 {
121 }
122 
123 Options *
124 CommandObjectExpression::GetOptions ()
125 {
126     return &m_options;
127 }
128 
129 
130 bool
131 CommandObjectExpression::Execute
132 (
133     CommandInterpreter &interpreter,
134     Args& command,
135     CommandReturnObject &result
136 )
137 {
138     return false;
139 }
140 
141 
142 size_t
143 CommandObjectExpression::MultiLineExpressionCallback
144 (
145     void *baton,
146     InputReader &reader,
147     lldb::InputReaderAction notification,
148     const char *bytes,
149     size_t bytes_len
150 )
151 {
152     CommandObjectExpression *cmd_object_expr = (CommandObjectExpression *) baton;
153 
154     switch (notification)
155     {
156     case eInputReaderActivate:
157         reader.GetDebugger().GetOutputStream().Printf("%s\n", "Enter expressions, then terminate with an empty line to evaluate:");
158         // Fall through
159     case eInputReaderReactivate:
160         //if (out_fh)
161         //    reader.GetDebugger().GetOutputStream().Printf ("%3u: ", cmd_object_expr->m_expr_line_count);
162         break;
163 
164     case eInputReaderDeactivate:
165         break;
166 
167     case eInputReaderGotToken:
168         ++cmd_object_expr->m_expr_line_count;
169         if (bytes && bytes_len)
170         {
171             cmd_object_expr->m_expr_lines.append (bytes, bytes_len + 1);
172         }
173 
174         if (bytes_len == 0)
175             reader.SetIsDone(true);
176         //else if (out_fh && !reader->IsDone())
177         //    ::fprintf (out_fh, "%3u: ", cmd_object_expr->m_expr_line_count);
178         break;
179 
180     case eInputReaderDone:
181         {
182             bool bare = false;
183             cmd_object_expr->EvaluateExpression (cmd_object_expr->m_expr_lines.c_str(),
184                                                  bare,
185                                                  reader.GetDebugger().GetOutputStream(),
186                                                  reader.GetDebugger().GetErrorStream());
187         }
188         break;
189     }
190 
191     return bytes_len;
192 }
193 
194 bool
195 CommandObjectExpression::EvaluateExpression (const char *expr, bool bare, Stream &output_stream, Stream &error_stream)
196 {
197     Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS);
198 
199     ////////////////////////////////////
200     // Set up the target and compiler
201     //
202 
203     Target *target = m_exe_ctx.target;
204 
205     if (!target)
206     {
207         error_stream.PutCString ("error: invalid target\n");
208         return false;
209     }
210 
211     ConstString target_triple;
212 
213     target->GetTargetTriple (target_triple);
214 
215     if (!target_triple)
216         target_triple = Host::GetTargetTriple ();
217 
218     if (!target_triple)
219     {
220         error_stream.PutCString ("error: invalid target triple\n");
221         return false;
222     }
223 
224     ClangExpressionDeclMap expr_decl_map (&m_exe_ctx);
225     ClangExpression clang_expr (target_triple.AsCString (), &expr_decl_map);
226 
227     //////////////////////////
228     // Parse the expression
229     //
230 
231     unsigned num_errors;
232 
233     if (bare)
234         num_errors = clang_expr.ParseBareExpression (llvm::StringRef (expr), error_stream);
235     else
236         num_errors = clang_expr.ParseExpression (expr, error_stream, m_options.use_ir);
237 
238     if (num_errors)
239     {
240         error_stream.Printf ("error: %d errors parsing expression\n", num_errors);
241         return false;
242     }
243 
244     ///////////////////////////////////////////////
245     // Convert the output of the parser to DWARF
246     //
247 
248     StreamString dwarf_opcodes;
249     dwarf_opcodes.SetByteOrder (eByteOrderHost);
250     dwarf_opcodes.GetFlags ().Set (Stream::eBinary);
251 
252     ClangExpressionVariableList expr_local_vars;
253 
254     bool success;
255     bool canInterpret = false;
256 
257     if (m_options.use_ir)
258     {
259         canInterpret = clang_expr.ConvertIRToDWARF (expr_local_vars, dwarf_opcodes);
260 
261         if (canInterpret)
262         {
263             if (log)
264                 log->Printf("Code can be interpreted.");
265             success = true;
266         }
267         else
268         {
269             if (log)
270                 log->Printf("Code cannot be interpreted and must be run in the target.");
271             success = clang_expr.PrepareIRForTarget (expr_local_vars);
272         }
273 
274         if (!success)
275         {
276             error_stream.PutCString ("error: expression couldn't be converted to IR\n");
277             return false;
278         }
279 
280         if (canInterpret)
281         {
282             // TODO interpret IR
283             return false;
284         }
285         else
286         {
287             if (!clang_expr.JITFunction (m_exe_ctx, "___clang_expr"))
288             {
289                 error_stream.PutCString ("error: IR could not be JIT compiled\n");
290                 return false;
291             }
292 
293             if (!clang_expr.WriteJITCode (m_exe_ctx))
294             {
295                 error_stream.PutCString ("error: JIT code could not be written to the target\n");
296                 return false;
297             }
298 
299             lldb::addr_t function_address(clang_expr.GetFunctionAddress ("___clang_expr"));
300 
301             if (function_address == LLDB_INVALID_ADDRESS)
302             {
303                 error_stream.PutCString ("JIT compiled code's address couldn't be found\n");
304                 return false;
305             }
306 
307             Error err;
308             lldb::addr_t struct_address;
309 
310             if (!expr_decl_map.Materialize(&m_exe_ctx, struct_address, err))
311             {
312                 error_stream.Printf ("Couldn't materialize struct: %s\n", err.AsCString("unknown error"));
313                 return false;
314             }
315 
316             log->Printf("Function address  : 0x%llx", (uint64_t)function_address);
317             log->Printf("Structure address : 0x%llx", (uint64_t)struct_address);
318         }
319 
320         return true;
321 
322     }
323     else
324     {
325         success = (clang_expr.ConvertExpressionToDWARF (expr_local_vars, dwarf_opcodes) == 0);
326 
327         if (!success)
328         {
329             error_stream.PutCString ("error: expression couldn't be translated to DWARF\n");
330             return false;
331         }
332 
333         //////////////////////////////////////////
334         // Evaluate the generated DWARF opcodes
335         //
336 
337         DataExtractor dwarf_opcodes_data (dwarf_opcodes.GetData (), dwarf_opcodes.GetSize (), eByteOrderHost, 8);
338         DWARFExpression dwarf_expr (dwarf_opcodes_data, 0, dwarf_opcodes_data.GetByteSize (), NULL);
339 
340         dwarf_expr.SetExpressionLocalVariableList(&expr_local_vars);
341 
342         if (log)
343         {
344             StreamString stream_string;
345 
346             log->PutCString ("Expression parsed ok, dwarf opcodes:");
347 
348             stream_string.PutCString ("\n");
349             stream_string.IndentMore ();
350             dwarf_expr.GetDescription (&stream_string, lldb::eDescriptionLevelVerbose);
351             stream_string.IndentLess ();
352             stream_string.EOL ();
353 
354             log->PutCString (stream_string.GetString ().c_str ());
355         }
356 
357         clang::ASTContext *ast_context = clang_expr.GetASTContext ();
358         Value expr_result;
359         Error expr_error;
360         success = dwarf_expr.Evaluate (&m_exe_ctx, ast_context, NULL, expr_result, &expr_error);
361 
362         if (!success)
363         {
364             error_stream.Printf ("error: couldn't evaluate DWARF expression: %s\n", expr_error.AsCString ());
365             return false;
366         }
367 
368         ///////////////////////////////////////
369         // Interpret the result and print it
370         //
371 
372         lldb::Format format = m_options.format;
373 
374         // Resolve any values that are possible
375         expr_result.ResolveValue (&m_exe_ctx, ast_context);
376 
377         if (expr_result.GetContextType () == Value::eContextTypeInvalid &&
378             expr_result.GetValueType () == Value::eValueTypeScalar &&
379             format == eFormatDefault)
380         {
381             // The expression result is just a scalar with no special formatting
382             expr_result.GetScalar ().GetValue (&output_stream, m_options.show_types);
383             output_stream.EOL ();
384             return true;
385         }
386 
387         // The expression result is more complext and requires special handling
388         DataExtractor data;
389         expr_error = expr_result.GetValueAsData (&m_exe_ctx, ast_context, data, 0);
390 
391         if (!expr_error.Success ())
392         {
393             error_stream.Printf ("error: couldn't resolve result value: %s\n", expr_error.AsCString ());
394             return false;
395         }
396 
397         if (format == eFormatDefault)
398             format = expr_result.GetValueDefaultFormat ();
399 
400         void *clang_type = expr_result.GetValueOpaqueClangQualType ();
401 
402         if (clang_type)
403         {
404             if (m_options.show_types)
405                 Type::DumpClangTypeName (&output_stream, clang_type);
406 
407             Type::DumpValue (&m_exe_ctx,                // The execution context for memory and variable access
408                              ast_context,               // The ASTContext that the clang type belongs to
409                              clang_type,                // The opaque clang type we want to dump that value of
410                              &output_stream,            // Stream to dump to
411                              format,                    // Format to use when dumping
412                              data,                      // A buffer containing the bytes for the clang type
413                              0,                         // Byte offset within "data" where value is
414                              data.GetByteSize (),       // Size in bytes of the value we are dumping
415                              0,                         // Bitfield bit size
416                              0,                         // Bitfield bit offset
417                              m_options.show_types,      // Show types?
418                              m_options.show_summary,    // Show summary?
419                              m_options.debug,           // Debug logging output?
420                              UINT32_MAX);               // Depth to dump in case this is an aggregate type
421         }
422         else
423         {
424             data.Dump (&output_stream,          // Stream to dump to
425                        0,                       // Byte offset within "data"
426                        format,                  // Format to use when dumping
427                        data.GetByteSize (),     // Size in bytes of each item we are dumping
428                        1,                       // Number of items to dump
429                        UINT32_MAX,              // Number of items per line
430                        LLDB_INVALID_ADDRESS,    // Invalid address, don't show any offset/address context
431                        0,                       // Bitfield bit size
432                        0);                      // Bitfield bit offset
433         }
434         output_stream.EOL();
435 
436         return true;
437     }
438 }
439 
440 bool
441 CommandObjectExpression::ExecuteRawCommandString
442 (
443     CommandInterpreter &interpreter,
444     const char *command,
445     CommandReturnObject &result
446 )
447 {
448     m_exe_ctx = interpreter.GetDebugger().GetExecutionContext();
449 
450     m_options.ResetOptionValues();
451 
452     const char * expr = NULL;
453 
454     if (command[0] == '\0')
455     {
456         m_expr_lines.clear();
457         m_expr_line_count = 0;
458 
459         InputReaderSP reader_sp (new InputReader(interpreter.GetDebugger()));
460         if (reader_sp)
461         {
462             Error err (reader_sp->Initialize (CommandObjectExpression::MultiLineExpressionCallback,
463                                               this,                         // baton
464                                               eInputReaderGranularityLine,  // token size, to pass to callback function
465                                               NULL,                         // end token
466                                               NULL,                         // prompt
467                                               true));                       // echo input
468             if (err.Success())
469             {
470                 interpreter.GetDebugger().PushInputReader (reader_sp);
471                 result.SetStatus (eReturnStatusSuccessFinishNoResult);
472             }
473             else
474             {
475                 result.AppendError (err.AsCString());
476                 result.SetStatus (eReturnStatusFailed);
477             }
478         }
479         else
480         {
481             result.AppendError("out of memory");
482             result.SetStatus (eReturnStatusFailed);
483         }
484         return result.Succeeded();
485     }
486 
487     if (command[0] == '-')
488     {
489         // We have some options and these options MUST end with --.
490         const char *end_options = NULL;
491         const char *s = command;
492         while (s && s[0])
493         {
494             end_options = ::strstr (s, "--");
495             if (end_options)
496             {
497                 end_options += 2; // Get past the "--"
498                 if (::isspace (end_options[0]))
499                 {
500                     expr = end_options;
501                     while (::isspace (*expr))
502                         ++expr;
503                     break;
504                 }
505             }
506             s = end_options;
507         }
508 
509         if (end_options)
510         {
511             Args args (command, end_options - command);
512             if (!ParseOptions (interpreter, args, result))
513                 return false;
514         }
515     }
516 
517     if (expr == NULL)
518         expr = command;
519 
520     return EvaluateExpression (expr, false, result.GetOutputStream(), result.GetErrorStream());
521 }
522 
523 lldb::OptionDefinition
524 CommandObjectExpression::CommandOptions::g_option_table[] =
525 {
526 { LLDB_OPT_SET_ALL, false, "language",   'l', required_argument, NULL, 0, "[c|c++|objc|objc++]",          "Sets the language to use when parsing the expression."},
527 { LLDB_OPT_SET_ALL, false, "format",     'f', required_argument, NULL, 0, "[ [bool|b] | [bin] | [char|c] | [oct|o] | [dec|i|d|u] | [hex|x] | [float|f] | [cstr|s] ]",  "Specify the format that the expression output should use."},
528 { LLDB_OPT_SET_ALL, false, "debug",      'g', no_argument,       NULL, 0, NULL,                           "Enable verbose debug logging of the expression parsing and evaluation."},
529 { LLDB_OPT_SET_ALL, false, "use-ir",     'i', no_argument,       NULL, 0, NULL,                           "[Temporary] Instructs the expression evaluator to use IR instead of ASTs."},
530 { 0, false, NULL, 0, 0, NULL, NULL, NULL, NULL }
531 };
532 
533