1//===-- ClangUserExpression.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 <cstdio>
10#include <sys/types.h>
11
12#include <cstdlib>
13#include <map>
14#include <string>
15
16#include "ClangUserExpression.h"
17
18#include "ASTResultSynthesizer.h"
19#include "ClangASTMetadata.h"
20#include "ClangDiagnostic.h"
21#include "ClangExpressionDeclMap.h"
22#include "ClangExpressionParser.h"
23#include "ClangModulesDeclVendor.h"
24#include "ClangPersistentVariables.h"
25#include "CppModuleConfiguration.h"
26
27#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
28#include "lldb/Core/Debugger.h"
29#include "lldb/Core/Module.h"
30#include "lldb/Expression/ExpressionSourceCode.h"
31#include "lldb/Expression/IRExecutionUnit.h"
32#include "lldb/Expression/IRInterpreter.h"
33#include "lldb/Expression/Materializer.h"
34#include "lldb/Host/HostInfo.h"
35#include "lldb/Symbol/Block.h"
36#include "lldb/Symbol/CompileUnit.h"
37#include "lldb/Symbol/Function.h"
38#include "lldb/Symbol/ObjectFile.h"
39#include "lldb/Symbol/SymbolFile.h"
40#include "lldb/Symbol/SymbolVendor.h"
41#include "lldb/Symbol/Type.h"
42#include "lldb/Symbol/VariableList.h"
43#include "lldb/Target/ExecutionContext.h"
44#include "lldb/Target/Process.h"
45#include "lldb/Target/StackFrame.h"
46#include "lldb/Target/Target.h"
47#include "lldb/Target/ThreadPlan.h"
48#include "lldb/Target/ThreadPlanCallUserExpression.h"
49#include "lldb/Utility/ConstString.h"
50#include "lldb/Utility/LLDBLog.h"
51#include "lldb/Utility/Log.h"
52#include "lldb/Utility/StreamString.h"
53#include "lldb/ValueObject/ValueObjectConstResult.h"
54
55#include "clang/AST/DeclCXX.h"
56#include "clang/AST/DeclObjC.h"
57
58#include "llvm/ADT/ScopeExit.h"
59#include "llvm/BinaryFormat/Dwarf.h"
60
61using namespace lldb_private;
62
63char ClangUserExpression::ID;
64
65ClangUserExpression::ClangUserExpression(
66 ExecutionContextScope &exe_scope, llvm::StringRef expr,
67 llvm::StringRef prefix, SourceLanguage language, ResultType desired_type,
68 const EvaluateExpressionOptions &options, ValueObject *ctx_obj)
69 : LLVMUserExpression(exe_scope, expr, prefix, language, desired_type,
70 options),
71 m_type_system_helper(*m_target_wp.lock(), options.GetExecutionPolicy() ==
72 eExecutionPolicyTopLevel),
73 m_result_delegate(exe_scope.CalculateTarget()), m_ctx_obj(ctx_obj) {
74 switch (m_language.name) {
75 case llvm::dwarf::DW_LNAME_C_plus_plus:
76 m_allow_cxx = true;
77 break;
78 case llvm::dwarf::DW_LNAME_ObjC:
79 m_allow_objc = true;
80 break;
81 case llvm::dwarf::DW_LNAME_ObjC_plus_plus:
82 default:
83 m_allow_cxx = true;
84 m_allow_objc = true;
85 break;
86 }
87}
88
89ClangUserExpression::~ClangUserExpression() = default;
90
91void ClangUserExpression::ScanContext(ExecutionContext &exe_ctx, Status &err) {
92 Log *log = GetLog(mask: LLDBLog::Expressions);
93
94 LLDB_LOGF(log, "ClangUserExpression::ScanContext()");
95
96 m_target = exe_ctx.GetTargetPtr();
97
98 if (!(m_allow_cxx || m_allow_objc)) {
99 LLDB_LOGF(log, " [CUE::SC] Settings inhibit C++ and Objective-C");
100 return;
101 }
102
103 StackFrame *frame = exe_ctx.GetFramePtr();
104 if (frame == nullptr) {
105 LLDB_LOGF(log, " [CUE::SC] Null stack frame");
106 return;
107 }
108
109 SymbolContext sym_ctx = frame->GetSymbolContext(resolve_scope: lldb::eSymbolContextFunction |
110 lldb::eSymbolContextBlock);
111
112 if (!sym_ctx.function) {
113 LLDB_LOGF(log, " [CUE::SC] Null function");
114 return;
115 }
116
117 // Find the block that defines the function represented by "sym_ctx"
118 Block *function_block = sym_ctx.GetFunctionBlock();
119
120 if (!function_block) {
121 LLDB_LOGF(log, " [CUE::SC] Null function block");
122 return;
123 }
124
125 CompilerDeclContext decl_context = function_block->GetDeclContext();
126
127 if (!decl_context) {
128 LLDB_LOGF(log, " [CUE::SC] Null decl context");
129 return;
130 }
131
132 if (m_ctx_obj) {
133 switch (m_ctx_obj->GetObjectRuntimeLanguage()) {
134 case lldb::eLanguageTypeC:
135 case lldb::eLanguageTypeC89:
136 case lldb::eLanguageTypeC99:
137 case lldb::eLanguageTypeC11:
138 case lldb::eLanguageTypeC_plus_plus:
139 case lldb::eLanguageTypeC_plus_plus_03:
140 case lldb::eLanguageTypeC_plus_plus_11:
141 case lldb::eLanguageTypeC_plus_plus_14:
142 m_in_cplusplus_method = true;
143 break;
144 case lldb::eLanguageTypeObjC:
145 case lldb::eLanguageTypeObjC_plus_plus:
146 m_in_objectivec_method = true;
147 break;
148 default:
149 break;
150 }
151 m_needs_object_ptr = true;
152 } else if (clang::CXXMethodDecl *method_decl =
153 TypeSystemClang::DeclContextGetAsCXXMethodDecl(dc: decl_context)) {
154 if (m_allow_cxx && method_decl->isInstance()) {
155 if (m_enforce_valid_object) {
156 lldb::VariableListSP variable_list_sp(
157 function_block->GetBlockVariableList(can_create: true));
158
159 const char *thisErrorString = "Stopped in a C++ method, but 'this' "
160 "isn't available; pretending we are in a "
161 "generic context";
162
163 if (!variable_list_sp) {
164 err = Status::FromErrorString(str: thisErrorString);
165 return;
166 }
167
168 lldb::VariableSP this_var_sp(
169 variable_list_sp->FindVariable(name: ConstString("this")));
170
171 if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
172 !this_var_sp->LocationIsValidForFrame(frame)) {
173 err = Status::FromErrorString(str: thisErrorString);
174 return;
175 }
176 }
177
178 m_in_cplusplus_method = true;
179 m_needs_object_ptr = true;
180 }
181 } else if (clang::ObjCMethodDecl *method_decl =
182 TypeSystemClang::DeclContextGetAsObjCMethodDecl(
183 dc: decl_context)) {
184 if (m_allow_objc) {
185 if (m_enforce_valid_object) {
186 lldb::VariableListSP variable_list_sp(
187 function_block->GetBlockVariableList(can_create: true));
188
189 const char *selfErrorString = "Stopped in an Objective-C method, but "
190 "'self' isn't available; pretending we "
191 "are in a generic context";
192
193 if (!variable_list_sp) {
194 err = Status::FromErrorString(str: selfErrorString);
195 return;
196 }
197
198 lldb::VariableSP self_variable_sp =
199 variable_list_sp->FindVariable(name: ConstString("self"));
200
201 if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
202 !self_variable_sp->LocationIsValidForFrame(frame)) {
203 err = Status::FromErrorString(str: selfErrorString);
204 return;
205 }
206 }
207
208 m_in_objectivec_method = true;
209 m_needs_object_ptr = true;
210
211 if (!method_decl->isInstanceMethod())
212 m_in_static_method = true;
213 }
214 } else if (clang::FunctionDecl *function_decl =
215 TypeSystemClang::DeclContextGetAsFunctionDecl(dc: decl_context)) {
216 // We might also have a function that said in the debug information that it
217 // captured an object pointer. The best way to deal with getting to the
218 // ivars at present is by pretending that this is a method of a class in
219 // whatever runtime the debug info says the object pointer belongs to. Do
220 // that here.
221
222 if (std::optional<ClangASTMetadata> metadata =
223 TypeSystemClang::DeclContextGetMetaData(decl_context,
224 function_decl);
225 metadata && metadata->HasObjectPtr()) {
226 lldb::LanguageType language = metadata->GetObjectPtrLanguage();
227 if (language == lldb::eLanguageTypeC_plus_plus) {
228 if (m_enforce_valid_object) {
229 lldb::VariableListSP variable_list_sp(
230 function_block->GetBlockVariableList(can_create: true));
231
232 const char *thisErrorString = "Stopped in a context claiming to "
233 "capture a C++ object pointer, but "
234 "'this' isn't available; pretending we "
235 "are in a generic context";
236
237 if (!variable_list_sp) {
238 err = Status::FromErrorString(str: thisErrorString);
239 return;
240 }
241
242 lldb::VariableSP this_var_sp(
243 variable_list_sp->FindVariable(name: ConstString("this")));
244
245 if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
246 !this_var_sp->LocationIsValidForFrame(frame)) {
247 err = Status::FromErrorString(str: thisErrorString);
248 return;
249 }
250 }
251
252 m_in_cplusplus_method = true;
253 m_needs_object_ptr = true;
254 } else if (language == lldb::eLanguageTypeObjC) {
255 if (m_enforce_valid_object) {
256 lldb::VariableListSP variable_list_sp(
257 function_block->GetBlockVariableList(can_create: true));
258
259 const char *selfErrorString =
260 "Stopped in a context claiming to capture an Objective-C object "
261 "pointer, but 'self' isn't available; pretending we are in a "
262 "generic context";
263
264 if (!variable_list_sp) {
265 err = Status::FromErrorString(str: selfErrorString);
266 return;
267 }
268
269 lldb::VariableSP self_variable_sp =
270 variable_list_sp->FindVariable(name: ConstString("self"));
271
272 if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
273 !self_variable_sp->LocationIsValidForFrame(frame)) {
274 err = Status::FromErrorString(str: selfErrorString);
275 return;
276 }
277
278 Type *self_type = self_variable_sp->GetType();
279
280 if (!self_type) {
281 err = Status::FromErrorString(str: selfErrorString);
282 return;
283 }
284
285 CompilerType self_clang_type = self_type->GetForwardCompilerType();
286
287 if (!self_clang_type) {
288 err = Status::FromErrorString(str: selfErrorString);
289 return;
290 }
291
292 if (TypeSystemClang::IsObjCClassType(type: self_clang_type)) {
293 return;
294 } else if (TypeSystemClang::IsObjCObjectPointerType(
295 type: self_clang_type)) {
296 m_in_objectivec_method = true;
297 m_needs_object_ptr = true;
298 } else {
299 err = Status::FromErrorString(str: selfErrorString);
300 return;
301 }
302 } else {
303 m_in_objectivec_method = true;
304 m_needs_object_ptr = true;
305 }
306 }
307 }
308 }
309}
310
311// This is a really nasty hack, meant to fix Objective-C expressions of the
312// form (int)[myArray count]. Right now, because the type information for
313// count is not available, [myArray count] returns id, which can't be directly
314// cast to int without causing a clang error.
315static void ApplyObjcCastHack(std::string &expr) {
316 const std::string from = "(int)[";
317 const std::string to = "(int)(long long)[";
318
319 size_t offset;
320
321 while ((offset = expr.find(str: from)) != expr.npos)
322 expr.replace(pos: offset, n: from.size(), str: to);
323}
324
325bool ClangUserExpression::SetupPersistentState(DiagnosticManager &diagnostic_manager,
326 ExecutionContext &exe_ctx) {
327 if (Target *target = exe_ctx.GetTargetPtr()) {
328 if (PersistentExpressionState *persistent_state =
329 target->GetPersistentExpressionStateForLanguage(
330 language: lldb::eLanguageTypeC)) {
331 m_clang_state = llvm::cast<ClangPersistentVariables>(Val: persistent_state);
332 m_result_delegate.RegisterPersistentState(persistent_state);
333 } else {
334 diagnostic_manager.PutString(
335 severity: lldb::eSeverityError, str: "couldn't start parsing (no persistent data)");
336 return false;
337 }
338 } else {
339 diagnostic_manager.PutString(severity: lldb::eSeverityError,
340 str: "error: couldn't start parsing (no target)");
341 return false;
342 }
343 return true;
344}
345
346static void SetupDeclVendor(ExecutionContext &exe_ctx, Target *target,
347 DiagnosticManager &diagnostic_manager) {
348 if (!target->GetEnableAutoImportClangModules())
349 return;
350
351 auto *persistent_state = llvm::cast<ClangPersistentVariables>(
352 Val: target->GetPersistentExpressionStateForLanguage(language: lldb::eLanguageTypeC));
353 if (!persistent_state)
354 return;
355
356 std::shared_ptr<ClangModulesDeclVendor> decl_vendor =
357 persistent_state->GetClangModulesDeclVendor();
358 if (!decl_vendor)
359 return;
360
361 StackFrame *frame = exe_ctx.GetFramePtr();
362 if (!frame)
363 return;
364
365 Block *block = frame->GetFrameBlock();
366 if (!block)
367 return;
368 SymbolContext sc;
369
370 block->CalculateSymbolContext(sc: &sc);
371
372 if (!sc.comp_unit)
373 return;
374 StreamString error_stream;
375
376 ClangModulesDeclVendor::ModuleVector modules_for_macros =
377 persistent_state->GetHandLoadedClangModules();
378 if (decl_vendor->AddModulesForCompileUnit(cu&: *sc.comp_unit, exported_modules&: modules_for_macros,
379 error_stream))
380 return;
381
382 // Failed to load some modules, so emit the error stream as a diagnostic.
383 if (!error_stream.Empty()) {
384 // The error stream already contains several Clang diagnostics that might
385 // be either errors or warnings, so just print them all as one remark
386 // diagnostic to prevent that the message starts with "error: error:".
387 diagnostic_manager.PutString(severity: lldb::eSeverityInfo, str: error_stream.GetString());
388 return;
389 }
390
391 diagnostic_manager.PutString(severity: lldb::eSeverityError,
392 str: "Unknown error while loading modules needed for "
393 "current compilation unit.");
394}
395
396ClangExpressionSourceCode::WrapKind ClangUserExpression::GetWrapKind() const {
397 assert(m_options.GetExecutionPolicy() != eExecutionPolicyTopLevel &&
398 "Top level expressions aren't wrapped.");
399 using Kind = ClangExpressionSourceCode::WrapKind;
400 if (m_in_cplusplus_method)
401 return Kind::CppMemberFunction;
402 else if (m_in_objectivec_method) {
403 if (m_in_static_method)
404 return Kind::ObjCStaticMethod;
405 return Kind::ObjCInstanceMethod;
406 }
407 // Not in any kind of 'special' function, so just wrap it in a normal C
408 // function.
409 return Kind::Function;
410}
411
412void ClangUserExpression::CreateSourceCode(
413 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
414 std::vector<std::string> modules_to_import, bool for_completion) {
415
416 std::string prefix = m_expr_prefix;
417
418 if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
419 m_transformed_text = m_expr_text;
420 } else {
421 m_source_code.reset(p: ClangExpressionSourceCode::CreateWrapped(
422 filename: m_filename, prefix, body: m_expr_text, wrap_kind: GetWrapKind()));
423
424 if (!m_source_code->GetText(text&: m_transformed_text, exe_ctx, add_locals: !m_ctx_obj,
425 force_add_all_locals: for_completion, modules: modules_to_import)) {
426 diagnostic_manager.PutString(severity: lldb::eSeverityError,
427 str: "couldn't construct expression body");
428 return;
429 }
430
431 // Find and store the start position of the original code inside the
432 // transformed code. We need this later for the code completion.
433 std::size_t original_start;
434 std::size_t original_end;
435 bool found_bounds = m_source_code->GetOriginalBodyBounds(
436 transformed_text: m_transformed_text, start_loc&: original_start, end_loc&: original_end);
437 if (found_bounds)
438 m_user_expression_start_pos = original_start;
439 }
440}
441
442static bool SupportsCxxModuleImport(lldb::LanguageType language) {
443 switch (language) {
444 case lldb::eLanguageTypeC_plus_plus:
445 case lldb::eLanguageTypeC_plus_plus_03:
446 case lldb::eLanguageTypeC_plus_plus_11:
447 case lldb::eLanguageTypeC_plus_plus_14:
448 case lldb::eLanguageTypeObjC_plus_plus:
449 return true;
450 default:
451 return false;
452 }
453}
454
455/// Utility method that puts a message into the expression log and
456/// returns an invalid module configuration.
457static CppModuleConfiguration LogConfigError(const std::string &msg) {
458 Log *log = GetLog(mask: LLDBLog::Expressions);
459 LLDB_LOG(log, "[C++ module config] {0}", msg);
460 return CppModuleConfiguration();
461}
462
463CppModuleConfiguration GetModuleConfig(lldb::LanguageType language,
464 ExecutionContext &exe_ctx) {
465 Log *log = GetLog(mask: LLDBLog::Expressions);
466
467 // Don't do anything if this is not a C++ module configuration.
468 if (!SupportsCxxModuleImport(language))
469 return LogConfigError(msg: "Language doesn't support C++ modules");
470
471 Target *target = exe_ctx.GetTargetPtr();
472 if (!target)
473 return LogConfigError(msg: "No target");
474
475 StackFrame *frame = exe_ctx.GetFramePtr();
476 if (!frame)
477 return LogConfigError(msg: "No frame");
478
479 Block *block = frame->GetFrameBlock();
480 if (!block)
481 return LogConfigError(msg: "No block");
482
483 SymbolContext sc;
484 block->CalculateSymbolContext(sc: &sc);
485 if (!sc.comp_unit)
486 return LogConfigError(msg: "Couldn't calculate symbol context");
487
488 // Build a list of files we need to analyze to build the configuration.
489 FileSpecList files;
490 for (auto &f : sc.comp_unit->GetSupportFiles())
491 files.AppendIfUnique(file: f->Materialize());
492 // We also need to look at external modules in the case of -gmodules as they
493 // contain the support files for libc++ and the C library.
494 llvm::DenseSet<SymbolFile *> visited_symbol_files;
495 sc.comp_unit->ForEachExternalModule(
496 visited_symbol_files, lambda: [&files](Module &module) {
497 for (std::size_t i = 0; i < module.GetNumCompileUnits(); ++i) {
498 const SupportFileList &support_files =
499 module.GetCompileUnitAtIndex(idx: i)->GetSupportFiles();
500 for (auto &f : support_files) {
501 files.AppendIfUnique(file: f->Materialize());
502 }
503 }
504 return false;
505 });
506
507 LLDB_LOG(log, "[C++ module config] Found {0} support files to analyze",
508 files.GetSize());
509 if (log && log->GetVerbose()) {
510 for (auto &f : files)
511 LLDB_LOGV(log, "[C++ module config] Analyzing support file: {0}",
512 f.GetPath());
513 }
514
515 // Try to create a configuration from the files. If there is no valid
516 // configuration possible with the files, this just returns an invalid
517 // configuration.
518 return CppModuleConfiguration(files, target->GetArchitecture().GetTriple());
519}
520
521bool ClangUserExpression::PrepareForParsing(
522 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
523 bool for_completion) {
524 InstallContext(exe_ctx);
525
526 if (!SetupPersistentState(diagnostic_manager, exe_ctx))
527 return false;
528
529 Status err;
530 ScanContext(exe_ctx, err);
531
532 if (!err.Success()) {
533 diagnostic_manager.PutString(severity: lldb::eSeverityWarning, str: err.AsCString());
534 }
535
536 ////////////////////////////////////
537 // Generate the expression
538 //
539
540 ApplyObjcCastHack(expr&: m_expr_text);
541
542 SetupDeclVendor(exe_ctx, target: m_target, diagnostic_manager);
543
544 m_filename = m_clang_state->GetNextExprFileName();
545
546 if (m_target->GetImportStdModule() == eImportStdModuleTrue)
547 SetupCppModuleImports(exe_ctx);
548
549 CreateSourceCode(diagnostic_manager, exe_ctx, modules_to_import: m_imported_cpp_modules,
550 for_completion);
551 return true;
552}
553
554bool ClangUserExpression::TryParse(
555 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
556 lldb_private::ExecutionPolicy execution_policy, bool keep_result_in_memory,
557 bool generate_debug_info) {
558 m_materializer_up = std::make_unique<Materializer>();
559
560 ResetDeclMap(exe_ctx, result_delegate&: m_result_delegate, keep_result_in_memory);
561
562 auto on_exit = llvm::make_scope_exit(F: [this]() { ResetDeclMap(); });
563
564 if (!DeclMap()->WillParse(exe_ctx, materializer: GetMaterializer())) {
565 diagnostic_manager.PutString(
566 severity: lldb::eSeverityError,
567 str: "current process state is unsuitable for expression parsing");
568 return false;
569 }
570
571 if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
572 DeclMap()->SetLookupsEnabled(true);
573 }
574
575 m_parser = std::make_unique<ClangExpressionParser>(
576 args: exe_ctx.GetBestExecutionContextScope(), args&: *this, args&: generate_debug_info,
577 args&: m_include_directories, args&: m_filename);
578
579 unsigned num_errors = m_parser->Parse(diagnostic_manager);
580
581 // Check here for FixItHints. If there are any try to apply the fixits and
582 // set the fixed text in m_fixed_text before returning an error.
583 if (num_errors) {
584 if (diagnostic_manager.HasFixIts()) {
585 if (m_parser->RewriteExpression(diagnostic_manager)) {
586 size_t fixed_start;
587 size_t fixed_end;
588 m_fixed_text = diagnostic_manager.GetFixedExpression();
589 // Retrieve the original expression in case we don't have a top level
590 // expression (which has no surrounding source code).
591 if (m_source_code && m_source_code->GetOriginalBodyBounds(
592 transformed_text: m_fixed_text, start_loc&: fixed_start, end_loc&: fixed_end))
593 m_fixed_text =
594 m_fixed_text.substr(pos: fixed_start, n: fixed_end - fixed_start);
595 }
596 }
597 return false;
598 }
599
600 //////////////////////////////////////////////////////////////////////////////
601 // Prepare the output of the parser for execution, evaluating it statically
602 // if possible
603 //
604
605 {
606 Status jit_error = m_parser->PrepareForExecution(
607 func_addr&: m_jit_start_addr, func_end&: m_jit_end_addr, execution_unit_sp&: m_execution_unit_sp, exe_ctx,
608 can_interpret&: m_can_interpret, execution_policy);
609
610 if (!jit_error.Success()) {
611 const char *error_cstr = jit_error.AsCString();
612 if (error_cstr && error_cstr[0])
613 diagnostic_manager.PutString(severity: lldb::eSeverityError, str: error_cstr);
614 else
615 diagnostic_manager.PutString(severity: lldb::eSeverityError,
616 str: "expression can't be interpreted or run");
617 return false;
618 }
619 }
620 return true;
621}
622
623void ClangUserExpression::SetupCppModuleImports(ExecutionContext &exe_ctx) {
624 Log *log = GetLog(mask: LLDBLog::Expressions);
625
626 CppModuleConfiguration module_config =
627 GetModuleConfig(language: m_language.AsLanguageType(), exe_ctx);
628 m_imported_cpp_modules = module_config.GetImportedModules();
629 m_include_directories = module_config.GetIncludeDirs();
630
631 LLDB_LOG(log, "List of imported modules in expression: {0}",
632 llvm::make_range(m_imported_cpp_modules.begin(),
633 m_imported_cpp_modules.end()));
634 LLDB_LOG(log, "List of include directories gathered for modules: {0}",
635 llvm::make_range(m_include_directories.begin(),
636 m_include_directories.end()));
637}
638
639static bool shouldRetryWithCppModule(Target &target, ExecutionPolicy exe_policy) {
640 // Top-level expression don't yet support importing C++ modules.
641 if (exe_policy == ExecutionPolicy::eExecutionPolicyTopLevel)
642 return false;
643 return target.GetImportStdModule() == eImportStdModuleFallback;
644}
645
646bool ClangUserExpression::Parse(DiagnosticManager &diagnostic_manager,
647 ExecutionContext &exe_ctx,
648 lldb_private::ExecutionPolicy execution_policy,
649 bool keep_result_in_memory,
650 bool generate_debug_info) {
651 Log *log = GetLog(mask: LLDBLog::Expressions);
652
653 if (!PrepareForParsing(diagnostic_manager, exe_ctx, /*for_completion*/ false))
654 return false;
655
656 LLDB_LOGF(log, "Parsing the following code:\n%s", m_transformed_text.c_str());
657
658 ////////////////////////////////////
659 // Set up the target and compiler
660 //
661
662 Target *target = exe_ctx.GetTargetPtr();
663
664 if (!target) {
665 diagnostic_manager.PutString(severity: lldb::eSeverityError, str: "invalid target");
666 return false;
667 }
668
669 //////////////////////////
670 // Parse the expression
671 //
672
673 bool parse_success = TryParse(diagnostic_manager, exe_ctx, execution_policy,
674 keep_result_in_memory, generate_debug_info);
675 // If the expression failed to parse, check if retrying parsing with a loaded
676 // C++ module is possible.
677 if (!parse_success && shouldRetryWithCppModule(target&: *target, exe_policy: execution_policy)) {
678 // Load the loaded C++ modules.
679 SetupCppModuleImports(exe_ctx);
680 // If we did load any modules, then retry parsing.
681 if (!m_imported_cpp_modules.empty()) {
682 // Create a dedicated diagnostic manager for the second parse attempt.
683 // These diagnostics are only returned to the caller if using the fallback
684 // actually succeeded in getting the expression to parse. This prevents
685 // that module-specific issues regress diagnostic quality with the
686 // fallback mode.
687 DiagnosticManager retry_manager;
688 // The module imports are injected into the source code wrapper,
689 // so recreate those.
690 CreateSourceCode(diagnostic_manager&: retry_manager, exe_ctx, modules_to_import: m_imported_cpp_modules,
691 /*for_completion*/ false);
692 parse_success = TryParse(diagnostic_manager&: retry_manager, exe_ctx, execution_policy,
693 keep_result_in_memory, generate_debug_info);
694 // Return the parse diagnostics if we were successful.
695 if (parse_success)
696 diagnostic_manager = std::move(retry_manager);
697 }
698 }
699 if (!parse_success)
700 return false;
701
702 if (m_execution_unit_sp) {
703 bool register_execution_unit = false;
704
705 if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
706 register_execution_unit = true;
707 }
708
709 // If there is more than one external function in the execution unit, it
710 // needs to keep living even if it's not top level, because the result
711 // could refer to that function.
712
713 if (m_execution_unit_sp->GetJittedFunctions().size() > 1) {
714 register_execution_unit = true;
715 }
716
717 if (register_execution_unit) {
718 if (auto *persistent_state =
719 exe_ctx.GetTargetPtr()->GetPersistentExpressionStateForLanguage(
720 language: m_language.AsLanguageType()))
721 persistent_state->RegisterExecutionUnit(execution_unit_sp&: m_execution_unit_sp);
722 }
723 }
724
725 if (generate_debug_info) {
726 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
727
728 if (jit_module_sp) {
729 ConstString const_func_name(FunctionName());
730 FileSpec jit_file;
731 jit_file.SetFilename(const_func_name);
732 jit_module_sp->SetFileSpecAndObjectName(file: jit_file, object_name: ConstString());
733 m_jit_module_wp = jit_module_sp;
734 target->GetImages().Append(module_sp: jit_module_sp);
735 }
736 }
737
738 Process *process = exe_ctx.GetProcessPtr();
739 if (process && m_jit_start_addr != LLDB_INVALID_ADDRESS)
740 m_jit_process_wp = lldb::ProcessWP(process->shared_from_this());
741 return true;
742}
743
744/// Converts an absolute position inside a given code string into
745/// a column/line pair.
746///
747/// \param[in] abs_pos
748/// A absolute position in the code string that we want to convert
749/// to a column/line pair.
750///
751/// \param[in] code
752/// A multi-line string usually representing source code.
753///
754/// \param[out] line
755/// The line in the code that contains the given absolute position.
756/// The first line in the string is indexed as 1.
757///
758/// \param[out] column
759/// The column in the line that contains the absolute position.
760/// The first character in a line is indexed as 0.
761static void AbsPosToLineColumnPos(size_t abs_pos, llvm::StringRef code,
762 unsigned &line, unsigned &column) {
763 // Reset to code position to beginning of the file.
764 line = 0;
765 column = 0;
766
767 assert(abs_pos <= code.size() && "Absolute position outside code string?");
768
769 // We have to walk up to the position and count lines/columns.
770 for (std::size_t i = 0; i < abs_pos; ++i) {
771 // If we hit a line break, we go back to column 0 and enter a new line.
772 // We only handle \n because that's what we internally use to make new
773 // lines for our temporary code strings.
774 if (code[i] == '\n') {
775 ++line;
776 column = 0;
777 continue;
778 }
779 ++column;
780 }
781}
782
783bool ClangUserExpression::Complete(ExecutionContext &exe_ctx,
784 CompletionRequest &request,
785 unsigned complete_pos) {
786 Log *log = GetLog(mask: LLDBLog::Expressions);
787
788 // We don't want any visible feedback when completing an expression. Mostly
789 // because the results we get from an incomplete invocation are probably not
790 // correct.
791 DiagnosticManager diagnostic_manager;
792
793 if (!PrepareForParsing(diagnostic_manager, exe_ctx, /*for_completion*/ true))
794 return false;
795
796 LLDB_LOGF(log, "Parsing the following code:\n%s", m_transformed_text.c_str());
797
798 //////////////////////////
799 // Parse the expression
800 //
801
802 m_materializer_up = std::make_unique<Materializer>();
803
804 ResetDeclMap(exe_ctx, result_delegate&: m_result_delegate, /*keep result in memory*/ keep_result_in_memory: true);
805
806 auto on_exit = llvm::make_scope_exit(F: [this]() { ResetDeclMap(); });
807
808 if (!DeclMap()->WillParse(exe_ctx, materializer: GetMaterializer())) {
809 diagnostic_manager.PutString(
810 severity: lldb::eSeverityError,
811 str: "current process state is unsuitable for expression parsing");
812
813 return false;
814 }
815
816 if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
817 DeclMap()->SetLookupsEnabled(true);
818 }
819
820 ClangExpressionParser parser(exe_ctx.GetBestExecutionContextScope(), *this,
821 false);
822
823 // We have to find the source code location where the user text is inside
824 // the transformed expression code. When creating the transformed text, we
825 // already stored the absolute position in the m_transformed_text string. The
826 // only thing left to do is to transform it into the line:column format that
827 // Clang expects.
828
829 // The line and column of the user expression inside the transformed source
830 // code.
831 unsigned user_expr_line, user_expr_column;
832 if (m_user_expression_start_pos)
833 AbsPosToLineColumnPos(abs_pos: *m_user_expression_start_pos, code: m_transformed_text,
834 line&: user_expr_line, column&: user_expr_column);
835 else
836 return false;
837
838 // The actual column where we have to complete is the start column of the
839 // user expression + the offset inside the user code that we were given.
840 const unsigned completion_column = user_expr_column + complete_pos;
841 parser.Complete(request, line: user_expr_line, pos: completion_column, typed_pos: complete_pos);
842
843 return true;
844}
845
846lldb::addr_t ClangUserExpression::GetCppObjectPointer(
847 lldb::StackFrameSP frame_sp, llvm::StringRef object_name, Status &err) {
848 auto valobj_sp =
849 GetObjectPointerValueObject(frame: std::move(frame_sp), object_name, err);
850
851 // We're inside a C++ class method. This could potentially be an unnamed
852 // lambda structure. If the lambda captured a "this", that should be
853 // the object pointer.
854 if (auto thisChildSP = valobj_sp->GetChildMemberWithName(name: "this")) {
855 valobj_sp = thisChildSP;
856 }
857
858 if (!err.Success() || !valobj_sp.get())
859 return LLDB_INVALID_ADDRESS;
860
861 lldb::addr_t ret = valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
862
863 if (ret == LLDB_INVALID_ADDRESS) {
864 err = Status::FromErrorStringWithFormatv(
865 format: "Couldn't load '{0}' because its value couldn't be evaluated",
866 args&: object_name);
867 return LLDB_INVALID_ADDRESS;
868 }
869
870 return ret;
871}
872
873bool ClangUserExpression::AddArguments(ExecutionContext &exe_ctx,
874 std::vector<lldb::addr_t> &args,
875 lldb::addr_t struct_address,
876 DiagnosticManager &diagnostic_manager) {
877 lldb::addr_t object_ptr = LLDB_INVALID_ADDRESS;
878 lldb::addr_t cmd_ptr = LLDB_INVALID_ADDRESS;
879
880 if (m_needs_object_ptr) {
881 lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP();
882 if (!frame_sp)
883 return true;
884
885 if (!m_in_cplusplus_method && !m_in_objectivec_method) {
886 diagnostic_manager.PutString(
887 severity: lldb::eSeverityError,
888 str: "need object pointer but don't know the language");
889 return false;
890 }
891
892 static constexpr llvm::StringLiteral g_cplusplus_object_name("this");
893 static constexpr llvm::StringLiteral g_objc_object_name("self");
894 llvm::StringRef object_name =
895 m_in_cplusplus_method ? g_cplusplus_object_name : g_objc_object_name;
896
897 Status object_ptr_error;
898
899 if (m_ctx_obj) {
900 ValueObject::AddrAndType address = m_ctx_obj->GetAddressOf(scalar_is_load_address: false);
901 if (address.address == LLDB_INVALID_ADDRESS ||
902 address.type != eAddressTypeLoad)
903 object_ptr_error = Status::FromErrorString(str: "Can't get context object's "
904 "debuggee address");
905 else
906 object_ptr = address.address;
907 } else {
908 if (m_in_cplusplus_method) {
909 object_ptr =
910 GetCppObjectPointer(frame_sp, object_name, err&: object_ptr_error);
911 } else {
912 object_ptr = GetObjectPointer(frame_sp, object_name, err&: object_ptr_error);
913 }
914 }
915
916 if (!object_ptr_error.Success()) {
917 exe_ctx.GetTargetRef().GetDebugger().GetAsyncOutputStream()->Format(
918 format: "warning: `{0}' is not accessible (substituting 0). {1}\n",
919 args&: object_name, args: object_ptr_error.AsCString());
920 object_ptr = 0;
921 }
922
923 if (m_in_objectivec_method) {
924 static constexpr llvm::StringLiteral cmd_name("_cmd");
925
926 cmd_ptr = GetObjectPointer(frame_sp, object_name: cmd_name, err&: object_ptr_error);
927
928 if (!object_ptr_error.Success()) {
929 diagnostic_manager.Printf(
930 severity: lldb::eSeverityWarning,
931 format: "couldn't get cmd pointer (substituting NULL): %s",
932 object_ptr_error.AsCString());
933 cmd_ptr = 0;
934 }
935 }
936
937 args.push_back(x: object_ptr);
938
939 if (m_in_objectivec_method)
940 args.push_back(x: cmd_ptr);
941
942 args.push_back(x: struct_address);
943 } else {
944 args.push_back(x: struct_address);
945 }
946 return true;
947}
948
949lldb::ExpressionVariableSP ClangUserExpression::GetResultAfterDematerialization(
950 ExecutionContextScope *exe_scope) {
951 return m_result_delegate.GetVariable();
952}
953
954char ClangUserExpression::ClangUserExpressionHelper::ID;
955
956void ClangUserExpression::ClangUserExpressionHelper::ResetDeclMap(
957 ExecutionContext &exe_ctx,
958 Materializer::PersistentVariableDelegate &delegate,
959 bool keep_result_in_memory,
960 ValueObject *ctx_obj) {
961 std::shared_ptr<ClangASTImporter> ast_importer;
962 auto *state = exe_ctx.GetTargetSP()->GetPersistentExpressionStateForLanguage(
963 language: lldb::eLanguageTypeC);
964 if (state) {
965 auto *persistent_vars = llvm::cast<ClangPersistentVariables>(Val: state);
966 ast_importer = persistent_vars->GetClangASTImporter();
967 }
968 m_expr_decl_map_up = std::make_unique<ClangExpressionDeclMap>(
969 args&: keep_result_in_memory, args: &delegate, args: exe_ctx.GetTargetSP(), args&: ast_importer,
970 args&: ctx_obj);
971}
972
973clang::ASTConsumer *
974ClangUserExpression::ClangUserExpressionHelper::ASTTransformer(
975 clang::ASTConsumer *passthrough) {
976 m_result_synthesizer_up = std::make_unique<ASTResultSynthesizer>(
977 args&: passthrough, args&: m_top_level, args&: m_target);
978
979 return m_result_synthesizer_up.get();
980}
981
982void ClangUserExpression::ClangUserExpressionHelper::CommitPersistentDecls() {
983 if (m_result_synthesizer_up) {
984 m_result_synthesizer_up->CommitPersistentDecls();
985 }
986}
987
988ConstString ClangUserExpression::ResultDelegate::GetName() {
989 return m_persistent_state->GetNextPersistentVariableName(is_error: false);
990}
991
992void ClangUserExpression::ResultDelegate::DidDematerialize(
993 lldb::ExpressionVariableSP &variable) {
994 m_variable = variable;
995}
996
997void ClangUserExpression::ResultDelegate::RegisterPersistentState(
998 PersistentExpressionState *persistent_state) {
999 m_persistent_state = persistent_state;
1000}
1001
1002lldb::ExpressionVariableSP &ClangUserExpression::ResultDelegate::GetVariable() {
1003 return m_variable;
1004}
1005

source code of lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp