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/Core/ValueObjectConstResult.h"
31#include "lldb/Expression/ExpressionSourceCode.h"
32#include "lldb/Expression/IRExecutionUnit.h"
33#include "lldb/Expression/IRInterpreter.h"
34#include "lldb/Expression/Materializer.h"
35#include "lldb/Host/HostInfo.h"
36#include "lldb/Symbol/Block.h"
37#include "lldb/Symbol/CompileUnit.h"
38#include "lldb/Symbol/Function.h"
39#include "lldb/Symbol/ObjectFile.h"
40#include "lldb/Symbol/SymbolFile.h"
41#include "lldb/Symbol/SymbolVendor.h"
42#include "lldb/Symbol/Type.h"
43#include "lldb/Symbol/VariableList.h"
44#include "lldb/Target/ExecutionContext.h"
45#include "lldb/Target/Process.h"
46#include "lldb/Target/StackFrame.h"
47#include "lldb/Target/Target.h"
48#include "lldb/Target/ThreadPlan.h"
49#include "lldb/Target/ThreadPlanCallUserExpression.h"
50#include "lldb/Utility/ConstString.h"
51#include "lldb/Utility/LLDBLog.h"
52#include "lldb/Utility/Log.h"
53#include "lldb/Utility/StreamString.h"
54
55#include "clang/AST/DeclCXX.h"
56#include "clang/AST/DeclObjC.h"
57
58#include "llvm/ADT/ScopeExit.h"
59
60using namespace lldb_private;
61
62char ClangUserExpression::ID;
63
64ClangUserExpression::ClangUserExpression(
65    ExecutionContextScope &exe_scope, llvm::StringRef expr,
66    llvm::StringRef prefix, lldb::LanguageType language,
67    ResultType desired_type, const EvaluateExpressionOptions &options,
68    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) {
75  case lldb::eLanguageTypeC_plus_plus:
76    m_allow_cxx = true;
77    break;
78  case lldb::eLanguageTypeObjC:
79    m_allow_objc = true;
80    break;
81  case lldb::eLanguageTypeObjC_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(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(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(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(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.SetErrorString(thisErrorString);
165          return;
166        }
167
168        lldb::VariableSP this_var_sp(
169            variable_list_sp->FindVariable(ConstString("this")));
170
171        if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
172            !this_var_sp->LocationIsValidForFrame(frame)) {
173          err.SetErrorString(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                     decl_context)) {
184    if (m_allow_objc) {
185      if (m_enforce_valid_object) {
186        lldb::VariableListSP variable_list_sp(
187            function_block->GetBlockVariableList(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.SetErrorString(selfErrorString);
195          return;
196        }
197
198        lldb::VariableSP self_variable_sp =
199            variable_list_sp->FindVariable(ConstString("self"));
200
201        if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
202            !self_variable_sp->LocationIsValidForFrame(frame)) {
203          err.SetErrorString(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(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    ClangASTMetadata *metadata =
223        TypeSystemClang::DeclContextGetMetaData(decl_context, function_decl);
224    if (metadata && metadata->HasObjectPtr()) {
225      lldb::LanguageType language = metadata->GetObjectPtrLanguage();
226      if (language == lldb::eLanguageTypeC_plus_plus) {
227        if (m_enforce_valid_object) {
228          lldb::VariableListSP variable_list_sp(
229              function_block->GetBlockVariableList(true));
230
231          const char *thisErrorString = "Stopped in a context claiming to "
232                                        "capture a C++ object pointer, but "
233                                        "'this' isn't available; pretending we "
234                                        "are in a generic context";
235
236          if (!variable_list_sp) {
237            err.SetErrorString(thisErrorString);
238            return;
239          }
240
241          lldb::VariableSP this_var_sp(
242              variable_list_sp->FindVariable(ConstString("this")));
243
244          if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
245              !this_var_sp->LocationIsValidForFrame(frame)) {
246            err.SetErrorString(thisErrorString);
247            return;
248          }
249        }
250
251        m_in_cplusplus_method = true;
252        m_needs_object_ptr = true;
253      } else if (language == lldb::eLanguageTypeObjC) {
254        if (m_enforce_valid_object) {
255          lldb::VariableListSP variable_list_sp(
256              function_block->GetBlockVariableList(true));
257
258          const char *selfErrorString =
259              "Stopped in a context claiming to capture an Objective-C object "
260              "pointer, but 'self' isn't available; pretending we are in a "
261              "generic context";
262
263          if (!variable_list_sp) {
264            err.SetErrorString(selfErrorString);
265            return;
266          }
267
268          lldb::VariableSP self_variable_sp =
269              variable_list_sp->FindVariable(ConstString("self"));
270
271          if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
272              !self_variable_sp->LocationIsValidForFrame(frame)) {
273            err.SetErrorString(selfErrorString);
274            return;
275          }
276
277          Type *self_type = self_variable_sp->GetType();
278
279          if (!self_type) {
280            err.SetErrorString(selfErrorString);
281            return;
282          }
283
284          CompilerType self_clang_type = self_type->GetForwardCompilerType();
285
286          if (!self_clang_type) {
287            err.SetErrorString(selfErrorString);
288            return;
289          }
290
291          if (TypeSystemClang::IsObjCClassType(self_clang_type)) {
292            return;
293          } else if (TypeSystemClang::IsObjCObjectPointerType(
294                         self_clang_type)) {
295            m_in_objectivec_method = true;
296            m_needs_object_ptr = true;
297          } else {
298            err.SetErrorString(selfErrorString);
299            return;
300          }
301        } else {
302          m_in_objectivec_method = true;
303          m_needs_object_ptr = true;
304        }
305      }
306    }
307  }
308}
309
310// This is a really nasty hack, meant to fix Objective-C expressions of the
311// form (int)[myArray count].  Right now, because the type information for
312// count is not available, [myArray count] returns id, which can't be directly
313// cast to int without causing a clang error.
314static void ApplyObjcCastHack(std::string &expr) {
315  const std::string from = "(int)[";
316  const std::string to = "(int)(long long)[";
317
318  size_t offset;
319
320  while ((offset = expr.find(from)) != expr.npos)
321    expr.replace(offset, from.size(), to);
322}
323
324bool ClangUserExpression::SetupPersistentState(DiagnosticManager &diagnostic_manager,
325                                 ExecutionContext &exe_ctx) {
326  if (Target *target = exe_ctx.GetTargetPtr()) {
327    if (PersistentExpressionState *persistent_state =
328            target->GetPersistentExpressionStateForLanguage(
329                lldb::eLanguageTypeC)) {
330      m_clang_state = llvm::cast<ClangPersistentVariables>(persistent_state);
331      m_result_delegate.RegisterPersistentState(persistent_state);
332    } else {
333      diagnostic_manager.PutString(
334          eDiagnosticSeverityError,
335          "couldn't start parsing (no persistent data)");
336      return false;
337    }
338  } else {
339    diagnostic_manager.PutString(eDiagnosticSeverityError,
340                                 "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      target->GetPersistentExpressionStateForLanguage(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);
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(*sc.comp_unit, 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(eDiagnosticSeverityRemark,
388                                 error_stream.GetString());
389    return;
390  }
391
392  diagnostic_manager.PutString(eDiagnosticSeverityError,
393                               "Unknown error while loading modules needed for "
394                               "current compilation unit.");
395}
396
397ClangExpressionSourceCode::WrapKind ClangUserExpression::GetWrapKind() const {
398  assert(m_options.GetExecutionPolicy() != eExecutionPolicyTopLevel &&
399         "Top level expressions aren't wrapped.");
400  using Kind = ClangExpressionSourceCode::WrapKind;
401  if (m_in_cplusplus_method)
402    return Kind::CppMemberFunction;
403  else if (m_in_objectivec_method) {
404    if (m_in_static_method)
405      return Kind::ObjCStaticMethod;
406    return Kind::ObjCInstanceMethod;
407  }
408  // Not in any kind of 'special' function, so just wrap it in a normal C
409  // function.
410  return Kind::Function;
411}
412
413void ClangUserExpression::CreateSourceCode(
414    DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
415    std::vector<std::string> modules_to_import, bool for_completion) {
416
417  std::string prefix = m_expr_prefix;
418
419  if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
420    m_transformed_text = m_expr_text;
421  } else {
422    m_source_code.reset(ClangExpressionSourceCode::CreateWrapped(
423        m_filename, prefix, m_expr_text, GetWrapKind()));
424
425    if (!m_source_code->GetText(m_transformed_text, exe_ctx, !m_ctx_obj,
426                                for_completion, modules_to_import)) {
427      diagnostic_manager.PutString(eDiagnosticSeverityError,
428                                   "couldn't construct expression body");
429      return;
430    }
431
432    // Find and store the start position of the original code inside the
433    // transformed code. We need this later for the code completion.
434    std::size_t original_start;
435    std::size_t original_end;
436    bool found_bounds = m_source_code->GetOriginalBodyBounds(
437        m_transformed_text, original_start, original_end);
438    if (found_bounds)
439      m_user_expression_start_pos = original_start;
440  }
441}
442
443static bool SupportsCxxModuleImport(lldb::LanguageType language) {
444  switch (language) {
445  case lldb::eLanguageTypeC_plus_plus:
446  case lldb::eLanguageTypeC_plus_plus_03:
447  case lldb::eLanguageTypeC_plus_plus_11:
448  case lldb::eLanguageTypeC_plus_plus_14:
449  case lldb::eLanguageTypeObjC_plus_plus:
450    return true;
451  default:
452    return false;
453  }
454}
455
456/// Utility method that puts a message into the expression log and
457/// returns an invalid module configuration.
458static CppModuleConfiguration LogConfigError(const std::string &msg) {
459  Log *log = GetLog(LLDBLog::Expressions);
460  LLDB_LOG(log, "[C++ module config] {0}", msg);
461  return CppModuleConfiguration();
462}
463
464CppModuleConfiguration GetModuleConfig(lldb::LanguageType language,
465                                       ExecutionContext &exe_ctx) {
466  Log *log = GetLog(LLDBLog::Expressions);
467
468  // Don't do anything if this is not a C++ module configuration.
469  if (!SupportsCxxModuleImport(language))
470    return LogConfigError("Language doesn't support C++ modules");
471
472  Target *target = exe_ctx.GetTargetPtr();
473  if (!target)
474    return LogConfigError("No target");
475
476  StackFrame *frame = exe_ctx.GetFramePtr();
477  if (!frame)
478    return LogConfigError("No frame");
479
480  Block *block = frame->GetFrameBlock();
481  if (!block)
482    return LogConfigError("No block");
483
484  SymbolContext sc;
485  block->CalculateSymbolContext(&sc);
486  if (!sc.comp_unit)
487    return LogConfigError("Couldn't calculate symbol context");
488
489  // Build a list of files we need to analyze to build the configuration.
490  FileSpecList files;
491  for (auto &f : sc.comp_unit->GetSupportFiles())
492    files.AppendIfUnique(f->Materialize());
493  // We also need to look at external modules in the case of -gmodules as they
494  // contain the support files for libc++ and the C library.
495  llvm::DenseSet<SymbolFile *> visited_symbol_files;
496  sc.comp_unit->ForEachExternalModule(
497      visited_symbol_files, [&files](Module &module) {
498        for (std::size_t i = 0; i < module.GetNumCompileUnits(); ++i) {
499          const SupportFileList &support_files =
500              module.GetCompileUnitAtIndex(i)->GetSupportFiles();
501          for (auto &f : support_files) {
502            files.AppendIfUnique(f->Materialize());
503          }
504        }
505        return false;
506      });
507
508  LLDB_LOG(log, "[C++ module config] Found {0} support files to analyze",
509           files.GetSize());
510  if (log && log->GetVerbose()) {
511    for (auto &f : files)
512      LLDB_LOGV(log, "[C++ module config] Analyzing support file: {0}",
513                f.GetPath());
514  }
515
516  // Try to create a configuration from the files. If there is no valid
517  // configuration possible with the files, this just returns an invalid
518  // configuration.
519  return CppModuleConfiguration(files, target->GetArchitecture().GetTriple());
520}
521
522bool ClangUserExpression::PrepareForParsing(
523    DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
524    bool for_completion) {
525  InstallContext(exe_ctx);
526
527  if (!SetupPersistentState(diagnostic_manager, exe_ctx))
528    return false;
529
530  Status err;
531  ScanContext(exe_ctx, err);
532
533  if (!err.Success()) {
534    diagnostic_manager.PutString(eDiagnosticSeverityWarning, err.AsCString());
535  }
536
537  ////////////////////////////////////
538  // Generate the expression
539  //
540
541  ApplyObjcCastHack(m_expr_text);
542
543  SetupDeclVendor(exe_ctx, m_target, diagnostic_manager);
544
545  m_filename = m_clang_state->GetNextExprFileName();
546
547  if (m_target->GetImportStdModule() == eImportStdModuleTrue)
548    SetupCppModuleImports(exe_ctx);
549
550  CreateSourceCode(diagnostic_manager, exe_ctx, m_imported_cpp_modules,
551                   for_completion);
552  return true;
553}
554
555bool ClangUserExpression::TryParse(
556    DiagnosticManager &diagnostic_manager, ExecutionContextScope *exe_scope,
557    ExecutionContext &exe_ctx, lldb_private::ExecutionPolicy execution_policy,
558    bool keep_result_in_memory, bool generate_debug_info) {
559  m_materializer_up = std::make_unique<Materializer>();
560
561  ResetDeclMap(exe_ctx, m_result_delegate, keep_result_in_memory);
562
563  auto on_exit = llvm::make_scope_exit([this]() { ResetDeclMap(); });
564
565  if (!DeclMap()->WillParse(exe_ctx, GetMaterializer())) {
566    diagnostic_manager.PutString(
567        eDiagnosticSeverityError,
568        "current process state is unsuitable for expression parsing");
569    return false;
570  }
571
572  if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
573    DeclMap()->SetLookupsEnabled(true);
574  }
575
576  m_parser = std::make_unique<ClangExpressionParser>(
577      exe_scope, *this, generate_debug_info, m_include_directories, 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                                 m_fixed_text, fixed_start, fixed_end))
593          m_fixed_text =
594              m_fixed_text.substr(fixed_start, 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        m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
608        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(eDiagnosticSeverityError, error_cstr);
614      else
615        diagnostic_manager.PutString(eDiagnosticSeverityError,
616                                     "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(LLDBLog::Expressions);
625
626  CppModuleConfiguration module_config = GetModuleConfig(m_language, exe_ctx);
627  m_imported_cpp_modules = module_config.GetImportedModules();
628  m_include_directories = module_config.GetIncludeDirs();
629
630  LLDB_LOG(log, "List of imported modules in expression: {0}",
631           llvm::make_range(m_imported_cpp_modules.begin(),
632                            m_imported_cpp_modules.end()));
633  LLDB_LOG(log, "List of include directories gathered for modules: {0}",
634           llvm::make_range(m_include_directories.begin(),
635                            m_include_directories.end()));
636}
637
638static bool shouldRetryWithCppModule(Target &target, ExecutionPolicy exe_policy) {
639  // Top-level expression don't yet support importing C++ modules.
640  if (exe_policy == ExecutionPolicy::eExecutionPolicyTopLevel)
641    return false;
642  return target.GetImportStdModule() == eImportStdModuleFallback;
643}
644
645bool ClangUserExpression::Parse(DiagnosticManager &diagnostic_manager,
646                                ExecutionContext &exe_ctx,
647                                lldb_private::ExecutionPolicy execution_policy,
648                                bool keep_result_in_memory,
649                                bool generate_debug_info) {
650  Log *log = GetLog(LLDBLog::Expressions);
651
652  if (!PrepareForParsing(diagnostic_manager, exe_ctx, /*for_completion*/ false))
653    return false;
654
655  LLDB_LOGF(log, "Parsing the following code:\n%s", m_transformed_text.c_str());
656
657  ////////////////////////////////////
658  // Set up the target and compiler
659  //
660
661  Target *target = exe_ctx.GetTargetPtr();
662
663  if (!target) {
664    diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid target");
665    return false;
666  }
667
668  //////////////////////////
669  // Parse the expression
670  //
671
672  Process *process = exe_ctx.GetProcessPtr();
673  ExecutionContextScope *exe_scope = process;
674
675  if (!exe_scope)
676    exe_scope = exe_ctx.GetTargetPtr();
677
678  bool parse_success = TryParse(diagnostic_manager, exe_scope, exe_ctx,
679                                execution_policy, keep_result_in_memory,
680                                generate_debug_info);
681  // If the expression failed to parse, check if retrying parsing with a loaded
682  // C++ module is possible.
683  if (!parse_success && shouldRetryWithCppModule(*target, execution_policy)) {
684    // Load the loaded C++ modules.
685    SetupCppModuleImports(exe_ctx);
686    // If we did load any modules, then retry parsing.
687    if (!m_imported_cpp_modules.empty()) {
688      // Create a dedicated diagnostic manager for the second parse attempt.
689      // These diagnostics are only returned to the caller if using the fallback
690      // actually succeeded in getting the expression to parse. This prevents
691      // that module-specific issues regress diagnostic quality with the
692      // fallback mode.
693      DiagnosticManager retry_manager;
694      // The module imports are injected into the source code wrapper,
695      // so recreate those.
696      CreateSourceCode(retry_manager, exe_ctx, m_imported_cpp_modules,
697                       /*for_completion*/ false);
698      parse_success = TryParse(retry_manager, exe_scope, exe_ctx,
699                               execution_policy, keep_result_in_memory,
700                               generate_debug_info);
701      // Return the parse diagnostics if we were successful.
702      if (parse_success)
703        diagnostic_manager = std::move(retry_manager);
704    }
705  }
706  if (!parse_success)
707    return false;
708
709  if (exe_ctx.GetProcessPtr() && execution_policy == eExecutionPolicyTopLevel) {
710    Status static_init_error =
711        m_parser->RunStaticInitializers(m_execution_unit_sp, exe_ctx);
712
713    if (!static_init_error.Success()) {
714      const char *error_cstr = static_init_error.AsCString();
715      if (error_cstr && error_cstr[0])
716        diagnostic_manager.Printf(eDiagnosticSeverityError,
717                                  "%s\n",
718                                  error_cstr);
719      else
720        diagnostic_manager.PutString(eDiagnosticSeverityError,
721                                     "couldn't run static initializers\n");
722      return false;
723    }
724  }
725
726  if (m_execution_unit_sp) {
727    bool register_execution_unit = false;
728
729    if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
730      register_execution_unit = true;
731    }
732
733    // If there is more than one external function in the execution unit, it
734    // needs to keep living even if it's not top level, because the result
735    // could refer to that function.
736
737    if (m_execution_unit_sp->GetJittedFunctions().size() > 1) {
738      register_execution_unit = true;
739    }
740
741    if (register_execution_unit) {
742      if (auto *persistent_state =
743              exe_ctx.GetTargetPtr()->GetPersistentExpressionStateForLanguage(
744                  m_language))
745        persistent_state->RegisterExecutionUnit(m_execution_unit_sp);
746    }
747  }
748
749  if (generate_debug_info) {
750    lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
751
752    if (jit_module_sp) {
753      ConstString const_func_name(FunctionName());
754      FileSpec jit_file;
755      jit_file.SetFilename(const_func_name);
756      jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
757      m_jit_module_wp = jit_module_sp;
758      target->GetImages().Append(jit_module_sp);
759    }
760  }
761
762  if (process && m_jit_start_addr != LLDB_INVALID_ADDRESS)
763    m_jit_process_wp = lldb::ProcessWP(process->shared_from_this());
764  return true;
765}
766
767/// Converts an absolute position inside a given code string into
768/// a column/line pair.
769///
770/// \param[in] abs_pos
771///     A absolute position in the code string that we want to convert
772///     to a column/line pair.
773///
774/// \param[in] code
775///     A multi-line string usually representing source code.
776///
777/// \param[out] line
778///     The line in the code that contains the given absolute position.
779///     The first line in the string is indexed as 1.
780///
781/// \param[out] column
782///     The column in the line that contains the absolute position.
783///     The first character in a line is indexed as 0.
784static void AbsPosToLineColumnPos(size_t abs_pos, llvm::StringRef code,
785                                  unsigned &line, unsigned &column) {
786  // Reset to code position to beginning of the file.
787  line = 0;
788  column = 0;
789
790  assert(abs_pos <= code.size() && "Absolute position outside code string?");
791
792  // We have to walk up to the position and count lines/columns.
793  for (std::size_t i = 0; i < abs_pos; ++i) {
794    // If we hit a line break, we go back to column 0 and enter a new line.
795    // We only handle \n because that's what we internally use to make new
796    // lines for our temporary code strings.
797    if (code[i] == '\n') {
798      ++line;
799      column = 0;
800      continue;
801    }
802    ++column;
803  }
804}
805
806bool ClangUserExpression::Complete(ExecutionContext &exe_ctx,
807                                   CompletionRequest &request,
808                                   unsigned complete_pos) {
809  Log *log = GetLog(LLDBLog::Expressions);
810
811  // We don't want any visible feedback when completing an expression. Mostly
812  // because the results we get from an incomplete invocation are probably not
813  // correct.
814  DiagnosticManager diagnostic_manager;
815
816  if (!PrepareForParsing(diagnostic_manager, exe_ctx, /*for_completion*/ true))
817    return false;
818
819  LLDB_LOGF(log, "Parsing the following code:\n%s", m_transformed_text.c_str());
820
821  //////////////////////////
822  // Parse the expression
823  //
824
825  m_materializer_up = std::make_unique<Materializer>();
826
827  ResetDeclMap(exe_ctx, m_result_delegate, /*keep result in memory*/ true);
828
829  auto on_exit = llvm::make_scope_exit([this]() { ResetDeclMap(); });
830
831  if (!DeclMap()->WillParse(exe_ctx, GetMaterializer())) {
832    diagnostic_manager.PutString(
833        eDiagnosticSeverityError,
834        "current process state is unsuitable for expression parsing");
835
836    return false;
837  }
838
839  if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
840    DeclMap()->SetLookupsEnabled(true);
841  }
842
843  Process *process = exe_ctx.GetProcessPtr();
844  ExecutionContextScope *exe_scope = process;
845
846  if (!exe_scope)
847    exe_scope = exe_ctx.GetTargetPtr();
848
849  ClangExpressionParser parser(exe_scope, *this, false);
850
851  // We have to find the source code location where the user text is inside
852  // the transformed expression code. When creating the transformed text, we
853  // already stored the absolute position in the m_transformed_text string. The
854  // only thing left to do is to transform it into the line:column format that
855  // Clang expects.
856
857  // The line and column of the user expression inside the transformed source
858  // code.
859  unsigned user_expr_line, user_expr_column;
860  if (m_user_expression_start_pos)
861    AbsPosToLineColumnPos(*m_user_expression_start_pos, m_transformed_text,
862                          user_expr_line, user_expr_column);
863  else
864    return false;
865
866  // The actual column where we have to complete is the start column of the
867  // user expression + the offset inside the user code that we were given.
868  const unsigned completion_column = user_expr_column + complete_pos;
869  parser.Complete(request, user_expr_line, completion_column, complete_pos);
870
871  return true;
872}
873
874lldb::addr_t ClangUserExpression::GetCppObjectPointer(
875    lldb::StackFrameSP frame_sp, llvm::StringRef object_name, Status &err) {
876  auto valobj_sp =
877      GetObjectPointerValueObject(std::move(frame_sp), object_name, err);
878
879  // We're inside a C++ class method. This could potentially be an unnamed
880  // lambda structure. If the lambda captured a "this", that should be
881  // the object pointer.
882  if (auto thisChildSP = valobj_sp->GetChildMemberWithName("this")) {
883    valobj_sp = thisChildSP;
884  }
885
886  if (!err.Success() || !valobj_sp.get())
887    return LLDB_INVALID_ADDRESS;
888
889  lldb::addr_t ret = valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
890
891  if (ret == LLDB_INVALID_ADDRESS) {
892    err.SetErrorStringWithFormatv(
893        "Couldn't load '{0}' because its value couldn't be evaluated",
894        object_name);
895    return LLDB_INVALID_ADDRESS;
896  }
897
898  return ret;
899}
900
901bool ClangUserExpression::AddArguments(ExecutionContext &exe_ctx,
902                                       std::vector<lldb::addr_t> &args,
903                                       lldb::addr_t struct_address,
904                                       DiagnosticManager &diagnostic_manager) {
905  lldb::addr_t object_ptr = LLDB_INVALID_ADDRESS;
906  lldb::addr_t cmd_ptr = LLDB_INVALID_ADDRESS;
907
908  if (m_needs_object_ptr) {
909    lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP();
910    if (!frame_sp)
911      return true;
912
913    if (!m_in_cplusplus_method && !m_in_objectivec_method) {
914      diagnostic_manager.PutString(
915          eDiagnosticSeverityError,
916          "need object pointer but don't know the language");
917      return false;
918    }
919
920    static constexpr llvm::StringLiteral g_cplusplus_object_name("this");
921    static constexpr llvm::StringLiteral g_objc_object_name("self");
922    llvm::StringRef object_name =
923        m_in_cplusplus_method ? g_cplusplus_object_name : g_objc_object_name;
924
925    Status object_ptr_error;
926
927    if (m_ctx_obj) {
928      AddressType address_type;
929      object_ptr = m_ctx_obj->GetAddressOf(false, &address_type);
930      if (object_ptr == LLDB_INVALID_ADDRESS ||
931          address_type != eAddressTypeLoad)
932        object_ptr_error.SetErrorString("Can't get context object's "
933                                        "debuggee address");
934    } else {
935      if (m_in_cplusplus_method) {
936        object_ptr =
937            GetCppObjectPointer(frame_sp, object_name, object_ptr_error);
938      } else {
939        object_ptr = GetObjectPointer(frame_sp, object_name, object_ptr_error);
940      }
941    }
942
943    if (!object_ptr_error.Success()) {
944      exe_ctx.GetTargetRef().GetDebugger().GetAsyncOutputStream()->Format(
945          "warning: `{0}' is not accessible (substituting 0). {1}\n",
946          object_name, object_ptr_error.AsCString());
947      object_ptr = 0;
948    }
949
950    if (m_in_objectivec_method) {
951      static constexpr llvm::StringLiteral cmd_name("_cmd");
952
953      cmd_ptr = GetObjectPointer(frame_sp, cmd_name, object_ptr_error);
954
955      if (!object_ptr_error.Success()) {
956        diagnostic_manager.Printf(
957            eDiagnosticSeverityWarning,
958            "couldn't get cmd pointer (substituting NULL): %s",
959            object_ptr_error.AsCString());
960        cmd_ptr = 0;
961      }
962    }
963
964    args.push_back(object_ptr);
965
966    if (m_in_objectivec_method)
967      args.push_back(cmd_ptr);
968
969    args.push_back(struct_address);
970  } else {
971    args.push_back(struct_address);
972  }
973  return true;
974}
975
976lldb::ExpressionVariableSP ClangUserExpression::GetResultAfterDematerialization(
977    ExecutionContextScope *exe_scope) {
978  return m_result_delegate.GetVariable();
979}
980
981char ClangUserExpression::ClangUserExpressionHelper::ID;
982
983void ClangUserExpression::ClangUserExpressionHelper::ResetDeclMap(
984    ExecutionContext &exe_ctx,
985    Materializer::PersistentVariableDelegate &delegate,
986    bool keep_result_in_memory,
987    ValueObject *ctx_obj) {
988  std::shared_ptr<ClangASTImporter> ast_importer;
989  auto *state = exe_ctx.GetTargetSP()->GetPersistentExpressionStateForLanguage(
990      lldb::eLanguageTypeC);
991  if (state) {
992    auto *persistent_vars = llvm::cast<ClangPersistentVariables>(state);
993    ast_importer = persistent_vars->GetClangASTImporter();
994  }
995  m_expr_decl_map_up = std::make_unique<ClangExpressionDeclMap>(
996      keep_result_in_memory, &delegate, exe_ctx.GetTargetSP(), ast_importer,
997      ctx_obj);
998}
999
1000clang::ASTConsumer *
1001ClangUserExpression::ClangUserExpressionHelper::ASTTransformer(
1002    clang::ASTConsumer *passthrough) {
1003  m_result_synthesizer_up = std::make_unique<ASTResultSynthesizer>(
1004      passthrough, m_top_level, m_target);
1005
1006  return m_result_synthesizer_up.get();
1007}
1008
1009void ClangUserExpression::ClangUserExpressionHelper::CommitPersistentDecls() {
1010  if (m_result_synthesizer_up) {
1011    m_result_synthesizer_up->CommitPersistentDecls();
1012  }
1013}
1014
1015ConstString ClangUserExpression::ResultDelegate::GetName() {
1016  return m_persistent_state->GetNextPersistentVariableName(false);
1017}
1018
1019void ClangUserExpression::ResultDelegate::DidDematerialize(
1020    lldb::ExpressionVariableSP &variable) {
1021  m_variable = variable;
1022}
1023
1024void ClangUserExpression::ResultDelegate::RegisterPersistentState(
1025    PersistentExpressionState *persistent_state) {
1026  m_persistent_state = persistent_state;
1027}
1028
1029lldb::ExpressionVariableSP &ClangUserExpression::ResultDelegate::GetVariable() {
1030  return m_variable;
1031}
1032