1 //===-- ClangExpressionParser.cpp -------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "clang/AST/ASTContext.h"
10 #include "clang/AST/ASTDiagnostic.h"
11 #include "clang/AST/ExternalASTSource.h"
12 #include "clang/AST/PrettyPrinter.h"
13 #include "clang/Basic/DiagnosticIDs.h"
14 #include "clang/Basic/SourceLocation.h"
15 #include "clang/Basic/TargetInfo.h"
16 #include "clang/Basic/Version.h"
17 #include "clang/CodeGen/CodeGenAction.h"
18 #include "clang/CodeGen/ModuleBuilder.h"
19 #include "clang/Edit/Commit.h"
20 #include "clang/Edit/EditedSource.h"
21 #include "clang/Edit/EditsReceiver.h"
22 #include "clang/Frontend/CompilerInstance.h"
23 #include "clang/Frontend/CompilerInvocation.h"
24 #include "clang/Frontend/FrontendActions.h"
25 #include "clang/Frontend/FrontendDiagnostic.h"
26 #include "clang/Frontend/FrontendPluginRegistry.h"
27 #include "clang/Frontend/TextDiagnosticBuffer.h"
28 #include "clang/Frontend/TextDiagnosticPrinter.h"
29 #include "clang/Lex/Preprocessor.h"
30 #include "clang/Parse/ParseAST.h"
31 #include "clang/Rewrite/Core/Rewriter.h"
32 #include "clang/Rewrite/Frontend/FrontendActions.h"
33 #include "clang/Sema/CodeCompleteConsumer.h"
34 #include "clang/Sema/Sema.h"
35 #include "clang/Sema/SemaConsumer.h"
36 
37 #include "llvm/ADT/StringRef.h"
38 #include "llvm/ExecutionEngine/ExecutionEngine.h"
39 #include "llvm/Support/CrashRecoveryContext.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/FileSystem.h"
42 #include "llvm/Support/TargetSelect.h"
43 
44 #include "llvm/IR/LLVMContext.h"
45 #include "llvm/IR/Module.h"
46 #include "llvm/Support/DynamicLibrary.h"
47 #include "llvm/Support/ErrorHandling.h"
48 #include "llvm/Support/Host.h"
49 #include "llvm/Support/MemoryBuffer.h"
50 #include "llvm/Support/Signals.h"
51 
52 #include "ClangDiagnostic.h"
53 #include "ClangExpressionParser.h"
54 #include "ClangUserExpression.h"
55 
56 #include "ASTUtils.h"
57 #include "ClangASTSource.h"
58 #include "ClangDiagnostic.h"
59 #include "ClangExpressionDeclMap.h"
60 #include "ClangExpressionHelper.h"
61 #include "ClangExpressionParser.h"
62 #include "ClangHost.h"
63 #include "ClangModulesDeclVendor.h"
64 #include "ClangPersistentVariables.h"
65 #include "IRForTarget.h"
66 #include "ModuleDependencyCollector.h"
67 
68 #include "lldb/Core/Debugger.h"
69 #include "lldb/Core/Disassembler.h"
70 #include "lldb/Core/Module.h"
71 #include "lldb/Core/StreamFile.h"
72 #include "lldb/Expression/IRDynamicChecks.h"
73 #include "lldb/Expression/IRExecutionUnit.h"
74 #include "lldb/Expression/IRInterpreter.h"
75 #include "lldb/Host/File.h"
76 #include "lldb/Host/HostInfo.h"
77 #include "lldb/Symbol/ClangASTContext.h"
78 #include "lldb/Symbol/SymbolVendor.h"
79 #include "lldb/Target/ExecutionContext.h"
80 #include "lldb/Target/Language.h"
81 #include "lldb/Target/ObjCLanguageRuntime.h"
82 #include "lldb/Target/Process.h"
83 #include "lldb/Target/Target.h"
84 #include "lldb/Target/ThreadPlanCallFunction.h"
85 #include "lldb/Utility/DataBufferHeap.h"
86 #include "lldb/Utility/LLDBAssert.h"
87 #include "lldb/Utility/Log.h"
88 #include "lldb/Utility/Reproducer.h"
89 #include "lldb/Utility/Stream.h"
90 #include "lldb/Utility/StreamString.h"
91 #include "lldb/Utility/StringList.h"
92 
93 #include <cctype>
94 #include <memory>
95 
96 using namespace clang;
97 using namespace llvm;
98 using namespace lldb_private;
99 
100 //===----------------------------------------------------------------------===//
101 // Utility Methods for Clang
102 //===----------------------------------------------------------------------===//
103 
104 class ClangExpressionParser::LLDBPreprocessorCallbacks : public PPCallbacks {
105   ClangModulesDeclVendor &m_decl_vendor;
106   ClangPersistentVariables &m_persistent_vars;
107   StreamString m_error_stream;
108   bool m_has_errors = false;
109 
110 public:
111   LLDBPreprocessorCallbacks(ClangModulesDeclVendor &decl_vendor,
112                             ClangPersistentVariables &persistent_vars)
113       : m_decl_vendor(decl_vendor), m_persistent_vars(persistent_vars) {}
114 
115   void moduleImport(SourceLocation import_location, clang::ModuleIdPath path,
116                     const clang::Module * /*null*/) override {
117     SourceModule module;
118 
119     for (const std::pair<IdentifierInfo *, SourceLocation> &component : path)
120       module.path.push_back(ConstString(component.first->getName()));
121 
122     StreamString error_stream;
123 
124     ClangModulesDeclVendor::ModuleVector exported_modules;
125     if (!m_decl_vendor.AddModule(module, &exported_modules, m_error_stream))
126       m_has_errors = true;
127 
128     for (ClangModulesDeclVendor::ModuleID module : exported_modules)
129       m_persistent_vars.AddHandLoadedClangModule(module);
130   }
131 
132   bool hasErrors() { return m_has_errors; }
133 
134   llvm::StringRef getErrorString() { return m_error_stream.GetString(); }
135 };
136 
137 class ClangDiagnosticManagerAdapter : public clang::DiagnosticConsumer {
138 public:
139   ClangDiagnosticManagerAdapter()
140       : m_passthrough(new clang::TextDiagnosticBuffer) {}
141 
142   ClangDiagnosticManagerAdapter(
143       const std::shared_ptr<clang::TextDiagnosticBuffer> &passthrough)
144       : m_passthrough(passthrough) {}
145 
146   void ResetManager(DiagnosticManager *manager = nullptr) {
147     m_manager = manager;
148   }
149 
150   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
151                         const clang::Diagnostic &Info) override {
152     if (m_manager) {
153       llvm::SmallVector<char, 32> diag_str;
154       Info.FormatDiagnostic(diag_str);
155       diag_str.push_back('\0');
156       const char *data = diag_str.data();
157 
158       lldb_private::DiagnosticSeverity severity;
159       bool make_new_diagnostic = true;
160 
161       switch (DiagLevel) {
162       case DiagnosticsEngine::Level::Fatal:
163       case DiagnosticsEngine::Level::Error:
164         severity = eDiagnosticSeverityError;
165         break;
166       case DiagnosticsEngine::Level::Warning:
167         severity = eDiagnosticSeverityWarning;
168         break;
169       case DiagnosticsEngine::Level::Remark:
170       case DiagnosticsEngine::Level::Ignored:
171         severity = eDiagnosticSeverityRemark;
172         break;
173       case DiagnosticsEngine::Level::Note:
174         m_manager->AppendMessageToDiagnostic(data);
175         make_new_diagnostic = false;
176       }
177       if (make_new_diagnostic) {
178         ClangDiagnostic *new_diagnostic =
179             new ClangDiagnostic(data, severity, Info.getID());
180         m_manager->AddDiagnostic(new_diagnostic);
181 
182         // Don't store away warning fixits, since the compiler doesn't have
183         // enough context in an expression for the warning to be useful.
184         // FIXME: Should we try to filter out FixIts that apply to our generated
185         // code, and not the user's expression?
186         if (severity == eDiagnosticSeverityError) {
187           size_t num_fixit_hints = Info.getNumFixItHints();
188           for (size_t i = 0; i < num_fixit_hints; i++) {
189             const clang::FixItHint &fixit = Info.getFixItHint(i);
190             if (!fixit.isNull())
191               new_diagnostic->AddFixitHint(fixit);
192           }
193         }
194       }
195     }
196 
197     m_passthrough->HandleDiagnostic(DiagLevel, Info);
198   }
199 
200   void FlushDiagnostics(DiagnosticsEngine &Diags) {
201     m_passthrough->FlushDiagnostics(Diags);
202   }
203 
204   DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
205     return new ClangDiagnosticManagerAdapter(m_passthrough);
206   }
207 
208   clang::TextDiagnosticBuffer *GetPassthrough() { return m_passthrough.get(); }
209 
210 private:
211   DiagnosticManager *m_manager = nullptr;
212   std::shared_ptr<clang::TextDiagnosticBuffer> m_passthrough;
213 };
214 
215 static void
216 SetupModuleHeaderPaths(CompilerInstance *compiler,
217                        std::vector<ConstString> include_directories,
218                        lldb::TargetSP target_sp) {
219   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
220 
221   HeaderSearchOptions &search_opts = compiler->getHeaderSearchOpts();
222 
223   for (ConstString dir : include_directories) {
224     search_opts.AddPath(dir.AsCString(), frontend::System, false, true);
225     LLDB_LOG(log, "Added user include dir: {0}", dir);
226   }
227 
228   llvm::SmallString<128> module_cache;
229   auto props = ModuleList::GetGlobalModuleListProperties();
230   props.GetClangModulesCachePath().GetPath(module_cache);
231   search_opts.ModuleCachePath = module_cache.str();
232   LLDB_LOG(log, "Using module cache path: {0}", module_cache.c_str());
233 
234   FileSpec clang_resource_dir = GetClangResourceDir();
235   std::string resource_dir = clang_resource_dir.GetPath();
236   if (FileSystem::Instance().IsDirectory(resource_dir)) {
237     search_opts.ResourceDir = resource_dir;
238     std::string resource_include = resource_dir + "/include";
239     search_opts.AddPath(resource_include, frontend::System, false, true);
240 
241     LLDB_LOG(log, "Added resource include dir: {0}", resource_include);
242   }
243 
244   search_opts.ImplicitModuleMaps = true;
245 
246   std::vector<std::string> system_include_directories =
247       target_sp->GetPlatform()->GetSystemIncludeDirectories(
248           lldb::eLanguageTypeC_plus_plus);
249 
250   for (const std::string &include_dir : system_include_directories) {
251     search_opts.AddPath(include_dir, frontend::System, false, true);
252 
253     LLDB_LOG(log, "Added system include dir: {0}", include_dir);
254   }
255 }
256 
257 //===----------------------------------------------------------------------===//
258 // Implementation of ClangExpressionParser
259 //===----------------------------------------------------------------------===//
260 
261 ClangExpressionParser::ClangExpressionParser(
262     ExecutionContextScope *exe_scope, Expression &expr,
263     bool generate_debug_info, std::vector<ConstString> include_directories)
264     : ExpressionParser(exe_scope, expr, generate_debug_info), m_compiler(),
265       m_pp_callbacks(nullptr),
266       m_include_directories(std::move(include_directories)) {
267   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
268 
269   // We can't compile expressions without a target.  So if the exe_scope is
270   // null or doesn't have a target, then we just need to get out of here.  I'll
271   // lldb_assert and not make any of the compiler objects since
272   // I can't return errors directly from the constructor.  Further calls will
273   // check if the compiler was made and
274   // bag out if it wasn't.
275 
276   if (!exe_scope) {
277     lldb_assert(exe_scope, "Can't make an expression parser with a null scope.",
278                 __FUNCTION__, __FILE__, __LINE__);
279     return;
280   }
281 
282   lldb::TargetSP target_sp;
283   target_sp = exe_scope->CalculateTarget();
284   if (!target_sp) {
285     lldb_assert(target_sp.get(),
286                 "Can't make an expression parser with a null target.",
287                 __FUNCTION__, __FILE__, __LINE__);
288     return;
289   }
290 
291   // 1. Create a new compiler instance.
292   m_compiler.reset(new CompilerInstance());
293 
294   // When capturing a reproducer, hook up the file collector with clang to
295   // collector modules and headers.
296   if (repro::Generator *g = repro::Reproducer::Instance().GetGenerator()) {
297     repro::FileProvider &fp = g->GetOrCreate<repro::FileProvider>();
298     m_compiler->setModuleDepCollector(
299         std::make_shared<ModuleDependencyCollectorAdaptor>(
300             fp.GetFileCollector()));
301     DependencyOutputOptions &opts = m_compiler->getDependencyOutputOpts();
302     opts.IncludeSystemHeaders = true;
303     opts.IncludeModuleFiles = true;
304   }
305 
306   // Make sure clang uses the same VFS as LLDB.
307   m_compiler->createFileManager(FileSystem::Instance().GetVirtualFileSystem());
308 
309   lldb::LanguageType frame_lang =
310       expr.Language(); // defaults to lldb::eLanguageTypeUnknown
311   bool overridden_target_opts = false;
312   lldb_private::LanguageRuntime *lang_rt = nullptr;
313 
314   std::string abi;
315   ArchSpec target_arch;
316   target_arch = target_sp->GetArchitecture();
317 
318   const auto target_machine = target_arch.GetMachine();
319 
320   // If the expression is being evaluated in the context of an existing stack
321   // frame, we introspect to see if the language runtime is available.
322 
323   lldb::StackFrameSP frame_sp = exe_scope->CalculateStackFrame();
324   lldb::ProcessSP process_sp = exe_scope->CalculateProcess();
325 
326   // Make sure the user hasn't provided a preferred execution language with
327   // `expression --language X -- ...`
328   if (frame_sp && frame_lang == lldb::eLanguageTypeUnknown)
329     frame_lang = frame_sp->GetLanguage();
330 
331   if (process_sp && frame_lang != lldb::eLanguageTypeUnknown) {
332     lang_rt = process_sp->GetLanguageRuntime(frame_lang);
333     if (log)
334       log->Printf("Frame has language of type %s",
335                   Language::GetNameForLanguageType(frame_lang));
336   }
337 
338   // 2. Configure the compiler with a set of default options that are
339   // appropriate for most situations.
340   if (target_arch.IsValid()) {
341     std::string triple = target_arch.GetTriple().str();
342     m_compiler->getTargetOpts().Triple = triple;
343     if (log)
344       log->Printf("Using %s as the target triple",
345                   m_compiler->getTargetOpts().Triple.c_str());
346   } else {
347     // If we get here we don't have a valid target and just have to guess.
348     // Sometimes this will be ok to just use the host target triple (when we
349     // evaluate say "2+3", but other expressions like breakpoint conditions and
350     // other things that _are_ target specific really shouldn't just be using
351     // the host triple. In such a case the language runtime should expose an
352     // overridden options set (3), below.
353     m_compiler->getTargetOpts().Triple = llvm::sys::getDefaultTargetTriple();
354     if (log)
355       log->Printf("Using default target triple of %s",
356                   m_compiler->getTargetOpts().Triple.c_str());
357   }
358   // Now add some special fixes for known architectures: Any arm32 iOS
359   // environment, but not on arm64
360   if (m_compiler->getTargetOpts().Triple.find("arm64") == std::string::npos &&
361       m_compiler->getTargetOpts().Triple.find("arm") != std::string::npos &&
362       m_compiler->getTargetOpts().Triple.find("ios") != std::string::npos) {
363     m_compiler->getTargetOpts().ABI = "apcs-gnu";
364   }
365   // Supported subsets of x86
366   if (target_machine == llvm::Triple::x86 ||
367       target_machine == llvm::Triple::x86_64) {
368     m_compiler->getTargetOpts().Features.push_back("+sse");
369     m_compiler->getTargetOpts().Features.push_back("+sse2");
370   }
371 
372   // Set the target CPU to generate code for. This will be empty for any CPU
373   // that doesn't really need to make a special
374   // CPU string.
375   m_compiler->getTargetOpts().CPU = target_arch.GetClangTargetCPU();
376 
377   // Set the target ABI
378   abi = GetClangTargetABI(target_arch);
379   if (!abi.empty())
380     m_compiler->getTargetOpts().ABI = abi;
381 
382   // 3. Now allow the runtime to provide custom configuration options for the
383   // target. In this case, a specialized language runtime is available and we
384   // can query it for extra options. For 99% of use cases, this will not be
385   // needed and should be provided when basic platform detection is not enough.
386   if (lang_rt)
387     overridden_target_opts =
388         lang_rt->GetOverrideExprOptions(m_compiler->getTargetOpts());
389 
390   if (overridden_target_opts)
391     if (log && log->GetVerbose()) {
392       LLDB_LOGV(
393           log, "Using overridden target options for the expression evaluation");
394 
395       auto opts = m_compiler->getTargetOpts();
396       LLDB_LOGV(log, "Triple: '{0}'", opts.Triple);
397       LLDB_LOGV(log, "CPU: '{0}'", opts.CPU);
398       LLDB_LOGV(log, "FPMath: '{0}'", opts.FPMath);
399       LLDB_LOGV(log, "ABI: '{0}'", opts.ABI);
400       LLDB_LOGV(log, "LinkerVersion: '{0}'", opts.LinkerVersion);
401       StringList::LogDump(log, opts.FeaturesAsWritten, "FeaturesAsWritten");
402       StringList::LogDump(log, opts.Features, "Features");
403     }
404 
405   // 4. Create and install the target on the compiler.
406   m_compiler->createDiagnostics();
407   auto target_info = TargetInfo::CreateTargetInfo(
408       m_compiler->getDiagnostics(), m_compiler->getInvocation().TargetOpts);
409   if (log) {
410     log->Printf("Using SIMD alignment: %d", target_info->getSimdDefaultAlign());
411     log->Printf("Target datalayout string: '%s'",
412                 target_info->getDataLayout().getStringRepresentation().c_str());
413     log->Printf("Target ABI: '%s'", target_info->getABI().str().c_str());
414     log->Printf("Target vector alignment: %d",
415                 target_info->getMaxVectorAlign());
416   }
417   m_compiler->setTarget(target_info);
418 
419   assert(m_compiler->hasTarget());
420 
421   // 5. Set language options.
422   lldb::LanguageType language = expr.Language();
423   LangOptions &lang_opts = m_compiler->getLangOpts();
424 
425   switch (language) {
426   case lldb::eLanguageTypeC:
427   case lldb::eLanguageTypeC89:
428   case lldb::eLanguageTypeC99:
429   case lldb::eLanguageTypeC11:
430     // FIXME: the following language option is a temporary workaround,
431     // to "ask for C, get C++."
432     // For now, the expression parser must use C++ anytime the language is a C
433     // family language, because the expression parser uses features of C++ to
434     // capture values.
435     lang_opts.CPlusPlus = true;
436     break;
437   case lldb::eLanguageTypeObjC:
438     lang_opts.ObjC = true;
439     // FIXME: the following language option is a temporary workaround,
440     // to "ask for ObjC, get ObjC++" (see comment above).
441     lang_opts.CPlusPlus = true;
442 
443     // Clang now sets as default C++14 as the default standard (with
444     // GNU extensions), so we do the same here to avoid mismatches that
445     // cause compiler error when evaluating expressions (e.g. nullptr not found
446     // as it's a C++11 feature). Currently lldb evaluates C++14 as C++11 (see
447     // two lines below) so we decide to be consistent with that, but this could
448     // be re-evaluated in the future.
449     lang_opts.CPlusPlus11 = true;
450     break;
451   case lldb::eLanguageTypeC_plus_plus:
452   case lldb::eLanguageTypeC_plus_plus_11:
453   case lldb::eLanguageTypeC_plus_plus_14:
454     lang_opts.CPlusPlus11 = true;
455     m_compiler->getHeaderSearchOpts().UseLibcxx = true;
456     LLVM_FALLTHROUGH;
457   case lldb::eLanguageTypeC_plus_plus_03:
458     lang_opts.CPlusPlus = true;
459     if (process_sp)
460       lang_opts.ObjC =
461           process_sp->GetLanguageRuntime(lldb::eLanguageTypeObjC) != nullptr;
462     break;
463   case lldb::eLanguageTypeObjC_plus_plus:
464   case lldb::eLanguageTypeUnknown:
465   default:
466     lang_opts.ObjC = true;
467     lang_opts.CPlusPlus = true;
468     lang_opts.CPlusPlus11 = true;
469     m_compiler->getHeaderSearchOpts().UseLibcxx = true;
470     break;
471   }
472 
473   lang_opts.Bool = true;
474   lang_opts.WChar = true;
475   lang_opts.Blocks = true;
476   lang_opts.DebuggerSupport =
477       true; // Features specifically for debugger clients
478   if (expr.DesiredResultType() == Expression::eResultTypeId)
479     lang_opts.DebuggerCastResultToId = true;
480 
481   lang_opts.CharIsSigned = ArchSpec(m_compiler->getTargetOpts().Triple.c_str())
482                                .CharIsSignedByDefault();
483 
484   // Spell checking is a nice feature, but it ends up completing a lot of types
485   // that we didn't strictly speaking need to complete. As a result, we spend a
486   // long time parsing and importing debug information.
487   lang_opts.SpellChecking = false;
488 
489   auto *clang_expr = dyn_cast<ClangUserExpression>(&m_expr);
490   if (clang_expr && clang_expr->DidImportCxxModules()) {
491     LLDB_LOG(log, "Adding lang options for importing C++ modules");
492 
493     lang_opts.Modules = true;
494     // We want to implicitly build modules.
495     lang_opts.ImplicitModules = true;
496     // To automatically import all submodules when we import 'std'.
497     lang_opts.ModulesLocalVisibility = false;
498 
499     // We use the @import statements, so we need this:
500     // FIXME: We could use the modules-ts, but that currently doesn't work.
501     lang_opts.ObjC = true;
502 
503     // Options we need to parse libc++ code successfully.
504     // FIXME: We should ask the driver for the appropriate default flags.
505     lang_opts.GNUMode = true;
506     lang_opts.GNUKeywords = true;
507     lang_opts.DoubleSquareBracketAttributes = true;
508     lang_opts.CPlusPlus11 = true;
509 
510     SetupModuleHeaderPaths(m_compiler.get(), m_include_directories,
511                            target_sp);
512   }
513 
514   if (process_sp && lang_opts.ObjC) {
515     if (process_sp->GetObjCLanguageRuntime()) {
516       if (process_sp->GetObjCLanguageRuntime()->GetRuntimeVersion() ==
517           ObjCLanguageRuntime::ObjCRuntimeVersions::eAppleObjC_V2)
518         lang_opts.ObjCRuntime.set(ObjCRuntime::MacOSX, VersionTuple(10, 7));
519       else
520         lang_opts.ObjCRuntime.set(ObjCRuntime::FragileMacOSX,
521                                   VersionTuple(10, 7));
522 
523       if (process_sp->GetObjCLanguageRuntime()->HasNewLiteralsAndIndexing())
524         lang_opts.DebuggerObjCLiteral = true;
525     }
526   }
527 
528   lang_opts.ThreadsafeStatics = false;
529   lang_opts.AccessControl = false; // Debuggers get universal access
530   lang_opts.DollarIdents = true;   // $ indicates a persistent variable name
531   // We enable all builtin functions beside the builtins from libc/libm (e.g.
532   // 'fopen'). Those libc functions are already correctly handled by LLDB, and
533   // additionally enabling them as expandable builtins is breaking Clang.
534   lang_opts.NoBuiltin = true;
535 
536   // Set CodeGen options
537   m_compiler->getCodeGenOpts().EmitDeclMetadata = true;
538   m_compiler->getCodeGenOpts().InstrumentFunctions = false;
539   m_compiler->getCodeGenOpts().DisableFPElim = true;
540   m_compiler->getCodeGenOpts().OmitLeafFramePointer = false;
541   if (generate_debug_info)
542     m_compiler->getCodeGenOpts().setDebugInfo(codegenoptions::FullDebugInfo);
543   else
544     m_compiler->getCodeGenOpts().setDebugInfo(codegenoptions::NoDebugInfo);
545 
546   // Disable some warnings.
547   m_compiler->getDiagnostics().setSeverityForGroup(
548       clang::diag::Flavor::WarningOrError, "unused-value",
549       clang::diag::Severity::Ignored, SourceLocation());
550   m_compiler->getDiagnostics().setSeverityForGroup(
551       clang::diag::Flavor::WarningOrError, "odr",
552       clang::diag::Severity::Ignored, SourceLocation());
553 
554   // Inform the target of the language options
555   //
556   // FIXME: We shouldn't need to do this, the target should be immutable once
557   // created. This complexity should be lifted elsewhere.
558   m_compiler->getTarget().adjust(m_compiler->getLangOpts());
559 
560   // 6. Set up the diagnostic buffer for reporting errors
561 
562   m_compiler->getDiagnostics().setClient(new ClangDiagnosticManagerAdapter);
563 
564   // 7. Set up the source management objects inside the compiler
565   m_compiler->createFileManager();
566   if (!m_compiler->hasSourceManager())
567     m_compiler->createSourceManager(m_compiler->getFileManager());
568   m_compiler->createPreprocessor(TU_Complete);
569 
570   if (ClangModulesDeclVendor *decl_vendor =
571           target_sp->GetClangModulesDeclVendor()) {
572     ClangPersistentVariables *clang_persistent_vars =
573         llvm::cast<ClangPersistentVariables>(
574             target_sp->GetPersistentExpressionStateForLanguage(
575                 lldb::eLanguageTypeC));
576     std::unique_ptr<PPCallbacks> pp_callbacks(
577         new LLDBPreprocessorCallbacks(*decl_vendor, *clang_persistent_vars));
578     m_pp_callbacks =
579         static_cast<LLDBPreprocessorCallbacks *>(pp_callbacks.get());
580     m_compiler->getPreprocessor().addPPCallbacks(std::move(pp_callbacks));
581   }
582 
583   // 8. Most of this we get from the CompilerInstance, but we also want to give
584   // the context an ExternalASTSource.
585 
586   auto &PP = m_compiler->getPreprocessor();
587   auto &builtin_context = PP.getBuiltinInfo();
588   builtin_context.initializeBuiltins(PP.getIdentifierTable(),
589                                      m_compiler->getLangOpts());
590 
591   m_compiler->createASTContext();
592   clang::ASTContext &ast_context = m_compiler->getASTContext();
593 
594   m_ast_context.reset(
595       new ClangASTContext(m_compiler->getTargetOpts().Triple.c_str()));
596   m_ast_context->setASTContext(&ast_context);
597 
598   std::string module_name("$__lldb_module");
599 
600   m_llvm_context.reset(new LLVMContext());
601   m_code_generator.reset(CreateLLVMCodeGen(
602       m_compiler->getDiagnostics(), module_name,
603       m_compiler->getHeaderSearchOpts(), m_compiler->getPreprocessorOpts(),
604       m_compiler->getCodeGenOpts(), *m_llvm_context));
605 }
606 
607 ClangExpressionParser::~ClangExpressionParser() {}
608 
609 namespace {
610 
611 /// \class CodeComplete
612 ///
613 /// A code completion consumer for the clang Sema that is responsible for
614 /// creating the completion suggestions when a user requests completion
615 /// of an incomplete `expr` invocation.
616 class CodeComplete : public CodeCompleteConsumer {
617   CodeCompletionTUInfo m_info;
618 
619   std::string m_expr;
620   unsigned m_position = 0;
621   CompletionRequest &m_request;
622   /// The printing policy we use when printing declarations for our completion
623   /// descriptions.
624   clang::PrintingPolicy m_desc_policy;
625 
626   /// Returns true if the given character can be used in an identifier.
627   /// This also returns true for numbers because for completion we usually
628   /// just iterate backwards over iterators.
629   ///
630   /// Note: lldb uses '$' in its internal identifiers, so we also allow this.
631   static bool IsIdChar(char c) {
632     return c == '_' || std::isalnum(c) || c == '$';
633   }
634 
635   /// Returns true if the given character is used to separate arguments
636   /// in the command line of lldb.
637   static bool IsTokenSeparator(char c) { return c == ' ' || c == '\t'; }
638 
639   /// Drops all tokens in front of the expression that are unrelated for
640   /// the completion of the cmd line. 'unrelated' means here that the token
641   /// is not interested for the lldb completion API result.
642   StringRef dropUnrelatedFrontTokens(StringRef cmd) {
643     if (cmd.empty())
644       return cmd;
645 
646     // If we are at the start of a word, then all tokens are unrelated to
647     // the current completion logic.
648     if (IsTokenSeparator(cmd.back()))
649       return StringRef();
650 
651     // Remove all previous tokens from the string as they are unrelated
652     // to completing the current token.
653     StringRef to_remove = cmd;
654     while (!to_remove.empty() && !IsTokenSeparator(to_remove.back())) {
655       to_remove = to_remove.drop_back();
656     }
657     cmd = cmd.drop_front(to_remove.size());
658 
659     return cmd;
660   }
661 
662   /// Removes the last identifier token from the given cmd line.
663   StringRef removeLastToken(StringRef cmd) {
664     while (!cmd.empty() && IsIdChar(cmd.back())) {
665       cmd = cmd.drop_back();
666     }
667     return cmd;
668   }
669 
670   /// Attemps to merge the given completion from the given position into the
671   /// existing command. Returns the completion string that can be returned to
672   /// the lldb completion API.
673   std::string mergeCompletion(StringRef existing, unsigned pos,
674                               StringRef completion) {
675     StringRef existing_command = existing.substr(0, pos);
676     // We rewrite the last token with the completion, so let's drop that
677     // token from the command.
678     existing_command = removeLastToken(existing_command);
679     // We also should remove all previous tokens from the command as they
680     // would otherwise be added to the completion that already has the
681     // completion.
682     existing_command = dropUnrelatedFrontTokens(existing_command);
683     return existing_command.str() + completion.str();
684   }
685 
686 public:
687   /// Constructs a CodeComplete consumer that can be attached to a Sema.
688   /// \param[out] matches
689   ///    The list of matches that the lldb completion API expects as a result.
690   ///    This may already contain matches, so it's only allowed to append
691   ///    to this variable.
692   /// \param[out] expr
693   ///    The whole expression string that we are currently parsing. This
694   ///    string needs to be equal to the input the user typed, and NOT the
695   ///    final code that Clang is parsing.
696   /// \param[out] position
697   ///    The character position of the user cursor in the `expr` parameter.
698   ///
699   CodeComplete(CompletionRequest &request, clang::LangOptions ops,
700                std::string expr, unsigned position)
701       : CodeCompleteConsumer(CodeCompleteOptions()),
702         m_info(std::make_shared<GlobalCodeCompletionAllocator>()), m_expr(expr),
703         m_position(position), m_request(request), m_desc_policy(ops) {
704 
705     // Ensure that the printing policy is producing a description that is as
706     // short as possible.
707     m_desc_policy.SuppressScope = true;
708     m_desc_policy.SuppressTagKeyword = true;
709     m_desc_policy.FullyQualifiedName = false;
710     m_desc_policy.TerseOutput = true;
711     m_desc_policy.IncludeNewlines = false;
712     m_desc_policy.UseVoidForZeroParams = false;
713     m_desc_policy.Bool = true;
714   }
715 
716   /// Deregisters and destroys this code-completion consumer.
717   ~CodeComplete() override {}
718 
719   /// \name Code-completion filtering
720   /// Check if the result should be filtered out.
721   bool isResultFilteredOut(StringRef Filter,
722                            CodeCompletionResult Result) override {
723     // This code is mostly copied from CodeCompleteConsumer.
724     switch (Result.Kind) {
725     case CodeCompletionResult::RK_Declaration:
726       return !(
727           Result.Declaration->getIdentifier() &&
728           Result.Declaration->getIdentifier()->getName().startswith(Filter));
729     case CodeCompletionResult::RK_Keyword:
730       return !StringRef(Result.Keyword).startswith(Filter);
731     case CodeCompletionResult::RK_Macro:
732       return !Result.Macro->getName().startswith(Filter);
733     case CodeCompletionResult::RK_Pattern:
734       return !StringRef(Result.Pattern->getAsString()).startswith(Filter);
735     }
736     // If we trigger this assert or the above switch yields a warning, then
737     // CodeCompletionResult has been enhanced with more kinds of completion
738     // results. Expand the switch above in this case.
739     assert(false && "Unknown completion result type?");
740     // If we reach this, then we should just ignore whatever kind of unknown
741     // result we got back. We probably can't turn it into any kind of useful
742     // completion suggestion with the existing code.
743     return true;
744   }
745 
746   /// \name Code-completion callbacks
747   /// Process the finalized code-completion results.
748   void ProcessCodeCompleteResults(Sema &SemaRef, CodeCompletionContext Context,
749                                   CodeCompletionResult *Results,
750                                   unsigned NumResults) override {
751 
752     // The Sema put the incomplete token we try to complete in here during
753     // lexing, so we need to retrieve it here to know what we are completing.
754     StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
755 
756     // Iterate over all the results. Filter out results we don't want and
757     // process the rest.
758     for (unsigned I = 0; I != NumResults; ++I) {
759       // Filter the results with the information from the Sema.
760       if (!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
761         continue;
762 
763       CodeCompletionResult &R = Results[I];
764       std::string ToInsert;
765       std::string Description;
766       // Handle the different completion kinds that come from the Sema.
767       switch (R.Kind) {
768       case CodeCompletionResult::RK_Declaration: {
769         const NamedDecl *D = R.Declaration;
770         ToInsert = R.Declaration->getNameAsString();
771         // If we have a function decl that has no arguments we want to
772         // complete the empty parantheses for the user. If the function has
773         // arguments, we at least complete the opening bracket.
774         if (const FunctionDecl *F = dyn_cast<FunctionDecl>(D)) {
775           if (F->getNumParams() == 0)
776             ToInsert += "()";
777           else
778             ToInsert += "(";
779           raw_string_ostream OS(Description);
780           F->print(OS, m_desc_policy, false);
781           OS.flush();
782         } else if (const VarDecl *V = dyn_cast<VarDecl>(D)) {
783           Description = V->getType().getAsString(m_desc_policy);
784         } else if (const FieldDecl *F = dyn_cast<FieldDecl>(D)) {
785           Description = F->getType().getAsString(m_desc_policy);
786         } else if (const NamespaceDecl *N = dyn_cast<NamespaceDecl>(D)) {
787           // If we try to complete a namespace, then we can directly append
788           // the '::'.
789           if (!N->isAnonymousNamespace())
790             ToInsert += "::";
791         }
792         break;
793       }
794       case CodeCompletionResult::RK_Keyword:
795         ToInsert = R.Keyword;
796         break;
797       case CodeCompletionResult::RK_Macro:
798         ToInsert = R.Macro->getName().str();
799         break;
800       case CodeCompletionResult::RK_Pattern:
801         ToInsert = R.Pattern->getTypedText();
802         break;
803       }
804       // At this point all information is in the ToInsert string.
805 
806       // We also filter some internal lldb identifiers here. The user
807       // shouldn't see these.
808       if (StringRef(ToInsert).startswith("$__lldb_"))
809         continue;
810       if (!ToInsert.empty()) {
811         // Merge the suggested Token into the existing command line to comply
812         // with the kind of result the lldb API expects.
813         std::string CompletionSuggestion =
814             mergeCompletion(m_expr, m_position, ToInsert);
815         m_request.AddCompletion(CompletionSuggestion, Description);
816       }
817     }
818   }
819 
820   /// \param S the semantic-analyzer object for which code-completion is being
821   /// done.
822   ///
823   /// \param CurrentArg the index of the current argument.
824   ///
825   /// \param Candidates an array of overload candidates.
826   ///
827   /// \param NumCandidates the number of overload candidates
828   void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
829                                  OverloadCandidate *Candidates,
830                                  unsigned NumCandidates,
831                                  SourceLocation OpenParLoc) override {
832     // At the moment we don't filter out any overloaded candidates.
833   }
834 
835   CodeCompletionAllocator &getAllocator() override {
836     return m_info.getAllocator();
837   }
838 
839   CodeCompletionTUInfo &getCodeCompletionTUInfo() override { return m_info; }
840 };
841 } // namespace
842 
843 bool ClangExpressionParser::Complete(CompletionRequest &request, unsigned line,
844                                      unsigned pos, unsigned typed_pos) {
845   DiagnosticManager mgr;
846   // We need the raw user expression here because that's what the CodeComplete
847   // class uses to provide completion suggestions.
848   // However, the `Text` method only gives us the transformed expression here.
849   // To actually get the raw user input here, we have to cast our expression to
850   // the LLVMUserExpression which exposes the right API. This should never fail
851   // as we always have a ClangUserExpression whenever we call this.
852   ClangUserExpression *llvm_expr = cast<ClangUserExpression>(&m_expr);
853   CodeComplete CC(request, m_compiler->getLangOpts(), llvm_expr->GetUserText(),
854                   typed_pos);
855   // We don't need a code generator for parsing.
856   m_code_generator.reset();
857   // Start parsing the expression with our custom code completion consumer.
858   ParseInternal(mgr, &CC, line, pos);
859   return true;
860 }
861 
862 unsigned ClangExpressionParser::Parse(DiagnosticManager &diagnostic_manager) {
863   return ParseInternal(diagnostic_manager);
864 }
865 
866 unsigned
867 ClangExpressionParser::ParseInternal(DiagnosticManager &diagnostic_manager,
868                                      CodeCompleteConsumer *completion_consumer,
869                                      unsigned completion_line,
870                                      unsigned completion_column) {
871   ClangDiagnosticManagerAdapter *adapter =
872       static_cast<ClangDiagnosticManagerAdapter *>(
873           m_compiler->getDiagnostics().getClient());
874   clang::TextDiagnosticBuffer *diag_buf = adapter->GetPassthrough();
875   diag_buf->FlushDiagnostics(m_compiler->getDiagnostics());
876 
877   adapter->ResetManager(&diagnostic_manager);
878 
879   const char *expr_text = m_expr.Text();
880 
881   clang::SourceManager &source_mgr = m_compiler->getSourceManager();
882   bool created_main_file = false;
883 
884   // Clang wants to do completion on a real file known by Clang's file manager,
885   // so we have to create one to make this work.
886   // TODO: We probably could also simulate to Clang's file manager that there
887   // is a real file that contains our code.
888   bool should_create_file = completion_consumer != nullptr;
889 
890   // We also want a real file on disk if we generate full debug info.
891   should_create_file |= m_compiler->getCodeGenOpts().getDebugInfo() ==
892                         codegenoptions::FullDebugInfo;
893 
894   if (should_create_file) {
895     int temp_fd = -1;
896     llvm::SmallString<128> result_path;
897     if (FileSpec tmpdir_file_spec = HostInfo::GetProcessTempDir()) {
898       tmpdir_file_spec.AppendPathComponent("lldb-%%%%%%.expr");
899       std::string temp_source_path = tmpdir_file_spec.GetPath();
900       llvm::sys::fs::createUniqueFile(temp_source_path, temp_fd, result_path);
901     } else {
902       llvm::sys::fs::createTemporaryFile("lldb", "expr", temp_fd, result_path);
903     }
904 
905     if (temp_fd != -1) {
906       lldb_private::File file(temp_fd, true);
907       const size_t expr_text_len = strlen(expr_text);
908       size_t bytes_written = expr_text_len;
909       if (file.Write(expr_text, bytes_written).Success()) {
910         if (bytes_written == expr_text_len) {
911           file.Close();
912           source_mgr.setMainFileID(source_mgr.createFileID(
913               m_compiler->getFileManager().getFile(result_path),
914               SourceLocation(), SrcMgr::C_User));
915           created_main_file = true;
916         }
917       }
918     }
919   }
920 
921   if (!created_main_file) {
922     std::unique_ptr<MemoryBuffer> memory_buffer =
923         MemoryBuffer::getMemBufferCopy(expr_text, __FUNCTION__);
924     source_mgr.setMainFileID(source_mgr.createFileID(std::move(memory_buffer)));
925   }
926 
927   diag_buf->BeginSourceFile(m_compiler->getLangOpts(),
928                             &m_compiler->getPreprocessor());
929 
930   ClangExpressionHelper *type_system_helper =
931       dyn_cast<ClangExpressionHelper>(m_expr.GetTypeSystemHelper());
932 
933   // If we want to parse for code completion, we need to attach our code
934   // completion consumer to the Sema and specify a completion position.
935   // While parsing the Sema will call this consumer with the provided
936   // completion suggestions.
937   if (completion_consumer) {
938     auto main_file = source_mgr.getFileEntryForID(source_mgr.getMainFileID());
939     auto &PP = m_compiler->getPreprocessor();
940     // Lines and columns start at 1 in Clang, but code completion positions are
941     // indexed from 0, so we need to add 1 to the line and column here.
942     ++completion_line;
943     ++completion_column;
944     PP.SetCodeCompletionPoint(main_file, completion_line, completion_column);
945   }
946 
947   ASTConsumer *ast_transformer =
948       type_system_helper->ASTTransformer(m_code_generator.get());
949 
950   std::unique_ptr<clang::ASTConsumer> Consumer;
951   if (ast_transformer) {
952     Consumer.reset(new ASTConsumerForwarder(ast_transformer));
953   } else if (m_code_generator) {
954     Consumer.reset(new ASTConsumerForwarder(m_code_generator.get()));
955   } else {
956     Consumer.reset(new ASTConsumer());
957   }
958 
959   clang::ASTContext &ast_context = m_compiler->getASTContext();
960 
961   m_compiler->setSema(new Sema(m_compiler->getPreprocessor(), ast_context,
962                                *Consumer, TU_Complete, completion_consumer));
963   m_compiler->setASTConsumer(std::move(Consumer));
964 
965   if (ast_context.getLangOpts().Modules) {
966     m_compiler->createModuleManager();
967     m_ast_context->setSema(&m_compiler->getSema());
968   }
969 
970   ClangExpressionDeclMap *decl_map = type_system_helper->DeclMap();
971   if (decl_map) {
972     decl_map->InstallCodeGenerator(&m_compiler->getASTConsumer());
973 
974     clang::ExternalASTSource *ast_source = decl_map->CreateProxy();
975 
976     if (ast_context.getExternalSource()) {
977       auto module_wrapper =
978           new ExternalASTSourceWrapper(ast_context.getExternalSource());
979 
980       auto ast_source_wrapper = new ExternalASTSourceWrapper(ast_source);
981 
982       auto multiplexer =
983           new SemaSourceWithPriorities(*module_wrapper, *ast_source_wrapper);
984       IntrusiveRefCntPtr<ExternalASTSource> Source(multiplexer);
985       ast_context.setExternalSource(Source);
986     } else {
987       ast_context.setExternalSource(ast_source);
988     }
989     decl_map->InstallASTContext(ast_context, m_compiler->getFileManager());
990   }
991 
992   // Check that the ASTReader is properly attached to ASTContext and Sema.
993   if (ast_context.getLangOpts().Modules) {
994     assert(m_compiler->getASTContext().getExternalSource() &&
995            "ASTContext doesn't know about the ASTReader?");
996     assert(m_compiler->getSema().getExternalSource() &&
997            "Sema doesn't know about the ASTReader?");
998   }
999 
1000   {
1001     llvm::CrashRecoveryContextCleanupRegistrar<Sema> CleanupSema(
1002         &m_compiler->getSema());
1003     ParseAST(m_compiler->getSema(), false, false);
1004   }
1005 
1006   // Make sure we have no pointer to the Sema we are about to destroy.
1007   if (ast_context.getLangOpts().Modules)
1008     m_ast_context->setSema(nullptr);
1009   // Destroy the Sema. This is necessary because we want to emulate the
1010   // original behavior of ParseAST (which also destroys the Sema after parsing).
1011   m_compiler->setSema(nullptr);
1012 
1013   diag_buf->EndSourceFile();
1014 
1015   unsigned num_errors = diag_buf->getNumErrors();
1016 
1017   if (m_pp_callbacks && m_pp_callbacks->hasErrors()) {
1018     num_errors++;
1019     diagnostic_manager.PutString(eDiagnosticSeverityError,
1020                                  "while importing modules:");
1021     diagnostic_manager.AppendMessageToDiagnostic(
1022         m_pp_callbacks->getErrorString());
1023   }
1024 
1025   if (!num_errors) {
1026     if (type_system_helper->DeclMap() &&
1027         !type_system_helper->DeclMap()->ResolveUnknownTypes()) {
1028       diagnostic_manager.Printf(eDiagnosticSeverityError,
1029                                 "Couldn't infer the type of a variable");
1030       num_errors++;
1031     }
1032   }
1033 
1034   if (!num_errors) {
1035     type_system_helper->CommitPersistentDecls();
1036   }
1037 
1038   adapter->ResetManager();
1039 
1040   return num_errors;
1041 }
1042 
1043 std::string
1044 ClangExpressionParser::GetClangTargetABI(const ArchSpec &target_arch) {
1045   std::string abi;
1046 
1047   if (target_arch.IsMIPS()) {
1048     switch (target_arch.GetFlags() & ArchSpec::eMIPSABI_mask) {
1049     case ArchSpec::eMIPSABI_N64:
1050       abi = "n64";
1051       break;
1052     case ArchSpec::eMIPSABI_N32:
1053       abi = "n32";
1054       break;
1055     case ArchSpec::eMIPSABI_O32:
1056       abi = "o32";
1057       break;
1058     default:
1059       break;
1060     }
1061   }
1062   return abi;
1063 }
1064 
1065 bool ClangExpressionParser::RewriteExpression(
1066     DiagnosticManager &diagnostic_manager) {
1067   clang::SourceManager &source_manager = m_compiler->getSourceManager();
1068   clang::edit::EditedSource editor(source_manager, m_compiler->getLangOpts(),
1069                                    nullptr);
1070   clang::edit::Commit commit(editor);
1071   clang::Rewriter rewriter(source_manager, m_compiler->getLangOpts());
1072 
1073   class RewritesReceiver : public edit::EditsReceiver {
1074     Rewriter &rewrite;
1075 
1076   public:
1077     RewritesReceiver(Rewriter &in_rewrite) : rewrite(in_rewrite) {}
1078 
1079     void insert(SourceLocation loc, StringRef text) override {
1080       rewrite.InsertText(loc, text);
1081     }
1082     void replace(CharSourceRange range, StringRef text) override {
1083       rewrite.ReplaceText(range.getBegin(), rewrite.getRangeSize(range), text);
1084     }
1085   };
1086 
1087   RewritesReceiver rewrites_receiver(rewriter);
1088 
1089   const DiagnosticList &diagnostics = diagnostic_manager.Diagnostics();
1090   size_t num_diags = diagnostics.size();
1091   if (num_diags == 0)
1092     return false;
1093 
1094   for (const Diagnostic *diag : diagnostic_manager.Diagnostics()) {
1095     const ClangDiagnostic *diagnostic = llvm::dyn_cast<ClangDiagnostic>(diag);
1096     if (diagnostic && diagnostic->HasFixIts()) {
1097       for (const FixItHint &fixit : diagnostic->FixIts()) {
1098         // This is cobbed from clang::Rewrite::FixItRewriter.
1099         if (fixit.CodeToInsert.empty()) {
1100           if (fixit.InsertFromRange.isValid()) {
1101             commit.insertFromRange(fixit.RemoveRange.getBegin(),
1102                                    fixit.InsertFromRange, /*afterToken=*/false,
1103                                    fixit.BeforePreviousInsertions);
1104           } else
1105             commit.remove(fixit.RemoveRange);
1106         } else {
1107           if (fixit.RemoveRange.isTokenRange() ||
1108               fixit.RemoveRange.getBegin() != fixit.RemoveRange.getEnd())
1109             commit.replace(fixit.RemoveRange, fixit.CodeToInsert);
1110           else
1111             commit.insert(fixit.RemoveRange.getBegin(), fixit.CodeToInsert,
1112                           /*afterToken=*/false, fixit.BeforePreviousInsertions);
1113         }
1114       }
1115     }
1116   }
1117 
1118   // FIXME - do we want to try to propagate specific errors here?
1119   if (!commit.isCommitable())
1120     return false;
1121   else if (!editor.commit(commit))
1122     return false;
1123 
1124   // Now play all the edits, and stash the result in the diagnostic manager.
1125   editor.applyRewrites(rewrites_receiver);
1126   RewriteBuffer &main_file_buffer =
1127       rewriter.getEditBuffer(source_manager.getMainFileID());
1128 
1129   std::string fixed_expression;
1130   llvm::raw_string_ostream out_stream(fixed_expression);
1131 
1132   main_file_buffer.write(out_stream);
1133   out_stream.flush();
1134   diagnostic_manager.SetFixedExpression(fixed_expression);
1135 
1136   return true;
1137 }
1138 
1139 static bool FindFunctionInModule(ConstString &mangled_name,
1140                                  llvm::Module *module, const char *orig_name) {
1141   for (const auto &func : module->getFunctionList()) {
1142     const StringRef &name = func.getName();
1143     if (name.find(orig_name) != StringRef::npos) {
1144       mangled_name.SetString(name);
1145       return true;
1146     }
1147   }
1148 
1149   return false;
1150 }
1151 
1152 lldb_private::Status ClangExpressionParser::PrepareForExecution(
1153     lldb::addr_t &func_addr, lldb::addr_t &func_end,
1154     lldb::IRExecutionUnitSP &execution_unit_sp, ExecutionContext &exe_ctx,
1155     bool &can_interpret, ExecutionPolicy execution_policy) {
1156   func_addr = LLDB_INVALID_ADDRESS;
1157   func_end = LLDB_INVALID_ADDRESS;
1158   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1159 
1160   lldb_private::Status err;
1161 
1162   std::unique_ptr<llvm::Module> llvm_module_up(
1163       m_code_generator->ReleaseModule());
1164 
1165   if (!llvm_module_up) {
1166     err.SetErrorToGenericError();
1167     err.SetErrorString("IR doesn't contain a module");
1168     return err;
1169   }
1170 
1171   ConstString function_name;
1172 
1173   if (execution_policy != eExecutionPolicyTopLevel) {
1174     // Find the actual name of the function (it's often mangled somehow)
1175 
1176     if (!FindFunctionInModule(function_name, llvm_module_up.get(),
1177                               m_expr.FunctionName())) {
1178       err.SetErrorToGenericError();
1179       err.SetErrorStringWithFormat("Couldn't find %s() in the module",
1180                                    m_expr.FunctionName());
1181       return err;
1182     } else {
1183       if (log)
1184         log->Printf("Found function %s for %s", function_name.AsCString(),
1185                     m_expr.FunctionName());
1186     }
1187   }
1188 
1189   SymbolContext sc;
1190 
1191   if (lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP()) {
1192     sc = frame_sp->GetSymbolContext(lldb::eSymbolContextEverything);
1193   } else if (lldb::TargetSP target_sp = exe_ctx.GetTargetSP()) {
1194     sc.target_sp = target_sp;
1195   }
1196 
1197   LLVMUserExpression::IRPasses custom_passes;
1198   {
1199     auto lang = m_expr.Language();
1200     if (log)
1201       log->Printf("%s - Current expression language is %s\n", __FUNCTION__,
1202                   Language::GetNameForLanguageType(lang));
1203     lldb::ProcessSP process_sp = exe_ctx.GetProcessSP();
1204     if (process_sp && lang != lldb::eLanguageTypeUnknown) {
1205       auto runtime = process_sp->GetLanguageRuntime(lang);
1206       if (runtime)
1207         runtime->GetIRPasses(custom_passes);
1208     }
1209   }
1210 
1211   if (custom_passes.EarlyPasses) {
1212     if (log)
1213       log->Printf("%s - Running Early IR Passes from LanguageRuntime on "
1214                   "expression module '%s'",
1215                   __FUNCTION__, m_expr.FunctionName());
1216 
1217     custom_passes.EarlyPasses->run(*llvm_module_up);
1218   }
1219 
1220   execution_unit_sp = std::make_shared<IRExecutionUnit>(
1221       m_llvm_context, // handed off here
1222       llvm_module_up, // handed off here
1223       function_name, exe_ctx.GetTargetSP(), sc,
1224       m_compiler->getTargetOpts().Features);
1225 
1226   ClangExpressionHelper *type_system_helper =
1227       dyn_cast<ClangExpressionHelper>(m_expr.GetTypeSystemHelper());
1228   ClangExpressionDeclMap *decl_map =
1229       type_system_helper->DeclMap(); // result can be NULL
1230 
1231   if (decl_map) {
1232     Stream *error_stream = nullptr;
1233     Target *target = exe_ctx.GetTargetPtr();
1234     error_stream = target->GetDebugger().GetErrorFile().get();
1235 
1236     IRForTarget ir_for_target(decl_map, m_expr.NeedsVariableResolution(),
1237                               *execution_unit_sp, *error_stream,
1238                               function_name.AsCString());
1239 
1240     bool ir_can_run =
1241         ir_for_target.runOnModule(*execution_unit_sp->GetModule());
1242 
1243     if (!ir_can_run) {
1244       err.SetErrorString(
1245           "The expression could not be prepared to run in the target");
1246       return err;
1247     }
1248 
1249     Process *process = exe_ctx.GetProcessPtr();
1250 
1251     if (execution_policy != eExecutionPolicyAlways &&
1252         execution_policy != eExecutionPolicyTopLevel) {
1253       lldb_private::Status interpret_error;
1254 
1255       bool interpret_function_calls =
1256           !process ? false : process->CanInterpretFunctionCalls();
1257       can_interpret = IRInterpreter::CanInterpret(
1258           *execution_unit_sp->GetModule(), *execution_unit_sp->GetFunction(),
1259           interpret_error, interpret_function_calls);
1260 
1261       if (!can_interpret && execution_policy == eExecutionPolicyNever) {
1262         err.SetErrorStringWithFormat("Can't run the expression locally: %s",
1263                                      interpret_error.AsCString());
1264         return err;
1265       }
1266     }
1267 
1268     if (!process && execution_policy == eExecutionPolicyAlways) {
1269       err.SetErrorString("Expression needed to run in the target, but the "
1270                          "target can't be run");
1271       return err;
1272     }
1273 
1274     if (!process && execution_policy == eExecutionPolicyTopLevel) {
1275       err.SetErrorString("Top-level code needs to be inserted into a runnable "
1276                          "target, but the target can't be run");
1277       return err;
1278     }
1279 
1280     if (execution_policy == eExecutionPolicyAlways ||
1281         (execution_policy != eExecutionPolicyTopLevel && !can_interpret)) {
1282       if (m_expr.NeedsValidation() && process) {
1283         if (!process->GetDynamicCheckers()) {
1284           DynamicCheckerFunctions *dynamic_checkers =
1285               new DynamicCheckerFunctions();
1286 
1287           DiagnosticManager install_diagnostics;
1288 
1289           if (!dynamic_checkers->Install(install_diagnostics, exe_ctx)) {
1290             if (install_diagnostics.Diagnostics().size())
1291               err.SetErrorString(install_diagnostics.GetString().c_str());
1292             else
1293               err.SetErrorString("couldn't install checkers, unknown error");
1294 
1295             return err;
1296           }
1297 
1298           process->SetDynamicCheckers(dynamic_checkers);
1299 
1300           if (log)
1301             log->Printf("== [ClangExpressionParser::PrepareForExecution] "
1302                         "Finished installing dynamic checkers ==");
1303         }
1304 
1305         IRDynamicChecks ir_dynamic_checks(*process->GetDynamicCheckers(),
1306                                           function_name.AsCString());
1307 
1308         llvm::Module *module = execution_unit_sp->GetModule();
1309         if (!module || !ir_dynamic_checks.runOnModule(*module)) {
1310           err.SetErrorToGenericError();
1311           err.SetErrorString("Couldn't add dynamic checks to the expression");
1312           return err;
1313         }
1314 
1315         if (custom_passes.LatePasses) {
1316           if (log)
1317             log->Printf("%s - Running Late IR Passes from LanguageRuntime on "
1318                         "expression module '%s'",
1319                         __FUNCTION__, m_expr.FunctionName());
1320 
1321           custom_passes.LatePasses->run(*module);
1322         }
1323       }
1324     }
1325 
1326     if (execution_policy == eExecutionPolicyAlways ||
1327         execution_policy == eExecutionPolicyTopLevel || !can_interpret) {
1328       execution_unit_sp->GetRunnableInfo(err, func_addr, func_end);
1329     }
1330   } else {
1331     execution_unit_sp->GetRunnableInfo(err, func_addr, func_end);
1332   }
1333 
1334   return err;
1335 }
1336 
1337 lldb_private::Status ClangExpressionParser::RunStaticInitializers(
1338     lldb::IRExecutionUnitSP &execution_unit_sp, ExecutionContext &exe_ctx) {
1339   lldb_private::Status err;
1340 
1341   lldbassert(execution_unit_sp.get());
1342   lldbassert(exe_ctx.HasThreadScope());
1343 
1344   if (!execution_unit_sp.get()) {
1345     err.SetErrorString(
1346         "can't run static initializers for a NULL execution unit");
1347     return err;
1348   }
1349 
1350   if (!exe_ctx.HasThreadScope()) {
1351     err.SetErrorString("can't run static initializers without a thread");
1352     return err;
1353   }
1354 
1355   std::vector<lldb::addr_t> static_initializers;
1356 
1357   execution_unit_sp->GetStaticInitializers(static_initializers);
1358 
1359   for (lldb::addr_t static_initializer : static_initializers) {
1360     EvaluateExpressionOptions options;
1361 
1362     lldb::ThreadPlanSP call_static_initializer(new ThreadPlanCallFunction(
1363         exe_ctx.GetThreadRef(), Address(static_initializer), CompilerType(),
1364         llvm::ArrayRef<lldb::addr_t>(), options));
1365 
1366     DiagnosticManager execution_errors;
1367     lldb::ExpressionResults results =
1368         exe_ctx.GetThreadRef().GetProcess()->RunThreadPlan(
1369             exe_ctx, call_static_initializer, options, execution_errors);
1370 
1371     if (results != lldb::eExpressionCompleted) {
1372       err.SetErrorStringWithFormat("couldn't run static initializer: %s",
1373                                    execution_errors.GetString().c_str());
1374       return err;
1375     }
1376   }
1377 
1378   return err;
1379 }
1380