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