1//===-- ClangExpressionParser.cpp -----------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "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/Builtins.h"
14#include "clang/Basic/DiagnosticIDs.h"
15#include "clang/Basic/SourceLocation.h"
16#include "clang/Basic/TargetInfo.h"
17#include "clang/Basic/Version.h"
18#include "clang/CodeGen/CodeGenAction.h"
19#include "clang/CodeGen/ModuleBuilder.h"
20#include "clang/Edit/Commit.h"
21#include "clang/Edit/EditedSource.h"
22#include "clang/Edit/EditsReceiver.h"
23#include "clang/Frontend/CompilerInstance.h"
24#include "clang/Frontend/CompilerInvocation.h"
25#include "clang/Frontend/FrontendActions.h"
26#include "clang/Frontend/FrontendDiagnostic.h"
27#include "clang/Frontend/FrontendPluginRegistry.h"
28#include "clang/Frontend/TextDiagnosticBuffer.h"
29#include "clang/Frontend/TextDiagnosticPrinter.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Parse/ParseAST.h"
32#include "clang/Rewrite/Core/Rewriter.h"
33#include "clang/Rewrite/Frontend/FrontendActions.h"
34#include "clang/Sema/CodeCompleteConsumer.h"
35#include "clang/Sema/Sema.h"
36#include "clang/Sema/SemaConsumer.h"
37
38#include "llvm/ADT/StringRef.h"
39#include "llvm/ExecutionEngine/ExecutionEngine.h"
40#include "llvm/Support/CrashRecoveryContext.h"
41#include "llvm/Support/Debug.h"
42#include "llvm/Support/FileSystem.h"
43#include "llvm/Support/TargetSelect.h"
44
45#include "llvm/IR/LLVMContext.h"
46#include "llvm/IR/Module.h"
47#include "llvm/Support/DynamicLibrary.h"
48#include "llvm/Support/ErrorHandling.h"
49#include "llvm/Support/MemoryBuffer.h"
50#include "llvm/Support/Signals.h"
51#include "llvm/TargetParser/Host.h"
52
53#include "ClangDiagnostic.h"
54#include "ClangExpressionParser.h"
55#include "ClangUserExpression.h"
56
57#include "ASTUtils.h"
58#include "ClangASTSource.h"
59#include "ClangDiagnostic.h"
60#include "ClangExpressionDeclMap.h"
61#include "ClangExpressionHelper.h"
62#include "ClangExpressionParser.h"
63#include "ClangHost.h"
64#include "ClangModulesDeclVendor.h"
65#include "ClangPersistentVariables.h"
66#include "IRDynamicChecks.h"
67#include "IRForTarget.h"
68#include "ModuleDependencyCollector.h"
69
70#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
71#include "lldb/Core/Debugger.h"
72#include "lldb/Core/Disassembler.h"
73#include "lldb/Core/Module.h"
74#include "lldb/Expression/IRExecutionUnit.h"
75#include "lldb/Expression/IRInterpreter.h"
76#include "lldb/Host/File.h"
77#include "lldb/Host/HostInfo.h"
78#include "lldb/Symbol/SymbolVendor.h"
79#include "lldb/Target/ExecutionContext.h"
80#include "lldb/Target/Language.h"
81#include "lldb/Target/Process.h"
82#include "lldb/Target/Target.h"
83#include "lldb/Target/ThreadPlanCallFunction.h"
84#include "lldb/Utility/DataBufferHeap.h"
85#include "lldb/Utility/LLDBAssert.h"
86#include "lldb/Utility/LLDBLog.h"
87#include "lldb/Utility/Log.h"
88#include "lldb/Utility/Stream.h"
89#include "lldb/Utility/StreamString.h"
90#include "lldb/Utility/StringList.h"
91
92#include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h"
93
94#include <cctype>
95#include <memory>
96#include <optional>
97
98using namespace clang;
99using namespace llvm;
100using namespace lldb_private;
101
102//===----------------------------------------------------------------------===//
103// Utility Methods for Clang
104//===----------------------------------------------------------------------===//
105
106class ClangExpressionParser::LLDBPreprocessorCallbacks : public PPCallbacks {
107  ClangModulesDeclVendor &m_decl_vendor;
108  ClangPersistentVariables &m_persistent_vars;
109  clang::SourceManager &m_source_mgr;
110  StreamString m_error_stream;
111  bool m_has_errors = false;
112
113public:
114  LLDBPreprocessorCallbacks(ClangModulesDeclVendor &decl_vendor,
115                            ClangPersistentVariables &persistent_vars,
116                            clang::SourceManager &source_mgr)
117      : m_decl_vendor(decl_vendor), m_persistent_vars(persistent_vars),
118        m_source_mgr(source_mgr) {}
119
120  void moduleImport(SourceLocation import_location, clang::ModuleIdPath path,
121                    const clang::Module * /*null*/) override {
122    // Ignore modules that are imported in the wrapper code as these are not
123    // loaded by the user.
124    llvm::StringRef filename =
125        m_source_mgr.getPresumedLoc(import_location).getFilename();
126    if (filename == ClangExpressionSourceCode::g_prefix_file_name)
127      return;
128
129    SourceModule module;
130
131    for (const std::pair<IdentifierInfo *, SourceLocation> &component : path)
132      module.path.push_back(ConstString(component.first->getName()));
133
134    StreamString error_stream;
135
136    ClangModulesDeclVendor::ModuleVector exported_modules;
137    if (!m_decl_vendor.AddModule(module, &exported_modules, m_error_stream))
138      m_has_errors = true;
139
140    for (ClangModulesDeclVendor::ModuleID module : exported_modules)
141      m_persistent_vars.AddHandLoadedClangModule(module);
142  }
143
144  bool hasErrors() { return m_has_errors; }
145
146  llvm::StringRef getErrorString() { return m_error_stream.GetString(); }
147};
148
149static void AddAllFixIts(ClangDiagnostic *diag, const clang::Diagnostic &Info) {
150  for (auto &fix_it : Info.getFixItHints()) {
151    if (fix_it.isNull())
152      continue;
153    diag->AddFixitHint(fix_it);
154  }
155}
156
157class ClangDiagnosticManagerAdapter : public clang::DiagnosticConsumer {
158public:
159  ClangDiagnosticManagerAdapter(DiagnosticOptions &opts) {
160    DiagnosticOptions *options = new DiagnosticOptions(opts);
161    options->ShowPresumedLoc = true;
162    options->ShowLevel = false;
163    m_os = std::make_shared<llvm::raw_string_ostream>(m_output);
164    m_passthrough =
165        std::make_shared<clang::TextDiagnosticPrinter>(*m_os, options);
166  }
167
168  void ResetManager(DiagnosticManager *manager = nullptr) {
169    m_manager = manager;
170  }
171
172  /// Returns the last ClangDiagnostic message that the DiagnosticManager
173  /// received or a nullptr if the DiagnosticMangager hasn't seen any
174  /// Clang diagnostics yet.
175  ClangDiagnostic *MaybeGetLastClangDiag() const {
176    if (m_manager->Diagnostics().empty())
177      return nullptr;
178    lldb_private::Diagnostic *diag = m_manager->Diagnostics().back().get();
179    ClangDiagnostic *clang_diag = dyn_cast<ClangDiagnostic>(diag);
180    return clang_diag;
181  }
182
183  void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
184                        const clang::Diagnostic &Info) override {
185    if (!m_manager) {
186      // We have no DiagnosticManager before/after parsing but we still could
187      // receive diagnostics (e.g., by the ASTImporter failing to copy decls
188      // when we move the expression result ot the ScratchASTContext). Let's at
189      // least log these diagnostics until we find a way to properly render
190      // them and display them to the user.
191      Log *log = GetLog(LLDBLog::Expressions);
192      if (log) {
193        llvm::SmallVector<char, 32> diag_str;
194        Info.FormatDiagnostic(diag_str);
195        diag_str.push_back('\0');
196        const char *plain_diag = diag_str.data();
197        LLDB_LOG(log, "Received diagnostic outside parsing: {0}", plain_diag);
198      }
199      return;
200    }
201
202    // Update error/warning counters.
203    DiagnosticConsumer::HandleDiagnostic(DiagLevel, Info);
204
205    // Render diagnostic message to m_output.
206    m_output.clear();
207    m_passthrough->HandleDiagnostic(DiagLevel, Info);
208    m_os->flush();
209
210    lldb_private::DiagnosticSeverity severity;
211    bool make_new_diagnostic = true;
212
213    switch (DiagLevel) {
214    case DiagnosticsEngine::Level::Fatal:
215    case DiagnosticsEngine::Level::Error:
216      severity = eDiagnosticSeverityError;
217      break;
218    case DiagnosticsEngine::Level::Warning:
219      severity = eDiagnosticSeverityWarning;
220      break;
221    case DiagnosticsEngine::Level::Remark:
222    case DiagnosticsEngine::Level::Ignored:
223      severity = eDiagnosticSeverityRemark;
224      break;
225    case DiagnosticsEngine::Level::Note:
226      m_manager->AppendMessageToDiagnostic(m_output);
227      make_new_diagnostic = false;
228
229      // 'note:' diagnostics for errors and warnings can also contain Fix-Its.
230      // We add these Fix-Its to the last error diagnostic to make sure
231      // that we later have all Fix-Its related to an 'error' diagnostic when
232      // we apply them to the user expression.
233      auto *clang_diag = MaybeGetLastClangDiag();
234      // If we don't have a previous diagnostic there is nothing to do.
235      // If the previous diagnostic already has its own Fix-Its, assume that
236      // the 'note:' Fix-It is just an alternative way to solve the issue and
237      // ignore these Fix-Its.
238      if (!clang_diag || clang_diag->HasFixIts())
239        break;
240      // Ignore all Fix-Its that are not associated with an error.
241      if (clang_diag->GetSeverity() != eDiagnosticSeverityError)
242        break;
243      AddAllFixIts(clang_diag, Info);
244      break;
245    }
246    if (make_new_diagnostic) {
247      // ClangDiagnostic messages are expected to have no whitespace/newlines
248      // around them.
249      std::string stripped_output =
250          std::string(llvm::StringRef(m_output).trim());
251
252      auto new_diagnostic = std::make_unique<ClangDiagnostic>(
253          stripped_output, severity, Info.getID());
254
255      // Don't store away warning fixits, since the compiler doesn't have
256      // enough context in an expression for the warning to be useful.
257      // FIXME: Should we try to filter out FixIts that apply to our generated
258      // code, and not the user's expression?
259      if (severity == eDiagnosticSeverityError)
260        AddAllFixIts(new_diagnostic.get(), Info);
261
262      m_manager->AddDiagnostic(std::move(new_diagnostic));
263    }
264  }
265
266  void BeginSourceFile(const LangOptions &LO, const Preprocessor *PP) override {
267    m_passthrough->BeginSourceFile(LO, PP);
268  }
269
270  void EndSourceFile() override { m_passthrough->EndSourceFile(); }
271
272private:
273  DiagnosticManager *m_manager = nullptr;
274  std::shared_ptr<clang::TextDiagnosticPrinter> m_passthrough;
275  /// Output stream of m_passthrough.
276  std::shared_ptr<llvm::raw_string_ostream> m_os;
277  /// Output string filled by m_os.
278  std::string m_output;
279};
280
281static void SetupModuleHeaderPaths(CompilerInstance *compiler,
282                                   std::vector<std::string> include_directories,
283                                   lldb::TargetSP target_sp) {
284  Log *log = GetLog(LLDBLog::Expressions);
285
286  HeaderSearchOptions &search_opts = compiler->getHeaderSearchOpts();
287
288  for (const std::string &dir : include_directories) {
289    search_opts.AddPath(dir, frontend::System, false, true);
290    LLDB_LOG(log, "Added user include dir: {0}", dir);
291  }
292
293  llvm::SmallString<128> module_cache;
294  const auto &props = ModuleList::GetGlobalModuleListProperties();
295  props.GetClangModulesCachePath().GetPath(module_cache);
296  search_opts.ModuleCachePath = std::string(module_cache.str());
297  LLDB_LOG(log, "Using module cache path: {0}", module_cache.c_str());
298
299  search_opts.ResourceDir = GetClangResourceDir().GetPath();
300
301  search_opts.ImplicitModuleMaps = true;
302}
303
304/// Iff the given identifier is a C++ keyword, remove it from the
305/// identifier table (i.e., make the token a normal identifier).
306static void RemoveCppKeyword(IdentifierTable &idents, llvm::StringRef token) {
307  // FIXME: 'using' is used by LLDB for local variables, so we can't remove
308  // this keyword without breaking this functionality.
309  if (token == "using")
310    return;
311  // GCC's '__null' is used by LLDB to define NULL/Nil/nil.
312  if (token == "__null")
313    return;
314
315  LangOptions cpp_lang_opts;
316  cpp_lang_opts.CPlusPlus = true;
317  cpp_lang_opts.CPlusPlus11 = true;
318  cpp_lang_opts.CPlusPlus20 = true;
319
320  clang::IdentifierInfo &ii = idents.get(token);
321  // The identifier has to be a C++-exclusive keyword. if not, then there is
322  // nothing to do.
323  if (!ii.isCPlusPlusKeyword(cpp_lang_opts))
324    return;
325  // If the token is already an identifier, then there is nothing to do.
326  if (ii.getTokenID() == clang::tok::identifier)
327    return;
328  // Otherwise the token is a C++ keyword, so turn it back into a normal
329  // identifier.
330  ii.revertTokenIDToIdentifier();
331}
332
333/// Remove all C++ keywords from the given identifier table.
334static void RemoveAllCppKeywords(IdentifierTable &idents) {
335#define KEYWORD(NAME, FLAGS) RemoveCppKeyword(idents, llvm::StringRef(#NAME));
336#include "clang/Basic/TokenKinds.def"
337}
338
339/// Configures Clang diagnostics for the expression parser.
340static void SetupDefaultClangDiagnostics(CompilerInstance &compiler) {
341  // List of Clang warning groups that are not useful when parsing expressions.
342  const std::vector<const char *> groupsToIgnore = {
343      "unused-value",
344      "odr",
345      "unused-getter-return-value",
346  };
347  for (const char *group : groupsToIgnore) {
348    compiler.getDiagnostics().setSeverityForGroup(
349        clang::diag::Flavor::WarningOrError, group,
350        clang::diag::Severity::Ignored, SourceLocation());
351  }
352}
353
354//===----------------------------------------------------------------------===//
355// Implementation of ClangExpressionParser
356//===----------------------------------------------------------------------===//
357
358ClangExpressionParser::ClangExpressionParser(
359    ExecutionContextScope *exe_scope, Expression &expr,
360    bool generate_debug_info, std::vector<std::string> include_directories,
361    std::string filename)
362    : ExpressionParser(exe_scope, expr, generate_debug_info), m_compiler(),
363      m_pp_callbacks(nullptr),
364      m_include_directories(std::move(include_directories)),
365      m_filename(std::move(filename)) {
366  Log *log = GetLog(LLDBLog::Expressions);
367
368  // We can't compile expressions without a target.  So if the exe_scope is
369  // null or doesn't have a target, then we just need to get out of here.  I'll
370  // lldbassert and not make any of the compiler objects since
371  // I can't return errors directly from the constructor.  Further calls will
372  // check if the compiler was made and
373  // bag out if it wasn't.
374
375  if (!exe_scope) {
376    lldbassert(exe_scope &&
377               "Can't make an expression parser with a null scope.");
378    return;
379  }
380
381  lldb::TargetSP target_sp;
382  target_sp = exe_scope->CalculateTarget();
383  if (!target_sp) {
384    lldbassert(target_sp.get() &&
385               "Can't make an expression parser with a null target.");
386    return;
387  }
388
389  // 1. Create a new compiler instance.
390  m_compiler = std::make_unique<CompilerInstance>();
391
392  // Make sure clang uses the same VFS as LLDB.
393  m_compiler->createFileManager(FileSystem::Instance().GetVirtualFileSystem());
394
395  lldb::LanguageType frame_lang =
396      expr.Language(); // defaults to lldb::eLanguageTypeUnknown
397
398  std::string abi;
399  ArchSpec target_arch;
400  target_arch = target_sp->GetArchitecture();
401
402  const auto target_machine = target_arch.GetMachine();
403
404  // If the expression is being evaluated in the context of an existing stack
405  // frame, we introspect to see if the language runtime is available.
406
407  lldb::StackFrameSP frame_sp = exe_scope->CalculateStackFrame();
408  lldb::ProcessSP process_sp = exe_scope->CalculateProcess();
409
410  // Make sure the user hasn't provided a preferred execution language with
411  // `expression --language X -- ...`
412  if (frame_sp && frame_lang == lldb::eLanguageTypeUnknown)
413    frame_lang = frame_sp->GetLanguage();
414
415  if (process_sp && frame_lang != lldb::eLanguageTypeUnknown) {
416    LLDB_LOGF(log, "Frame has language of type %s",
417              Language::GetNameForLanguageType(frame_lang));
418  }
419
420  // 2. Configure the compiler with a set of default options that are
421  // appropriate for most situations.
422  if (target_arch.IsValid()) {
423    std::string triple = target_arch.GetTriple().str();
424    m_compiler->getTargetOpts().Triple = triple;
425    LLDB_LOGF(log, "Using %s as the target triple",
426              m_compiler->getTargetOpts().Triple.c_str());
427  } else {
428    // If we get here we don't have a valid target and just have to guess.
429    // Sometimes this will be ok to just use the host target triple (when we
430    // evaluate say "2+3", but other expressions like breakpoint conditions and
431    // other things that _are_ target specific really shouldn't just be using
432    // the host triple. In such a case the language runtime should expose an
433    // overridden options set (3), below.
434    m_compiler->getTargetOpts().Triple = llvm::sys::getDefaultTargetTriple();
435    LLDB_LOGF(log, "Using default target triple of %s",
436              m_compiler->getTargetOpts().Triple.c_str());
437  }
438  // Now add some special fixes for known architectures: Any arm32 iOS
439  // environment, but not on arm64
440  if (m_compiler->getTargetOpts().Triple.find("arm64") == std::string::npos &&
441      m_compiler->getTargetOpts().Triple.find("arm") != std::string::npos &&
442      m_compiler->getTargetOpts().Triple.find("ios") != std::string::npos) {
443    m_compiler->getTargetOpts().ABI = "apcs-gnu";
444  }
445  // Supported subsets of x86
446  if (target_machine == llvm::Triple::x86 ||
447      target_machine == llvm::Triple::x86_64) {
448    m_compiler->getTargetOpts().Features.push_back("+sse");
449    m_compiler->getTargetOpts().Features.push_back("+sse2");
450  }
451
452  // Set the target CPU to generate code for. This will be empty for any CPU
453  // that doesn't really need to make a special
454  // CPU string.
455  m_compiler->getTargetOpts().CPU = target_arch.GetClangTargetCPU();
456
457  // Set the target ABI
458  abi = GetClangTargetABI(target_arch);
459  if (!abi.empty())
460    m_compiler->getTargetOpts().ABI = abi;
461
462  // 3. Create and install the target on the compiler.
463  m_compiler->createDiagnostics();
464  // Limit the number of error diagnostics we emit.
465  // A value of 0 means no limit for both LLDB and Clang.
466  m_compiler->getDiagnostics().setErrorLimit(target_sp->GetExprErrorLimit());
467
468  auto target_info = TargetInfo::CreateTargetInfo(
469      m_compiler->getDiagnostics(), m_compiler->getInvocation().TargetOpts);
470  if (log) {
471    LLDB_LOGF(log, "Target datalayout string: '%s'",
472              target_info->getDataLayoutString());
473    LLDB_LOGF(log, "Target ABI: '%s'", target_info->getABI().str().c_str());
474    LLDB_LOGF(log, "Target vector alignment: %d",
475              target_info->getMaxVectorAlign());
476  }
477  m_compiler->setTarget(target_info);
478
479  assert(m_compiler->hasTarget());
480
481  // 4. Set language options.
482  lldb::LanguageType language = expr.Language();
483  LangOptions &lang_opts = m_compiler->getLangOpts();
484
485  switch (language) {
486  case lldb::eLanguageTypeC:
487  case lldb::eLanguageTypeC89:
488  case lldb::eLanguageTypeC99:
489  case lldb::eLanguageTypeC11:
490    // FIXME: the following language option is a temporary workaround,
491    // to "ask for C, get C++."
492    // For now, the expression parser must use C++ anytime the language is a C
493    // family language, because the expression parser uses features of C++ to
494    // capture values.
495    lang_opts.CPlusPlus = true;
496    break;
497  case lldb::eLanguageTypeObjC:
498    lang_opts.ObjC = true;
499    // FIXME: the following language option is a temporary workaround,
500    // to "ask for ObjC, get ObjC++" (see comment above).
501    lang_opts.CPlusPlus = true;
502
503    // Clang now sets as default C++14 as the default standard (with
504    // GNU extensions), so we do the same here to avoid mismatches that
505    // cause compiler error when evaluating expressions (e.g. nullptr not found
506    // as it's a C++11 feature). Currently lldb evaluates C++14 as C++11 (see
507    // two lines below) so we decide to be consistent with that, but this could
508    // be re-evaluated in the future.
509    lang_opts.CPlusPlus11 = true;
510    break;
511  case lldb::eLanguageTypeC_plus_plus_20:
512    lang_opts.CPlusPlus20 = true;
513    [[fallthrough]];
514  case lldb::eLanguageTypeC_plus_plus_17:
515    // FIXME: add a separate case for CPlusPlus14. Currently folded into C++17
516    // because C++14 is the default standard for Clang but enabling CPlusPlus14
517    // expression evaluatino doesn't pass the test-suite cleanly.
518    lang_opts.CPlusPlus14 = true;
519    lang_opts.CPlusPlus17 = true;
520    [[fallthrough]];
521  case lldb::eLanguageTypeC_plus_plus:
522  case lldb::eLanguageTypeC_plus_plus_11:
523  case lldb::eLanguageTypeC_plus_plus_14:
524    lang_opts.CPlusPlus11 = true;
525    m_compiler->getHeaderSearchOpts().UseLibcxx = true;
526    [[fallthrough]];
527  case lldb::eLanguageTypeC_plus_plus_03:
528    lang_opts.CPlusPlus = true;
529    if (process_sp)
530      lang_opts.ObjC =
531          process_sp->GetLanguageRuntime(lldb::eLanguageTypeObjC) != nullptr;
532    break;
533  case lldb::eLanguageTypeObjC_plus_plus:
534  case lldb::eLanguageTypeUnknown:
535  default:
536    lang_opts.ObjC = true;
537    lang_opts.CPlusPlus = true;
538    lang_opts.CPlusPlus11 = true;
539    m_compiler->getHeaderSearchOpts().UseLibcxx = true;
540    break;
541  }
542
543  lang_opts.Bool = true;
544  lang_opts.WChar = true;
545  lang_opts.Blocks = true;
546  lang_opts.DebuggerSupport =
547      true; // Features specifically for debugger clients
548  if (expr.DesiredResultType() == Expression::eResultTypeId)
549    lang_opts.DebuggerCastResultToId = true;
550
551  lang_opts.CharIsSigned = ArchSpec(m_compiler->getTargetOpts().Triple.c_str())
552                               .CharIsSignedByDefault();
553
554  // Spell checking is a nice feature, but it ends up completing a lot of types
555  // that we didn't strictly speaking need to complete. As a result, we spend a
556  // long time parsing and importing debug information.
557  lang_opts.SpellChecking = false;
558
559  auto *clang_expr = dyn_cast<ClangUserExpression>(&m_expr);
560  if (clang_expr && clang_expr->DidImportCxxModules()) {
561    LLDB_LOG(log, "Adding lang options for importing C++ modules");
562
563    lang_opts.Modules = true;
564    // We want to implicitly build modules.
565    lang_opts.ImplicitModules = true;
566    // To automatically import all submodules when we import 'std'.
567    lang_opts.ModulesLocalVisibility = false;
568
569    // We use the @import statements, so we need this:
570    // FIXME: We could use the modules-ts, but that currently doesn't work.
571    lang_opts.ObjC = true;
572
573    // Options we need to parse libc++ code successfully.
574    // FIXME: We should ask the driver for the appropriate default flags.
575    lang_opts.GNUMode = true;
576    lang_opts.GNUKeywords = true;
577    lang_opts.CPlusPlus11 = true;
578    lang_opts.BuiltinHeadersInSystemModules = true;
579
580    // The Darwin libc expects this macro to be set.
581    lang_opts.GNUCVersion = 40201;
582
583    SetupModuleHeaderPaths(m_compiler.get(), m_include_directories,
584                           target_sp);
585  }
586
587  if (process_sp && lang_opts.ObjC) {
588    if (auto *runtime = ObjCLanguageRuntime::Get(*process_sp)) {
589      switch (runtime->GetRuntimeVersion()) {
590      case ObjCLanguageRuntime::ObjCRuntimeVersions::eAppleObjC_V2:
591        lang_opts.ObjCRuntime.set(ObjCRuntime::MacOSX, VersionTuple(10, 7));
592        break;
593      case ObjCLanguageRuntime::ObjCRuntimeVersions::eObjC_VersionUnknown:
594      case ObjCLanguageRuntime::ObjCRuntimeVersions::eAppleObjC_V1:
595        lang_opts.ObjCRuntime.set(ObjCRuntime::FragileMacOSX,
596                                  VersionTuple(10, 7));
597        break;
598      case ObjCLanguageRuntime::ObjCRuntimeVersions::eGNUstep_libobjc2:
599        lang_opts.ObjCRuntime.set(ObjCRuntime::GNUstep, VersionTuple(2, 0));
600        break;
601      }
602
603      if (runtime->HasNewLiteralsAndIndexing())
604        lang_opts.DebuggerObjCLiteral = true;
605    }
606  }
607
608  lang_opts.ThreadsafeStatics = false;
609  lang_opts.AccessControl = false; // Debuggers get universal access
610  lang_opts.DollarIdents = true;   // $ indicates a persistent variable name
611  // We enable all builtin functions beside the builtins from libc/libm (e.g.
612  // 'fopen'). Those libc functions are already correctly handled by LLDB, and
613  // additionally enabling them as expandable builtins is breaking Clang.
614  lang_opts.NoBuiltin = true;
615
616  // Set CodeGen options
617  m_compiler->getCodeGenOpts().EmitDeclMetadata = true;
618  m_compiler->getCodeGenOpts().InstrumentFunctions = false;
619  m_compiler->getCodeGenOpts().setFramePointer(
620                                    CodeGenOptions::FramePointerKind::All);
621  if (generate_debug_info)
622    m_compiler->getCodeGenOpts().setDebugInfo(codegenoptions::FullDebugInfo);
623  else
624    m_compiler->getCodeGenOpts().setDebugInfo(codegenoptions::NoDebugInfo);
625
626  // Disable some warnings.
627  SetupDefaultClangDiagnostics(*m_compiler);
628
629  // Inform the target of the language options
630  //
631  // FIXME: We shouldn't need to do this, the target should be immutable once
632  // created. This complexity should be lifted elsewhere.
633  m_compiler->getTarget().adjust(m_compiler->getDiagnostics(),
634		                 m_compiler->getLangOpts());
635
636  // 5. Set up the diagnostic buffer for reporting errors
637
638  auto diag_mgr = new ClangDiagnosticManagerAdapter(
639      m_compiler->getDiagnostics().getDiagnosticOptions());
640  m_compiler->getDiagnostics().setClient(diag_mgr);
641
642  // 6. Set up the source management objects inside the compiler
643  m_compiler->createFileManager();
644  if (!m_compiler->hasSourceManager())
645    m_compiler->createSourceManager(m_compiler->getFileManager());
646  m_compiler->createPreprocessor(TU_Complete);
647
648  switch (language) {
649  case lldb::eLanguageTypeC:
650  case lldb::eLanguageTypeC89:
651  case lldb::eLanguageTypeC99:
652  case lldb::eLanguageTypeC11:
653  case lldb::eLanguageTypeObjC:
654    // This is not a C++ expression but we enabled C++ as explained above.
655    // Remove all C++ keywords from the PP so that the user can still use
656    // variables that have C++ keywords as names (e.g. 'int template;').
657    RemoveAllCppKeywords(m_compiler->getPreprocessor().getIdentifierTable());
658    break;
659  default:
660    break;
661  }
662
663  if (auto *clang_persistent_vars = llvm::cast<ClangPersistentVariables>(
664          target_sp->GetPersistentExpressionStateForLanguage(
665              lldb::eLanguageTypeC))) {
666    if (std::shared_ptr<ClangModulesDeclVendor> decl_vendor =
667            clang_persistent_vars->GetClangModulesDeclVendor()) {
668      std::unique_ptr<PPCallbacks> pp_callbacks(
669          new LLDBPreprocessorCallbacks(*decl_vendor, *clang_persistent_vars,
670                                        m_compiler->getSourceManager()));
671      m_pp_callbacks =
672          static_cast<LLDBPreprocessorCallbacks *>(pp_callbacks.get());
673      m_compiler->getPreprocessor().addPPCallbacks(std::move(pp_callbacks));
674    }
675  }
676
677  // 7. Most of this we get from the CompilerInstance, but we also want to give
678  // the context an ExternalASTSource.
679
680  auto &PP = m_compiler->getPreprocessor();
681  auto &builtin_context = PP.getBuiltinInfo();
682  builtin_context.initializeBuiltins(PP.getIdentifierTable(),
683                                     m_compiler->getLangOpts());
684
685  m_compiler->createASTContext();
686  clang::ASTContext &ast_context = m_compiler->getASTContext();
687
688  m_ast_context = std::make_shared<TypeSystemClang>(
689      "Expression ASTContext for '" + m_filename + "'", ast_context);
690
691  std::string module_name("$__lldb_module");
692
693  m_llvm_context = std::make_unique<LLVMContext>();
694  m_code_generator.reset(CreateLLVMCodeGen(
695      m_compiler->getDiagnostics(), module_name,
696      &m_compiler->getVirtualFileSystem(), m_compiler->getHeaderSearchOpts(),
697      m_compiler->getPreprocessorOpts(), m_compiler->getCodeGenOpts(),
698      *m_llvm_context));
699}
700
701ClangExpressionParser::~ClangExpressionParser() = default;
702
703namespace {
704
705/// \class CodeComplete
706///
707/// A code completion consumer for the clang Sema that is responsible for
708/// creating the completion suggestions when a user requests completion
709/// of an incomplete `expr` invocation.
710class CodeComplete : public CodeCompleteConsumer {
711  CodeCompletionTUInfo m_info;
712
713  std::string m_expr;
714  unsigned m_position = 0;
715  /// The printing policy we use when printing declarations for our completion
716  /// descriptions.
717  clang::PrintingPolicy m_desc_policy;
718
719  struct CompletionWithPriority {
720    CompletionResult::Completion completion;
721    /// See CodeCompletionResult::Priority;
722    unsigned Priority;
723
724    /// Establishes a deterministic order in a list of CompletionWithPriority.
725    /// The order returned here is the order in which the completions are
726    /// displayed to the user.
727    bool operator<(const CompletionWithPriority &o) const {
728      // High priority results should come first.
729      if (Priority != o.Priority)
730        return Priority > o.Priority;
731
732      // Identical priority, so just make sure it's a deterministic order.
733      return completion.GetUniqueKey() < o.completion.GetUniqueKey();
734    }
735  };
736
737  /// The stored completions.
738  /// Warning: These are in a non-deterministic order until they are sorted
739  /// and returned back to the caller.
740  std::vector<CompletionWithPriority> m_completions;
741
742  /// Returns true if the given character can be used in an identifier.
743  /// This also returns true for numbers because for completion we usually
744  /// just iterate backwards over iterators.
745  ///
746  /// Note: lldb uses '$' in its internal identifiers, so we also allow this.
747  static bool IsIdChar(char c) {
748    return c == '_' || std::isalnum(c) || c == '$';
749  }
750
751  /// Returns true if the given character is used to separate arguments
752  /// in the command line of lldb.
753  static bool IsTokenSeparator(char c) { return c == ' ' || c == '\t'; }
754
755  /// Drops all tokens in front of the expression that are unrelated for
756  /// the completion of the cmd line. 'unrelated' means here that the token
757  /// is not interested for the lldb completion API result.
758  StringRef dropUnrelatedFrontTokens(StringRef cmd) const {
759    if (cmd.empty())
760      return cmd;
761
762    // If we are at the start of a word, then all tokens are unrelated to
763    // the current completion logic.
764    if (IsTokenSeparator(cmd.back()))
765      return StringRef();
766
767    // Remove all previous tokens from the string as they are unrelated
768    // to completing the current token.
769    StringRef to_remove = cmd;
770    while (!to_remove.empty() && !IsTokenSeparator(to_remove.back())) {
771      to_remove = to_remove.drop_back();
772    }
773    cmd = cmd.drop_front(to_remove.size());
774
775    return cmd;
776  }
777
778  /// Removes the last identifier token from the given cmd line.
779  StringRef removeLastToken(StringRef cmd) const {
780    while (!cmd.empty() && IsIdChar(cmd.back())) {
781      cmd = cmd.drop_back();
782    }
783    return cmd;
784  }
785
786  /// Attempts to merge the given completion from the given position into the
787  /// existing command. Returns the completion string that can be returned to
788  /// the lldb completion API.
789  std::string mergeCompletion(StringRef existing, unsigned pos,
790                              StringRef completion) const {
791    StringRef existing_command = existing.substr(0, pos);
792    // We rewrite the last token with the completion, so let's drop that
793    // token from the command.
794    existing_command = removeLastToken(existing_command);
795    // We also should remove all previous tokens from the command as they
796    // would otherwise be added to the completion that already has the
797    // completion.
798    existing_command = dropUnrelatedFrontTokens(existing_command);
799    return existing_command.str() + completion.str();
800  }
801
802public:
803  /// Constructs a CodeComplete consumer that can be attached to a Sema.
804  ///
805  /// \param[out] expr
806  ///    The whole expression string that we are currently parsing. This
807  ///    string needs to be equal to the input the user typed, and NOT the
808  ///    final code that Clang is parsing.
809  /// \param[out] position
810  ///    The character position of the user cursor in the `expr` parameter.
811  ///
812  CodeComplete(clang::LangOptions ops, std::string expr, unsigned position)
813      : CodeCompleteConsumer(CodeCompleteOptions()),
814        m_info(std::make_shared<GlobalCodeCompletionAllocator>()), m_expr(expr),
815        m_position(position), m_desc_policy(ops) {
816
817    // Ensure that the printing policy is producing a description that is as
818    // short as possible.
819    m_desc_policy.SuppressScope = true;
820    m_desc_policy.SuppressTagKeyword = true;
821    m_desc_policy.FullyQualifiedName = false;
822    m_desc_policy.TerseOutput = true;
823    m_desc_policy.IncludeNewlines = false;
824    m_desc_policy.UseVoidForZeroParams = false;
825    m_desc_policy.Bool = true;
826  }
827
828  /// \name Code-completion filtering
829  /// Check if the result should be filtered out.
830  bool isResultFilteredOut(StringRef Filter,
831                           CodeCompletionResult Result) override {
832    // This code is mostly copied from CodeCompleteConsumer.
833    switch (Result.Kind) {
834    case CodeCompletionResult::RK_Declaration:
835      return !(
836          Result.Declaration->getIdentifier() &&
837          Result.Declaration->getIdentifier()->getName().starts_with(Filter));
838    case CodeCompletionResult::RK_Keyword:
839      return !StringRef(Result.Keyword).starts_with(Filter);
840    case CodeCompletionResult::RK_Macro:
841      return !Result.Macro->getName().starts_with(Filter);
842    case CodeCompletionResult::RK_Pattern:
843      return !StringRef(Result.Pattern->getAsString()).starts_with(Filter);
844    }
845    // If we trigger this assert or the above switch yields a warning, then
846    // CodeCompletionResult has been enhanced with more kinds of completion
847    // results. Expand the switch above in this case.
848    assert(false && "Unknown completion result type?");
849    // If we reach this, then we should just ignore whatever kind of unknown
850    // result we got back. We probably can't turn it into any kind of useful
851    // completion suggestion with the existing code.
852    return true;
853  }
854
855private:
856  /// Generate the completion strings for the given CodeCompletionResult.
857  /// Note that this function has to process results that could come in
858  /// non-deterministic order, so this function should have no side effects.
859  /// To make this easier to enforce, this function and all its parameters
860  /// should always be const-qualified.
861  /// \return Returns std::nullopt if no completion should be provided for the
862  ///         given CodeCompletionResult.
863  std::optional<CompletionWithPriority>
864  getCompletionForResult(const CodeCompletionResult &R) const {
865    std::string ToInsert;
866    std::string Description;
867    // Handle the different completion kinds that come from the Sema.
868    switch (R.Kind) {
869    case CodeCompletionResult::RK_Declaration: {
870      const NamedDecl *D = R.Declaration;
871      ToInsert = R.Declaration->getNameAsString();
872      // If we have a function decl that has no arguments we want to
873      // complete the empty parantheses for the user. If the function has
874      // arguments, we at least complete the opening bracket.
875      if (const FunctionDecl *F = dyn_cast<FunctionDecl>(D)) {
876        if (F->getNumParams() == 0)
877          ToInsert += "()";
878        else
879          ToInsert += "(";
880        raw_string_ostream OS(Description);
881        F->print(OS, m_desc_policy, false);
882        OS.flush();
883      } else if (const VarDecl *V = dyn_cast<VarDecl>(D)) {
884        Description = V->getType().getAsString(m_desc_policy);
885      } else if (const FieldDecl *F = dyn_cast<FieldDecl>(D)) {
886        Description = F->getType().getAsString(m_desc_policy);
887      } else if (const NamespaceDecl *N = dyn_cast<NamespaceDecl>(D)) {
888        // If we try to complete a namespace, then we can directly append
889        // the '::'.
890        if (!N->isAnonymousNamespace())
891          ToInsert += "::";
892      }
893      break;
894    }
895    case CodeCompletionResult::RK_Keyword:
896      ToInsert = R.Keyword;
897      break;
898    case CodeCompletionResult::RK_Macro:
899      ToInsert = R.Macro->getName().str();
900      break;
901    case CodeCompletionResult::RK_Pattern:
902      ToInsert = R.Pattern->getTypedText();
903      break;
904    }
905    // We also filter some internal lldb identifiers here. The user
906    // shouldn't see these.
907    if (llvm::StringRef(ToInsert).starts_with("$__lldb_"))
908      return std::nullopt;
909    if (ToInsert.empty())
910      return std::nullopt;
911    // Merge the suggested Token into the existing command line to comply
912    // with the kind of result the lldb API expects.
913    std::string CompletionSuggestion =
914        mergeCompletion(m_expr, m_position, ToInsert);
915
916    CompletionResult::Completion completion(CompletionSuggestion, Description,
917                                            CompletionMode::Normal);
918    return {{completion, R.Priority}};
919  }
920
921public:
922  /// Adds the completions to the given CompletionRequest.
923  void GetCompletions(CompletionRequest &request) {
924    // Bring m_completions into a deterministic order and pass it on to the
925    // CompletionRequest.
926    llvm::sort(m_completions);
927
928    for (const CompletionWithPriority &C : m_completions)
929      request.AddCompletion(C.completion.GetCompletion(),
930                            C.completion.GetDescription(),
931                            C.completion.GetMode());
932  }
933
934  /// \name Code-completion callbacks
935  /// Process the finalized code-completion results.
936  void ProcessCodeCompleteResults(Sema &SemaRef, CodeCompletionContext Context,
937                                  CodeCompletionResult *Results,
938                                  unsigned NumResults) override {
939
940    // The Sema put the incomplete token we try to complete in here during
941    // lexing, so we need to retrieve it here to know what we are completing.
942    StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
943
944    // Iterate over all the results. Filter out results we don't want and
945    // process the rest.
946    for (unsigned I = 0; I != NumResults; ++I) {
947      // Filter the results with the information from the Sema.
948      if (!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
949        continue;
950
951      CodeCompletionResult &R = Results[I];
952      std::optional<CompletionWithPriority> CompletionAndPriority =
953          getCompletionForResult(R);
954      if (!CompletionAndPriority)
955        continue;
956      m_completions.push_back(*CompletionAndPriority);
957    }
958  }
959
960  /// \param S the semantic-analyzer object for which code-completion is being
961  /// done.
962  ///
963  /// \param CurrentArg the index of the current argument.
964  ///
965  /// \param Candidates an array of overload candidates.
966  ///
967  /// \param NumCandidates the number of overload candidates
968  void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
969                                 OverloadCandidate *Candidates,
970                                 unsigned NumCandidates,
971                                 SourceLocation OpenParLoc,
972                                 bool Braced) override {
973    // At the moment we don't filter out any overloaded candidates.
974  }
975
976  CodeCompletionAllocator &getAllocator() override {
977    return m_info.getAllocator();
978  }
979
980  CodeCompletionTUInfo &getCodeCompletionTUInfo() override { return m_info; }
981};
982} // namespace
983
984bool ClangExpressionParser::Complete(CompletionRequest &request, unsigned line,
985                                     unsigned pos, unsigned typed_pos) {
986  DiagnosticManager mgr;
987  // We need the raw user expression here because that's what the CodeComplete
988  // class uses to provide completion suggestions.
989  // However, the `Text` method only gives us the transformed expression here.
990  // To actually get the raw user input here, we have to cast our expression to
991  // the LLVMUserExpression which exposes the right API. This should never fail
992  // as we always have a ClangUserExpression whenever we call this.
993  ClangUserExpression *llvm_expr = cast<ClangUserExpression>(&m_expr);
994  CodeComplete CC(m_compiler->getLangOpts(), llvm_expr->GetUserText(),
995                  typed_pos);
996  // We don't need a code generator for parsing.
997  m_code_generator.reset();
998  // Start parsing the expression with our custom code completion consumer.
999  ParseInternal(mgr, &CC, line, pos);
1000  CC.GetCompletions(request);
1001  return true;
1002}
1003
1004unsigned ClangExpressionParser::Parse(DiagnosticManager &diagnostic_manager) {
1005  return ParseInternal(diagnostic_manager);
1006}
1007
1008unsigned
1009ClangExpressionParser::ParseInternal(DiagnosticManager &diagnostic_manager,
1010                                     CodeCompleteConsumer *completion_consumer,
1011                                     unsigned completion_line,
1012                                     unsigned completion_column) {
1013  ClangDiagnosticManagerAdapter *adapter =
1014      static_cast<ClangDiagnosticManagerAdapter *>(
1015          m_compiler->getDiagnostics().getClient());
1016
1017  adapter->ResetManager(&diagnostic_manager);
1018
1019  const char *expr_text = m_expr.Text();
1020
1021  clang::SourceManager &source_mgr = m_compiler->getSourceManager();
1022  bool created_main_file = false;
1023
1024  // Clang wants to do completion on a real file known by Clang's file manager,
1025  // so we have to create one to make this work.
1026  // TODO: We probably could also simulate to Clang's file manager that there
1027  // is a real file that contains our code.
1028  bool should_create_file = completion_consumer != nullptr;
1029
1030  // We also want a real file on disk if we generate full debug info.
1031  should_create_file |= m_compiler->getCodeGenOpts().getDebugInfo() ==
1032                        codegenoptions::FullDebugInfo;
1033
1034  if (should_create_file) {
1035    int temp_fd = -1;
1036    llvm::SmallString<128> result_path;
1037    if (FileSpec tmpdir_file_spec = HostInfo::GetProcessTempDir()) {
1038      tmpdir_file_spec.AppendPathComponent("lldb-%%%%%%.expr");
1039      std::string temp_source_path = tmpdir_file_spec.GetPath();
1040      llvm::sys::fs::createUniqueFile(temp_source_path, temp_fd, result_path);
1041    } else {
1042      llvm::sys::fs::createTemporaryFile("lldb", "expr", temp_fd, result_path);
1043    }
1044
1045    if (temp_fd != -1) {
1046      lldb_private::NativeFile file(temp_fd, File::eOpenOptionWriteOnly, true);
1047      const size_t expr_text_len = strlen(expr_text);
1048      size_t bytes_written = expr_text_len;
1049      if (file.Write(expr_text, bytes_written).Success()) {
1050        if (bytes_written == expr_text_len) {
1051          file.Close();
1052          if (auto fileEntry = m_compiler->getFileManager().getOptionalFileRef(
1053                  result_path)) {
1054            source_mgr.setMainFileID(source_mgr.createFileID(
1055                *fileEntry,
1056                SourceLocation(), SrcMgr::C_User));
1057            created_main_file = true;
1058          }
1059        }
1060      }
1061    }
1062  }
1063
1064  if (!created_main_file) {
1065    std::unique_ptr<MemoryBuffer> memory_buffer =
1066        MemoryBuffer::getMemBufferCopy(expr_text, m_filename);
1067    source_mgr.setMainFileID(source_mgr.createFileID(std::move(memory_buffer)));
1068  }
1069
1070  adapter->BeginSourceFile(m_compiler->getLangOpts(),
1071                           &m_compiler->getPreprocessor());
1072
1073  ClangExpressionHelper *type_system_helper =
1074      dyn_cast<ClangExpressionHelper>(m_expr.GetTypeSystemHelper());
1075
1076  // If we want to parse for code completion, we need to attach our code
1077  // completion consumer to the Sema and specify a completion position.
1078  // While parsing the Sema will call this consumer with the provided
1079  // completion suggestions.
1080  if (completion_consumer) {
1081    auto main_file =
1082        source_mgr.getFileEntryRefForID(source_mgr.getMainFileID());
1083    auto &PP = m_compiler->getPreprocessor();
1084    // Lines and columns start at 1 in Clang, but code completion positions are
1085    // indexed from 0, so we need to add 1 to the line and column here.
1086    ++completion_line;
1087    ++completion_column;
1088    PP.SetCodeCompletionPoint(*main_file, completion_line, completion_column);
1089  }
1090
1091  ASTConsumer *ast_transformer =
1092      type_system_helper->ASTTransformer(m_code_generator.get());
1093
1094  std::unique_ptr<clang::ASTConsumer> Consumer;
1095  if (ast_transformer) {
1096    Consumer = std::make_unique<ASTConsumerForwarder>(ast_transformer);
1097  } else if (m_code_generator) {
1098    Consumer = std::make_unique<ASTConsumerForwarder>(m_code_generator.get());
1099  } else {
1100    Consumer = std::make_unique<ASTConsumer>();
1101  }
1102
1103  clang::ASTContext &ast_context = m_compiler->getASTContext();
1104
1105  m_compiler->setSema(new Sema(m_compiler->getPreprocessor(), ast_context,
1106                               *Consumer, TU_Complete, completion_consumer));
1107  m_compiler->setASTConsumer(std::move(Consumer));
1108
1109  if (ast_context.getLangOpts().Modules) {
1110    m_compiler->createASTReader();
1111    m_ast_context->setSema(&m_compiler->getSema());
1112  }
1113
1114  ClangExpressionDeclMap *decl_map = type_system_helper->DeclMap();
1115  if (decl_map) {
1116    decl_map->InstallCodeGenerator(&m_compiler->getASTConsumer());
1117    decl_map->InstallDiagnosticManager(diagnostic_manager);
1118
1119    clang::ExternalASTSource *ast_source = decl_map->CreateProxy();
1120
1121    if (ast_context.getExternalSource()) {
1122      auto module_wrapper =
1123          new ExternalASTSourceWrapper(ast_context.getExternalSource());
1124
1125      auto ast_source_wrapper = new ExternalASTSourceWrapper(ast_source);
1126
1127      auto multiplexer =
1128          new SemaSourceWithPriorities(*module_wrapper, *ast_source_wrapper);
1129      IntrusiveRefCntPtr<ExternalASTSource> Source(multiplexer);
1130      ast_context.setExternalSource(Source);
1131    } else {
1132      ast_context.setExternalSource(ast_source);
1133    }
1134    decl_map->InstallASTContext(*m_ast_context);
1135  }
1136
1137  // Check that the ASTReader is properly attached to ASTContext and Sema.
1138  if (ast_context.getLangOpts().Modules) {
1139    assert(m_compiler->getASTContext().getExternalSource() &&
1140           "ASTContext doesn't know about the ASTReader?");
1141    assert(m_compiler->getSema().getExternalSource() &&
1142           "Sema doesn't know about the ASTReader?");
1143  }
1144
1145  {
1146    llvm::CrashRecoveryContextCleanupRegistrar<Sema> CleanupSema(
1147        &m_compiler->getSema());
1148    ParseAST(m_compiler->getSema(), false, false);
1149  }
1150
1151  // Make sure we have no pointer to the Sema we are about to destroy.
1152  if (ast_context.getLangOpts().Modules)
1153    m_ast_context->setSema(nullptr);
1154  // Destroy the Sema. This is necessary because we want to emulate the
1155  // original behavior of ParseAST (which also destroys the Sema after parsing).
1156  m_compiler->setSema(nullptr);
1157
1158  adapter->EndSourceFile();
1159
1160  unsigned num_errors = adapter->getNumErrors();
1161
1162  if (m_pp_callbacks && m_pp_callbacks->hasErrors()) {
1163    num_errors++;
1164    diagnostic_manager.PutString(eDiagnosticSeverityError,
1165                                 "while importing modules:");
1166    diagnostic_manager.AppendMessageToDiagnostic(
1167        m_pp_callbacks->getErrorString());
1168  }
1169
1170  if (!num_errors) {
1171    type_system_helper->CommitPersistentDecls();
1172  }
1173
1174  adapter->ResetManager();
1175
1176  return num_errors;
1177}
1178
1179std::string
1180ClangExpressionParser::GetClangTargetABI(const ArchSpec &target_arch) {
1181  std::string abi;
1182
1183  if (target_arch.IsMIPS()) {
1184    switch (target_arch.GetFlags() & ArchSpec::eMIPSABI_mask) {
1185    case ArchSpec::eMIPSABI_N64:
1186      abi = "n64";
1187      break;
1188    case ArchSpec::eMIPSABI_N32:
1189      abi = "n32";
1190      break;
1191    case ArchSpec::eMIPSABI_O32:
1192      abi = "o32";
1193      break;
1194    default:
1195      break;
1196    }
1197  }
1198  return abi;
1199}
1200
1201/// Applies the given Fix-It hint to the given commit.
1202static void ApplyFixIt(const FixItHint &fixit, clang::edit::Commit &commit) {
1203  // This is cobbed from clang::Rewrite::FixItRewriter.
1204  if (fixit.CodeToInsert.empty()) {
1205    if (fixit.InsertFromRange.isValid()) {
1206      commit.insertFromRange(fixit.RemoveRange.getBegin(),
1207                             fixit.InsertFromRange, /*afterToken=*/false,
1208                             fixit.BeforePreviousInsertions);
1209      return;
1210    }
1211    commit.remove(fixit.RemoveRange);
1212    return;
1213  }
1214  if (fixit.RemoveRange.isTokenRange() ||
1215      fixit.RemoveRange.getBegin() != fixit.RemoveRange.getEnd()) {
1216    commit.replace(fixit.RemoveRange, fixit.CodeToInsert);
1217    return;
1218  }
1219  commit.insert(fixit.RemoveRange.getBegin(), fixit.CodeToInsert,
1220                /*afterToken=*/false, fixit.BeforePreviousInsertions);
1221}
1222
1223bool ClangExpressionParser::RewriteExpression(
1224    DiagnosticManager &diagnostic_manager) {
1225  clang::SourceManager &source_manager = m_compiler->getSourceManager();
1226  clang::edit::EditedSource editor(source_manager, m_compiler->getLangOpts(),
1227                                   nullptr);
1228  clang::edit::Commit commit(editor);
1229  clang::Rewriter rewriter(source_manager, m_compiler->getLangOpts());
1230
1231  class RewritesReceiver : public edit::EditsReceiver {
1232    Rewriter &rewrite;
1233
1234  public:
1235    RewritesReceiver(Rewriter &in_rewrite) : rewrite(in_rewrite) {}
1236
1237    void insert(SourceLocation loc, StringRef text) override {
1238      rewrite.InsertText(loc, text);
1239    }
1240    void replace(CharSourceRange range, StringRef text) override {
1241      rewrite.ReplaceText(range.getBegin(), rewrite.getRangeSize(range), text);
1242    }
1243  };
1244
1245  RewritesReceiver rewrites_receiver(rewriter);
1246
1247  const DiagnosticList &diagnostics = diagnostic_manager.Diagnostics();
1248  size_t num_diags = diagnostics.size();
1249  if (num_diags == 0)
1250    return false;
1251
1252  for (const auto &diag : diagnostic_manager.Diagnostics()) {
1253    const auto *diagnostic = llvm::dyn_cast<ClangDiagnostic>(diag.get());
1254    if (!diagnostic)
1255      continue;
1256    if (!diagnostic->HasFixIts())
1257      continue;
1258    for (const FixItHint &fixit : diagnostic->FixIts())
1259      ApplyFixIt(fixit, commit);
1260  }
1261
1262  // FIXME - do we want to try to propagate specific errors here?
1263  if (!commit.isCommitable())
1264    return false;
1265  else if (!editor.commit(commit))
1266    return false;
1267
1268  // Now play all the edits, and stash the result in the diagnostic manager.
1269  editor.applyRewrites(rewrites_receiver);
1270  RewriteBuffer &main_file_buffer =
1271      rewriter.getEditBuffer(source_manager.getMainFileID());
1272
1273  std::string fixed_expression;
1274  llvm::raw_string_ostream out_stream(fixed_expression);
1275
1276  main_file_buffer.write(out_stream);
1277  out_stream.flush();
1278  diagnostic_manager.SetFixedExpression(fixed_expression);
1279
1280  return true;
1281}
1282
1283static bool FindFunctionInModule(ConstString &mangled_name,
1284                                 llvm::Module *module, const char *orig_name) {
1285  for (const auto &func : module->getFunctionList()) {
1286    const StringRef &name = func.getName();
1287    if (name.contains(orig_name)) {
1288      mangled_name.SetString(name);
1289      return true;
1290    }
1291  }
1292
1293  return false;
1294}
1295
1296lldb_private::Status ClangExpressionParser::PrepareForExecution(
1297    lldb::addr_t &func_addr, lldb::addr_t &func_end,
1298    lldb::IRExecutionUnitSP &execution_unit_sp, ExecutionContext &exe_ctx,
1299    bool &can_interpret, ExecutionPolicy execution_policy) {
1300  func_addr = LLDB_INVALID_ADDRESS;
1301  func_end = LLDB_INVALID_ADDRESS;
1302  Log *log = GetLog(LLDBLog::Expressions);
1303
1304  lldb_private::Status err;
1305
1306  std::unique_ptr<llvm::Module> llvm_module_up(
1307      m_code_generator->ReleaseModule());
1308
1309  if (!llvm_module_up) {
1310    err.SetErrorToGenericError();
1311    err.SetErrorString("IR doesn't contain a module");
1312    return err;
1313  }
1314
1315  ConstString function_name;
1316
1317  if (execution_policy != eExecutionPolicyTopLevel) {
1318    // Find the actual name of the function (it's often mangled somehow)
1319
1320    if (!FindFunctionInModule(function_name, llvm_module_up.get(),
1321                              m_expr.FunctionName())) {
1322      err.SetErrorToGenericError();
1323      err.SetErrorStringWithFormat("Couldn't find %s() in the module",
1324                                   m_expr.FunctionName());
1325      return err;
1326    } else {
1327      LLDB_LOGF(log, "Found function %s for %s", function_name.AsCString(),
1328                m_expr.FunctionName());
1329    }
1330  }
1331
1332  SymbolContext sc;
1333
1334  if (lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP()) {
1335    sc = frame_sp->GetSymbolContext(lldb::eSymbolContextEverything);
1336  } else if (lldb::TargetSP target_sp = exe_ctx.GetTargetSP()) {
1337    sc.target_sp = target_sp;
1338  }
1339
1340  LLVMUserExpression::IRPasses custom_passes;
1341  {
1342    auto lang = m_expr.Language();
1343    LLDB_LOGF(log, "%s - Current expression language is %s\n", __FUNCTION__,
1344              Language::GetNameForLanguageType(lang));
1345    lldb::ProcessSP process_sp = exe_ctx.GetProcessSP();
1346    if (process_sp && lang != lldb::eLanguageTypeUnknown) {
1347      auto runtime = process_sp->GetLanguageRuntime(lang);
1348      if (runtime)
1349        runtime->GetIRPasses(custom_passes);
1350    }
1351  }
1352
1353  if (custom_passes.EarlyPasses) {
1354    LLDB_LOGF(log,
1355              "%s - Running Early IR Passes from LanguageRuntime on "
1356              "expression module '%s'",
1357              __FUNCTION__, m_expr.FunctionName());
1358
1359    custom_passes.EarlyPasses->run(*llvm_module_up);
1360  }
1361
1362  execution_unit_sp = std::make_shared<IRExecutionUnit>(
1363      m_llvm_context, // handed off here
1364      llvm_module_up, // handed off here
1365      function_name, exe_ctx.GetTargetSP(), sc,
1366      m_compiler->getTargetOpts().Features);
1367
1368  ClangExpressionHelper *type_system_helper =
1369      dyn_cast<ClangExpressionHelper>(m_expr.GetTypeSystemHelper());
1370  ClangExpressionDeclMap *decl_map =
1371      type_system_helper->DeclMap(); // result can be NULL
1372
1373  if (decl_map) {
1374    StreamString error_stream;
1375    IRForTarget ir_for_target(decl_map, m_expr.NeedsVariableResolution(),
1376                              *execution_unit_sp, error_stream,
1377                              function_name.AsCString());
1378
1379    if (!ir_for_target.runOnModule(*execution_unit_sp->GetModule())) {
1380      err.SetErrorString(error_stream.GetString());
1381      return err;
1382    }
1383
1384    Process *process = exe_ctx.GetProcessPtr();
1385
1386    if (execution_policy != eExecutionPolicyAlways &&
1387        execution_policy != eExecutionPolicyTopLevel) {
1388      lldb_private::Status interpret_error;
1389
1390      bool interpret_function_calls =
1391          !process ? false : process->CanInterpretFunctionCalls();
1392      can_interpret = IRInterpreter::CanInterpret(
1393          *execution_unit_sp->GetModule(), *execution_unit_sp->GetFunction(),
1394          interpret_error, interpret_function_calls);
1395
1396      if (!can_interpret && execution_policy == eExecutionPolicyNever) {
1397        err.SetErrorStringWithFormat(
1398            "Can't evaluate the expression without a running target due to: %s",
1399            interpret_error.AsCString());
1400        return err;
1401      }
1402    }
1403
1404    if (!process && execution_policy == eExecutionPolicyAlways) {
1405      err.SetErrorString("Expression needed to run in the target, but the "
1406                         "target can't be run");
1407      return err;
1408    }
1409
1410    if (!process && execution_policy == eExecutionPolicyTopLevel) {
1411      err.SetErrorString("Top-level code needs to be inserted into a runnable "
1412                         "target, but the target can't be run");
1413      return err;
1414    }
1415
1416    if (execution_policy == eExecutionPolicyAlways ||
1417        (execution_policy != eExecutionPolicyTopLevel && !can_interpret)) {
1418      if (m_expr.NeedsValidation() && process) {
1419        if (!process->GetDynamicCheckers()) {
1420          ClangDynamicCheckerFunctions *dynamic_checkers =
1421              new ClangDynamicCheckerFunctions();
1422
1423          DiagnosticManager install_diags;
1424          if (Error Err = dynamic_checkers->Install(install_diags, exe_ctx)) {
1425            std::string ErrMsg = "couldn't install checkers: " + toString(std::move(Err));
1426            if (install_diags.Diagnostics().size())
1427              ErrMsg = ErrMsg + "\n" + install_diags.GetString().c_str();
1428            err.SetErrorString(ErrMsg);
1429            return err;
1430          }
1431
1432          process->SetDynamicCheckers(dynamic_checkers);
1433
1434          LLDB_LOGF(log, "== [ClangExpressionParser::PrepareForExecution] "
1435                         "Finished installing dynamic checkers ==");
1436        }
1437
1438        if (auto *checker_funcs = llvm::dyn_cast<ClangDynamicCheckerFunctions>(
1439                process->GetDynamicCheckers())) {
1440          IRDynamicChecks ir_dynamic_checks(*checker_funcs,
1441                                            function_name.AsCString());
1442
1443          llvm::Module *module = execution_unit_sp->GetModule();
1444          if (!module || !ir_dynamic_checks.runOnModule(*module)) {
1445            err.SetErrorToGenericError();
1446            err.SetErrorString("Couldn't add dynamic checks to the expression");
1447            return err;
1448          }
1449
1450          if (custom_passes.LatePasses) {
1451            LLDB_LOGF(log,
1452                      "%s - Running Late IR Passes from LanguageRuntime on "
1453                      "expression module '%s'",
1454                      __FUNCTION__, m_expr.FunctionName());
1455
1456            custom_passes.LatePasses->run(*module);
1457          }
1458        }
1459      }
1460    }
1461
1462    if (execution_policy == eExecutionPolicyAlways ||
1463        execution_policy == eExecutionPolicyTopLevel || !can_interpret) {
1464      execution_unit_sp->GetRunnableInfo(err, func_addr, func_end);
1465    }
1466  } else {
1467    execution_unit_sp->GetRunnableInfo(err, func_addr, func_end);
1468  }
1469
1470  return err;
1471}
1472
1473lldb_private::Status ClangExpressionParser::RunStaticInitializers(
1474    lldb::IRExecutionUnitSP &execution_unit_sp, ExecutionContext &exe_ctx) {
1475  lldb_private::Status err;
1476
1477  lldbassert(execution_unit_sp.get());
1478  lldbassert(exe_ctx.HasThreadScope());
1479
1480  if (!execution_unit_sp.get()) {
1481    err.SetErrorString(
1482        "can't run static initializers for a NULL execution unit");
1483    return err;
1484  }
1485
1486  if (!exe_ctx.HasThreadScope()) {
1487    err.SetErrorString("can't run static initializers without a thread");
1488    return err;
1489  }
1490
1491  std::vector<lldb::addr_t> static_initializers;
1492
1493  execution_unit_sp->GetStaticInitializers(static_initializers);
1494
1495  for (lldb::addr_t static_initializer : static_initializers) {
1496    EvaluateExpressionOptions options;
1497
1498    lldb::ThreadPlanSP call_static_initializer(new ThreadPlanCallFunction(
1499        exe_ctx.GetThreadRef(), Address(static_initializer), CompilerType(),
1500        llvm::ArrayRef<lldb::addr_t>(), options));
1501
1502    DiagnosticManager execution_errors;
1503    lldb::ExpressionResults results =
1504        exe_ctx.GetThreadRef().GetProcess()->RunThreadPlan(
1505            exe_ctx, call_static_initializer, options, execution_errors);
1506
1507    if (results != lldb::eExpressionCompleted) {
1508      err.SetErrorStringWithFormat("couldn't run static initializer: %s",
1509                                   execution_errors.GetString().c_str());
1510      return err;
1511    }
1512  }
1513
1514  return err;
1515}
1516