1 files changed, 294 insertions, 6 deletions

diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index f81eaa31e9..b5d0f93954 100644
--- a/lib/Lex/Pragma.cpp
+++ b/lib/Lex/Pragma.cpp
@@ -20,6 +20,7 @@
 #include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/LexDiagnostic.h"
+#include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
@@ -475,9 +476,9 @@ void Preprocessor::HandlePragmaSystemHeader(Token &SysHeaderTok) {
   // Emit a line marker.  This will change any source locations from this point
   // forward to realize they are in a system header.
   // Create a line note with this information.
-  SourceMgr.AddLineNote(SysHeaderTok.getLocation(), PLoc.getLine()+1,
+  SourceMgr.AddLineNote(SysHeaderTok.getLocation(), PLoc.getLine() + 1,
                         FilenameID, /*IsEntry=*/false, /*IsExit=*/false,
-                        /*IsSystem=*/true, /*IsExternC=*/false);
+                        SrcMgr::C_System);
 }
 
 /// HandlePragmaDependency - Handle \#pragma GCC dependency "foo" blah.
@@ -508,7 +509,7 @@ void Preprocessor::HandlePragmaDependency(Token &DependencyTok) {
   const DirectoryLookup *CurDir;
   const FileEntry *File =
       LookupFile(FilenameTok.getLocation(), Filename, isAngled, nullptr,
-                 nullptr, CurDir, nullptr, nullptr, nullptr);
+                 nullptr, CurDir, nullptr, nullptr, nullptr, nullptr);
   if (!File) {
     if (!SuppressIncludeNotFoundError)
       Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
@@ -754,6 +755,125 @@ void Preprocessor::HandlePragmaIncludeAlias(Token &Tok) {
   getHeaderSearchInfo().AddIncludeAlias(OriginalSource, ReplaceFileName);
 }
 
+// Lex a component of a module name: either an identifier or a string literal;
+// for components that can be expressed both ways, the two forms are equivalent.
+static bool LexModuleNameComponent(
+    Preprocessor &PP, Token &Tok,
+    std::pair<IdentifierInfo *, SourceLocation> &ModuleNameComponent,
+    bool First) {
+  PP.LexUnexpandedToken(Tok);
+  if (Tok.is(tok::string_literal) && !Tok.hasUDSuffix()) {
+    StringLiteralParser Literal(Tok, PP);
+    if (Literal.hadError)
+      return true;
+    ModuleNameComponent = std::make_pair(
+        PP.getIdentifierInfo(Literal.GetString()), Tok.getLocation());
+  } else if (!Tok.isAnnotation() && Tok.getIdentifierInfo()) {
+    ModuleNameComponent =
+        std::make_pair(Tok.getIdentifierInfo(), Tok.getLocation());
+  } else {
+    PP.Diag(Tok.getLocation(), diag::err_pp_expected_module_name) << First;
+    return true;
+  }
+  return false;
+}
+
+static bool LexModuleName(
+    Preprocessor &PP, Token &Tok,
+    llvm::SmallVectorImpl<std::pair<IdentifierInfo *, SourceLocation>>
+        &ModuleName) {
+  while (true) {
+    std::pair<IdentifierInfo*, SourceLocation> NameComponent;
+    if (LexModuleNameComponent(PP, Tok, NameComponent, ModuleName.empty()))
+      return true;
+    ModuleName.push_back(NameComponent);
+
+    PP.LexUnexpandedToken(Tok);
+    if (Tok.isNot(tok::period))
+      return false;
+  }
+}
+
+void Preprocessor::HandlePragmaModuleBuild(Token &Tok) {
+  SourceLocation Loc = Tok.getLocation();
+
+  std::pair<IdentifierInfo *, SourceLocation> ModuleNameLoc;
+  if (LexModuleNameComponent(*this, Tok, ModuleNameLoc, true))
+    return;
+  IdentifierInfo *ModuleName = ModuleNameLoc.first;
+
+  LexUnexpandedToken(Tok);
+  if (Tok.isNot(tok::eod)) {
+    Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+    DiscardUntilEndOfDirective();
+  }
+
+  if (CurPTHLexer) {
+    // FIXME: Support this somehow?
+    Diag(Loc, diag::err_pp_module_build_pth);
+    return;
+  }
+
+  CurLexer->LexingRawMode = true;
+
+  auto TryConsumeIdentifier = [&](StringRef Ident) -> bool {
+    if (Tok.getKind() != tok::raw_identifier ||
+        Tok.getRawIdentifier() != Ident)
+      return false;
+    CurLexer->Lex(Tok);
+    return true;
+  };
+
+  // Scan forward looking for the end of the module.
+  const char *Start = CurLexer->getBufferLocation();
+  const char *End = nullptr;
+  unsigned NestingLevel = 1;
+  while (true) {
+    End = CurLexer->getBufferLocation();
+    CurLexer->Lex(Tok);
+
+    if (Tok.is(tok::eof)) {
+      Diag(Loc, diag::err_pp_module_build_missing_end);
+      break;
+    }
+
+    if (Tok.isNot(tok::hash) || !Tok.isAtStartOfLine()) {
+      // Token was part of module; keep going.
+      continue;
+    }
+
+    // We hit something directive-shaped; check to see if this is the end
+    // of the module build.
+    CurLexer->ParsingPreprocessorDirective = true;
+    CurLexer->Lex(Tok);
+    if (TryConsumeIdentifier("pragma") && TryConsumeIdentifier("clang") &&
+        TryConsumeIdentifier("module")) {
+      if (TryConsumeIdentifier("build"))
+        // #pragma clang module build -> entering a nested module build.
+        ++NestingLevel;
+      else if (TryConsumeIdentifier("endbuild")) {
+        // #pragma clang module endbuild -> leaving a module build.
+        if (--NestingLevel == 0)
+          break;
+      }
+      // We should either be looking at the EOD or more of the current directive
+      // preceding the EOD. Either way we can ignore this token and keep going.
+      assert(Tok.getKind() != tok::eof && "missing EOD before EOF");
+    }
+  }
+
+  CurLexer->LexingRawMode = false;
+
+  // Load the extracted text as a preprocessed module.
+  assert(CurLexer->getBuffer().begin() <= Start &&
+         Start <= CurLexer->getBuffer().end() &&
+         CurLexer->getBuffer().begin() <= End &&
+         End <= CurLexer->getBuffer().end() &&
+         "module source range not contained within same file buffer");
+  TheModuleLoader.loadModuleFromSource(Loc, ModuleName->getName(),
+                                       StringRef(Start, End - Start));
+}
+
 /// AddPragmaHandler - Add the specified pragma handler to the preprocessor.
 /// If 'Namespace' is non-null, then it is a token required to exist on the
 /// pragma line before the pragma string starts, e.g. "STDC" or "GCC".
@@ -989,9 +1109,9 @@ struct PragmaDebugHandler : public PragmaHandler {
 #ifdef _MSC_VER
     #pragma warning(disable : 4717)
 #endif
-  static void DebugOverflowStack() {
-    void (*volatile Self)() = DebugOverflowStack;
-    Self();
+  static void DebugOverflowStack(void (*P)() = nullptr) {
+    void (*volatile Self)(void(*P)()) = DebugOverflowStack;
+    Self(reinterpret_cast<void(*)()>(Self));
   }
 #ifdef _MSC_VER
     #pragma warning(default : 4717)
@@ -1301,6 +1421,160 @@ public:
   }
 };
 
+/// Handle the clang \#pragma module import extension. The syntax is:
+/// \code
+///   #pragma clang module import some.module.name
+/// \endcode
+struct PragmaModuleImportHandler : public PragmaHandler {
+  PragmaModuleImportHandler() : PragmaHandler("import") {}
+
+  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                    Token &Tok) override {
+    SourceLocation ImportLoc = Tok.getLocation();
+
+    // Read the module name.
+    llvm::SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 8>
+        ModuleName;
+    if (LexModuleName(PP, Tok, ModuleName))
+      return;
+
+    if (Tok.isNot(tok::eod))
+      PP.Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+
+    // If we have a non-empty module path, load the named module.
+    Module *Imported =
+        PP.getModuleLoader().loadModule(ImportLoc, ModuleName, Module::Hidden,
+                                      /*IsIncludeDirective=*/false);
+    if (!Imported)
+      return;
+
+    PP.makeModuleVisible(Imported, ImportLoc);
+    PP.EnterAnnotationToken(SourceRange(ImportLoc, ModuleName.back().second),
+                            tok::annot_module_include, Imported);
+    if (auto *CB = PP.getPPCallbacks())
+      CB->moduleImport(ImportLoc, ModuleName, Imported);
+  }
+};
+
+/// Handle the clang \#pragma module begin extension. The syntax is:
+/// \code
+///   #pragma clang module begin some.module.name
+///   ...
+///   #pragma clang module end
+/// \endcode
+struct PragmaModuleBeginHandler : public PragmaHandler {
+  PragmaModuleBeginHandler() : PragmaHandler("begin") {}
+
+  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                    Token &Tok) override {
+    SourceLocation BeginLoc = Tok.getLocation();
+
+    // Read the module name.
+    llvm::SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 8>
+        ModuleName;
+    if (LexModuleName(PP, Tok, ModuleName))
+      return;
+
+    if (Tok.isNot(tok::eod))
+      PP.Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+
+    // We can only enter submodules of the current module.
+    StringRef Current = PP.getLangOpts().CurrentModule;
+    if (ModuleName.front().first->getName() != Current) {
+      PP.Diag(ModuleName.front().second, diag::err_pp_module_begin_wrong_module)
+        << ModuleName.front().first << (ModuleName.size() > 1)
+        << Current.empty() << Current;
+      return;
+    }
+
+    // Find the module we're entering. We require that a module map for it
+    // be loaded or implicitly loadable.
+    // FIXME: We could create the submodule here. We'd need to know whether
+    // it's supposed to be explicit, but not much else.
+    Module *M = PP.getHeaderSearchInfo().lookupModule(Current);
+    if (!M) {
+      PP.Diag(ModuleName.front().second,
+              diag::err_pp_module_begin_no_module_map) << Current;
+      return;
+    }
+    for (unsigned I = 1; I != ModuleName.size(); ++I) {
+      auto *NewM = M->findSubmodule(ModuleName[I].first->getName());
+      if (!NewM) {
+        PP.Diag(ModuleName[I].second, diag::err_pp_module_begin_no_submodule)
+          << M->getFullModuleName() << ModuleName[I].first;
+        return;
+      }
+      M = NewM;
+    }
+
+    // If the module isn't available, it doesn't make sense to enter it.
+    if (Preprocessor::checkModuleIsAvailable(
+            PP.getLangOpts(), PP.getTargetInfo(), PP.getDiagnostics(), M)) {
+      PP.Diag(BeginLoc, diag::note_pp_module_begin_here)
+        << M->getTopLevelModuleName();
+      return;
+    }
+
+    // Enter the scope of the submodule.
+    PP.EnterSubmodule(M, BeginLoc, /*ForPragma*/true);
+    PP.EnterAnnotationToken(SourceRange(BeginLoc, ModuleName.back().second),
+                            tok::annot_module_begin, M);
+  }
+};
+
+/// Handle the clang \#pragma module end extension.
+struct PragmaModuleEndHandler : public PragmaHandler {
+  PragmaModuleEndHandler() : PragmaHandler("end") {}
+
+  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                    Token &Tok) override {
+    SourceLocation Loc = Tok.getLocation();
+
+    PP.LexUnexpandedToken(Tok);
+    if (Tok.isNot(tok::eod))
+      PP.Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+
+    Module *M = PP.LeaveSubmodule(/*ForPragma*/true);
+    if (M)
+      PP.EnterAnnotationToken(SourceRange(Loc), tok::annot_module_end, M);
+    else
+      PP.Diag(Loc, diag::err_pp_module_end_without_module_begin);
+  }
+};
+
+/// Handle the clang \#pragma module build extension.
+struct PragmaModuleBuildHandler : public PragmaHandler {
+  PragmaModuleBuildHandler() : PragmaHandler("build") {}
+
+  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                    Token &Tok) override {
+    PP.HandlePragmaModuleBuild(Tok);
+  }
+};
+
+/// Handle the clang \#pragma module load extension.
+struct PragmaModuleLoadHandler : public PragmaHandler {
+  PragmaModuleLoadHandler() : PragmaHandler("load") {}
+
+  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                    Token &Tok) override {
+    SourceLocation Loc = Tok.getLocation();
+
+    // Read the module name.
+    llvm::SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 8>
+        ModuleName;
+    if (LexModuleName(PP, Tok, ModuleName))
+      return;
+
+    if (Tok.isNot(tok::eod))
+      PP.Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+
+    // Load the module, don't make it visible.
+    PP.getModuleLoader().loadModule(Loc, ModuleName, Module::Hidden,
+                                    /*IsIncludeDirective=*/false);
+  }
+};
+
 /// PragmaPushMacroHandler - "\#pragma push_macro" saves the value of the
 /// macro on the top of the stack.
 struct PragmaPushMacroHandler : public PragmaHandler {
@@ -1451,6 +1725,7 @@ struct PragmaAssumeNonNullHandler : public PragmaHandler {
 
     // The start location we want after processing this.
     SourceLocation NewLoc;
+    PPCallbacks *Callbacks = PP.getPPCallbacks();
 
     if (IsBegin) {
       // Complain about attempts to re-enter an audit.
@@ -1459,6 +1734,8 @@ struct PragmaAssumeNonNullHandler : public PragmaHandler {
         PP.Diag(BeginLoc, diag::note_pragma_entered_here);
       }
       NewLoc = Loc;
+      if (Callbacks)
+        Callbacks->PragmaAssumeNonNullBegin(NewLoc);
     } else {
       // Complain about attempts to leave an audit that doesn't exist.
       if (!BeginLoc.isValid()) {
@@ -1466,6 +1743,8 @@ struct PragmaAssumeNonNullHandler : public PragmaHandler {
         return;
       }
       NewLoc = SourceLocation();
+      if (Callbacks)
+        Callbacks->PragmaAssumeNonNullEnd(NewLoc);
     }
 
     PP.setPragmaAssumeNonNullLoc(NewLoc);
@@ -1524,6 +1803,15 @@ void Preprocessor::RegisterBuiltinPragmas() {
   AddPragmaHandler("clang", new PragmaARCCFCodeAuditedHandler());
   AddPragmaHandler("clang", new PragmaAssumeNonNullHandler());
 
+  // #pragma clang module ...
+  auto *ModuleHandler = new PragmaNamespace("module");
+  AddPragmaHandler("clang", ModuleHandler);
+  ModuleHandler->AddPragma(new PragmaModuleImportHandler());
+  ModuleHandler->AddPragma(new PragmaModuleBeginHandler());
+  ModuleHandler->AddPragma(new PragmaModuleEndHandler());
+  ModuleHandler->AddPragma(new PragmaModuleBuildHandler());
+  ModuleHandler->AddPragma(new PragmaModuleLoadHandler());
+
   AddPragmaHandler("STDC", new PragmaSTDC_FENV_ACCESSHandler());
   AddPragmaHandler("STDC", new PragmaSTDC_CX_LIMITED_RANGEHandler());
   AddPragmaHandler("STDC", new PragmaSTDC_UnknownHandler());