Revert "[Clang] Implement P3034R1 Module Declarations Shouldn’t be Macros" (#99838)

Reverts #90574

Author: yronglin

clang/docs/ReleaseNotes.rst

@@ -285,8 +285,6 @@ C++2c Feature Support
 
 - Implemented `P2963R3 Ordering of constraints involving fold expressions <https://wg21.link/P2963R3>`_.
 
-- Implemented `P3034R1 Module Declarations Shouldn’t be Macros <https://wg21.link/P3034R1>`_.
-
 
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/Basic/DiagnosticLexKinds.td

@@ -952,11 +952,6 @@ def warn_module_conflict : Warning<
   InGroup<ModuleConflict>;
 
 // C++20 modules
-def err_module_decl_cannot_be_macros : Error<
-  "the module name in a module%select{| partition}0 declaration cannot contain "
-  "an object-like macro %1">;
-def err_unxepected_paren_in_module_decl : Error<
-  "unexpected '(' after the module name in a module%select{| partition}0 declaration">;
 def err_header_import_semi_in_macro : Error<
   "semicolon terminating header import declaration cannot be produced "
   "by a macro">;

clang/include/clang/Basic/IdentifierTable.h

@@ -180,10 +180,6 @@ class alignas(IdentifierInfoAlignment) IdentifierInfo {
   LLVM_PREFERRED_TYPE(bool)
   unsigned IsModulesImport : 1;
 
-  // True if this is the 'module' contextual keyword.
-  LLVM_PREFERRED_TYPE(bool)
-  unsigned IsModulesDecl : 1;
-
   // True if this is a mangled OpenMP variant name.
   LLVM_PREFERRED_TYPE(bool)
   unsigned IsMangledOpenMPVariantName : 1;
@@ -200,7 +196,7 @@ class alignas(IdentifierInfoAlignment) IdentifierInfo {
   LLVM_PREFERRED_TYPE(bool)
   unsigned IsFinal : 1;
 
-  // 21 bits left in a 64-bit word.
+  // 22 bits left in a 64-bit word.
 
   // Managed by the language front-end.
   void *FETokenInfo = nullptr;
@@ -216,8 +212,8 @@ class alignas(IdentifierInfoAlignment) IdentifierInfo {
         IsCPPOperatorKeyword(false), NeedsHandleIdentifier(false),
         IsFromAST(false), ChangedAfterLoad(false), FEChangedAfterLoad(false),
         RevertedTokenID(false), OutOfDate(false), IsModulesImport(false),
-        IsModulesDecl(false), IsMangledOpenMPVariantName(false),
-        IsDeprecatedMacro(false), IsRestrictExpansion(false), IsFinal(false) {}
+        IsMangledOpenMPVariantName(false), IsDeprecatedMacro(false),
+        IsRestrictExpansion(false), IsFinal(false) {}
 
 public:
   IdentifierInfo(const IdentifierInfo &) = delete;
@@ -524,18 +520,6 @@ class alignas(IdentifierInfoAlignment) IdentifierInfo {
       RecomputeNeedsHandleIdentifier();
   }
 
-  /// Determine whether this is the contextual keyword \c module.
-  bool isModulesDeclaration() const { return IsModulesDecl; }
-
-  /// Set whether this identifier is the contextual keyword \c module.
-  void setModulesDeclaration(bool I) {
-    IsModulesDecl = I;
-    if (I)
-      NeedsHandleIdentifier = true;
-    else
-      RecomputeNeedsHandleIdentifier();
-  }
-
   /// Determine whether this is the mangled name of an OpenMP variant.
   bool isMangledOpenMPVariantName() const { return IsMangledOpenMPVariantName; }
 
@@ -756,8 +740,6 @@ class IdentifierTable {
     // If this is the 'import' contextual keyword, mark it as such.
     if (Name == "import")
       II->setModulesImport(true);
-    else if (Name == "module")
-      II->setModulesDeclaration(true);
 
     return *II;
   }

clang/include/clang/Basic/TokenKinds.def

@@ -1003,9 +1003,6 @@ ANNOTATION(module_include)
 ANNOTATION(module_begin)
 ANNOTATION(module_end)
 
-// Annotations for C++, Clang and Objective-C named modules.
-ANNOTATION(module_name)
-
 // Annotation for a header_name token that has been looked up and transformed
 // into the name of a header unit.
 ANNOTATION(header_unit)

clang/include/clang/Lex/Preprocessor.h

@@ -615,6 +615,10 @@ class Preprocessor {
 
   ModuleDeclSeq ModuleDeclState;
 
+  /// Whether the module import expects an identifier next. Otherwise,
+  /// it expects a '.' or ';'.
+  bool ModuleImportExpectsIdentifier = false;
+
   /// The identifier and source location of the currently-active
   /// \#pragma clang arc_cf_code_audited begin.
   std::pair<IdentifierInfo *, SourceLocation> PragmaARCCFCodeAuditedInfo;
@@ -1740,14 +1744,11 @@ class Preprocessor {
   /// Lex a token, forming a header-name token if possible.
   bool LexHeaderName(Token &Result, bool AllowMacroExpansion = true);
 
-  /// Lex a module name or a partition name.
-  bool LexModuleName(Token &Result, bool IsImport);
-
   /// Lex the parameters for an #embed directive, returns nullopt on error.
   std::optional<LexEmbedParametersResult> LexEmbedParameters(Token &Current,
                                                              bool ForHasEmbed);
+
   bool LexAfterModuleImport(Token &Result);
-  bool LexAfterModuleDecl(Token &Result);
   void CollectPpImportSuffix(SmallVectorImpl<Token> &Toks);
 
   void makeModuleVisible(Module *M, SourceLocation Loc);
@@ -3038,9 +3039,6 @@ class Preprocessor {
   static bool CLK_LexAfterModuleImport(Preprocessor &P, Token &Result) {
     return P.LexAfterModuleImport(Result);
   }
-  static bool CLK_LexAfterModuleDecl(Preprocessor &P, Token &Result) {
-    return P.LexAfterModuleDecl(Result);
-  }
 };
 
 /// Abstract base class that describes a handler that will receive
@@ -3073,77 +3071,6 @@ struct EmbedAnnotationData {
 /// Registry of pragma handlers added by plugins
 using PragmaHandlerRegistry = llvm::Registry<PragmaHandler>;
 
-/// Represents module or partition name token sequance.
-///
-///     module-name:
-///           module-name-qualifier[opt] identifier
-///
-///     partition-name: [C++20]
-///           : module-name-qualifier[opt] identifier
-///
-///     module-name-qualifier
-///           module-name-qualifier[opt] identifier .
-///
-/// This class can only be created by the preprocessor and guarantees that the
-/// two source array being contiguous in memory and only contains 3 kind of
-/// tokens (identifier, '.' and ':'). And only available when the preprocessor
-/// returns annot_module_name token.
-///
-/// For exmaple:
-///
-/// export module m.n:c.d
-///
-/// The module name array has 3 tokens ['m', '.', 'n'].
-/// The partition name array has 4 tokens [':', 'c', '.', 'd'].
-///
-/// When import a partition in a named module fragment (Eg. import :part1;),
-/// the module name array will be empty, and the partition name array has 2
-/// tokens.
-///
-/// When we meet a private-module-fragment (Eg. module :private;), preprocessor
-/// will not return a annot_module_name token, but will return 2 separate tokens
-/// [':', 'kw_private'].
-
-class ModuleNameInfo {
-  friend class Preprocessor;
-  ArrayRef<Token> ModuleName;
-  ArrayRef<Token> PartitionName;
-
-  ModuleNameInfo(ArrayRef<Token> AnnotToks, std::optional<unsigned> ColonIndex);
-
-public:
-  /// Return the contiguous token array.
-  ArrayRef<Token> getTokens() const {
-    if (ModuleName.empty())
-      return PartitionName;
-    if (PartitionName.empty())
-      return ModuleName;
-    return ArrayRef(ModuleName.begin(), PartitionName.end());
-  }
-  bool hasModuleName() const { return !ModuleName.empty(); }
-  bool hasPartitionName() const { return !PartitionName.empty(); }
-  ArrayRef<Token> getModuleName() const { return ModuleName; }
-  ArrayRef<Token> getPartitionName() const { return PartitionName; }
-  Token getColonToken() const {
-    assert(hasPartitionName() && "Do not have a partition name");
-    return getPartitionName().front();
-  }
-
-  /// Under the standard C++ Modules, the dot is just part of the module name,
-  /// and not a real hierarchy separator. Flatten such module names now.
-  std::string getFlatName() const;
-
-  /// Build a module id path from the contiguous token array, both include
-  /// module name and partition name.
-  void getModuleIdPath(
-      SmallVectorImpl<std::pair<IdentifierInfo *, SourceLocation>> &Path) const;
-
-  /// Build a module id path from \param ModuleName.
-  static void getModuleIdPath(
-      ArrayRef<Token> ModuleName,
-      SmallVectorImpl<std::pair<IdentifierInfo *, SourceLocation>> &Path);
-};
-
 } // namespace clang
 
 #endif // LLVM_CLANG_LEX_PREPROCESSOR_H

clang/include/clang/Lex/Token.h

@@ -235,9 +235,6 @@ class Token {
     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
     return PtrData;
   }
-  template <class T> T getAnnotationValueAs() const {
-    return static_cast<T>(getAnnotationValue());
-  }
   void setAnnotationValue(void *val) {
     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
     PtrData = val;

clang/include/clang/Parse/Parser.h

@@ -3876,7 +3876,7 @@ class Parser : public CodeCompletionHandler {
   }
 
   bool ParseModuleName(
-      SourceLocation UseLoc, ArrayRef<Token> ModuleName,
+      SourceLocation UseLoc,
       SmallVectorImpl<std::pair<IdentifierInfo *, SourceLocation>> &Path,
       bool IsImport);
 

clang/lib/Basic/IdentifierTable.cpp

@@ -322,9 +322,8 @@ void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
   if (LangOpts.IEEE128)
     AddKeyword("__ieee128", tok::kw___float128, KEYALL, LangOpts, *this);
 
-  // Add the 'import' and 'module' contextual keyword.
+  // Add the 'import' contextual keyword.
   get("import").setModulesImport(true);
-  get("module").setModulesDeclaration(true);
 }
 
 /// Checks if the specified token kind represents a keyword in the

clang/lib/Frontend/PrintPreprocessedOutput.cpp

@@ -758,10 +758,9 @@ void PrintPPOutputPPCallbacks::HandleWhitespaceBeforeTok(const Token &Tok,
   // These tokens are not expanded to anything and don't need whitespace before
   // them.
   if (Tok.is(tok::eof) ||
-      (Tok.isAnnotation() && Tok.isNot(tok::annot_header_unit) &&
-       Tok.isNot(tok::annot_module_begin) && Tok.isNot(tok::annot_module_end) &&
-       Tok.isNot(tok::annot_module_name) &&
-       Tok.isNot(tok::annot_repl_input_end) && Tok.isNot(tok::annot_embed)))
+      (Tok.isAnnotation() && !Tok.is(tok::annot_header_unit) &&
+       !Tok.is(tok::annot_module_begin) && !Tok.is(tok::annot_module_end) &&
+       !Tok.is(tok::annot_repl_input_end) && !Tok.is(tok::annot_embed)))
     return;
 
   // EmittedDirectiveOnThisLine takes priority over RequireSameLine.
@@ -952,11 +951,6 @@ static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
       PP.Lex(Tok);
       IsStartOfLine = true;
       continue;
-    } else if (Tok.is(tok::annot_module_name)) {
-      auto *Info = static_cast<ModuleNameInfo *>(Tok.getAnnotationValue());
-      *Callbacks->OS << Info->getFlatName();
-      PP.Lex(Tok);
-      continue;
     } else if (Tok.is(tok::annot_header_unit)) {
       // This is a header-name that has been (effectively) converted into a
       // module-name.

clang/lib/Lex/PPLexerChange.cpp

@@ -122,8 +122,7 @@ void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
   CurPPLexer = TheLexer;
   CurDirLookup = CurDir;
   CurLexerSubmodule = nullptr;
-  if (CurLexerCallback != CLK_LexAfterModuleImport &&
-      CurLexerCallback != CLK_LexAfterModuleDecl)
+  if (CurLexerCallback != CLK_LexAfterModuleImport)
     CurLexerCallback = TheLexer->isDependencyDirectivesLexer()
                            ? CLK_DependencyDirectivesLexer
                            : CLK_Lexer;
@@ -162,7 +161,8 @@ void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
   PushIncludeMacroStack();
   CurDirLookup = nullptr;
   CurTokenLexer = std::move(TokLexer);
-  CurLexerCallback = CLK_TokenLexer;
+  if (CurLexerCallback != CLK_LexAfterModuleImport)
+    CurLexerCallback = CLK_TokenLexer;
 }
 
 /// EnterTokenStream - Add a "macro" context to the top of the include stack,
@@ -216,8 +216,7 @@ void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
   PushIncludeMacroStack();
   CurDirLookup = nullptr;
   CurTokenLexer = std::move(TokLexer);
-  if (CurLexerCallback != CLK_LexAfterModuleImport &&
-      CurLexerCallback != CLK_LexAfterModuleDecl)
+  if (CurLexerCallback != CLK_LexAfterModuleImport)
     CurLexerCallback = CLK_TokenLexer;
 }