Remove error recovery

Signed-off-by: yronglin <[email protected]>

Author: yronglin

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -1780,16 +1780,6 @@ def ext_bit_int : Extension<
 } // end of Parse Issue category.
 
 let CategoryName = "Modules Issue" in {
-def err_invalid_module_or_import_directive : Error<
-  "the %select{module|import}0 directive is ill-formed, "
-  "%select{module keyword must be immediately "
-  "followed on the same line by an identifier, "
-  "or a ';' after being at the start of a line, or preceded by "
-  "an export keyword at the start of a line|"
-  "import keyword must be immediately followed "
-  "on the same line by an identifier, '<', '\"', or ':', but not '::', "
-  "after being at the start of a line or preceded by an export at "
-  "the start of the line}0">;
 def err_unexpected_module_or_import_decl : Error<
   "%select{module|import}0 declaration can only appear at the top level">;
 def err_module_expected_ident : Error<

clang/lib/Lex/Preprocessor.cpp

@@ -61,6 +61,7 @@
 #include "llvm/Support/Capacity.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cassert>
@@ -1195,21 +1196,20 @@ bool Preprocessor::HandleModuleContextualKeyword(
   } else if (!TokAtPhysicalStartOfLine)
     return false;
 
-  bool SavedParsingPreprocessorDirective =
-      CurPPLexer->ParsingPreprocessorDirective;
-  CurPPLexer->ParsingPreprocessorDirective = true;
-  auto _ = llvm::make_scope_exit([&]() {
-    CurPPLexer->ParsingPreprocessorDirective =
-        SavedParsingPreprocessorDirective;
-  });
-
-  if (Result.getIdentifierInfo()->isModulesImport() &&
-      isNextPPTokenOneOf(tok::raw_identifier, tok::less, tok::string_literal,
-                         tok::colon)) {
-    Result.setKind(tok::kw_import);
-    ModuleImportLoc = Result.getLocation();
-    IsAtImport = false;
-    return true;
+  llvm::SaveAndRestore<bool> SavedParsingPreprocessorDirective(
+      CurPPLexer->ParsingPreprocessorDirective, true);
+
+  if (Result.getIdentifierInfo()->isModulesImport()) {
+    // The next token may be an angled string literal.
+    llvm::SaveAndRestore<bool> SavedParsingFilemame(CurPPLexer->ParsingFilename,
+                                                    true);
+    if (isNextPPTokenOneOf(tok::raw_identifier, tok::less, tok::string_literal,
+                           tok::colon, tok::header_name)) {
+      Result.setKind(tok::kw_import);
+      ModuleImportLoc = Result.getLocation();
+      IsAtImport = false;
+      return true;
+    }
   }
 
   if (Result.getIdentifierInfo()->isModulesDeclaration() &&

clang/lib/Parse/Parser.cpp

@@ -623,24 +623,6 @@ bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result,
       goto module_decl;
     case tok::kw_import:
       goto import_decl;
-    // Error recovery and recognize context-sensitive C++20 'export module' and
-    // 'export import' declarations. If the module/import directive is
-    // well-formed, it should be converted to a keyword in preprocessor, but not
-    // an identifier we saw here.
-    //
-    // FIXME: We should generate better diagnostic information here to explain
-    // why the module/import directive is ill-formed.
-    case tok::identifier: {
-      if (NextToken().isModuleContextualKeyword(getLangOpts()) &&
-          GetLookAheadToken(2).isNot(tok::coloncolon)) {
-        if (NextToken().getIdentifierInfo()->isStr(
-                tok::getKeywordSpelling(tok::kw_module)))
-          goto module_decl;
-        else
-          goto import_decl;
-      }
-      break;
-    }
     default:
       break;
     }
@@ -708,25 +690,6 @@ bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result,
     Actions.ActOnEndOfTranslationUnit();
     //else don't tell Sema that we ended parsing: more input might come.
     return true;
-  case tok::identifier:
-    // C++20 [basic.link]p3:
-    //   A token sequence beginning with 'export[opt] module' or
-    //   'export[opt] import' and not immediately followed by '::'
-    //   is never interpreted as the declaration of a top-level-declaration.
-    //
-    // Error recovery and recognize context-sensitive C++20 'export module' and
-    // 'export import' declarations. If the module/import directive is
-    // well-formed, it should be converted to a keyword in preprocessor, but not
-    // an identifier we saw here.
-    if (Tok.isModuleContextualKeyword(getLangOpts()) &&
-        NextToken().isNot(tok::coloncolon)) {
-      if (Tok.getIdentifierInfo()->isStr(
-              tok::getKeywordSpelling(tok::kw_module)))
-        goto module_decl;
-      else
-        goto import_decl;
-    }
-    break;
   default:
     break;
   }
@@ -2362,10 +2325,6 @@ Parser::ParseModuleDecl(Sema::ModuleImportState &ImportState) {
                tok::getKeywordSpelling(tok::kw_module)))) &&
          "not a module declaration");
 
-  if (getLangOpts().CPlusPlusModules && Tok.is(tok::identifier))
-    Diag(StartLoc, diag::err_invalid_module_or_import_directive)
-        << /*IsImport=*/false;
-
   SourceLocation ModuleLoc = ConsumeToken();
 
   // Attributes appear after the module name, not before.
@@ -2449,12 +2408,6 @@ Decl *Parser::ParseModuleImport(SourceLocation AtLoc,
                             : Tok.isObjCAtKeyword(tok::objc_import)) &&
          "Improper start to module import");
   bool IsObjCAtImport = Tok.isObjCAtKeyword(tok::objc_import);
-  if (getLangOpts().CPlusPlusModules && !IsObjCAtImport &&
-      Tok.is(tok::identifier)) {
-    Diag(StartLoc, diag::err_invalid_module_or_import_directive)
-        << /*IsImport=*/true;
-  }
-
   SourceLocation ImportLoc = ConsumeToken();
 
   // For C++20 modules, we can have "name" or ":Partition name" as valid input.

clang/test/CXX/module/cpp.pre/p1.cpp

@@ -20,6 +20,9 @@
 // RUN: %clang_cc1 -std=c++20 %t/foo.cppm -emit-module-interface -o %t/foo.pcm
 // RUN: %clang_cc1 -std=c++20 %t/import_decl_not_in_same_line.cpp -fmodule-file=foo=%t/foo.pcm -fsyntax-only -verify
 // RUN: %clang_cc1 -std=c++20 %t/not_import.cpp -fsyntax-only -verify
+// RUN: %clang_cc1 -std=c++20 %t/import_spaceship.cpp -fsyntax-only -verify
+// RUN: %clang_cc1 -std=c++20 %t/leading_empty_macro.cpp -fsyntax-only -verify
+
 
 //--- hash.cpp
 // expected-no-diagnostics
@@ -54,22 +57,34 @@ import rightpad;        // preprocessing directive
 import :part;           // preprocessing directive
 
 //--- module_decl_not_in_same_line.cpp
-module                  // expected-error {{the module directive is ill-formed, module keyword must be immediately followed on the same line by an identifier, or a ';' after being at the start of a line, or preceded by an export keyword at the start of a line}}
-;export module M;       // expected-error {{the module directive is ill-formed, module keyword must be immediately followed on the same line by an identifier, or a ';' after being at the start of a line, or preceded by an export keyword at the start of a line}}
+module                  // expected-error {{a type specifier is required for all declarations}}
+;export module M;       // expected-error {{export declaration can only be used within a module interface}} \
+                        // expected-error {{unknown type name 'module'}}
 
 //--- foo.cppm
 export module foo;
 
 //--- import_decl_not_in_same_line.cpp
 export module M;
-export                  // expected-error {{the import directive is ill-formed, import keyword must be immediately followed on the same line by an identifier, '<', '"', or ':', but not '::', after being at the start of a line or preceded by an export at the start of the line}}
-import
+export
+import                  // expected-error {{unknown type name 'import'}}
 foo;
 
-export                  // expected-error {{the import directive is ill-formed, import keyword must be immediately followed on the same line by an identifier, '<', '"', or ':', but not '::', after being at the start of a line or preceded by an export at the start of the line}}
-import foo;
+export
+import foo;             // expected-error {{unknown type name 'import'}}
 
 //--- not_import.cpp
 export module M;
 import ::               // expected-error {{use of undeclared identifier 'import'}}
 import ->               // expected-error {{cannot use arrow operator on a type}}
+
+//--- import_spaceship.cpp
+export module M;
+import <=>; // expected-error {{'=' file not found}}
+
+//--- leading_empty_macro.cpp
+// expected-no-diagnostics
+export module M;
+typedef int import;
+#define EMP
+EMP import m; // The phase 7 grammar should see import as a typedef-name.

clang/test/CXX/module/dcl.dcl/dcl.module/dcl.module.import/p1.cppm

@@ -45,7 +45,7 @@ import x [[blarg::noreturn]]; // expected-warning-re {{unknown attribute 'blarg:
 
 import x.y;
 import x.; // expected-error {{expected identifier after '.' in module name}}
-import .x; // expected-error-re {{the import directive is ill-formed{{.*}}}} expected-error {{expected module name}}
+import .x; // expected-error {{unknown type name 'import'}} expected-error {{cannot use dot operator on a type}}
 
 import blarg; // expected-error {{module 'blarg' not found}}
 
@@ -63,7 +63,7 @@ import x [[blarg::noreturn]]; // expected-warning-re {{unknown attribute 'blarg:
 
 import x.y;
 import x.; // expected-error {{expected identifier after '.' in module name}}
-import .x; // expected-error-re {{the import directive is ill-formed{{.*}}}} expected-error {{expected module name}}
+import .x; // expected-error {{unknown type name 'import'}} expected-error {{cannot use dot operator on a type}}
 
 import blarg; // expected-error {{module 'blarg' not found}}