Merge pull request SonarOpenCommunity#2738 from guwirth/cpp23-meaning…

…ful-exports C++23: meaningful exports
guwirth · Sep 2, 2024 · 1136201 · 1136201
2 parents fab0556 + be44729
commit 1136201
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Showing 5 changed files with 58 additions and 51 deletions.
diff --git a/cxx-squid/dox/diff-cpp20-cpp23_grammar.txt b/cxx-squid/dox/diff-cpp20-cpp23_grammar.txt
@@ -143,27 +143,6 @@ requirement-seq:
 
 **A.7 Declarations [gram.dcl]**
 
-declaration:
-   name-declaration
-   special-declaration
-
-name-declaration:
-   block-declaration
-   nodeclspec-function-declaration
-   function-definition
-   template-declaration
-   deduction-guide
-   linkage-specification
-   namespace-definition
-   empty-declaration
-   attribute-declaration
-   module-import-declaration
-
-special-declaration:
-   explicit-instantiation
-   explicit-specialization
-   export-declaration
-
 elaborated-type-specifier:
    class-key attribute-specifier-seqopt nested-name-specifieropt identifier
    class-key simple-template-id
@@ -177,17 +156,6 @@ using-enum-declarator:
    nested-name-specifieropt identifier
    nested-name-specifieropt simple-template-id
 
-linkage-specification:
-   extern string-literal { declaration-seqopt }
-   extern string-literal name-declaration
-
-**A.8 Modules [gram.module]**
-
-export-declaration:
-   export name-declaration
-   export { declaration-seqopt }
-   export-keyword module-import-declaration
-
 **A.11 Templates [gram.temp]**
 
 concept-definition:

diff --git a/cxx-squid/src/main/java/org/sonar/cxx/parser/CxxGrammarImpl.java b/cxx-squid/src/main/java/org/sonar/cxx/parser/CxxGrammarImpl.java
@@ -133,6 +133,8 @@ public enum CxxGrammarImpl implements GrammarRuleKey {
   // Declarations
   declarationSeq,
   declaration,
+  nameDeclaration,
+  specialDeclaration,
   blockDeclaration,
   nodeclspecFunctionDeclaration,
   aliasDeclaration,
@@ -1079,6 +1081,13 @@ private static void declarations(LexerfulGrammarBuilder b) {
     ).skipIfOneChild();
 
     b.rule(declaration).is(
+      b.firstOf(
+        nameDeclaration,
+        specialDeclaration
+      )
+    );
+
+    b.rule(nameDeclaration).is(
       b.firstOf(
         // identifiers with special meaning: import and module => must be placed before rules that start with an identifier!
         moduleImportDeclaration, // C++ import ...
@@ -1088,15 +1097,19 @@ private static void declarations(LexerfulGrammarBuilder b) {
         functionDefinition, // C++
         templateDeclaration, // C++
         deductionGuide, // C++
-        cliGenericDeclaration, // C++/CLI
-        explicitInstantiation, // C++
-        explicitSpecialization, // C++
-        exportDeclaration, // C++
         linkageSpecification, // C++
         namespaceDefinition, // C++
         emptyDeclaration, // C++
-        attributeDeclaration, // C++
+        attributeDeclaration // C++
+      )
+    );
 
+    b.rule(specialDeclaration).is(
+      b.firstOf(
+        cliGenericDeclaration, // C++/CLI
+        explicitInstantiation, // C++
+        explicitSpecialization, // C++
+        exportDeclaration, // C++
         vcAtlDeclaration // Attributted-ATL
       )
     );
@@ -1713,7 +1726,7 @@ private static void declarations(LexerfulGrammarBuilder b) {
       CxxKeyword.EXTERN, STRING,
       b.firstOf(
         b.sequence("{", b.optional(declarationSeq), "}"), // C++
-        declaration // C++
+        nameDeclaration // C++
       )
     );
 
@@ -1807,7 +1820,7 @@ private static void modules(LexerfulGrammarBuilder b) {
     b.rule(exportDeclaration).is( // C++
       "export",
       b.firstOf(
-        declaration,
+        nameDeclaration,
         b.sequence("{", b.optional(declarationSeq), "}"),
         moduleImportDeclaration
       )

diff --git a/cxx-squid/src/test/java/org/sonar/cxx/parser/DeclarationsTest.java b/cxx-squid/src/test/java/org/sonar/cxx/parser/DeclarationsTest.java
@@ -38,33 +38,55 @@ void declarationSeq() {
   void declaration() {
     setRootRule(CxxGrammarImpl.declaration);
 
+    mockRule(CxxGrammarImpl.nameDeclaration);
+    mockRule(CxxGrammarImpl.specialDeclaration);
+
+    assertThatParser()
+      .matches("nameDeclaration")
+      .matches("specialDeclaration");
+  }
+
+  @Test
+  void nameDeclaration() {
+    setRootRule(CxxGrammarImpl.nameDeclaration);
+
     mockRule(CxxGrammarImpl.blockDeclaration);
     mockRule(CxxGrammarImpl.nodeclspecFunctionDeclaration);
     mockRule(CxxGrammarImpl.functionDefinition);
     mockRule(CxxGrammarImpl.templateDeclaration);
     mockRule(CxxGrammarImpl.deductionGuide);
-    mockRule(CxxGrammarImpl.cliGenericDeclaration);
-    mockRule(CxxGrammarImpl.explicitInstantiation);
-    mockRule(CxxGrammarImpl.explicitSpecialization);
     mockRule(CxxGrammarImpl.linkageSpecification);
     mockRule(CxxGrammarImpl.namespaceDefinition);
     mockRule(CxxGrammarImpl.emptyDeclaration);
     mockRule(CxxGrammarImpl.attributeDeclaration);
-    mockRule(CxxGrammarImpl.vcAtlDeclaration);
 
     assertThatParser()
       .matches("blockDeclaration")
       .matches("nodeclspecFunctionDeclaration")
       .matches("functionDefinition")
       .matches("templateDeclaration")
       .matches("deductionGuide")
-      .matches("cliGenericDeclaration")
-      .matches("explicitInstantiation")
-      .matches("explicitSpecialization")
       .matches("linkageSpecification")
       .matches("namespaceDefinition")
       .matches("emptyDeclaration")
-      .matches("attributeDeclaration")
+      .matches("attributeDeclaration");
+  }
+
+  @Test
+  void specialDeclaration() {
+    setRootRule(CxxGrammarImpl.specialDeclaration);
+
+    mockRule(CxxGrammarImpl.cliGenericDeclaration);
+    mockRule(CxxGrammarImpl.explicitInstantiation);
+    mockRule(CxxGrammarImpl.explicitSpecialization);
+    mockRule(CxxGrammarImpl.exportDeclaration);
+    mockRule(CxxGrammarImpl.vcAtlDeclaration);
+
+    assertThatParser()
+      .matches("cliGenericDeclaration")
+      .matches("explicitInstantiation")
+      .matches("explicitSpecialization")
+      .matches("exportDeclaration")
       .matches("vcAtlDeclaration");
   }
 
@@ -650,12 +672,12 @@ void usingDirective() {
   void linkageSpecification() {
     setRootRule(CxxGrammarImpl.linkageSpecification);
 
-    mockRule(CxxGrammarImpl.declaration);
+    mockRule(CxxGrammarImpl.nameDeclaration);
     mockRule(CxxGrammarImpl.declarationSeq);
 
     assertThatParser()
       .matches("extern \"foo\" { declarationSeq }")
-      .matches("extern \"foo\" declaration");
+      .matches("extern \"foo\" nameDeclaration");
   }
 
   @Test

diff --git a/cxx-squid/src/test/java/org/sonar/cxx/parser/ModuleTest.java b/cxx-squid/src/test/java/org/sonar/cxx/parser/ModuleTest.java
@@ -117,12 +117,12 @@ void moduleNameQualifier() {
   void exportDeclaration() {
     setRootRule(CxxGrammarImpl.exportDeclaration);
 
-    mockRule(CxxGrammarImpl.declaration);
+    mockRule(CxxGrammarImpl.nameDeclaration);
     mockRule(CxxGrammarImpl.declarationSeq);
     mockRule(CxxGrammarImpl.moduleImportDeclaration);
 
     assertThatParser()
-      .matches("export declaration")
+      .matches("export nameDeclaration")
       .matches("export { }")
       .matches("export { declarationSeq }")
       .matches("export moduleImportDeclaration");

diff --git a/cxx-squid/src/test/resources/parser/own/C++23/meaningful-exports.cc b/cxx-squid/src/test/resources/parser/own/C++23/meaningful-exports.cc
@@ -0,0 +1,4 @@
+export module M;                // OK
+export int f();                 // OK
+export namespace N { }          // OK
+export using namespace N;       // OK