Handle variable templates in isInstantiated and isInTemplateInstantiation matchers

Fix isInstantiated and isInTemplateInstantiation matchers, so they return true for instantiations of variable templates, and any declaration in statements contained in such instantiations.

Author: frederic-tingaud-sonarsource

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -6750,7 +6750,8 @@ AST_POLYMORPHIC_MATCHER(isTemplateInstantiation,
 ///   matches 'A(int) {...};' and 'A(unsigned) {...}'.
 AST_MATCHER_FUNCTION(internal::Matcher<Decl>, isInstantiated) {
   auto IsInstantiation = decl(anyOf(cxxRecordDecl(isTemplateInstantiation()),
-                                    functionDecl(isTemplateInstantiation())));
+                                    functionDecl(isTemplateInstantiation()),
+                                    varDecl(isTemplateInstantiation())));
   return decl(anyOf(IsInstantiation, hasAncestor(IsInstantiation)));
 }
 
@@ -6769,9 +6770,9 @@ AST_MATCHER_FUNCTION(internal::Matcher<Decl>, isInstantiated) {
 ///   will NOT match j += 42; as it's shared between the template definition and
 ///   instantiation.
 AST_MATCHER_FUNCTION(internal::Matcher<Stmt>, isInTemplateInstantiation) {
-  return stmt(
-      hasAncestor(decl(anyOf(cxxRecordDecl(isTemplateInstantiation()),
-                             functionDecl(isTemplateInstantiation())))));
+  return stmt(hasAncestor(decl(anyOf(cxxRecordDecl(isTemplateInstantiation()),
+                                     functionDecl(isTemplateInstantiation()),
+                                     varDecl(isTemplateInstantiation())))));
 }
 
 /// Matches explicit template specializations of function, class, or

clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

@@ -3313,6 +3313,45 @@ TEST_P(ASTMatchersTest,
                          declStmt(isInTemplateInstantiation())));
 }
 
+TEST_P(ASTMatchersTest, IsInstantiated_MatchesVariableInstantiation) {
+  if (!GetParam().isCXX14OrLater()) {
+    return;
+  }
+
+  EXPECT_TRUE(matches("template<typename T> int V = 10; void x() { V<int>; }",
+                      varDecl(isInstantiated())));
+}
+
+TEST_P(ASTMatchersTest, IsInstantiated_NotMatchesVariableDefinition) {
+  if (!GetParam().isCXX14OrLater()) {
+    return;
+  }
+
+  EXPECT_TRUE(notMatches("template<typename T> int V = 10;",
+                         varDecl(isInstantiated())));
+}
+
+TEST_P(ASTMatchersTest,
+       IsInTemplateInstantiation_MatchesVariableInstantiationStmt) {
+  if (!GetParam().isCXX14OrLater()) {
+    return;
+  }
+
+  EXPECT_TRUE(matches(
+      "template<typename T> auto V = []() { T i; }; void x() { V<int>(); }",
+      declStmt(isInTemplateInstantiation())));
+}
+
+TEST_P(ASTMatchersTest,
+       IsInTemplateInstantiation_NotMatchesVariableDefinitionStmt) {
+  if (!GetParam().isCXX14OrLater()) {
+    return;
+  }
+
+  EXPECT_TRUE(notMatches("template<typename T> auto V = []() { T i; };",
+                         declStmt(isInTemplateInstantiation())));
+}
+
 TEST_P(ASTMatchersTest, IsInTemplateInstantiation_Sharing) {
   if (!GetParam().isCXX()) {
     return;