Parse type arguments after callable reference as error

Is likely to be supported in the future

compiler/frontend/src/org/jetbrains/kotlin/parsing/JetExpressionParsing.java

@@ -370,7 +370,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
 
     /*
      * callableReference
-     *   : (userType "?"*)? "::" SimpleName
+     *   : (userType "?"*)? "::" SimpleName typeArguments?
      *   ;
      */
     private boolean parseDoubleColonExpression() {
@@ -396,6 +396,17 @@ public class JetExpressionParsing extends AbstractJetParsing {
         }
         else {
             parseSimpleNameExpression();
+
+            if (at(LT)) {
+                PsiBuilder.Marker typeArgumentList = mark();
+                if (myJetParsing.tryParseTypeArgumentList(TYPE_ARGUMENT_LIST_STOPPERS)) {
+                    typeArgumentList.error("Type arguments are not allowed");
+                }
+                else {
+                    typeArgumentList.rollbackTo();
+                }
+            }
+
             expression.done(CALLABLE_REFERENCE_EXPRESSION);
         }
 

compiler/testData/psi/DoubleColon.kt

@@ -50,3 +50,11 @@ fun err2() {
 fun err3() {
     ::
 }
+
+fun typeArgumentsError() {
+    ::a<b>
+    ::a<b,c<*>>
+    a::b<c>
+
+    ::a<b>()
+}

compiler/testData/psi/DoubleColon.txt

@@ -609,3 +609,86 @@ JetFile: DoubleColon.kt
           PsiErrorElement:Expecting an identifier
             <empty list>
       PsiElement(RBRACE)('}')
+  PsiWhiteSpace('\n\n')
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('typeArgumentsError')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      CALLABLE_REFERENCE_EXPRESSION
+        PsiElement(COLONCOLON)('::')
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('a')
+        PsiErrorElement:Type arguments are not allowed
+          PsiElement(LT)('<')
+          TYPE_PROJECTION
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('b')
+          PsiElement(GT)('>')
+      PsiWhiteSpace('\n    ')
+      CALLABLE_REFERENCE_EXPRESSION
+        PsiElement(COLONCOLON)('::')
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('a')
+        PsiErrorElement:Type arguments are not allowed
+          PsiElement(LT)('<')
+          TYPE_PROJECTION
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('b')
+          PsiElement(COMMA)(',')
+          TYPE_PROJECTION
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('c')
+                TYPE_ARGUMENT_LIST
+                  PsiElement(LT)('<')
+                  TYPE_PROJECTION
+                    PsiElement(MUL)('*')
+                  PsiElement(GT)('>')
+          PsiElement(GT)('>')
+      PsiWhiteSpace('\n    ')
+      CALLABLE_REFERENCE_EXPRESSION
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('a')
+        PsiElement(COLONCOLON)('::')
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('b')
+        PsiErrorElement:Type arguments are not allowed
+          PsiElement(LT)('<')
+          TYPE_PROJECTION
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('c')
+          PsiElement(GT)('>')
+      PsiWhiteSpace('\n\n    ')
+      CALLABLE_REFERENCE_EXPRESSION
+        PsiElement(COLONCOLON)('::')
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('a')
+        PsiErrorElement:Type arguments are not allowed
+          PsiElement(LT)('<')
+          TYPE_PROJECTION
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('b')
+          PsiElement(GT)('>')
+      PsiErrorElement:Unexpected tokens (use ';' to separate expressions on the same line)
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')

grammar/src/expressions.grm

@@ -104,7 +104,7 @@ postfixUnaryExpression
 
 // TODO: callSuffix is forbidden after callableReference, since parentheses will be used to provide parameter types
 callableReference
-  : (userType "?"*)? "::" SimpleName
+  : (userType "?"*)? "::" SimpleName typeArguments?
   ;
 
 // !!! When you add here, remember to update the FIRST set in the parser