Deprecate traits(isVirtualFunction) and traits(getVirtualFunctions) (#14802)

changelog/dmd.get-is-virtual-function.dd

@@ -0,0 +1,11 @@
+Deprecate `traits(isVirtualFunction)` and `traits(getVirtualFunctions)`
+
+Up until this release, D had both `traits(isVirtualFunction)` and `traits(isVirtualMethod)`
+(and their coressponding `traits(get...)` counterpart). The differenrcte between the two is
+that `isVirtualFunction` returns true for `final` methods that do not override anything. This
+is in contradiction with the D spec which states that `final` functions that do not override
+other functions cannot be virtual. `isVirtualMethod` correctly returns `false` in that case.
+
+Starting with this release, both `traits(isVirtualFunction)` and `traits(getVirtualFunctions)`
+are deprecated. If the behavior of `traits(isVirtualFunction)` is desired, it can be achieved by
+`traits(isVirtualMethod, f) || (traits(isFinalFunction, f) && !traits(isOverrideFunction, f))`.

compiler/src/dmd/traits.d

@@ -634,6 +634,10 @@ Expression semanticTraits(TraitsExp e, Scope* sc)
     }
     if (e.ident == Id.isVirtualFunction)
     {
+        // @@@DEPRECATED2.121@@@
+        // Deprecated in 2.101 - Can be removed from 2.121
+        e.deprecation("`traits(isVirtualFunction)` is deprecated. Use `traits(isVirtualMethod)` instead");
+
         if (dim != 1)
             return dimError(1);
 
@@ -995,6 +999,13 @@ Expression semanticTraits(TraitsExp e, Scope* sc)
             if (errors < global.errors)
                 e.error("`%s` cannot be resolved", eorig.toChars());
 
+            if (e.ident == Id.getVirtualFunctions)
+            {
+                // @@@DEPRECATED2.121@@@
+                // Deprecated in 2.101 - Can be removed from 2.121
+                e.deprecation("`traits(getVirtualFunctions)` is deprecated. Use `traits(getVirtualMethods)` instead");
+            }
+
             /* Create tuple of functions of ex
              */
             auto exps = new Expressions();

compiler/test/compilable/ice13920.d

@@ -14,11 +14,6 @@ class Foo
         {
             auto dg = &f;
         }
-
-        foreach (f; __traits(getVirtualFunctions, typeof(this), "bar"))
-        {
-            auto dg = &f;
-        }
     }
 
     uint bar() { return 0; }

compiler/test/fail_compilation/deprecate_getVirtualFunctions.d

@@ -0,0 +1,20 @@
+// REQUIRED_ARGS: -de
+
+/*
+TEST_OUTPUT:
+---
+fail_compilation/deprecate_getVirtualFunctions.d(18): Deprecation: `traits(isVirtualFunction)` is deprecated. Use `traits(isVirtualMethod)` instead
+fail_compilation/deprecate_getVirtualFunctions.d(19): Deprecation: `traits(getVirtualFunctions)` is deprecated. Use `traits(getVirtualMethods)` instead
+---
+*/
+
+class A
+{
+    void fun() {}
+}
+
+void main()
+{
+    auto a = __traits(isVirtualFunction, A.fun);
+    foreach(f; __traits(getVirtualFunctions, A, "fun")) {}
+}

compiler/test/fail_compilation/fail19076.d

@@ -8,4 +8,4 @@ fail_compilation/fail19076.d(11): Error: `(I).V` cannot be resolved
 
 interface P { }
 interface I : P { }
-auto F = __traits(getVirtualFunctions, I, "V");
+auto F = __traits(getVirtualMethods, I, "V");

compiler/test/fail_compilation/test17096.d

@@ -1,28 +1,29 @@
 /* TEST_OUTPUT:
 ---
-fail_compilation/test17096.d(28): Error: expected 1 arguments for `isPOD` but had 2
+fail_compilation/test17096.d(29): Error: expected 1 arguments for `isPOD` but had 2
-fail_compilation/test17096.d(29): Error: expected 1 arguments for `isNested` but had 2
+fail_compilation/test17096.d(30): Error: expected 1 arguments for `isNested` but had 2
-fail_compilation/test17096.d(30): Error: expected 1 arguments for `isVirtualFunction` but had 2
+fail_compilation/test17096.d(31): Deprecation: `traits(isVirtualFunction)` is deprecated. Use `traits(isVirtualMethod)` instead
-fail_compilation/test17096.d(31): Error: expected 1 arguments for `isVirtualMethod` but had 2
+fail_compilation/test17096.d(31): Error: expected 1 arguments for `isVirtualFunction` but had 2
-fail_compilation/test17096.d(32): Error: expected 1 arguments for `isAbstractFunction` but had 2
+fail_compilation/test17096.d(32): Error: expected 1 arguments for `isVirtualMethod` but had 2
-fail_compilation/test17096.d(33): Error: expected 1 arguments for `isFinalFunction` but had 2
+fail_compilation/test17096.d(33): Error: expected 1 arguments for `isAbstractFunction` but had 2
-fail_compilation/test17096.d(34): Error: expected 1 arguments for `isOverrideFunction` but had 2
+fail_compilation/test17096.d(34): Error: expected 1 arguments for `isFinalFunction` but had 2
-fail_compilation/test17096.d(35): Error: expected 1 arguments for `isStaticFunction` but had 2
+fail_compilation/test17096.d(35): Error: expected 1 arguments for `isOverrideFunction` but had 2
-fail_compilation/test17096.d(36): Error: expected 1 arguments for `isRef` but had 2
+fail_compilation/test17096.d(36): Error: expected 1 arguments for `isStaticFunction` but had 2
-fail_compilation/test17096.d(37): Error: expected 1 arguments for `isOut` but had 2
+fail_compilation/test17096.d(37): Error: expected 1 arguments for `isRef` but had 2
-fail_compilation/test17096.d(38): Error: expected 1 arguments for `isLazy` but had 2
+fail_compilation/test17096.d(38): Error: expected 1 arguments for `isOut` but had 2
-fail_compilation/test17096.d(39): Error: expected 1 arguments for `identifier` but had 2
+fail_compilation/test17096.d(39): Error: expected 1 arguments for `isLazy` but had 2
-fail_compilation/test17096.d(40): Error: expected 1 arguments for `getProtection` but had 2
+fail_compilation/test17096.d(40): Error: expected 1 arguments for `identifier` but had 2
-fail_compilation/test17096.d(41): Error: expected 1 arguments for `parent` but had 2
+fail_compilation/test17096.d(41): Error: expected 1 arguments for `getProtection` but had 2
-fail_compilation/test17096.d(42): Error: expected 1 arguments for `classInstanceSize` but had 2
+fail_compilation/test17096.d(42): Error: expected 1 arguments for `parent` but had 2
-fail_compilation/test17096.d(43): Error: expected 1 arguments for `allMembers` but had 2
+fail_compilation/test17096.d(43): Error: expected 1 arguments for `classInstanceSize` but had 2
-fail_compilation/test17096.d(44): Error: expected 1 arguments for `derivedMembers` but had 2
+fail_compilation/test17096.d(44): Error: expected 1 arguments for `allMembers` but had 2
-fail_compilation/test17096.d(45): Error: expected 1 arguments for `getAliasThis` but had 2
+fail_compilation/test17096.d(45): Error: expected 1 arguments for `derivedMembers` but had 2
-fail_compilation/test17096.d(46): Error: expected 1 arguments for `getAttributes` but had 2
+fail_compilation/test17096.d(46): Error: expected 1 arguments for `getAliasThis` but had 2
-fail_compilation/test17096.d(47): Error: expected 1 arguments for `getFunctionAttributes` but had 2
+fail_compilation/test17096.d(47): Error: expected 1 arguments for `getAttributes` but had 2
-fail_compilation/test17096.d(48): Error: expected 1 arguments for `getUnitTests` but had 2
+fail_compilation/test17096.d(48): Error: expected 1 arguments for `getFunctionAttributes` but had 2
-fail_compilation/test17096.d(49): Error: expected 1 arguments for `getVirtualIndex` but had 2
+fail_compilation/test17096.d(49): Error: expected 1 arguments for `getUnitTests` but had 2
-fail_compilation/test17096.d(50): Error: a single type expected for trait pointerBitmap
+fail_compilation/test17096.d(50): Error: expected 1 arguments for `getVirtualIndex` but had 2
+fail_compilation/test17096.d(51): Error: a single type expected for trait pointerBitmap
 ---
 */
 enum b03 = __traits(isPOD, 1, 2);

compiler/test/runnable/e7804.d

@@ -63,8 +63,6 @@ TmpPrm!(__traits(getMember, Foo, "MyInt")) tpt = TmpPrm!(__traits(getMember, Foo
     int virtual(int p){return p;}
     void test(this T)()
     {
-        alias vf = __traits(getVirtualFunctions, Class, "virtual");
-        assert(vf.length == 2);
         alias vm = __traits(getVirtualMethods, Class, "virtual");
         assert(vm.length == 1);
         assert(vm[0](42) == 42);

compiler/test/runnable/traits.d

@@ -312,14 +312,6 @@ void test9()
 
 /********************************************************/
 
-void test10()
-{
-    assert(__traits(isVirtualFunction, C.bar) == true);
-    assert(__traits(isVirtualFunction, S.bar) == false);
-}
-
-/********************************************************/
-
 void test11()
 {
     assert(__traits(isAbstractFunction, C.bar) == false);
@@ -403,24 +395,6 @@ class D15
     int foo(int) { return 2; }
 }
 
-void test15()
-{
-    D15 d = new D15();
-
-    assert(__traits(getVirtualFunctions, D15, "foo").length == 2);
-    assert(typeid(typeof(__traits(getVirtualFunctions, D15, "foo")[0])).toString()
-           == "void function()");
-    assert(typeid(typeof(__traits(getVirtualFunctions, D15, "foo")[1])).toString()
-           == "int function(int)");
-
-    alias typeof(__traits(getVirtualFunctions, D15, "foo")) b;
-    assert(typeid(b[0]).toString() == "void function()");
-    assert(typeid(b[1]).toString() == "int function(int)");
-
-    auto i = __traits(getVirtualFunctions, d, "foo")[1](1);
-    assert(i == 2);
-}
-
 /********************************************************/
 
 struct S16 { }
@@ -714,14 +688,6 @@ interface AA
      int YYY();
 }
 
-class CC : AA
-{
-    final int YYY() { return 4; }
-}
-
-static assert(__traits(isVirtualMethod, CC.YYY));
-static assert(__traits(getVirtualMethods, CC, "YYY").length == 1);
-
 class DD
 {
     final int YYY() { return 4; }
@@ -790,8 +756,6 @@ void test7858()
 
     static assert(__traits(isFinalFunction, C.ffunc) ==
                   __traits(isFinalFunction, __traits(getOverloads, C, "ffunc")[0]));    // NG
-    static assert(__traits(isVirtualFunction, C.vfunc) ==
-                  __traits(isVirtualFunction, __traits(getOverloads, C, "vfunc")[0]));  // NG
     static assert(__traits(isVirtualMethod, C.vfunc) ==
                   __traits(isVirtualMethod, __traits(getOverloads, C, "vfunc")[0]));    // NG
     static assert(__traits(isAbstractFunction, C.afunc) ==
@@ -1456,13 +1420,11 @@ int main()
     test7();
     test8();
     test9();
-    test10();
     test11();
     test12();
     test13();
     test7123();
     test14();
-    test15();
     test16();
     test17();
     test18();

druntime/src/core/internal/traits.d

@@ -654,7 +654,7 @@ if (func.length == 1 /*&& isCallable!func*/)
         int  test(int);
         int  test() @property;
     }
-    alias ov = __traits(getVirtualFunctions, Overloads, "test");
+    alias ov = __traits(getVirtualMethods, Overloads, "test");
     alias F_ov0 = FunctionTypeOf!(ov[0]);
     alias F_ov1 = FunctionTypeOf!(ov[1]);
     alias F_ov2 = FunctionTypeOf!(ov[2]);

druntime/src/object.d

@@ -1417,7 +1417,7 @@ class TypeInfo_Function : TypeInfo
        int func(int a, int b);
     }
 
-    alias functionTypes = typeof(__traits(getVirtualFunctions, C, "func"));
+    alias functionTypes = typeof(__traits(getVirtualMethods, C, "func"));
     assert(typeid(functionTypes[0]).toString() == "void function()");
     assert(typeid(functionTypes[1]).toString() == "void function(int)");
     assert(typeid(functionTypes[2]).toString() == "int function(int, int)");
@@ -1431,7 +1431,7 @@ class TypeInfo_Function : TypeInfo
        void func(int a);
     }
 
-    alias functionTypes = typeof(__traits(getVirtualFunctions, C, "func"));
+    alias functionTypes = typeof(__traits(getVirtualMethods, C, "func"));
 
     Object obj = typeid(functionTypes[0]);
     assert(obj.opEquals(typeid(functionTypes[0])));