From b5ddf51ea87e43a00441eed2185961baf29e7eab Mon Sep 17 00:00:00 2001
From: Nick Treleaven <ntrel002@gmail.com>
Date: Wed, 8 May 2024 08:11:38 +0100
Subject: [PATCH] Improve `@__future` deprecation message (#16447)

Show location of base method.
Remove duplicate content in compilable/future.d.
---
 compiler/src/dmd/funcsem.d        |  5 +++-
 compiler/test/compilable/future.d | 47 -------------------------------
 compiler/test/runnable/future.d   |  3 +-
 3 files changed, 6 insertions(+), 49 deletions(-)
 delete mode 100644 compiler/test/compilable/future.d

diff --git a/compiler/src/dmd/funcsem.d b/compiler/src/dmd/funcsem.d
index e058deb0f9..31ed744d92 100644
--- a/compiler/src/dmd/funcsem.d
+++ b/compiler/src/dmd/funcsem.d
@@ -742,7 +742,10 @@ void funcDeclarationSemantic(Scope* sc, FuncDeclaration funcdecl)
                 {
                     if (fdv.isFuture())
                     {
-                        deprecation(funcdecl.loc, "`@__future` base class method `%s` is being overridden by `%s`; rename the latter", fdv.toPrettyChars(), funcdecl.toPrettyChars());
+                        deprecation(funcdecl.loc, "method `%s` implicitly overrides `@__future` base class method; rename the former",
+                            funcdecl.toPrettyChars());
+                        deprecationSupplemental(fdv.loc, "base method `%s` defined here",
+                            fdv.toPrettyChars());
                         // Treat 'this' as an introducing function, giving it a separate hierarchy in the vtbl[]
                         goto Lintro;
                     }
diff --git a/compiler/test/compilable/future.d b/compiler/test/compilable/future.d
deleted file mode 100644
index 30439847ef..0000000000
--- a/compiler/test/compilable/future.d
+++ /dev/null
@@ -1,47 +0,0 @@
-/* PERMUTE_ARGS:
- * TEST_OUTPUT:
----
-compilable/future.d(15): Deprecation: `@__future` base class method `future.A.msg` is being overridden by `future.B.msg`; rename the latter
----
- */
-
-class A
-{
-    @__future char msg() { return 'a'; }
-}
-
-class B : A
-{
-    char msg() { return 'b'; }
-}
-
-class C : B
-{
-    override char msg() { return 'c'; }
-}
-
-class D : A
-{
-    override char msg() { return 'd'; }
-}
-
-int main()
-{
-    auto a = new A();
-    assert(a.msg() == 'a');
-    auto b = new B();
-    assert(b.msg() == 'b');
-    auto c = new C();
-    assert(c.msg() == 'c');
-    auto d = new D();
-    assert(d.msg() == 'd');
-
-    assert(b.A.msg() == 'a');
-
-    auto ba = cast(A)b;
-    assert(ba.msg() == 'a');
-
-    auto da = cast(A)d;
-    assert(da.msg() == 'd');
-    return 0;
-}
diff --git a/compiler/test/runnable/future.d b/compiler/test/runnable/future.d
index 1a91d30535..e0ef466395 100644
--- a/compiler/test/runnable/future.d
+++ b/compiler/test/runnable/future.d
@@ -1,7 +1,8 @@
 /* PERMUTE_ARGS:
 TEST_OUTPUT:
 ---
-runnable/future.d(15): Deprecation: `@__future` base class method `future.A.msg` is being overridden by `future.B.msg`; rename the latter
+runnable/future.d(16): Deprecation: method `future.B.msg` implicitly overrides `@__future` base class method; rename the former
+runnable/future.d(11):        base method `future.A.msg` defined here
 ---
  */