Integrated: 8325088: Overloads that differ in type parameters may be lost

[Pavel Rappo]

On Wed, 27 Mar 2024 17:19:35 GMT, Pavel Rappo <prappo at openjdk.org> wrote:

> Creating a link to a constructor or a method or comparing constructors or methods __does not__ factor in type parameters. When constructors or methods are overloaded and differ only in type parameters -- a situation which is absent in JDK API, but present elsewhere -- that causes significant defects, such as:
> 
>   - missing entries in summary tables, lists and indexes,
>   - duplicating links in the table of contents.
> 
> This PR fixes those defects, and the fix is two-fold. Firstly, we update comparators to consider type parameters. That takes care of missing constructors and methods. Secondly, we update id (anchor) and link generation to always use the "erased" notation. That takes care of duplicating links.
> 
> What's the "erased" notation? Suppose we have the following method:
> 
>     <T extends String> T m(T arg)
> 
> The current notation refers to it as `m(T)`. That works fine until there's no other method, such as
> 
>     <T> T m(T arg)
> 
> In which case, the current notation will produce a collision: `m(T)`. By contrast, the erased notation for those two methods is `m(java.lang.String)` and `m(java.lang.Object)` respectively. No collision.
> 
> While longer, I believe that the erased notation is collision-proof. Why? Because [JLS 8.4.2][] says that "it is a compile-time error to declare two methods with override-equivalent signatures in a class". Which means that for any two constructors or methods the erasure of their signatures must differ, or else it won't compile.
> 
> The change is pretty straightforward, except for some test fallout that required attention.
> 
> [JLS 8.4.2]: https://docs.oracle.com/javase/specs/jls/se22/html/jls-8.html#jls-8.4.2

This pull request has now been integrated.

Changeset: 7c664657
Author:    Pavel Rappo <prappo at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/7c664657630a50ab83d218028cec114ea2d907ac
Stats:     531 lines in 8 files changed: 488 ins; 15 del; 28 mod

8325088: Overloads that differ in type parameters may be lost

Reviewed-by: jjg

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PR: https://git.openjdk.org/jdk/pull/18519