Integrated: 8364103: Convert existing sprintf-chains to stringStream

[Paul Hübner]

On Fri, 22 Aug 2025 08:49:56 GMT, Paul Hübner <phubner at openjdk.org> wrote:

> Hi all,
> 
> This PR refactors `javaClasses`' `print_stack_element_to_stream` to use a `stringStream` instead of manually maintaining a buffer with `os::snprintf` chains.
> 
> The JBS issue outlines to do this for all occurrences of `snprintf`-like chains. The majority of the calls to `os::snprintf`, `os::snprintf_checked`, `os::vsnprintf`, etc. occur just once. `LogTagSet::vwrite` is the only place to my knowledge where there remains a `vsnprintf` chain using manual buffer arithmetic. After consulting @jdksjolen, we decided that due to the
> a) low-level nature of the code, and 
> b) widespread usage of logging in the VM, 
> this should probably warrant a larger discussion and/or separate issue. Personally, I feel like the performance & correctness risks of introducing a high-level abstraction here outweighs the benefits. 
> 
> I've run tests with JDK tiers 1-3 on macOS (AArch64, x64), Linux (AArch64, x64), and Windows (x64); all green.

This pull request has now been integrated.

Changeset: cfb80934
Author:    Paul Hübner <phubner at openjdk.org>
Committer: David Holmes <dholmes at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/cfb809344c0205875b35991ce6807333df41c949
Stats:     48 lines in 1 file changed: 5 ins; 26 del; 17 mod

8364103: Convert existing sprintf-chains to stringStream

Reviewed-by: kbarrett, dholmes, iklam

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PR: https://git.openjdk.org/jdk/pull/26894