RFR: 8364103: Convert existing sprintf-chains to stringStream
Paul Hübner
duke at openjdk.org
Fri Aug 22 08:58:34 UTC 2025
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.
-------------
Commit messages:
- Refactor stack trace printing to use stringStream.
Changes: https://git.openjdk.org/jdk/pull/26894/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26894&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8364103
Stats: 20 lines in 1 file changed: 1 ins; 6 del; 13 mod
Patch: https://git.openjdk.org/jdk/pull/26894.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/26894/head:pull/26894
PR: https://git.openjdk.org/jdk/pull/26894
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