RFR: 8364103: Convert existing sprintf-chains to stringStream [v3]
    Paul Hübner 
    phubner at openjdk.org
       
    Fri Sep  5 14:03:55 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.
Paul Hübner has updated the pull request incrementally with one additional commit since the last revision:
  Clean up method a bit.
-------------
Changes:
  - all: https://git.openjdk.org/jdk/pull/26894/files
  - new: https://git.openjdk.org/jdk/pull/26894/files/c6da1f57..3a87b884
Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26894&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26894&range=01-02
  Stats: 28 lines in 1 file changed: 8 ins; 16 del; 4 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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