On Wed, 27 May 2026 15:11:19 GMT, George Adams <[email protected]> wrote:
> Building the JDK on macOS with the Xcode 26 linker (ld version 1267) produces:
>
>
> ld: warning: reducing alignment of section __DATA,__common from 0x8000 to
> 0x4000 because it exceeds segment maximum alignment
>
>
> This comes from libawt, specifically the tentative definitions of `mul8table`
> and `div8table` in `AlphaMath.c`. These are 64KB uninitialized global arrays
> that the compiler places in the __common section with 32KB alignment. The
> Xcode 26 linker caps segment alignment at 16KB (the arm64 page size) and
> warns when clamping.
>
> The fix is to change the tentative definitions to explicit zero-initialized
> definitions:
>
> Before:
>
> JNIEXPORT unsigned char mul8table[256][256];
> JNIEXPORT unsigned char div8table[256][256];
>
>
> After:
>
> JNIEXPORT unsigned char mul8table[256][256] = { { 0 } };
> JNIEXPORT unsigned char div8table[256][256] = { { 0 } };
>
>
> This moves the symbols from __common to __bss, avoiding the alignment
> warning. Both sections are zero-filled at load time, and `initAlphaTables()`
> populates the actual values at runtime, so the change is functionally
> identical. No impact on other platforms.
>
> ---------
> - [x] I confirm that I make this contribution in accordance with the [OpenJDK
> Interim AI Policy](https://openjdk.org/legal/ai).
This pull request has now been integrated.
Changeset: a453a8bd
Author: George Adams <[email protected]>
Committer: Phil Race <[email protected]>
URL:
https://git.openjdk.org/jdk/commit/a453a8bd0c77885f35b9cf4d63737bd2436207cf
Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
8385528: Fix linker alignment warning for libawt on macOS with Xcode 26
Reviewed-by: prr, kizune
-------------
PR: https://git.openjdk.org/jdk/pull/31294
