On Wed, 31 May 2023 15:39:31 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> In C, arguments smaller than `int` are promoted to (`unsigned`) `int`, and >> `float` is promoted to `double`, when being passed as variadic argument (see >> e.g. >> https://en.cppreference.com/w/c/language/conversion#Default_argument_promotions). >> This patch restricts the layouts that can be used as variadic layouts to >> what is allowed by the C specification. >> >> The fallback linker is also updated to use to correct function to link >> variadic calls (not doing this turned out not to be a problem so far, but it >> is problematic for instance on Mac/AArch64 when using the fallback linker). >> Adding the restriction on layouts for all linkers is also partly motivated >> by the fallback linker rejecting such unsupported variadic layouts already. >> >> I've added a small paragraph to the Linker javadoc as well that explains the >> restriction. Comments on that are welcome, but please explain. >> >> The tests are updated to no longer try to link variadic functions with the >> illegal layouts, and I've added some more negative tests to TestIllegalLink. >> >> Testing: >> - local testing on Windows/x64 >> - tier1-3 + jdk-tier5 (ongoing) >> - manual test run on mac/aarch64 with the fallback linker to verify the >> correctness of the fallback linker changes. > > test/jdk/java/foreign/StdLibTest.java line 386: > >> 384: return arena.allocateUtf8String("str"); >> 385: }, "str"), >> 386: CHAR(int.class, C_INT, "%c", arena -> (int) 'h', (int) 'h'), // >> promote to int, per C spec > > is it important to retain this, given that there's already an INT case? Maybe adding a long case would be more useful? ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/14225#discussion_r1211927710
