Bug #79356 [Opn]: FFI:structure/union alignment [ext/ffi/tests/022.phpt] failure

Edit report at https://bugs.php.net/bug.php?id=79356&edit=1 ID: 79356 Updated by: nikic@php.net Reported by: vibhutisawant18 at gmail dot com Summary: FFI:structure/union alignment [ext/ffi/tests/022.phpt] failure Status: Open Type: Bug Package: Testing related Operating System: Ubuntu 16.04 PHP Version: master-Git-2020-03-09 (Git) Block user comment: N Private report: N New Comment: Okay, I see now. __attribute__((aligned)) is the same as __attribute__((__BIGGEST_ALIGNMENT__)). I happened to use an -march=sandybridge build, where __BIGGEST_ALIGNMENT__ is 32. Previous Comments: ------------------------------------------------------------------------ [2020-03-09 10:09:21] nikic@php.net Something odd is going on here. The test passes for me on 7.4, but fails on master. Adding a bit more debug output I get: FAIL: sizeof(struct {char a; uint32_t b __attribute__((aligned));}) Expected: 32 Actual: 64 FAIL: alignof(struct {char a; uint32_t b __attribute__((aligned));}) Expected: 16 Actual: 32 So I'm seeing a higher size/alignment for some reason. ------------------------------------------------------------------------ [2020-03-09 09:50:26] vibhutisawant18 at gmail dot com ext/ffi/tests/022.phpt passed on x86-64.PFB the test log. root@a11efdc33877:~/php/php-src# sapi/cli/php -f "ext/ffi/tests/022.phpt" --TEST-- FFI 022: structure/union alignment --SKIPIF-- --INI-- ffi.enable=1 --FILE-- ok --EXPECT-- ok root@a11efdc33877:~/php/php-src# arch x86_64 root@a11efdc33877:~/php/php-src# ------------------------------------------------------------------------ [2020-03-09 08:17:12] nikic@php.net This test also fails for me on a x86-64, so not big endian specific. ------------------------------------------------------------------------ [2020-03-09 05:53:16] vibhutisawant18 at gmail dot com The following patch has been added/updated: Patch Name: FFI_structure_union_alignment_s390x Revision: 1583733196 URL: https://bugs.php.net/patch-display.php?bug=79356&patch=FFI_structure_union_alignment_s390x&revision=1583733196 ------------------------------------------------------------------------ [2020-03-09 05:49:17] vibhutisawant18 at gmail dot com Description: ------------ FFI:structure/union alignment [ext/ffi/tests/022.phpt] fails on Big endian systems. The TC fails in the following code block: if (substr(PHP_OS, 0, 3) != 'WIN') { test_size(32, "struct {char a; uint32_t b __attribute__((aligned));}"); test_align(16, "struct {char a; uint32_t b __attribute__((aligned));}"); } The __attribute__((aligned(__BIGGEST_ALIGNMENT__))) returns 8 bytes on s390x, whereas its 16 bytes on x86 architecture. Hence the test functions output observed on s390x is : test_size expects the size returned to be 16. test_align expects the alignment returned to be 8. Added a patch with TC changes specific to s390x. Kindly let me know if I shall raise a PR with this changes. Also Could you please ensure if additional source code changes are needed? ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79356&edit=1