Compiler flag gets erroneously removed

[nielsdos]

Description

When compiling with:

export CFLAGS="-Xclang -disable-O0-optnone"
./configure --enable-debug

The Xclang command passed to the compiler is -Xclang -disable-O0-optnone, i.e. the -O0 gets removed.
I know there's some compiler optimization flag sanitization happening somewhere, but in this case it's breaking legit usage.
The workaround I used in the end was adding -O0 to CFLAGS and removing --enable-debug from the configure command.

PHP Version

master 8.2

Operating System

Linux

[petk]

Is there anything more in the CFLAGS? Also probably the CC is set to clang? In the generated Makefile I see the -O0 in CFLAGS_CLEAN variable. Meaning: I can't reproduce this one.

[nielsdos]

Apologies, the version I reported this on is wrong. It works on master but does not work on the branch PHP-8.2.
CC is indeed set to clang.
Sample compiler command line:

/bin/sh /home/niels/experiments/php-src-up/libtool --silent --preserve-dup-deps --tag=CC --mode=compile clang -Iext/date/ -I/home/niels/experiments/php-src-up/ext/date/ -I/home/niels/experiments/php-src-up/include -I/home/niels/experiments/php-src-up/main -I/home/niels/experiments/php-src-up -I/usr/include/valgrind -I/home/niels/experiments/php-src-up/ext/date/lib -I/home/niels/experiments/php-src-up/TSRM -I/home/niels/experiments/php-src-up/Zend  -D_GNU_SOURCE  -Wall -Wextra -Wno-strict-aliasing -Wno-unused-parameter -Wno-sign-compare -Xclang -disable-optnone -ffp-contract=off -fvisibility=hidden -O0 -g    -Iext/date/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1 -c /home/niels/experiments/php-src-up/ext/date/php_date.c -o ext/date/php_date.lo  -MMD -MF ext/date/php_date.dep -MT ext/date/php_date.lo
error: unknown argument: '-disable-optnone'
make: *** [Makefile:514: ext/date/php_date.lo] Error 1

[petk]

This one #9647 wasn't added to PHP-8.2 but only to master branch. Then this probably could go to PHP-8.2 also.

[nielsdos]

Good find, I guess so, cc @arnaud-lb

[arnaud-lb]

I think that #9647 fixes this by chance, but an option like -disable-O0 (that ends with -O0) would also be wrongly changed to just -disable. #15828 backports that to 8.2 and improves it to handle this case.