Extensions should have the final say on their compiler flags

Currently compiler flags passed by extensions using the standard
``PHP_NEW_EXTENSION`` and ``PHP_ADD_SOURCES`` m4 macros are prepended
before the ones defined by ``Zend/Zend.m4``.

This was not really an issue before as ``Zend.m4`` only included
``-Wall`` but since the addition of ``-Wextra`` various issue about
disabling flags have been brought up.

A preliminary attempt was done in commit 5c1cf7669b
but this turns out to be more or less irrelevant.

The root issue is that  ``PHP_NEW_EXTENSION`` and ``PHP_ADD_SOURCES`` call the
``PHP_ADD_SOURCES_X`` macro and pass their flags as the 3rd argument which prepends
the flags. There exists a 6th argument for this macro which appends them but from a
cursory look at https://heap.space/search?full=PHP_ADD_SOURCES_X&project=php-src
this is not used. Moreover, the comment describing this macro explicitly informs
that this macro should not be used directly.

As such we drop the 6th argument of ``PHP_ADD_SOURCES_X`` and move the `special-flags`
argument to be appended instead of prepended.

Closes GH-6204
This commit is contained in:
George Peter Banyard 2020-09-24 13:28:56 +01:00
parent 978a44c9c6
commit 07a2f30417
2 changed files with 13 additions and 5 deletions

View File

@ -440,6 +440,14 @@ PHP 8.0 INTERNALS UPGRADE NOTES
2. The PHP_CHECK_GCC_ARG() m4 macro has been removed in favor of
AX_CHECK_COMPILE_FLAG().
3. The 6th argument of PHP_ADD_SOURCES_X has been removed.
4. The 'special-flags' (3rd) argument of PHP_ADD_SOURCES_X are
now appended instead of prepended to previous compiler flags.
This means compiler flags passed to PHP_NEW_EXTENSION and PHP_ADD_SOURCES
are now appended, this allows to disable compiler flags set by Zend/Zend.m4
(e.g. disable certain compiler flags enabled by -Wextra)
c. Windows build system changes
- The configuration option --enable-crt-debug has been removed. The VC

View File

@ -218,7 +218,7 @@ ifelse($1,shared,[
])
dnl
dnl PHP_ADD_SOURCES_X(source-path, sources[, special-flags[, target-var[, shared[, special-post-flags]]]])
dnl PHP_ADD_SOURCES_X(source-path, sources[, special-flags[, target-var[, shared]]])
dnl
dnl Additional to PHP_ADD_SOURCES (see above), this lets you set the name of the
dnl array target-var directly, as well as whether shared objects will be built
@ -251,10 +251,10 @@ dnl Append to the array which has been dynamically chosen at m4 time.
dnl Choose the right compiler/flags/etc. for the source-file.
case $ac_src in
*.c[)] ac_comp="$b_c_pre $3 $ac_inc $b_c_meta -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $6$b_c_post" ;;
*.s[)] ac_comp="$b_c_pre $3 $ac_inc $b_c_meta -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $6$b_c_post" ;;
*.S[)] ac_comp="$b_c_pre $3 $ac_inc $b_c_meta -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $6$b_c_post" ;;
*.cpp|*.cc|*.cxx[)] ac_comp="$b_cxx_pre $3 $ac_inc $b_cxx_meta -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $6$b_cxx_post" ;;
*.c[)] ac_comp="$b_c_pre $ac_inc $b_c_meta $3 -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $b_c_post" ;;
*.s[)] ac_comp="$b_c_pre $ac_inc $b_c_meta $3 -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $b_c_post" ;;
*.S[)] ac_comp="$b_c_pre $ac_inc $b_c_meta $3 -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $b_c_post" ;;
*.cpp|*.cc|*.cxx[)] ac_comp="$b_cxx_pre $ac_inc $b_cxx_meta $3 -c $ac_srcdir$ac_src -o $ac_bdir$ac_obj.$b_lo $b_cxx_post" ;;
esac
dnl Create a rule for the object/source combo.