Getting error for installing intl extension

[adeshmrane]

Description

I am trying to compile PHP 8.4.1 on AlmaLinux release 8.10

When I enable the IMAPintl extension with the --enable-intl=shared option i ran into below errors.

/usr/lib/gcc/x86_64-redhat-linux/8/include/stddef.h:437:2: error: expected ‘;’ after struct definition
 } max_align_t;
  ^
  ;
/usr/lib/gcc/x86_64-redhat-linux/8/include/stddef.h:437:1: error: missing type-name in typedef-declaration
 } max_align_t;
 ^
/usr/lib/gcc/x86_64-redhat-linux/8/include/stddef.h:437:14: error: expected unqualified-id before ‘;’ token
 } max_align_t;
              ^
<command-line>: error: expected unqualified-id before ‘void’
In file included from /setups/php-8.4.1/Zend/zend_portability.h:798,
                 from /setups/php-8.4.1/Zend/zend_types.h:25,
                 from /setups/php-8.4.1/ext/intl/intl_convertcpp.h:23,
                 from /setups/php-8.4.1/ext/intl/intl_convertcpp.cpp:17:
/usr/include/c++/8/cstddef:56:11: error: expected ‘;’ before ‘void’
   using ::max_align_t;
           ^
           ;
/usr/include/c++/8/cstddef:56:22: error: expected unqualified-id before ‘;’ token
   using ::max_align_t;
                      ^
<command-line>: error: expected unqualified-id before ‘void’
/setups/php-8.4.1/Zend/zend_portability.h:800:14: note: in expansion of macro ‘max_align_t’
 typedef std::max_align_t zend_max_align_t;
              ^~~~~~~~~~~
In file included from /setups/php-8.4.1/main/php.h:31,
                 from /setups/php-8.4.1/ext/intl/intl_convertcpp.cpp:20:
/setups/php-8.4.1/Zend/zend.h:240:2: error: ‘zend_max_align_t’ does not name a type; did you mean ‘max_align_t’?
  zend_max_align_t align;
  ^~~~~~~~~~~~~~~~
  max_align_t

I am using gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-22)

PHP Version

php 8.4.1

Operating System

AlmaLinux release 8.10

[iluuu1994]

Getting error for installing IMAP extension

To clarify: You mean intl, not imap? The imap extension now lives at https://github.com/php/pecl-mail-imap.

[cmb69]

php-src/Zend/zend_portability.h

Line 58 in d90b5fa

#include <stddef.h>

vs

php-src/Zend/zend_portability.h

Line 798 in d90b5fa

# include <cstddef>

I guess.

[cmb69]

This is caused by #15096. Need to double check whether including <cstddef> is really necessary (would better be avoided if possible).

[cmb69]

I've checked that more thoroughly, and the problem is that stddef.h does not define max_align_t at all on Windows (regardless of the language standard specified). So prior to ab449a7 C builds would take the fallback definition (while C++ builds would fail). The fix was based on the assumption that additionally including cstdef as extern C++ would not interfere with the already included stddef.h, but that was apparently presumptuous; while GCC 8.5 is a bit old, it is not ancient.

An alternative fix would have been to just not relying on max_align_t being defined on Windows, instead of including cstddef for C++ builds. The fallback definition likely would have been okay in all circumstances for Windows (at least MSVC), since its size is 8, what matches the max_align_t definition in cstddef (where it is defined as double; note that long double is identical to double on Windows).

But dropping the cstddef include now might introduce an ABI break (what would be very bad). So I don't know what to do. Any suggestions welcome!