add imap support

[DubbleClick]

this was considerably easier with the musl toolchains since it allows debian/ubuntu to build slx, which doesn't require libpam

closes #202

tests:

• x86 alpine
• x86 rhel
• x86 debian
• aarch64 alpine
• aarch64 rhel
• aarch64 debian

todo: (have no experience with bsd, don't own a mac or aarch64 hardware)

• bsd x86
• bsd aarch64
• mac aarch64

[DubbleClick]

I can't do aarch64 debian testing (only alma & alpine) so I'm not sure if libpam will be required for aarch64 debian. I don't think so, though. And if it's not required, it's not worth including it imo.

[DubbleClick]

If you can create a debian aarch64 vhdx that I can upload to azure, I'll be able to test aarch64 debian in the future, by the way. Otherwise, it will have to wait until the 12c snapdragon releases - will finally get a laptop then.

[crazywhalecc]

I'm writing a manually triggered testing actions here. It can specify different branches and repositories to test the extension combinations in the matrix of PHP8.0-8.2, Linux, macOS (using the official runner and local arm matrix).

I am now separating the download file process to avoid repeated test failures due to accidental download errors, but I don’t know why only arm-macos cannot hit the cache and cannot get the output of the previous workflow. I'm working on it.

FreeBSD is not a major platform, but it has good support for some common libraries. I currently reuse a lot of unix builds. However, imap is a relatively special library and may not be well suited to directly reusing unix compilation scripts for compilation. It may not be the main consideration for the current branch.

[crazywhalecc]

Debian aarch64 is good. But macOS support is still bad:

./tcp_unix.c:535:19: error: variable has incomplete type 'struct pollfd'
    struct pollfd pfd;
                  ^
./tcp_unix.c:535:12: note: forward declaration of 'struct pollfd'
    struct pollfd pfd;
           ^
./tcp_unix.c:545:20: error: use of undeclared identifier 'POLLIN'
      pfd.events = POLLIN;
                   ^
./tcp_unix.c:550:6: error: call to undeclared function 'poll'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
            ^
./tcp_unix.c:591:17: error: variable has incomplete type 'struct pollfd'
  struct pollfd pfd;
                ^
./tcp_unix.c:591:10: note: forward declaration of 'struct pollfd'
  struct pollfd pfd;
         ^
./tcp_unix.c:602:18: error: use of undeclared identifier 'POLLIN'
    pfd.events = POLLIN;
                 ^
./tcp_unix.c:606:11: error: call to undeclared function 'poll'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
      i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
          ^
./tcp_unix.c:659:17: error: variable has incomplete type 'struct pollfd'
  struct pollfd pfd;
                ^
./tcp_unix.c:659:10: note: forward declaration of 'struct pollfd'
  struct pollfd pfd;
         ^
./tcp_unix.c:670:18: error: use of undeclared identifier 'POLLOUT'
    pfd.events = POLLOUT;
                 ^
./tcp_unix.c:674:11: error: call to undeclared function 'poll'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
      i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
          ^

[crazywhalecc]

Updates:

I found that macOS is basically caused by the lack of system headers. Among them, tcp_unix.c file is missing #include <poll.h>, and at least 10 other files are missing #include <time.h> and #include <utime.h>. After adding them, use osx instead of slx to compile successfully.

[crazywhalecc]

But this causes a problem. I don't want to repeat so much repetitive content in the patch, and making the patch file seems to conflict with the existing patch.

I wonder if we can directly fork uw-imap/imap and then apply the relevant patches to the code (except environment-related ones, such as SSL and CC). For macOS, a special .patch file will be run before compilation to fix this error.

[crazywhalecc]

Currently, it has been tested and runs well on Linux and macOS. Is it time to merge? BTW it would be better if you had checking code for imap extension.

[DubbleClick]

Checking code for imap extension? The default check with php --ri "imap" should work, right?

[crazywhalecc]

Checking code for imap extension? The default check with php --ri "imap" should work, right?

In fact, it is a runtime test script, such as gd.

If we don’t add it, and just use --ri to make sure it can run, then it doesn’t matter if we don’t add this test. It’s just an option.

[DubbleClick]

Yeah we don't need to write a test here I think. Just the default check is fine, since it won't show up if imap isn't supported.

If MacOS works fine this is good to merge for me!