Add sendmail and switch build to wasixcc by zebreus · Pull Request #11 · wasix-org/php

zebreus · 2026-02-03T11:50:34Z

Add sendmail and switch build to wasixcc

Copilot

Pull request overview

This PR transitions the PHP WASIX build system from using direct LLVM/Clang toolchain to the wasixcc wrapper toolchain, and adds the sendmail dependency to support PHP mail functionality through a standard sendmail executable instead of a custom Rust-based WASIX sendmail library.

Changes:

Replaced manual LLVM 20/21 toolchain setup with wasixcc wrapper toolchain
Added sendmail/sendmail package dependency to wasmer-32.toml and wasmer-64.toml
Removed custom wasix_sendmail C integration code and Rust library dependency from ext/standard/mail.c and config.m4
Removed SMTP configuration parameters from execution scripts

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
wasmer-64.toml	Added sendmail/sendmail dependency
wasmer-32.toml	Added sendmail/sendmail dependency
wasix-execute.sh	Removed SMTP configuration parameters
wasix-execute-eh.sh	Removed SMTP configuration parameters
wasix-configure.sh	Replaced LLVM toolchain with wasixcc, simplified build flags, removed SYSROOT and WASIX_SENDMAIL_LIBS
wasix-configure-eh.sh	Replaced LLVM toolchain with wasixcc, simplified build flags, removed SYSROOT and WASIX_SENDMAIL_LIBS
ext/standard/mail.c	Removed custom wasix_sendmail integration code, now uses standard sendmail_path
ext/standard/config.m4	Removed WASIX_SENDMAIL_LIBS build configuration
.github/workflows/wasix-pr.yaml	Replaced LLVM 21 installation with wasixcc installation action, updated tool version checks

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wasix-configure-eh.sh

.github/workflows/wasix-pr.yaml

wasix-configure-eh.sh

wasmer-64.toml

wasmer-32.toml

Copilot

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 7 comments.

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Copilot · 2026-02-09T15:10:38Z

ext/standard/mail.c

 #include <ctype.h>
 #include <stdio.h>
 #include <time.h>
+#ifndef PHP_WIN32


<spawn.h> is included unconditionally on non-Windows builds, but the repository doesn't appear to feature-test for this header (compare to ext/standard/proc_open.c which only includes it behind a configure-derived macro). This can break builds on platforms where <spawn.h> is unavailable even though PHP otherwise supports them. Consider guarding the include and the posix_spawn implementation behind an appropriate HAVE_* macro and retaining the existing popen() path as a fallback when spawn.h/posix_spawn are not available.

Suggested change

#ifndef PHP_WIN32

#if !defined(PHP_WIN32) && defined(HAVE_SPAWN_H)

Copilot · 2026-02-09T15:10:38Z

ext/standard/mail.c

+	/* Use posix_spawn to avoid spawning a shell */
+	ret = php_mail_send_via_posix_spawn(sendmail_cmd, to, subject, message, hdr, line_sep);
+
+	if (extra_cmd != NULL) {
+		efree(sendmail_cmd);
+	}
+#endif


Switching non-Windows mail delivery from popen("...", "w") to posix_spawn changes the long-standing behavior that sendmail_path may be an arbitrary shell command (including redirections/pipelines). This will break existing behavior and the existing test suite (e.g. ext/standard/tests/mail/mail_basic2.phpt uses sendmail_path="cat > /tmp/..."). If the goal is only to change WASIX behavior, consider keeping the popen(/bin/sh -c) implementation for non-wasi targets or adding a compatibility fallback when sendmail_path contains shell metacharacters.

Suggested change

/* Use posix_spawn to avoid spawning a shell */

ret = php_mail_send_via_posix_spawn(sendmail_cmd, to, subject, message, hdr, line_sep);

if (extra_cmd != NULL) {

efree(sendmail_cmd);

}

#endif

# ifdef __wasi__

/* On WASI/WASIX, continue to use posix_spawn-based implementation. */

ret = php_mail_send_via_posix_spawn(sendmail_cmd, to, subject, message, hdr, line_sep);

if (extra_cmd != NULL) {

efree(sendmail_cmd);

}

# else

/* On non-WASI Unix-like platforms, preserve historical behavior by using popen(),

* which executes sendmail_path via /bin/sh -c and thus supports shell syntax. */

sendmail = popen(sendmail_cmd, "w");

if (extra_cmd != NULL) {

efree(sendmail_cmd);

}

if (sendmail) {

fprintf(sendmail, "To: %s%s", to, line_sep);

fprintf(sendmail, "Subject: %s%s", subject, line_sep);

if (hdr != NULL) {

fprintf(sendmail, "%s%s", hdr, line_sep);

}

fprintf(sendmail, "%s%s%s", line_sep, message, line_sep);

ret = pclose(sendmail);

} else {

php_error_docref(NULL, E_WARNING, "Could not execute mail delivery program '%s'", sendmail_path);

#if PHP_SIGCHILD

if (sig_handler) {

signal(SIGCHLD, sig_handler);

}

#endif

MAIL_RET(0);

}

# endif

#endif

Copilot · 2026-02-09T15:10:39Z

ext/standard/mail.c

+		php_mail_free_argv(&args);
+		return -1;
+	}
+


pipe(pipefd) creates fds without close-on-exec. In a multi-threaded process, concurrent calls to mail()/posix_spawn can cause unrelated children to inherit these pipe fds, potentially preventing EOF delivery and hanging the sendmail process (same class of issue documented in ext/fileinfo/libmagic/compress.c). Prefer creating the pipe with O_CLOEXEC (pipe2) or setting FD_CLOEXEC via fcntl on both ends before spawning.

Suggested change

#ifdef FD_CLOEXEC

/* Ensure pipe fds are not unintentionally inherited by unrelated children */

if (fcntl(pipefd[0], F_SETFD, FD_CLOEXEC) == -1

|| fcntl(pipefd[1], F_SETFD, FD_CLOEXEC) == -1

) {

php_error_docref(NULL, E_WARNING, "Could not set FD_CLOEXEC on pipe for mail delivery: %s", strerror(errno));

close(pipefd[0]);

close(pipefd[1]);

php_mail_free_argv(&args);

return -1;

}

#endif

Copilot · 2026-02-09T15:10:39Z

ext/standard/mail.c

+	posix_spawn_file_actions_addclose(&file_actions, pipefd[0]);
+	posix_spawn_file_actions_addclose(&file_actions, pipefd[1]);


Return values from posix_spawn_file_actions_addclose() are ignored. These calls can fail (e.g. ENOMEM), in which case the child may inherit unintended fds. Handle and propagate errors similarly to ext/standard/proc_open.c (check the return code and abort/clean up on failure).

Suggested change

posix_spawn_file_actions_addclose(&file_actions, pipefd[0]);

posix_spawn_file_actions_addclose(&file_actions, pipefd[1]);

if (posix_spawn_file_actions_addclose(&file_actions, pipefd[0]) != 0) {

php_error_docref(NULL, E_WARNING, "Could not set up file actions: %s", strerror(errno));

posix_spawn_file_actions_destroy(&file_actions);

close(pipefd[0]);

close(pipefd[1]);

php_mail_free_argv(&args);

return -1;

}

if (posix_spawn_file_actions_addclose(&file_actions, pipefd[1]) != 0) {

php_error_docref(NULL, E_WARNING, "Could not set up file actions: %s", strerror(errno));

posix_spawn_file_actions_destroy(&file_actions);

close(pipefd[0]);

close(pipefd[1]);

php_mail_free_argv(&args);

return -1;

}

Copilot · 2026-02-09T15:10:39Z

ext/standard/mail.c

+	/* Spawn the process */
+	errno = 0;
+	spawn_errno = posix_spawn(&pid, args.argv[0], &file_actions, NULL, args.argv, environ);
+	posix_spawn_file_actions_destroy(&file_actions);


posix_spawn() is used with args.argv[0], which will not search PATH. Previously, popen() executed via the shell and therefore respected PATH lookups (e.g. sendmail_path="sendmail -t"). To preserve behavior, consider using posix_spawnp() (or conditionally use spawnp when argv[0] is not an absolute/relative path containing '/').

Copilot · 2026-02-09T15:10:39Z

build/php.m4

    AC_PROG_CXX
    AC_PROG_CXXCPP
-    PHP_ADD_LIBRARY(stdc++)
+    PHP_ADD_LIBRARY(c++)


Changing PHP_REQUIRE_CXX to always link -lc++ is likely to break builds on platforms where the C++ standard library is libstdc++ (common on Linux/GCC) and libc++ is not installed. Consider selecting the library based on compiler/stdlib availability (feature-test link for -lstdc++ vs -lc++), or avoiding forcing a stdlib link flag when the linker driver is already C++.

Suggested change

PHP_ADD_LIBRARY(c++)

dnl Try to detect an available C++ standard library (libstdc++ or libc++).

AC_CACHE_CHECK([for C++ standard library], [php_cv_lib_cxx],[

php_cv_lib_cxx=none

AC_CHECK_LIB([stdc++], [main],

[php_cv_lib_cxx=stdc++],

[AC_CHECK_LIB([c++], [main],

[php_cv_lib_cxx=c++],

[php_cv_lib_cxx=none]

)]

)

])

if test "$php_cv_lib_cxx" != "none"; then

PHP_ADD_LIBRARY([$php_cv_lib_cxx])

fi

I'll do you one better @zebreus, since you're using wasixcc now, you can just do WASIXCC_INCLUDE_CPP_SYMBOLS=yes and remove this line entirely.

I can try that

Well, I looked at it again and think it is safer to leave it that way. This is 20 years old upstream code, I am afraid that not setting it here will break something down the line. Changing from libstdc++ to libc++ is required though.

.github/workflows/wasix-pr.yaml

Arshia001 · 2026-02-09T15:26:09Z

ext/standard/mail.c

 #include <ctype.h>
 #include <stdio.h>
 #include <time.h>
+#ifndef PHP_WIN32


Is this file now the same as the unmodified version PHP used to have? If not, what's changed?

No, there are some bugs around popen/pclose, I couldn't figure out. This now uses a completly new posix_spawn based implementation for spawning sendmail. The code around posix_spawn is llm generated but I tested it.

wasix-configure.sh

Arshia001

LGTM overall; a few questions, and I find copilot's comment about pinning the wasixcc version valid.

zebreus added 3 commits February 2, 2026 17:11

Remove custom sendmail

6d65e9c

Declare sendmail in wasmer.toml

fff8d84

Build with wasixcc

f349886

Copilot AI review requested due to automatic review settings February 3, 2026 11:50

github-actions bot added Category: Build System Extension: standard labels Feb 3, 2026

Copilot started reviewing on behalf of zebreus February 3, 2026 11:50 View session

Adjust wasix-pr action to use wasixcc

c85e31d

zebreus force-pushed the zebreus-8.3.21-wasix branch from 0c40eb6 to c85e31d Compare February 3, 2026 11:52

Copilot AI reviewed Feb 3, 2026

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zebreus added 4 commits February 3, 2026 13:01

Change default c++ lib from libstdc++ to libc++

be83db1

Remove two old sendmail config options

4299293

Replace mapdir with volume

1bbe56f

Set the correct path to the sendmail binary

c34a08c

zebreus requested review from Arshia001 and Copilot February 9, 2026 15:01

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zebreus added 2 commits February 13, 2026 13:40

Delete non-eh build scripts

50e65ef

Remove sendmail secrets from CI

c687e81

zebreus force-pushed the zebreus-8.3.21-wasix branch from bbdedbd to c687e81 Compare February 13, 2026 12:47

	#ifndef PHP_WIN32
	#if !defined(PHP_WIN32) && defined(HAVE_SPAWN_H)

-	/* Use posix_spawn to avoid spawning a shell */
-	ret = php_mail_send_via_posix_spawn(sendmail_cmd, to, subject, message, hdr, line_sep);
-	if (extra_cmd != NULL) {
-		efree(sendmail_cmd);
-	}
-#endif
+# ifdef __wasi__
+	/* On WASI/WASIX, continue to use posix_spawn-based implementation. */
+	ret = php_mail_send_via_posix_spawn(sendmail_cmd, to, subject, message, hdr, line_sep);
+	if (extra_cmd != NULL) {
+		efree(sendmail_cmd);
+	}
+# else
+	/* On non-WASI Unix-like platforms, preserve historical behavior by using popen(),
+	 * which executes sendmail_path via /bin/sh -c and thus supports shell syntax. */
+	sendmail = popen(sendmail_cmd, "w");
+	if (extra_cmd != NULL) {
+		efree(sendmail_cmd);
+	}
+	if (sendmail) {
+		fprintf(sendmail, "To: %s%s", to, line_sep);
+		fprintf(sendmail, "Subject: %s%s", subject, line_sep);
+		if (hdr != NULL) {
+			fprintf(sendmail, "%s%s", hdr, line_sep);
+		}
+		fprintf(sendmail, "%s%s%s", line_sep, message, line_sep);
+		ret = pclose(sendmail);
+	} else {
+		php_error_docref(NULL, E_WARNING, "Could not execute mail delivery program '%s'", sendmail_path);
+#if PHP_SIGCHILD
+		if (sig_handler) {
+			signal(SIGCHLD, sig_handler);
+		}
+#endif
+		MAIL_RET(0);
+	}
+# endif
+#endif

+#ifdef FD_CLOEXEC
+	/* Ensure pipe fds are not unintentionally inherited by unrelated children */
+	if (fcntl(pipefd[0], F_SETFD, FD_CLOEXEC) == -1
+		|| fcntl(pipefd[1], F_SETFD, FD_CLOEXEC) == -1
+	) {
+		php_error_docref(NULL, E_WARNING, "Could not set FD_CLOEXEC on pipe for mail delivery: %s", strerror(errno));
+		close(pipefd[0]);
+		close(pipefd[1]);
+		php_mail_free_argv(&args);
+		return -1;
+	}
+#endif

		posix_spawn_file_actions_addclose(&file_actions, pipefd[0]);
		posix_spawn_file_actions_addclose(&file_actions, pipefd[1]);

-    PHP_ADD_LIBRARY(c++)
+    dnl Try to detect an available C++ standard library (libstdc++ or libc++).
+    AC_CACHE_CHECK([for C++ standard library], [php_cv_lib_cxx],[
+      php_cv_lib_cxx=none
+      AC_CHECK_LIB([stdc++], [main],
+        [php_cv_lib_cxx=stdc++],
+        [AC_CHECK_LIB([c++], [main],
+          [php_cv_lib_cxx=c++],
+          [php_cv_lib_cxx=none]
+        )]
+      )
+    ])
+    if test "$php_cv_lib_cxx" != "none"; then
+      PHP_ADD_LIBRARY([$php_cv_lib_cxx])
+    fi

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zebreus Feb 9, 2026 •

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