Add PHP_BUILD_DATE constant

This information can be occasionally useful, and would otherwise need
to be parsed from `phpinfo()` output.

However, maybe more importantly we unify the build date between what is
given by `php -v` and `php -i`, since these compilation units are not
necessarily preprocessed within the same second.

Closes GH-16747.

Author: cmb69

NEWS

@@ -8,6 +8,7 @@ PHP                                                                        NEWS
 - Core:
   . Fixed bug GH-16665 (\array and \callable should not be usable in
     class_alias). (nielsdos)
+  . Added PHP_BUILD_DATE constant. (cmb)
 
 - Curl:
   . Added curl_multi_get_handles(). (timwolla)

UPGRADING

@@ -129,6 +129,9 @@ PHP 8.5 UPGRADE NOTES
 10. New Global Constants
 ========================================
 
+- Core:
+  . PHP_BUILD_DATE.
+
 - POSIX:
   . POSIX_SC_OPEN_MAX.
 

ext/standard/info.c

@@ -801,7 +801,7 @@ PHPAPI ZEND_COLD void php_print_info(int flag)
 		php_info_print_box_end();
 		php_info_print_table_start();
 		php_info_print_table_row(2, "System", ZSTR_VAL(php_uname));
-		php_info_print_table_row(2, "Build Date", __DATE__ " " __TIME__);
+		php_info_print_table_row(2, "Build Date", php_build_date);
 #ifdef PHP_BUILD_SYSTEM
 		php_info_print_table_row(2, "Build System", PHP_BUILD_SYSTEM);
 #endif

main/main.c

@@ -97,6 +97,8 @@ PHPAPI size_t core_globals_offset;
 
 #define SAFE_FILENAME(f) ((f)?(f):"-")
 
+const char php_build_date[] = __DATE__ " " __TIME__;
+
 PHPAPI const char *php_version(void)
 {
 	return PHP_VERSION;
@@ -110,8 +112,8 @@ PHPAPI unsigned int php_version_id(void)
 PHPAPI char *php_get_version(sapi_module_struct *sapi_module)
 {
 	char *version_info;
-	spprintf(&version_info, 0, "PHP %s (%s) (built: %s %s) (%s)\nCopyright (c) The PHP Group\n%s%s",
-		PHP_VERSION, sapi_module->name, __DATE__, __TIME__,
+	spprintf(&version_info, 0, "PHP %s (%s) (built: %s) (%s)\nCopyright (c) The PHP Group\n%s%s",
+		PHP_VERSION, sapi_module->name, php_build_date,
 #ifdef ZTS
 		"ZTS"
 #else

main/main.stub.php

@@ -34,6 +34,13 @@
  * @cvalue PHP_VERSION_ID
  */
 const PHP_VERSION_ID = UNKNOWN;
+
+/**
+ * @var string
+ * @cvalue php_build_date
+ */
+const PHP_BUILD_DATE = UNKNOWN;
+
 /**
  * @var bool
  * @cvalue PHP_ZTS

main/main_arginfo.h

@@ -265,6 +265,8 @@ END_EXTERN_C()
 extern char **environ;
 #endif	/* ifndef PHP_WIN32 */
 
+extern const char php_build_date[];
+
 #ifdef PHP_PWRITE_64
 ssize_t pwrite(int, void *, size_t, off64_t);
 #endif

main/php.h

@@ -0,0 +1,8 @@
+--TEST--
+PHP_BUILD_DATE
+--FILE--
+<?php
+var_dump(PHP_BUILD_DATE);
+?>
+--EXPECTREGEX--
+string\(20\) "[A-Za-z]{3} \d{2} \d{4} \d{2}:\d{2}:\d{2}"