zend_compile: Deprecate backticks as an alias for shell_exec() (php#19443)

RFC: https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_backticks_as_an_alias_for_shell_exec

Author: TimWolla

NEWS

@@ -9,6 +9,8 @@ PHP                                                                        NEWS
     been deprecated, as it no longer has any effect since PHP 8.0. (Girgias)
   . Terminating case statements with a semicolon instead of a colon has
     been deprecated. (theodorejb)
+  . The backtick operator as an alias for shell_exec() has been deprecated.
+    (timwolla)
 
 - DOM:
   . Fixed bug GH-18877 (\Dom\HTMLDocument querySelectorAll selecting only the

UPGRADING

@@ -328,6 +328,8 @@ PHP 8.5 UPGRADE NOTES
   . Terminating case statements with a semicolon instead of a colon has
     been deprecated.
     RFC: https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_semicolon_after_case_in_switch_statement
+  . The backtick operator as an alias for shell_exec() has been deprecated.
+    RFC: https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_backticks_as_an_alias_for_shell_exec
 
 - FileInfo:
   . The finfo_close() function has been deprecated.

Zend/tests/bug40236.phpt

@@ -8,7 +8,7 @@ if (extension_loaded("readline")) die("skip Test doesn't support readline");
 <?php
 $php = getenv('TEST_PHP_EXECUTABLE_ESCAPED');
 $cmd = "$php -n -d memory_limit=4M -a \"".__DIR__."\"/bug40236.inc";
-echo `$cmd`;
+echo shell_exec($cmd);
 ?>
 --EXPECT--
 Interactive shell (-a) requires the readline extension.

Zend/tests/bug55509.phpt

@@ -28,7 +28,7 @@ if (PHP_OS == 'Linux') {
   }
 }
 elseif (PHP_OS == 'FreeBSD') {
-  $lines = explode("\n",`sysctl -a`);
+  $lines = explode("\n", shell_exec("sysctl -a"));
   $infos = array();
   foreach ($lines as $line) {
     if (!$line){

Zend/tests/bug64677.phpt

@@ -17,5 +17,12 @@ function show_outputa($prepend, $output) {
 show_outputa('Files: ', `cd .`); // this works as expected
 
 ?>
---EXPECT--
+--EXPECTF--
+Deprecated: The backtick (`) operator is deprecated, use shell_exec() instead in %s on line %d
+
+Deprecated: The backtick (`) operator is deprecated, use shell_exec() instead in %s on line %d
+
+Deprecated: The backtick (`) operator is deprecated, use shell_exec() instead in %s on line %d
+
+Deprecated: The backtick (`) operator is deprecated, use shell_exec() instead in %s on line %d
 Okey

Zend/zend_compile.c

@@ -10847,6 +10847,8 @@ static void zend_compile_shell_exec(znode *result, zend_ast *ast) /* {{{ */
 	zval fn_name;
 	zend_ast *name_ast, *args_ast, *call_ast;
 
+	zend_error(E_DEPRECATED, "The backtick (`) operator is deprecated, use shell_exec() instead");
+
 	ZVAL_STRING(&fn_name, "shell_exec");
 	name_ast = zend_ast_create_zval(&fn_name);
 	args_ast = zend_ast_create_list(1, ZEND_AST_ARG_LIST, expr_ast);

ext/opcache/tests/revalidate_path_01.phpt

@@ -30,7 +30,7 @@ if (substr(PHP_OS, 0, 3) == 'WIN') {
     @rmdir($link);
     $ln = str_replace('/', '\\', $link);
     $d1 = realpath($dir1);
-    `mklink /j $ln $d1`;
+    shell_exec("mklink /j $ln $d1");
 } else {
     @unlink($link);
     @symlink($dir1, $link);
@@ -45,7 +45,7 @@ if (substr(PHP_OS, 0, 3) == 'WIN') {
     @rmdir($link);
     $ln = str_replace('/', '\\', $link);
     $d2 = realpath($dir2);
-    `mklink /j $ln $d2`;
+    shell_exec("mklink /j $ln $d2");
 } else {
     @unlink($link);
     @symlink($dir2, $link);

ext/phar/phar/pharcommand.inc

@@ -225,13 +225,13 @@ class PharCommand extends CLICommand
                 }
             }
             if ($pear) {
-                $apiver = (string) `pear -q info PHP_Archive 2>/dev/null|grep 'API Version'`;
+                $apiver = (string) shell_exec("pear -q info PHP_Archive 2>/dev/null|grep 'API Version'");
                 $apiver = trim(substr($apiver, strlen('API Version')));
             }
             if ($apiver) {
                 self::notice("PEAR package PHP_Archive: API Version: $apiver.\n");
-                $files  = explode("\n", (string) `pear list-files PHP_Archive`);
-                $phpdir = (string) `pear config-get php_dir 2>/dev/null`;
+                $files  = explode("\n", (string) shell_exec("pear list-files PHP_Archive"));
+                $phpdir = (string) shell_exec("pear config-get php_dir 2>/dev/null");
                 $phpdir = trim($phpdir);
                 self::notice("PEAR package PHP_Archive: $phpdir.\n");
                 if (is_dir($phpdir)) {

ext/session/tests/session_regenerate_id_cookie.phpt

@@ -55,7 +55,7 @@ ob_end_flush();
 ?>');
 
 $extra_arguments = getenv('TEST_PHP_EXTRA_ARGS');
-var_dump(`$php $extra_arguments -d session.name=PHPSESSID $file`);
+var_dump(shell_exec("$php $extra_arguments -d session.name=PHPSESSID $file"));
 
 unlink($file);
 

ext/standard/tests/dir/bug73877.phpt

@@ -18,7 +18,7 @@ $junk0 = $base . DIRECTORY_SEPARATOR . "Серёжка2";
 mkdir($base);
 mkdir($dir0);
 mkdir($dir1);
-`mklink /J $junk0 $dir0`;
+shell_exec("mklink /J $junk0 $dir0");
 
 var_dump(
     readlink($dir0),