php: add arginfo to php bindings

Starting with PHP8, arginfo is mandatory for PHP extensions. This patch
updates the generator for the PHP bindings to generate the arginfo
structures, using the Zend API macros. Only basic arginfo is added,
without full documentation of argument and return types, in order to
ensure compatibility with as many versions of PHP as possible.

.gitignore

@@ -325,6 +325,7 @@ Makefile.in
 /php/extension/configure.in
 /php/extension/env
 /php/extension/guestfs_php.c
+/php/extension/guestfs_php.dep
 /php/extension/install-sh
 /php/extension/libtool
 /php/extension/ltmain.sh

generator/php.ml

@@ -130,6 +130,37 @@ typedef size_t guestfs_string_length;
 typedef int guestfs_string_length;
 #endif
 
+/* Declare argument info structures */
+ZEND_BEGIN_ARG_INFO_EX(arginfo_create, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_last_error, 0, 0, 1)
+  ZEND_ARG_INFO(0, g)
+ZEND_END_ARG_INFO()
+
+";
+  List.iter (
+    fun { name = shortname; style = ret, args, optargs; } ->
+      let len = List.length args in
+      pr "ZEND_BEGIN_ARG_INFO_EX(arginfo_%s, 0, 0, %d)\n" shortname (len + 1);
+      pr "  ZEND_ARG_INFO(0, g)\n";
+      List.iter (
+        function
+        | BufferIn n | Bool n | Int n | Int64 n | OptString n
+        | Pointer(_, n) | String (_, n) | StringList (_, n) ->
+          pr "  ZEND_ARG_INFO(0, %s)\n" n
+        ) args;
+
+      List.iter (
+        function
+        | OBool n | OInt n | OInt64 n | OString n | OStringList n ->
+          pr "  ZEND_ARG_INFO(0, %s)\n" n
+      ) optargs;
+      pr "ZEND_END_ARG_INFO()\n\n";
+  ) (actions |> external_functions |> sort);
+
+  pr "
+
 /* Convert array to list of strings.
  * http://marc.info/?l=pecl-dev&m=112205192100631&w=2
  */
@@ -204,12 +235,12 @@ PHP_MINIT_FUNCTION (guestfs_php)
 }
 
 static zend_function_entry guestfs_php_functions[] = {
-  PHP_FE (guestfs_create, NULL)
-  PHP_FE (guestfs_last_error, NULL)
+  PHP_FE (guestfs_create, arginfo_create)
+  PHP_FE (guestfs_last_error, arginfo_last_error)
 ";
 
   List.iter (
-    fun { name } -> pr "  PHP_FE (guestfs_%s, NULL)\n" name
+    fun { name } -> pr "  PHP_FE (guestfs_%s, arginfo_%s)\n" name name
   ) (actions |> external_functions |> sort);
 
   pr "  { NULL, NULL, NULL }