From 129bdeeef39ba8dac2b6215ce95279dec8c39a8d Mon Sep 17 00:00:00 2001
From: Philipp Schafft <lion@lion.leolix.org>
Date: Thu, 27 Jun 2019 12:36:16 +0000
Subject: [PATCH] Feature: Make interface decleration much nicer

---
 include/igloo/interface.h | 12 ++++++++++++
 src/interface.c           | 30 ++++++++++++++++++++++++++++++
 src/io.c                  | 23 +----------------------
 src/private.h             |  3 +++
 src/stdio.c               |  4 +++-
 5 files changed, 49 insertions(+), 23 deletions(-)

diff --git a/include/igloo/interface.h b/include/igloo/interface.h
index 59292b1..45febc3 100644
--- a/include/igloo/interface.h
+++ b/include/igloo/interface.h
@@ -42,11 +42,23 @@ extern "C" {
  */
 typedef int (*igloo_interface_free_t)(igloo_INTERFACE_BASIC_ARGS);
 
+#define igloo_INTERFACE_DESCRIPTION_BASE__VERSION	1
 
 typedef struct {
+    size_t base_length;
+    int base_version;
+    size_t description_length;
     igloo_interface_free_t free;
 } igloo_interface_base_ifdesc_t;
 
+#define igloo_INTERFACE_DESCRIPTION_BASE(type, ...) \
+    .__base = { \
+        .base_length = sizeof(igloo_interface_base_ifdesc_t), \
+        .base_version = igloo_INTERFACE_DESCRIPTION_BASE__VERSION, \
+        .description_length = sizeof(type) \
+        , ## __VA_ARGS__ \
+    }
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/interface.c b/src/interface.c
index 5271d65..0a57aef 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -30,3 +30,33 @@ void igloo_interface_base_free(igloo_ro_t self)
         free(iface->backend_userdata);
 }
 
+igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
+{
+    igloo_ro_t self;
+    igloo__interface_base_t *base;
+
+    if (!ifdesc)
+        return igloo_RO_NULL;
+
+    if (ifdesc->base_length != sizeof(igloo_interface_base_ifdesc_t) || ifdesc->base_version != igloo_INTERFACE_DESCRIPTION_BASE__VERSION || ifdesc->description_length != description_length)
+        return igloo_RO_NULL;
+
+    self = igloo_ro_new__raw(type, name, associated);
+    base = igloo_INTERFACE_CAST(self);
+
+    if (igloo_RO_IS_NULL(self))
+        return igloo_RO_NULL;
+
+    if (!igloo_RO_IS_NULL(backend_object)) {
+        if (igloo_ro_ref(backend_object) != 0) {
+            igloo_ro_unref(self);
+            return igloo_RO_NULL;
+        }
+    }
+
+    base->ifdesc = ifdesc;
+    base->backend_object = backend_object;
+    base->backend_userdata = backend_userdata;
+
+    return self;
+}
diff --git a/src/io.c b/src/io.c
index 2b54b62..21c6a49 100644
--- a/src/io.c
+++ b/src/io.c
@@ -32,28 +32,7 @@ igloo_RO_PUBLIC_TYPE(igloo_io_t,
 
 igloo_io_t * igloo_io_new(const igloo_io_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
 {
-    igloo_io_t *io;
-
-    if (!ifdesc)
-        return NULL;
-
-    io = igloo_ro_new_raw(igloo_io_t, name, associated);
-
-    if (!io)
-        return NULL;
-
-    if (!igloo_RO_IS_NULL(backend_object)) {
-        if (igloo_ro_ref(backend_object) != 0) {
-            igloo_ro_unref(io);
-            return NULL;
-        }
-    }
-
-    io->ifdesc = ifdesc;
-    io->backend_object = backend_object;
-    io->backend_userdata = backend_userdata;
-
-    return io;
+    return igloo_interface_base_new(igloo_io_t, ifdesc, backend_object, backend_userdata, name, associated);
 }
 
 
diff --git a/src/private.h b/src/private.h
index 113519f..35d0791 100644
--- a/src/private.h
+++ b/src/private.h
@@ -52,4 +52,7 @@ void igloo_interface_base_free(igloo_ro_t self);
 #define igloo_INTERFACE_CAST(obj) ((igloo__interface_base_t*)igloo_RO__GETBASE(obj))
 #define igloo_INTERFACE_BASIC_CALL(obj) (obj), &(igloo_INTERFACE_CAST(obj)->backend_object), &(igloo_INTERFACE_CAST(obj)->backend_userdata)
 
+igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated);
+#define igloo_interface_base_new(type, ifdesc, backend_object, backend_userdata, name, associated) igloo_RO_TO_TYPE(igloo_interface_base_new_real(igloo_ro__type__ ## type, sizeof(*(ifdesc)), (const igloo_interface_base_ifdesc_t*)(ifdesc), (backend_object), (backend_userdata), (name), (associated)), type)
+
 #endif
diff --git a/src/stdio.c b/src/stdio.c
index 1078f0a..27f9ced 100644
--- a/src/stdio.c
+++ b/src/stdio.c
@@ -49,7 +49,9 @@ static int __get_fd_for_systemcall(igloo_INTERFACE_BASIC_ARGS)
 }
 
 static const igloo_io_ifdesc_t igloo_stdio_ifdesc = {
-    .__base = {.free = __free},
+    igloo_INTERFACE_DESCRIPTION_BASE(igloo_io_ifdesc_t,
+            .free = __free
+            ),
     .read = __read,
     .write = __write,
     .flush = __flush,