[gtk+/wip/otte/shader: 3/98] gsksltype: Turn void into a custom type class

[Benjamin Otte <otte src gnome org>]

commit 660abbf65b96813d9c629dbeb88cec85f96022f1
Author: Benjamin Otte <otte redhat com>
Date:   Sun Oct 1 04:31:18 2017 +0200

    gsksltype: Turn void into a custom type class
    
    Previously, void was a scalar type. It's not anymore.
    
    On the plus side, we now got a gsk_sl_type_is_void() function that's
    kinda useful in places.

 gsk/gskslpointertype.c |    3 +-
 gsk/gskslstatement.c   |    4 +-
 gsk/gsksltype.c        |  141 ++++++++++++++++++++++++++++++++++++++++++++++--
 gsk/gsksltypeprivate.h |    2 +
 4 files changed, 142 insertions(+), 8 deletions(-)
---
diff --git a/gsk/gskslpointertype.c b/gsk/gskslpointertype.c
index 7886225..cdc9dbe 100644
--- a/gsk/gskslpointertype.c
+++ b/gsk/gskslpointertype.c
@@ -186,7 +186,6 @@ gsk_sl_decoration_list_parse_layout (GskSlPreprocessor *preproc,
         {
           gsk_sl_preprocessor_error (preproc, SYNTAX, "Expected layout identifier.");
           gsk_sl_preprocessor_consume (preproc, NULL);
-          continue;
         }
 
       token = gsk_sl_preprocessor_get (preproc);
@@ -332,7 +331,7 @@ gsk_sl_decoration_list_parse (GskSlScope        *scope,
           gsk_sl_decoration_list_parse_layout (preproc, scope, list);
 
           token = gsk_sl_preprocessor_get (preproc);
-          if (gsk_sl_token_is (token, GSK_SL_TOKEN_RIGHT_PAREN))
+          if (!gsk_sl_token_is (token, GSK_SL_TOKEN_RIGHT_PAREN))
             {
               gsk_sl_preprocessor_error (preproc, SYNTAX, "Expected closing \")\" at end of layout 
specifier");
               gsk_sl_preprocessor_sync (preproc, GSK_SL_TOKEN_RIGHT_PAREN);
diff --git a/gsk/gskslstatement.c b/gsk/gskslstatement.c
index 4e08e14..299bd56 100644
--- a/gsk/gskslstatement.c
+++ b/gsk/gskslstatement.c
@@ -743,14 +743,14 @@ its_a_type:
           }
         else if (return_statement->value == NULL)
           {
-            if (!gsk_sl_type_equal (return_type, gsk_sl_type_get_scalar (GSK_SL_VOID)))
+            if (!gsk_sl_type_is_void (return_type))
               {
                 gsk_sl_preprocessor_error (preproc, TYPE_MISMATCH,"Functions expectes a return value of type 
%s", gsk_sl_type_get_name (return_type));
               }
           }
         else
           {
-            if (gsk_sl_type_equal (return_type, gsk_sl_type_get_scalar (GSK_SL_VOID)))
+            if (gsk_sl_type_is_void (return_type))
               {
                 gsk_sl_preprocessor_error (preproc, TYPE_MISMATCH, "Cannot return a value from a void 
function.");
               }
diff --git a/gsk/gsksltype.c b/gsk/gsksltype.c
index a34b544..787f090 100644
--- a/gsk/gsksltype.c
+++ b/gsk/gsksltype.c
@@ -333,6 +333,125 @@ gsk_sl_type_alloc (const GskSlTypeClass *klass,
 }
 #define gsk_sl_type_new(_name, _klass) ((_name *) gsk_sl_type_alloc ((_klass), sizeof (_name)))
 
+/* VOID */
+
+typedef struct _GskSlTypeVoid GskSlTypeVoid;
+
+struct _GskSlTypeVoid {
+  GskSlType parent;
+};
+
+static void
+gsk_sl_type_void_free (GskSlType *type)
+{
+  g_assert_not_reached ();
+}
+
+static const char *
+gsk_sl_type_void_get_name (const GskSlType *type)
+{
+  return "void";
+}
+
+static GskSlScalarType
+gsk_sl_type_void_get_scalar_type (const GskSlType *type)
+{
+  return GSK_SL_VOID;
+}
+
+static GskSlType *
+gsk_sl_type_void_get_index_type (const GskSlType *type)
+{
+  return NULL;
+}
+
+static gsize
+gsk_sl_type_void_get_index_stride (const GskSlType *type)
+{
+  return 0;
+}
+
+static guint
+gsk_sl_type_void_get_length (const GskSlType *type)
+{
+  return 0;
+}
+
+static gsize
+gsk_sl_type_void_get_size (const GskSlType *type)
+{
+  return 0;
+}
+
+static guint
+gsk_sl_type_void_get_n_members (const GskSlType *type)
+{
+  return 0;
+}
+
+static const GskSlTypeMember *
+gsk_sl_type_void_get_member (const GskSlType *type,
+                             guint            n)
+{
+  return NULL;
+}
+
+static gboolean
+gsk_sl_type_void_can_convert (const GskSlType *target,
+                              const GskSlType *source)
+{
+  return FALSE;
+}
+
+static guint32
+gsk_sl_type_void_write_spv (GskSlType    *type,
+                            GskSpvWriter *writer)
+{
+  guint32 result;
+
+  result = gsk_spv_writer_next_id (writer);
+  gsk_spv_writer_add (writer,
+                      GSK_SPV_WRITER_SECTION_DECLARE,
+                      2, GSK_SPV_OP_TYPE_VOID,
+                      (guint32[1]) { result });
+
+  return result;
+}
+
+static void
+gsk_sl_type_void_print_value (const GskSlType *type,
+                              GskSlPrinter    *printer,
+                              gconstpointer    value)
+{
+  g_assert_not_reached ();
+}
+
+static guint32
+gsk_sl_type_void_write_value_spv (GskSlType     *type,
+                                  GskSpvWriter  *writer,
+                                  gconstpointer  value)
+{
+  g_assert_not_reached ();
+
+  return 0;
+}
+
+static const GskSlTypeClass GSK_SL_TYPE_VOID = {
+  gsk_sl_type_void_free,
+  gsk_sl_type_void_get_name,
+  gsk_sl_type_void_get_scalar_type,
+  gsk_sl_type_void_get_index_type,
+  gsk_sl_type_void_get_index_stride,
+  gsk_sl_type_void_get_length,
+  gsk_sl_type_void_get_size,
+  gsk_sl_type_void_get_n_members,
+  gsk_sl_type_void_get_member,
+  gsk_sl_type_void_can_convert,
+  gsk_sl_type_void_write_spv,
+  gsk_sl_type_void_print_value,
+  gsk_sl_type_void_write_value_spv
+};
+
 /* SCALAR */
 
 typedef struct _GskSlTypeScalar GskSlTypeScalar;
@@ -1198,7 +1317,7 @@ gsk_sl_type_get_builtin (GskSlBuiltinType builtin)
   switch (builtin)
     {
     case GSK_SL_BUILTIN_VOID:
-      return gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_VOID));
+      return gsk_sl_type_ref (gsk_sl_type_get_void ());
     case GSK_SL_BUILTIN_FLOAT:
       return gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_FLOAT));
     case GSK_SL_BUILTIN_DOUBLE:
@@ -1277,7 +1396,7 @@ gsk_sl_type_get_builtin (GskSlBuiltinType builtin)
       return gsk_sl_type_ref (gsk_sl_type_get_matrix (GSK_SL_DOUBLE, 4, 4));
     default:
       g_assert_not_reached ();
-      return gsk_sl_type_get_scalar (GSK_SL_VOID);
+      return gsk_sl_type_get_void ();
     }
 }
 
@@ -1293,7 +1412,7 @@ gsk_sl_type_new_parse (GskSlScope        *scope,
   switch ((guint) token->type)
   {
     case GSK_SL_TOKEN_VOID:
-      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_VOID));
+      type = gsk_sl_type_ref (gsk_sl_type_get_void ());
       break;
     case GSK_SL_TOKEN_FLOAT:
       type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_FLOAT));
@@ -1438,9 +1557,16 @@ gsk_sl_type_new_parse (GskSlScope        *scope,
   return type;
 }
 
+static GskSlTypeVoid void_type = { { &GSK_SL_TYPE_VOID, 1 } };
+
+GskSlType *
+gsk_sl_type_get_void (void)
+{
+  return &void_type.parent;
+}
+
 static GskSlTypeScalar
 builtin_scalar_types[N_SCALAR_TYPES] = {
-  [GSK_SL_VOID] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_VOID },
   [GSK_SL_FLOAT] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_FLOAT },
   [GSK_SL_DOUBLE] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_DOUBLE },
   [GSK_SL_INT] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_INT },
@@ -1452,6 +1578,7 @@ GskSlType *
 gsk_sl_type_get_scalar (GskSlScalarType scalar)
 {
   g_assert (scalar < N_SCALAR_TYPES);
+  g_return_val_if_fail (scalar != GSK_SL_VOID, &void_type.parent);
 
   return &builtin_scalar_types[scalar].parent;
 }
@@ -1580,6 +1707,12 @@ gsk_sl_type_get_name (const GskSlType *type)
 }
 
 gboolean
+gsk_sl_type_is_void (const GskSlType *type)
+{
+  return type->class == &GSK_SL_TYPE_VOID;
+}
+
+gboolean
 gsk_sl_type_is_scalar (const GskSlType *type)
 {
   return type->class == &GSK_SL_TYPE_SCALAR;
diff --git a/gsk/gsksltypeprivate.h b/gsk/gsksltypeprivate.h
index f21c382..6e4f1f7 100644
--- a/gsk/gsksltypeprivate.h
+++ b/gsk/gsksltypeprivate.h
@@ -29,6 +29,7 @@ typedef struct _GskSlTypeBuilder GskSlTypeBuilder;
 
 GskSlType *             gsk_sl_type_new_parse                   (GskSlScope          *scope,
                                                                  GskSlPreprocessor   *preproc);
+GskSlType *             gsk_sl_type_get_void                    (void);
 GskSlType *             gsk_sl_type_get_scalar                  (GskSlScalarType      scalar);
 GskSlType *             gsk_sl_type_get_vector                  (GskSlScalarType      scalar,
                                                                  guint                length);
@@ -40,6 +41,7 @@ GskSlType *             gsk_sl_type_get_builtin                 (GskSlBuiltinTyp
 GskSlType *             gsk_sl_type_ref                         (GskSlType           *type);
 void                    gsk_sl_type_unref                       (GskSlType           *type);
 
+gboolean                gsk_sl_type_is_void                     (const GskSlType     *type);
 gboolean                gsk_sl_type_is_scalar                   (const GskSlType     *type);
 gboolean                gsk_sl_type_is_vector                   (const GskSlType     *type);
 gboolean                gsk_sl_type_is_matrix                   (const GskSlType     *type);