initial import of the C runtime

src/runtime/c/gu/variant.h

@@ -0,0 +1,167 @@
+/* 
+ * Copyright 2010 University of Helsinki.
+ *   
+ * This file is part of libgu.
+ * 
+ * Libgu is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ * 
+ * Libgu is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with libgu. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file
+ *
+ * Lightweight tagged data.    
+ */
+
+#ifndef GU_VARIANT_H_
+#define GU_VARIANT_H_
+
+#include <gu/defs.h>
+#include <gu/mem.h>
+#include <gu/type.h>
+
+/** @name Variants
+ * @{
+ */
+
+typedef struct GuVariant GuVariant;
+
+
+void* gu_alloc_variant(uint8_t tag, 
+		       size_t size, size_t align, 
+		       GuVariant* variant_out, GuPool* pool);
+
+GuVariant gu_make_variant(uint8_t tag, 
+			  size_t size, size_t align, 
+			  const void* init, GuPool* pool);
+
+#define gu_new_variant(tag, type, variant_out, pool)	    \
+	((type*)gu_alloc_variant(tag, sizeof(type), \
+				 gu_alignof(type), variant_out, pool))
+
+/**< 
+ * @hideinitializer */
+
+#define gu_new_variant_i(POOL, TAG, T, ...)				\
+	gu_make_variant(TAG, sizeof(T), gu_alignof(T),			\
+			&(T){ __VA_ARGS__ }, POOL)
+
+
+
+#define gu_new_flex_variant(tag, type, flex_mem, n_elems, variant_out, pool)	\
+	((type*)gu_alloc_variant(tag,				\
+				 GU_FLEX_SIZE(type, flex_mem, n_elems), \
+				 gu_flex_alignof(type),			\
+				 variant_out, pool))
+/**< 
+ * @hideinitializer */
+
+enum {
+	GU_VARIANT_NULL = -1
+};
+
+int gu_variant_tag(GuVariant variant);
+
+void* gu_variant_data(GuVariant variant);
+
+
+typedef struct GuVariantInfo GuVariantInfo;
+
+struct GuVariantInfo {
+	int tag;
+	void* data;
+};
+
+GuVariantInfo gu_variant_open(GuVariant variant);
+
+/** @privatesection */
+struct GuVariant {
+	uintptr_t p;
+	/**< @private */
+};
+
+/** @} */
+
+static inline void*
+gu_variant_to_ptr(GuVariant variant)
+{
+	return (void*)variant.p;
+}
+
+static inline GuVariant
+gu_variant_from_ptr(const void* p)
+{
+	GuVariant v = { (uintptr_t)p };
+	return v;
+}
+
+extern const GuVariant gu_null_variant;
+
+static inline bool
+gu_variant_is_null(GuVariant v) {
+	return ((void*)v.p == NULL);
+}
+
+
+// variant
+
+typedef const struct GuConstructor GuConstructor;
+
+struct GuConstructor {
+	int c_tag;
+	const char* c_name;
+	const GuType* type;
+};
+
+#define GU_CONSTRUCTOR_V(ctag, c_type) {		\
+		.c_tag = ctag,	 \
+		.c_name = #ctag, \
+		.type = c_type \
+}
+
+#define GU_CONSTRUCTOR(ctag, t_) \
+	GU_CONSTRUCTOR_V(ctag, gu_type(t_))
+
+#define GU_CONSTRUCTOR_P(ctag, t_) \
+	GU_CONSTRUCTOR_V(ctag, gu_ptr_type(t_))
+
+#define GU_CONSTRUCTOR_S(ctag, t_, ...)		\
+	GU_CONSTRUCTOR_V(ctag, GU_TYPE_LIT(struct, t_, __VA_ARGS__))
+
+#define GU_CONSTRUCTOR_S1(ctag, t_, mem1_, type1_)			\
+	GU_CONSTRUCTOR_S(ctag, t_,					\
+			 GU_MEMBER(t_, mem1_, type1_))
+
+#define GU_CONSTRUCTOR_S2(ctag, t_, mem1_, type1_, mem2_, type2_)	\
+	GU_CONSTRUCTOR_S(ctag, t_,					\
+			 GU_MEMBER(t_, mem1_, type1_),			\
+			 GU_MEMBER(t_, mem2_, type2_))
+
+
+
+typedef GuSList(GuConstructor) GuConstructors;
+
+typedef const struct GuVariantType GuVariantType, GuType_GuVariant;
+
+struct GuVariantType {
+	GuType_repr repr_base;
+	GuConstructors ctors;
+};
+
+#define GU_TYPE_INIT_GuVariant(k_, t_, ...) {			\
+	.repr_base = GU_TYPE_INIT_repr(k_, GuVariant, _),	\
+	.ctors = GU_SLIST(GuConstructor, __VA_ARGS__) \
+}
+
+extern GU_DECLARE_KIND(GuVariant);
+
+#endif // GU_VARIANT_H_