nir: Add a simple growing array data structure

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

src/glsl/nir/nir_array.h

@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Jason Ekstrand (jason@jlekstrand.net)
+ *
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+   void *mem_ctx;
+   size_t size;
+   size_t alloc;
+   void *data;
+} nir_array;
+
+static inline void
+nir_array_init(nir_array *arr, void *mem_ctx)
+{
+   arr->mem_ctx = mem_ctx;
+   arr->size = 0;
+   arr->alloc = 0;
+   arr->data = NULL;
+}
+
+static inline void
+nir_array_fini(nir_array *arr)
+{
+   if (arr->mem_ctx)
+      ralloc_free(arr->data);
+   else
+      free(arr->data);
+}
+
+#define NIR_ARRAY_INITIAL_SIZE 64
+
+/* Increments the size of the array by the given ammount and returns a
+ * pointer to the beginning of the newly added space.
+ */
+static inline void *
+nir_array_grow(nir_array *arr, size_t additional)
+{
+   size_t new_size = arr->size + additional;
+   if (new_size > arr->alloc) {
+      if (arr->alloc == 0)
+         arr->alloc = NIR_ARRAY_INITIAL_SIZE;
+
+      while (new_size > arr->alloc)
+         arr->alloc *= 2;
+
+      if (arr->mem_ctx)
+         arr->data = reralloc_size(arr->mem_ctx, arr->data, arr->alloc);
+      else
+         arr->data = realloc(arr->data, arr->alloc);
+   }
+
+   void *ptr = (void *)((char *)arr->data + arr->size);
+   arr->size = new_size;
+
+   return ptr;
+}
+
+#define nir_array_add(arr, type, elem) \
+   *(type *)nir_array_grow(arr, sizeof(type)) = (elem)
+
+#define nir_array_foreach(arr, type, elem) \
+   for (type *elem = (type *)(arr)->data; \
+        elem < (type *)((char *)(arr)->data + (arr)->size); elem++)
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif