--- /dev/null	Tue Feb 13 07:11:51 2018
+++ new/usr/src/lib/libc/port/regex/tre-mem.c	Tue Feb 13 07:11:51 2018
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+  tre-mem.c - TRE memory allocator
+*/
+
+/*
+  This memory allocator is for allocating small memory blocks efficiently
+  in terms of memory overhead and execution speed.  The allocated blocks
+  cannot be freed individually, only all at once.  There can be multiple
+  allocators, though.
+*/
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "tre-internal.h"
+#include "tre-mem.h"
+
+/* Returns a new memory allocator or NULL if out of memory. */
+tre_mem_t
+tre_mem_new_impl(int provided, void *provided_block)
+{
+  tre_mem_t mem;
+  if (provided)
+    {
+      mem = provided_block;
+      memset(mem, 0, sizeof(*mem));
+    }
+  else
+    mem = calloc(1, sizeof(*mem));
+  if (mem == NULL)
+    return NULL;
+  return mem;
+}
+
+/* Frees the memory allocator and all memory allocated with it. */
+void
+tre_mem_destroy(tre_mem_t mem)
+{
+  tre_list_t *tmp, *l = mem->blocks;
+
+  while (l != NULL)
+    {
+      free(l->data);
+      tmp = l->next;
+      free(l);
+      l = tmp;
+    }
+  free(mem);
+}
+
+/* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
+   allocated block or NULL if an underlying malloc() failed. */
+void *
+tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
+		   int zero, size_t size)
+{
+  void *ptr;
+
+  if (mem->failed)
+    {
+      DPRINT(("tre_mem_alloc: oops, called after failure?!\n"));
+      return NULL;
+    }
+
+  if (mem->n < size)
+    {
+      /* We need more memory than is available in the current block.
+	 Allocate a new block. */
+      tre_list_t *l;
+      if (provided)
+	{
+	  DPRINT(("tre_mem_alloc: using provided block\n"));
+	  if (provided_block == NULL)
+	    {
+	      DPRINT(("tre_mem_alloc: provided block was NULL\n"));
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  mem->ptr = provided_block;
+	  mem->n = TRE_MEM_BLOCK_SIZE;
+	}
+      else
+	{
+	  int block_size;
+	  if (size * 8 > TRE_MEM_BLOCK_SIZE)
+	    block_size = size * 8;
+	  else
+	    block_size = TRE_MEM_BLOCK_SIZE;
+	  DPRINT(("tre_mem_alloc: allocating new %d byte block\n",
+		  block_size));
+	  l = malloc(sizeof(*l));
+	  if (l == NULL)
+	    {
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  l->data = malloc(block_size);
+	  if (l->data == NULL)
+	    {
+	      free(l);
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  l->next = NULL;
+	  if (mem->current != NULL)
+	    mem->current->next = l;
+	  if (mem->blocks == NULL)
+	    mem->blocks = l;
+	  mem->current = l;
+	  mem->ptr = l->data;
+	  mem->n = block_size;
+	}
+    }
+
+  /* Make sure the next pointer will be aligned. */
+  size += ALIGN(mem->ptr + size, long);
+
+  /* Allocate from current block. */
+  ptr = mem->ptr;
+  mem->ptr += size;
+  mem->n -= size;
+
+  /* Set to zero if needed. */
+  if (zero)
+    memset(ptr, 0, size);
+
+  return ptr;
+}
