1 files changed, 312 insertions, 0 deletions
diff --git a/thirdparty/pcre2/src/sljit/sljitExecAllocator.c b/thirdparty/pcre2/src/sljit/sljitExecAllocator.c
new file mode 100644
index 0000000000..9f88f990b0
--- /dev/null
+++ b/thirdparty/pcre2/src/sljit/sljitExecAllocator.c
@@ -0,0 +1,312 @@
+/*
+ *    Stack-less Just-In-Time compiler
+ *
+ *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). 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(S) 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(S) 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.
+ */
+
+/*
+   This file contains a simple executable memory allocator
+
+   It is assumed, that executable code blocks are usually medium (or sometimes
+   large) memory blocks, and the allocator is not too frequently called (less
+   optimized than other allocators). Thus, using it as a generic allocator is
+   not suggested.
+
+   How does it work:
+     Memory is allocated in continuous memory areas called chunks by alloc_chunk()
+     Chunk format:
+     [ block ][ block ] ... [ block ][ block terminator ]
+
+   All blocks and the block terminator is started with block_header. The block
+   header contains the size of the previous and the next block. These sizes
+   can also contain special values.
+     Block size:
+       0 - The block is a free_block, with a different size member.
+       1 - The block is a block terminator.
+       n - The block is used at the moment, and the value contains its size.
+     Previous block size:
+       0 - This is the first block of the memory chunk.
+       n - The size of the previous block.
+
+   Using these size values we can go forward or backward on the block chain.
+   The unused blocks are stored in a chain list pointed by free_blocks. This
+   list is useful if we need to find a suitable memory area when the allocator
+   is called.
+
+   When a block is freed, the new free block is connected to its adjacent free
+   blocks if possible.
+
+     [ free block ][ used block ][ free block ]
+   and "used block" is freed, the three blocks are connected together:
+     [           one big free block           ]
+*/
+
+/* --------------------------------------------------------------------- */
+/*  System (OS) functions                                                */
+/* --------------------------------------------------------------------- */
+
+/* 64 KByte. */
+#define CHUNK_SIZE	0x10000
+
+/*
+   alloc_chunk / free_chunk :
+     * allocate executable system memory chunks
+     * the size is always divisible by CHUNK_SIZE
+   allocator_grab_lock / allocator_release_lock :
+     * make the allocator thread safe
+     * can be empty if the OS (or the application) does not support threading
+     * only the allocator requires this lock, sljit is fully thread safe
+       as it only uses local variables
+*/
+
+#ifdef _WIN32
+
+static SLJIT_INLINE void* alloc_chunk(sljit_uw size)
+{
+	return VirtualAlloc(NULL, size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
+}
+
+static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size)
+{
+	SLJIT_UNUSED_ARG(size);
+	VirtualFree(chunk, 0, MEM_RELEASE);
+}
+
+#else
+
+static SLJIT_INLINE void* alloc_chunk(sljit_uw size)
+{
+	void *retval;
+
+#ifdef MAP_ANON
+	retval = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0);
+#else
+	if (dev_zero < 0) {
+		if (open_dev_zero())
+			return NULL;
+	}
+	retval = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, dev_zero, 0);
+#endif
+
+	return (retval != MAP_FAILED) ? retval : NULL;
+}
+
+static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size)
+{
+	munmap(chunk, size);
+}
+
+#endif
+
+/* --------------------------------------------------------------------- */
+/*  Common functions                                                     */
+/* --------------------------------------------------------------------- */
+
+#define CHUNK_MASK	(~(CHUNK_SIZE - 1))
+
+struct block_header {
+	sljit_uw size;
+	sljit_uw prev_size;
+};
+
+struct free_block {
+	struct block_header header;
+	struct free_block *next;
+	struct free_block *prev;
+	sljit_uw size;
+};
+
+#define AS_BLOCK_HEADER(base, offset) \
+	((struct block_header*)(((sljit_u8*)base) + offset))
+#define AS_FREE_BLOCK(base, offset) \
+	((struct free_block*)(((sljit_u8*)base) + offset))
+#define MEM_START(base)		((void*)(((sljit_u8*)base) + sizeof(struct block_header)))
+#define ALIGN_SIZE(size)	(((size) + sizeof(struct block_header) + 7) & ~7)
+
+static struct free_block* free_blocks;
+static sljit_uw allocated_size;
+static sljit_uw total_size;
+
+static SLJIT_INLINE void sljit_insert_free_block(struct free_block *free_block, sljit_uw size)
+{
+	free_block->header.size = 0;
+	free_block->size = size;
+
+	free_block->next = free_blocks;
+	free_block->prev = NULL;
+	if (free_blocks)
+		free_blocks->prev = free_block;
+	free_blocks = free_block;
+}
+
+static SLJIT_INLINE void sljit_remove_free_block(struct free_block *free_block)
+{
+	if (free_block->next)
+		free_block->next->prev = free_block->prev;
+
+	if (free_block->prev)
+		free_block->prev->next = free_block->next;
+	else {
+		SLJIT_ASSERT(free_blocks == free_block);
+		free_blocks = free_block->next;
+	}
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void* sljit_malloc_exec(sljit_uw size)
+{
+	struct block_header *header;
+	struct block_header *next_header;
+	struct free_block *free_block;
+	sljit_uw chunk_size;
+
+	allocator_grab_lock();
+	if (size < (64 - sizeof(struct block_header)))
+		size = (64 - sizeof(struct block_header));
+	size = ALIGN_SIZE(size);
+
+	free_block = free_blocks;
+	while (free_block) {
+		if (free_block->size >= size) {
+			chunk_size = free_block->size;
+			if (chunk_size > size + 64) {
+				/* We just cut a block from the end of the free block. */
+				chunk_size -= size;
+				free_block->size = chunk_size;
+				header = AS_BLOCK_HEADER(free_block, chunk_size);
+				header->prev_size = chunk_size;
+				AS_BLOCK_HEADER(header, size)->prev_size = size;
+			}
+			else {
+				sljit_remove_free_block(free_block);
+				header = (struct block_header*)free_block;
+				size = chunk_size;
+			}
+			allocated_size += size;
+			header->size = size;
+			allocator_release_lock();
+			return MEM_START(header);
+		}
+		free_block = free_block->next;
+	}
+
+	chunk_size = (size + sizeof(struct block_header) + CHUNK_SIZE - 1) & CHUNK_MASK;
+	header = (struct block_header*)alloc_chunk(chunk_size);
+	if (!header) {
+		allocator_release_lock();
+		return NULL;
+	}
+
+	chunk_size -= sizeof(struct block_header);
+	total_size += chunk_size;
+
+	header->prev_size = 0;
+	if (chunk_size > size + 64) {
+		/* Cut the allocated space into a free and a used block. */
+		allocated_size += size;
+		header->size = size;
+		chunk_size -= size;
+
+		free_block = AS_FREE_BLOCK(header, size);
+		free_block->header.prev_size = size;
+		sljit_insert_free_block(free_block, chunk_size);
+		next_header = AS_BLOCK_HEADER(free_block, chunk_size);
+	}
+	else {
+		/* All space belongs to this allocation. */
+		allocated_size += chunk_size;
+		header->size = chunk_size;
+		next_header = AS_BLOCK_HEADER(header, chunk_size);
+	}
+	next_header->size = 1;
+	next_header->prev_size = chunk_size;
+	allocator_release_lock();
+	return MEM_START(header);
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
+{
+	struct block_header *header;
+	struct free_block* free_block;
+
+	allocator_grab_lock();
+	header = AS_BLOCK_HEADER(ptr, -(sljit_sw)sizeof(struct block_header));
+	allocated_size -= header->size;
+
+	/* Connecting free blocks together if possible. */
+
+	/* If header->prev_size == 0, free_block will equal to header.
+	   In this case, free_block->header.size will be > 0. */
+	free_block = AS_FREE_BLOCK(header, -(sljit_sw)header->prev_size);
+	if (SLJIT_UNLIKELY(!free_block->header.size)) {
+		free_block->size += header->size;
+		header = AS_BLOCK_HEADER(free_block, free_block->size);
+		header->prev_size = free_block->size;
+	}
+	else {
+		free_block = (struct free_block*)header;
+		sljit_insert_free_block(free_block, header->size);
+	}
+
+	header = AS_BLOCK_HEADER(free_block, free_block->size);
+	if (SLJIT_UNLIKELY(!header->size)) {
+		free_block->size += ((struct free_block*)header)->size;
+		sljit_remove_free_block((struct free_block*)header);
+		header = AS_BLOCK_HEADER(free_block, free_block->size);
+		header->prev_size = free_block->size;
+	}
+
+	/* The whole chunk is free. */
+	if (SLJIT_UNLIKELY(!free_block->header.prev_size && header->size == 1)) {
+		/* If this block is freed, we still have (allocated_size / 2) free space. */
+		if (total_size - free_block->size > (allocated_size * 3 / 2)) {
+			total_size -= free_block->size;
+			sljit_remove_free_block(free_block);
+			free_chunk(free_block, free_block->size + sizeof(struct block_header));
+		}
+	}
+
+	allocator_release_lock();
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void)
+{
+	struct free_block* free_block;
+	struct free_block* next_free_block;
+
+	allocator_grab_lock();
+
+	free_block = free_blocks;
+	while (free_block) {
+		next_free_block = free_block->next;
+		if (!free_block->header.prev_size && 
+				AS_BLOCK_HEADER(free_block, free_block->size)->size == 1) {
+			total_size -= free_block->size;
+			sljit_remove_free_block(free_block);
+			free_chunk(free_block, free_block->size + sizeof(struct block_header));
+		}
+		free_block = next_free_block;
+	}
+
+	SLJIT_ASSERT((total_size && free_blocks) || (!total_size && !free_blocks));
+	allocator_release_lock();
+}