From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Mon, 31 Jul 2017 12:59:51 +0000 (+0100)
Subject: Fixed unaligned memory access.
X-Git-Tag: 1.0~33
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c7b8af0f6134c7675e5559165be5514a17286ae8;p=re2c

Fixed unaligned memory access.

With CXXFLAGS='-fsanitize=undefined' GCC complains about unaligned access:
if custom allocator is used to allocate structs or other alignment-sensitive
things, then it must take care of the alignment (for example, add padding
to all unaligned blocks of memory which it allocates).
---

diff --git a/re2c/src/dfa/tcmd.h b/re2c/src/dfa/tcmd.h
index d48890bb..0badf037 100644
--- a/re2c/src/dfa/tcmd.h
+++ b/re2c/src/dfa/tcmd.h
@@ -33,7 +33,7 @@ static const tcid_t TCID0 = 0;
 
 class tcpool_t
 {
-	typedef slab_allocator_t<~0u, 4096> alc_t;
+	typedef slab_allocator_t<~0u, 4096, sizeof(void*)> alc_t;
 	typedef lookup_t<const tcmd_t*> index_t;
 
 	alc_t alc;
diff --git a/re2c/src/re/re.h b/re2c/src/re/re.h
index e7472c99..305c28b4 100644
--- a/re2c/src/re/re.h
+++ b/re2c/src/re/re.h
@@ -15,7 +15,7 @@ namespace re2c
 
 struct RE
 {
-	typedef slab_allocator_t<~0u, 4096> alc_t;
+	typedef slab_allocator_t<~0u, 4096, sizeof(void*)> alc_t;
 	enum type_t {NIL, SYM, ALT, CAT, ITER, TAG} type;
 	union {
 		const Range *sym;
diff --git a/re2c/src/util/slab_allocator.h b/re2c/src/util/slab_allocator.h
index 4baa8c13..f34600d9 100644
--- a/re2c/src/util/slab_allocator.h
+++ b/re2c/src/util/slab_allocator.h
@@ -15,7 +15,8 @@
  * Works ~20 times faster, than linux's glibc allocator :]
  */
 template<uint32_t MAXIMUM_INLINE = 4 * 1024,
-	uint32_t SLAB_SIZE = 1024 * 1024>
+	uint32_t SLAB_SIZE = 1024 * 1024,
+	size_t ALIGN = 1>
 class slab_allocator_t
 {
 	typedef std::vector<char*> slabs_t;
@@ -33,6 +34,9 @@ public:
 	{
 		char *result;
 
+		/* alignment */
+		size += ALIGN - size % ALIGN;
+
 		/* very large objects */
 		if (size > MAXIMUM_INLINE) {
 			result = static_cast<char*>(malloc(size));