xzcat: more cleanup and some shrinking.

-drop __always_inline (c. 1.5k of binary size),
-remove the xz_dec_bcj_end and memzero macros
(memeq is left because of negative returns),
-disable XZ_DEC_SINGLE and XZ_DEC_PREALLOC, since we aren't using them.
(160 bytes)
-Merge xz_dec_lzma2_end into xz_dec_end
-Move xz_crc32 to where it's defined.
(That does not seem to be duplicated elsewhere in toybox.)

1 files changed, 34 insertions, 65 deletions

diff --git a/toys/pending/xzcat.c b/toys/pending/xzcat.c
index 8ed36ecc..5e96cf6f 100644
--- a/toys/pending/xzcat.c
+++ b/toys/pending/xzcat.c
@@ -43,9 +43,8 @@ config XZCAT
  *
  * It is possible to enable support only for a subset of the above
  * modes at compile time by defining XZ_DEC_SINGLE, XZ_DEC_PREALLOC,
- * or XZ_DEC_DYNALLOC. The xz_dec kernel module is always compiled
- * with support for all operation modes, but the preboot code may
- * be built with fewer features to minimize code size.
+ * or XZ_DEC_DYNALLOC. xzcat uses only XZ_DEC_DYNALLOC, 
+ * so that is the default.
  */
 enum xz_mode {
 	XZ_SINGLE,
@@ -236,7 +235,19 @@ void xz_dec_end(struct xz_dec *s);
  * calculation, the third argument must be zero. To continue the calculation,
  * the previously returned value is passed as the third argument.
  */
-uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc);
+static uint32_t xz_crc32_table[256];
+
+uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
+{
+	crc = ~crc;
+
+	while (size != 0) {
+		crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
+		--size;
+	}
+
+	return ~crc;
+}
 
 /*
  * This must be called before any other xz_* function (but after crc_init())
@@ -281,7 +292,6 @@ uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc)
 }
 
 // END xz.h
-static uint32_t xz_crc32_table[256];
 
 static uint8_t in[BUFSIZ];
 static uint8_t out[BUFSIZ];
@@ -395,31 +405,12 @@ error:
 
 
 #define memeq(a, b, size) (memcmp(a, b, size) == 0)
-#define memzero(buf, size) memset(buf, 0, size)
 
 #ifndef min
 #	define min(x, y) ((x) < (y) ? (x) : (y))
 #endif
 #define min_t(type, x, y) min(x, y)
 
-/*
- * Some functions have been marked with __always_inline to keep the
- * performance reasonable even when the compiler is optimizing for
- * small code size. You may be able to save a few bytes by #defining
- * __always_inline to plain inline, but don't complain if the code
- * becomes slow.
- *
- * NOTE: System headers on GNU/Linux may #define this macro already,
- * so if you want to change it, you need to #undef it first.
- */
-#ifndef __always_inline
-#	ifdef __GNUC__
-#		define __always_inline \
-			inline __attribute__((__always_inline__))
-#	else
-#		define __always_inline inline
-#	endif
-#endif
 
 /* Inline functions to access unaligned unsigned 32-bit integers */
 #ifndef get_unaligned_le32
@@ -471,13 +462,12 @@ static inline void put_unaligned_be32(uint32_t val, uint8_t *buf)
 #	define get_le32 get_unaligned_le32
 #endif
 
-/* If no specific decoding mode is requested, enable support for all modes. */
-#if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
-		&& !defined(XZ_DEC_DYNALLOC)
-#	define XZ_DEC_SINGLE
-#	define XZ_DEC_PREALLOC
-#	define XZ_DEC_DYNALLOC
-#endif
+
+#define XZ_DEC_DYNALLOC
+/* DYNALLOC is what we use, but we may want these later.
+#define XZ_DEC_SINGLE
+#define XZ_DEC_PREALLOC
+*/
 
 /*
  * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
@@ -543,9 +533,6 @@ enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s,
 enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
 				       struct xz_buf *b);
 
-/* Free the memory allocated for the LZMA2 decoder. */
-void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
-
 #ifdef XZ_DEC_BCJ
 /*
  * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
@@ -569,24 +556,10 @@ enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
 enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
 				     struct xz_dec_lzma2 *lzma2,
 				     struct xz_buf *b);
-
-/* Free the memory allocated for the BCJ filters. */
-#define xz_dec_bcj_end(s) free(s)
 #endif
 
 // END "xz_private.h"
 
-uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
-{
-	crc = ~crc;
-
-	while (size != 0) {
-		crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
-		--size;
-	}
-
-	return ~crc;
-}
 
 
 
@@ -1820,7 +1793,7 @@ static inline int rc_is_finished(const struct rc_dec *rc)
 }
 
 /* Read the next input byte if needed. */
-static __always_inline void rc_normalize(struct rc_dec *rc)
+static inline void rc_normalize(struct rc_dec *rc)
 {
 	if (rc->range < RC_TOP_VALUE) {
 		rc->range <<= RC_SHIFT_BITS;
@@ -1839,7 +1812,7 @@ static __always_inline void rc_normalize(struct rc_dec *rc)
  * of the code generated by GCC 3.x decreases 10-15 %. (GCC 4.3 doesn't care,
  * and it generates 10-20 % faster code than GCC 3.x from this file anyway.)
  */
-static __always_inline int rc_bit(struct rc_dec *rc, uint16_t *prob)
+static inline int rc_bit(struct rc_dec *rc, uint16_t *prob)
 {
 	uint32_t bound;
 	int bit;
@@ -1861,7 +1834,7 @@ static __always_inline int rc_bit(struct rc_dec *rc, uint16_t *prob)
 }
 
 /* Decode a bittree starting from the most significant bit. */
-static __always_inline uint32_t rc_bittree(struct rc_dec *rc,
+static inline uint32_t rc_bittree(struct rc_dec *rc,
 					   uint16_t *probs, uint32_t limit)
 {
 	uint32_t symbol = 1;
@@ -1877,7 +1850,7 @@ static __always_inline uint32_t rc_bittree(struct rc_dec *rc,
 }
 
 /* Decode a bittree starting from the least significant bit. */
-static __always_inline void rc_bittree_reverse(struct rc_dec *rc,
+static inline void rc_bittree_reverse(struct rc_dec *rc,
 					       uint16_t *probs,
 					       uint32_t *dest, uint32_t limit)
 {
@@ -2204,7 +2177,7 @@ static int lzma2_lzma(struct xz_dec_lzma2 *s, struct xz_buf *b)
 		memcpy(s->temp.buf + s->temp.size, b->in + b->in_pos, tmp);
 
 		if (s->temp.size + tmp == s->lzma2.compressed) {
-			memzero(s->temp.buf + s->temp.size + tmp,
+			memset(s->temp.buf + s->temp.size + tmp, 0,
 					sizeof(s->temp.buf)
 						- s->temp.size - tmp);
 			s->rc.in_limit = s->temp.size + tmp;
@@ -2506,13 +2479,6 @@ enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props)
 	return XZ_OK;
 }
 
-void xz_dec_lzma2_end(struct xz_dec_lzma2 *s)
-{
-	if (DEC_IS_MULTI(s->dict.mode))
-		free(s->dict.buf);
-
-	free(s);
-}
 /*
  * .xz Stream decoder
  */
@@ -3342,7 +3308,7 @@ struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max)
 
 error_lzma2:
 #ifdef XZ_DEC_BCJ
-	xz_dec_bcj_end(s->bcj);
+	free(s->bcj);
 error_bcj:
 #endif
 	free(s);
@@ -3355,8 +3321,8 @@ void xz_dec_reset(struct xz_dec *s)
 	s->allow_buf_error = 0;
 	s->pos = 0;
 	s->crc = 0;
-	memzero(&s->block, sizeof(s->block));
-	memzero(&s->index, sizeof(s->index));
+	memset(&s->block, 0, sizeof(s->block));
+	memset(&s->index, 0, sizeof(s->index));
 	s->temp.pos = 0;
 	s->temp.size = STREAM_HEADER_SIZE;
 }
@@ -3364,9 +3330,12 @@ void xz_dec_reset(struct xz_dec *s)
 void xz_dec_end(struct xz_dec *s)
 {
 	if (s != NULL) {
-		xz_dec_lzma2_end(s->lzma2);
+		if (DEC_IS_MULTI((s->lzma2)->dict.mode))
+			free((s->lzma2)->dict.buf);
+		free(s->lzma2);
+
 #ifdef XZ_DEC_BCJ
-		xz_dec_bcj_end(s->bcj);
+		free(s->bcj);
 #endif
 		free(s);
 	}