liblzma 2018-04-29 (b5be61cc)

Code extracted from:

    https://git.tukaani.org/xz.git

at commit b5be61cc06088bb07f488f9baf7d447ff47b37c1 (v5.2.4).

1 files changed, 57 insertions, 50 deletions

diff --git a/liblzma/lzma/lzma_decoder.c b/liblzma/lzma/lzma_decoder.c
index 9979bb4261..d0f29b763a 100644
--- a/liblzma/lzma/lzma_decoder.c
+++ b/liblzma/lzma/lzma_decoder.c
@@ -16,6 +16,12 @@
 #include "lzma_decoder.h"
 #include "range_decoder.h"
 
+// The macros unroll loops with switch statements.
+// Silence warnings about missing fall-through comments.
+#if TUKLIB_GNUC_REQ(7, 0)
+#	pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+#endif
+
 
 #ifdef HAVE_SMALL
 
@@ -161,7 +167,7 @@ typedef struct {
 } lzma_length_decoder;
 
 
-struct lzma_coder_s {
+typedef struct {
 	///////////////////
 	// Probabilities //
 	///////////////////
@@ -193,15 +199,15 @@ struct lzma_coder_s {
 	/// Probability tree for the highest two bits of the match distance.
 	/// There is a separate probability tree for match lengths of
 	/// 2 (i.e. MATCH_LEN_MIN), 3, 4, and [5, 273].
-	probability pos_slot[LEN_TO_POS_STATES][POS_SLOTS];
+	probability dist_slot[DIST_STATES][DIST_SLOTS];
 
 	/// Probability trees for additional bits for match distance when the
 	/// distance is in the range [4, 127].
-	probability pos_special[FULL_DISTANCES - END_POS_MODEL_INDEX];
+	probability pos_special[FULL_DISTANCES - DIST_MODEL_END];
 
 	/// Probability tree for the lowest four bits of a match distance
 	/// that is equal to or greater than 128.
-	probability pos_align[ALIGN_TABLE_SIZE];
+	probability pos_align[ALIGN_SIZE];
 
 	/// Length of a normal match
 	lzma_length_decoder match_len_decoder;
@@ -245,8 +251,8 @@ struct lzma_coder_s {
 		SEQ_LITERAL_WRITE,
 		SEQ_IS_REP,
 		seq_len(SEQ_MATCH_LEN),
-		seq_6(SEQ_POS_SLOT),
-		SEQ_POS_MODEL,
+		seq_6(SEQ_DIST_SLOT),
+		SEQ_DIST_MODEL,
 		SEQ_DIRECT,
 		seq_4(SEQ_ALIGN),
 		SEQ_EOPM,
@@ -277,20 +283,26 @@ struct lzma_coder_s {
 	/// If decoding a literal: match byte.
 	/// If decoding a match: length of the match.
 	uint32_t len;
-};
+} lzma_lzma1_decoder;
 
 
 static lzma_ret
-lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
+lzma_decode(void *coder_ptr, lzma_dict *restrict dictptr,
 		const uint8_t *restrict in,
 		size_t *restrict in_pos, size_t in_size)
 {
+	lzma_lzma1_decoder *restrict coder = coder_ptr;
+
 	////////////////////
 	// Initialization //
 	////////////////////
 
-	if (!rc_read_init(&coder->rc, in, in_pos, in_size))
-		return LZMA_OK;
+	{
+		const lzma_ret ret = rc_read_init(
+				&coder->rc, in, in_pos, in_size);
+		if (ret != LZMA_STREAM_END)
+			return ret;
+	}
 
 	///////////////
 	// Variables //
@@ -502,28 +514,28 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 
 			// Prepare to decode the highest two bits of the
 			// match distance.
-			probs = coder->pos_slot[get_len_to_pos_state(len)];
+			probs = coder->dist_slot[get_dist_state(len)];
 			symbol = 1;
 
 #ifdef HAVE_SMALL
-	case SEQ_POS_SLOT:
+	case SEQ_DIST_SLOT:
 			do {
-				rc_bit(probs[symbol], , , SEQ_POS_SLOT);
-			} while (symbol < POS_SLOTS);
+				rc_bit(probs[symbol], , , SEQ_DIST_SLOT);
+			} while (symbol < DIST_SLOTS);
 #else
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT0);
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT1);
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT2);
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT3);
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT4);
-			rc_bit_case(probs[symbol], , , SEQ_POS_SLOT5);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT0);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT1);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT2);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT3);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT4);
+			rc_bit_case(probs[symbol], , , SEQ_DIST_SLOT5);
 #endif
 			// Get rid of the highest bit that was needed for
 			// indexing of the probability array.
-			symbol -= POS_SLOTS;
+			symbol -= DIST_SLOTS;
 			assert(symbol <= 63);
 
-			if (symbol < START_POS_MODEL_INDEX) {
+			if (symbol < DIST_MODEL_START) {
 				// Match distances [0, 3] have only two bits.
 				rep0 = symbol;
 			} else {
@@ -533,7 +545,7 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 				assert(limit >= 1 && limit <= 30);
 				rep0 = 2 + (symbol & 1);
 
-				if (symbol < END_POS_MODEL_INDEX) {
+				if (symbol < DIST_MODEL_END) {
 					// Prepare to decode the low bits for
 					// a distance of [4, 127].
 					assert(limit <= 5);
@@ -553,12 +565,12 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 							- symbol - 1;
 					symbol = 1;
 					offset = 0;
-	case SEQ_POS_MODEL:
+	case SEQ_DIST_MODEL:
 #ifdef HAVE_SMALL
 					do {
 						rc_bit(probs[symbol], ,
 							rep0 += 1 << offset,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 					} while (++offset < limit);
 #else
 					switch (limit) {
@@ -566,25 +578,25 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 						assert(offset == 0);
 						rc_bit(probs[symbol], ,
 							rep0 += 1,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 						++offset;
 						--limit;
 					case 4:
 						rc_bit(probs[symbol], ,
 							rep0 += 1 << offset,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 						++offset;
 						--limit;
 					case 3:
 						rc_bit(probs[symbol], ,
 							rep0 += 1 << offset,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 						++offset;
 						--limit;
 					case 2:
 						rc_bit(probs[symbol], ,
 							rep0 += 1 << offset,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 						++offset;
 						--limit;
 					case 1:
@@ -596,7 +608,7 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 						// "symbol".
 						rc_bit_last(probs[symbol], ,
 							rep0 += 1 << offset,
-							SEQ_POS_MODEL);
+							SEQ_DIST_MODEL);
 					}
 #endif
 				} else {
@@ -637,7 +649,7 @@ lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
 					rc_bit(coder->pos_align[symbol], ,
 							rep0 += 4, SEQ_ALIGN2);
 	case SEQ_ALIGN3:
-					// Like in SEQ_POS_MODEL, we don't
+					// Like in SEQ_DIST_MODEL, we don't
 					// need "symbol" for anything else
 					// than indexing the probability array.
 					rc_bit_last(coder->pos_align[symbol], ,
@@ -836,23 +848,17 @@ out:
 
 
 static void
-lzma_decoder_uncompressed(lzma_coder *coder, lzma_vli uncompressed_size)
+lzma_decoder_uncompressed(void *coder_ptr, lzma_vli uncompressed_size)
 {
+	lzma_lzma1_decoder *coder = coder_ptr;
 	coder->uncompressed_size = uncompressed_size;
 }
 
-/*
-extern void
-lzma_lzma_decoder_uncompressed(void *coder_ptr, lzma_vli uncompressed_size)
-{
-	// This is hack.
-	(*(lzma_coder **)(coder))->uncompressed_size = uncompressed_size;
-}
-*/
 
 static void
-lzma_decoder_reset(lzma_coder *coder, const void *opt)
+lzma_decoder_reset(void *coder_ptr, const void *opt)
 {
+	lzma_lzma1_decoder *coder = coder_ptr;
 	const lzma_options_lzma *options = opt;
 
 	// NOTE: We assume that lc/lp/pb are valid since they were
@@ -891,10 +897,10 @@ lzma_decoder_reset(lzma_coder *coder, const void *opt)
 		bit_reset(coder->is_rep2[i]);
 	}
 
-	for (uint32_t i = 0; i < LEN_TO_POS_STATES; ++i)
-		bittree_reset(coder->pos_slot[i], POS_SLOT_BITS);
+	for (uint32_t i = 0; i < DIST_STATES; ++i)
+		bittree_reset(coder->dist_slot[i], DIST_SLOT_BITS);
 
-	for (uint32_t i = 0; i < FULL_DISTANCES - END_POS_MODEL_INDEX; ++i)
+	for (uint32_t i = 0; i < FULL_DISTANCES - DIST_MODEL_END; ++i)
 		bit_reset(coder->pos_special[i]);
 
 	bittree_reset(coder->pos_align, ALIGN_BITS);
@@ -933,11 +939,11 @@ lzma_decoder_reset(lzma_coder *coder, const void *opt)
 
 
 extern lzma_ret
-lzma_lzma_decoder_create(lzma_lz_decoder *lz, lzma_allocator *allocator,
+lzma_lzma_decoder_create(lzma_lz_decoder *lz, const lzma_allocator *allocator,
 		const void *opt, lzma_lz_options *lz_options)
 {
 	if (lz->coder == NULL) {
-		lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		lz->coder = lzma_alloc(sizeof(lzma_lzma1_decoder), allocator);
 		if (lz->coder == NULL)
 			return LZMA_MEM_ERROR;
 
@@ -961,7 +967,7 @@ lzma_lzma_decoder_create(lzma_lz_decoder *lz, lzma_allocator *allocator,
 /// initialization (lzma_lzma_decoder_init() passes function pointer to
 /// the LZ initialization).
 static lzma_ret
-lzma_decoder_init(lzma_lz_decoder *lz, lzma_allocator *allocator,
+lzma_decoder_init(lzma_lz_decoder *lz, const lzma_allocator *allocator,
 		const void *options, lzma_lz_options *lz_options)
 {
 	if (!is_lclppb_valid(options))
@@ -978,7 +984,7 @@ lzma_decoder_init(lzma_lz_decoder *lz, lzma_allocator *allocator,
 
 
 extern lzma_ret
-lzma_lzma_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+lzma_lzma_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters)
 {
 	// LZMA can only be the last filter in the chain. This is enforced
@@ -1010,7 +1016,8 @@ extern uint64_t
 lzma_lzma_decoder_memusage_nocheck(const void *options)
 {
 	const lzma_options_lzma *const opt = options;
-	return sizeof(lzma_coder) + lzma_lz_decoder_memusage(opt->dict_size);
+	return sizeof(lzma_lzma1_decoder)
+			+ lzma_lz_decoder_memusage(opt->dict_size);
 }
 
 
@@ -1025,7 +1032,7 @@ lzma_lzma_decoder_memusage(const void *options)
 
 
 extern lzma_ret
-lzma_lzma_props_decode(void **options, lzma_allocator *allocator,
+lzma_lzma_props_decode(void **options, const lzma_allocator *allocator,
 		const uint8_t *props, size_t props_size)
 {
 	if (props_size != 5)