Bug Summary

File:root/firefox-clang/modules/zlib/src/deflate.h
Warning:line 104, column 16
Excessive padding in 'struct internal_state' (40 padding bytes, where 0 is optimal). Optimal fields order: strm, pending_buf, pending_buf_size, pending_out, pending, gzhead, gzindex, window, window_size, prev, head, block_start, sym_buf, opt_len, static_len, high_water, l_desc, d_desc, bl_desc, status, wrap, last_flush, w_size, w_bits, w_mask, ins_h, hash_size, hash_bits, hash_mask, hash_shift, match_length, prev_match, match_available, strstart, match_start, lookahead, prev_length, max_chain_length, max_lazy_match, level, strategy, good_match, nice_match, heap_len, heap_max, lit_bufsize, sym_next, sym_end, matches, insert, bi_valid, bi_used, slid, heap, bi_buf, bl_count, bl_tree, dyn_dtree, dyn_ltree, method, depth, consider reordering the fields or adding explicit padding members

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -O2 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name trees.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -ffp-contract=off -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/root/firefox-clang/obj-x86_64-pc-linux-gnu/modules/zlib/src -fcoverage-compilation-dir=/root/firefox-clang/obj-x86_64-pc-linux-gnu/modules/zlib/src -resource-dir /usr/lib/llvm-23/lib/clang/23 -include /root/firefox-clang/config/gcc_hidden.h -include /root/firefox-clang/obj-x86_64-pc-linux-gnu/mozilla-config.h -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/system_wrappers -U _FORTIFY_SOURCE -D _FORTIFY_SOURCE=2 -D DEBUG=1 -I /root/firefox-clang/modules/zlib/src -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/modules/zlib/src -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nspr -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nss -D MOZILLA_CLIENT -internal-isystem /usr/lib/llvm-23/lib/clang/23/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/16/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -Wno-error=tautological-type-limit-compare -Wno-range-loop-analysis -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wno-error=deprecated-builtins -Wno-psabi -Wno-error=builtin-macro-redefined -Wno-unknown-warning-option -Wno-character-conversion -Wno-deprecated-non-prototype -ferror-limit 19 -fstrict-flex-arrays=1 -stack-protector 2 -fstack-clash-protection -ftrivial-auto-var-init=pattern -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fdiagnostics-absolute-paths -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -mllvm -dwarf-linkage-names=Abstract -faddrsig -fdwarf2-cfi-asm -o /tmp/scan-build-2026-09-01-224014-2642839-1 -x c /root/firefox-clang/modules/zlib/src/trees.c
1/* deflate.h -- internal compression state
2 * Copyright (C) 1995-2026 Jean-loup Gailly
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/* WARNING: this file should *not* be used by applications. It is
7 part of the implementation of the compression library and is
8 subject to change. Applications should only use zlib.h.
9 */
10
11/* @(#) $Id$ */
12
13#ifndef DEFLATE_H
14#define DEFLATE_H
15
16#include "zutil.h"
17
18/* define NO_GZIP when compiling if you want to disable gzip header and
19 trailer creation by deflate(). NO_GZIP would be used to avoid linking in
20 the crc code when it is not needed. For shared libraries, gzip encoding
21 should be left enabled. */
22#ifndef NO_GZIP
23# define GZIP
24#endif
25
26/* define LIT_MEM to slightly increase the speed of deflate (order 1% to 2%) at
27 the cost of a larger memory footprint */
28/* #define LIT_MEM */
29
30/* ===========================================================================
31 * Internal compression state.
32 */
33
34#define LENGTH_CODES29 29
35/* number of length codes, not counting the special END_BLOCK code */
36
37#define LITERALS256 256
38/* number of literal bytes 0..255 */
39
40#define L_CODES(256 +1+29) (LITERALS256+1+LENGTH_CODES29)
41/* number of Literal or Length codes, including the END_BLOCK code */
42
43#define D_CODES30 30
44/* number of distance codes */
45
46#define BL_CODES19 19
47/* number of codes used to transfer the bit lengths */
48
49#define HEAP_SIZE(2*(256 +1+29)+1) (2*L_CODES(256 +1+29)+1)
50/* maximum heap size */
51
52#define MAX_BITS15 15
53/* All codes must not exceed MAX_BITS bits */
54
55#define Buf_size16 16
56/* size of bit buffer in bi_buf */
57
58#define INIT_STATE42 42 /* zlib header -> BUSY_STATE */
59#ifdef GZIP
60# define GZIP_STATE57 57 /* gzip header -> BUSY_STATE | EXTRA_STATE */
61#endif
62#define EXTRA_STATE69 69 /* gzip extra block -> NAME_STATE */
63#define NAME_STATE73 73 /* gzip file name -> COMMENT_STATE */
64#define COMMENT_STATE91 91 /* gzip comment -> HCRC_STATE */
65#define HCRC_STATE103 103 /* gzip header CRC -> BUSY_STATE */
66#define BUSY_STATE113 113 /* deflate -> FINISH_STATE */
67#define FINISH_STATE666 666 /* stream complete */
68/* Stream status */
69
70
71/* Data structure describing a single value and its code string. */
72typedef struct ct_data_s {
73 union {
74 ush freq; /* frequency count */
75 ush code; /* bit string */
76 } fc;
77 union {
78 ush dad; /* father node in Huffman tree */
79 ush len; /* length of bit string */
80 } dl;
81} FAR ct_data;
82
83#define Freqfc.freq fc.freq
84#define Codefc.code fc.code
85#define Daddl.dad dl.dad
86#define Lendl.len dl.len
87
88typedef struct static_tree_desc_s static_tree_desc;
89
90typedef struct tree_desc_s {
91 ct_data *dyn_tree; /* the dynamic tree */
92 int max_code; /* largest code with non zero frequency */
93 const static_tree_desc *stat_desc; /* the corresponding static tree */
94} FAR tree_desc;
95
96typedef ush Pos;
97typedef Pos FAR Posf;
98typedef unsigned IPos;
99
100/* A Pos is an index in the character window. We use short instead of int to
101 * save space in the various tables. IPos is used only for parameter passing.
102 */
103
104typedef struct internal_state {
Excessive padding in 'struct internal_state' (40 padding bytes, where 0 is optimal). Optimal fields order: strm, pending_buf, pending_buf_size, pending_out, pending, gzhead, gzindex, window, window_size, prev, head, block_start, sym_buf, opt_len, static_len, high_water, l_desc, d_desc, bl_desc, status, wrap, last_flush, w_size, w_bits, w_mask, ins_h, hash_size, hash_bits, hash_mask, hash_shift, match_length, prev_match, match_available, strstart, match_start, lookahead, prev_length, max_chain_length, max_lazy_match, level, strategy, good_match, nice_match, heap_len, heap_max, lit_bufsize, sym_next, sym_end, matches, insert, bi_valid, bi_used, slid, heap, bi_buf, bl_count, bl_tree, dyn_dtree, dyn_ltree, method, depth, consider reordering the fields or adding explicit padding members
105 z_streamp strm; /* pointer back to this zlib stream */
106 int status; /* as the name implies */
107 Bytef *pending_buf; /* output still pending */
108 ulg pending_buf_size; /* size of pending_buf */
109 Bytef *pending_out; /* next pending byte to output to the stream */
110 ulg pending; /* nb of bytes in the pending buffer */
111 int wrap; /* bit 0 true for zlib, bit 1 true for gzip */
112 gz_headerp gzhead; /* gzip header information to write */
113 ulg gzindex; /* where in extra, name, or comment */
114 Byte method; /* can only be DEFLATED */
115 int last_flush; /* value of flush param for previous deflate call */
116
117 /* used by deflate.c: */
118
119 uInt w_size; /* LZ77 window size (32K by default) */
120 uInt w_bits; /* log2(w_size) (8..16) */
121 uInt w_mask; /* w_size - 1 */
122
123 Bytef *window;
124 /* Sliding window. Input bytes are read into the second half of the window,
125 * and move to the first half later to keep a dictionary of at least wSize
126 * bytes. With this organization, matches are limited to a distance of
127 * wSize-MAX_MATCH bytes, but this ensures that IO is always
128 * performed with a length multiple of the block size. Also, it limits
129 * the window size to 64K, which is quite useful on MSDOS.
130 * To do: use the user input buffer as sliding window.
131 */
132
133 ulg window_size;
134 /* Actual size of window: 2*wSize, except when the user input buffer
135 * is directly used as sliding window.
136 */
137
138 Posf *prev;
139 /* Link to older string with same hash index. To limit the size of this
140 * array to 64K, this link is maintained only for the last 32K strings.
141 * An index in this array is thus a window index modulo 32K.
142 */
143
144 Posf *head; /* Heads of the hash chains or NIL. */
145
146 uInt ins_h; /* hash index of string to be inserted */
147 uInt hash_size; /* number of elements in hash table */
148 uInt hash_bits; /* log2(hash_size) */
149 uInt hash_mask; /* hash_size-1 */
150
151 uInt hash_shift;
152 /* Number of bits by which ins_h must be shifted at each input
153 * step. It must be such that after MIN_MATCH steps, the oldest
154 * byte no longer takes part in the hash key, that is:
155 * hash_shift * MIN_MATCH >= hash_bits
156 */
157
158 long block_start;
159 /* Window position at the beginning of the current output block. Gets
160 * negative when the window is moved backwards.
161 */
162
163 uInt match_length; /* length of best match */
164 IPos prev_match; /* previous match */
165 int match_available; /* set if previous match exists */
166 uInt strstart; /* start of string to insert */
167 uInt match_start; /* start of matching string */
168 uInt lookahead; /* number of valid bytes ahead in window */
169
170 uInt prev_length;
171 /* Length of the best match at previous step. Matches not greater than this
172 * are discarded. This is used in the lazy match evaluation.
173 */
174
175 uInt max_chain_length;
176 /* To speed up deflation, hash chains are never searched beyond this
177 * length. A higher limit improves compression ratio but degrades the
178 * speed.
179 */
180
181 uInt max_lazy_match;
182 /* Attempt to find a better match only when the current match is strictly
183 * smaller than this value. This mechanism is used only for compression
184 * levels >= 4.
185 */
186# define max_insert_lengthmax_lazy_match max_lazy_match
187 /* Insert new strings in the hash table only if the match length is not
188 * greater than this length. This saves time but degrades compression.
189 * max_insert_length is used only for compression levels <= 3.
190 */
191
192 int level; /* compression level (1..9) */
193 int strategy; /* favor or force Huffman coding*/
194
195 uInt good_match;
196 /* Use a faster search when the previous match is longer than this */
197
198 int nice_match; /* Stop searching when current match exceeds this */
199
200 /* used by trees.c: */
201 /* Didn't use ct_data typedef below to suppress compiler warning */
202 struct ct_data_s dyn_ltree[HEAP_SIZE(2*(256 +1+29)+1)]; /* literal and length tree */
203 struct ct_data_s dyn_dtree[2*D_CODES30+1]; /* distance tree */
204 struct ct_data_s bl_tree[2*BL_CODES19+1]; /* Huffman tree for bit lengths */
205
206 struct tree_desc_s l_desc; /* desc. for literal tree */
207 struct tree_desc_s d_desc; /* desc. for distance tree */
208 struct tree_desc_s bl_desc; /* desc. for bit length tree */
209
210 ush bl_count[MAX_BITS15+1];
211 /* number of codes at each bit length for an optimal tree */
212
213 int heap[2*L_CODES(256 +1+29)+1]; /* heap used to build the Huffman trees */
214 int heap_len; /* number of elements in the heap */
215 int heap_max; /* element of largest frequency */
216 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
217 * The same heap array is used to build all trees.
218 */
219
220 uch depth[2*L_CODES(256 +1+29)+1];
221 /* Depth of each subtree used as tie breaker for trees of equal frequency
222 */
223
224#ifdef LIT_MEM
225# define LIT_BUFS4 5
226 ushf *d_buf; /* buffer for distances */
227 uchf *l_buf; /* buffer for literals/lengths */
228#else
229# define LIT_BUFS4 4
230 uchf *sym_buf; /* buffer for distances and literals/lengths */
231#endif
232
233 uInt lit_bufsize;
234 /* Size of match buffer for literals/lengths. There are 4 reasons for
235 * limiting lit_bufsize to 64K:
236 * - frequencies can be kept in 16 bit counters
237 * - if compression is not successful for the first block, all input
238 * data is still in the window so we can still emit a stored block even
239 * when input comes from standard input. (This can also be done for
240 * all blocks if lit_bufsize is not greater than 32K.)
241 * - if compression is not successful for a file smaller than 64K, we can
242 * even emit a stored file instead of a stored block (saving 5 bytes).
243 * This is applicable only for zip (not gzip or zlib).
244 * - creating new Huffman trees less frequently may not provide fast
245 * adaptation to changes in the input data statistics. (Take for
246 * example a binary file with poorly compressible code followed by
247 * a highly compressible string table.) Smaller buffer sizes give
248 * fast adaptation but have of course the overhead of transmitting
249 * trees more frequently.
250 * - I can't count above 4
251 */
252
253 uInt sym_next; /* running index in symbol buffer */
254 uInt sym_end; /* symbol table full when sym_next reaches this */
255
256 ulg opt_len; /* bit length of current block with optimal trees */
257 ulg static_len; /* bit length of current block with static trees */
258 uInt matches; /* number of string matches in current block */
259 uInt insert; /* bytes at end of window left to insert */
260
261#ifdef ZLIB_DEBUG
262 ulg compressed_len; /* total bit length of compressed file mod 2^32 */
263 ulg bits_sent; /* bit length of compressed data sent mod 2^32 */
264#endif
265
266 ush bi_buf;
267 /* Output buffer. bits are inserted starting at the bottom (least
268 * significant bits).
269 */
270 int bi_valid;
271 /* Number of valid bits in bi_buf. All bits above the last valid bit
272 * are always zero.
273 */
274 int bi_used;
275 /* Last number of used bits when going to a byte boundary.
276 */
277
278 ulg high_water;
279 /* High water mark offset in window for initialized bytes -- bytes above
280 * this are set to zero in order to avoid memory check warnings when
281 * longest match routines access bytes past the input. This is then
282 * updated to the new high water mark.
283 */
284
285 int slid;
286 /* True if the hash table has been slid since it was cleared. */
287
288} FAR deflate_state;
289
290/* Output a byte on the stream.
291 * IN assertion: there is enough room in pending_buf.
292 */
293#define put_byte(s, c){s->pending_buf[s->pending++] = (Bytef)(c);} {s->pending_buf[s->pending++] = (Bytef)(c);}
294
295
296#define MIN_LOOKAHEAD(258 +3 +1) (MAX_MATCH258+MIN_MATCH3+1)
297/* Minimum amount of lookahead, except at the end of the input file.
298 * See deflate.c for comments about the MIN_MATCH+1.
299 */
300
301#define MAX_DIST(s)((s)->w_size-(258 +3 +1)) ((s)->w_size-MIN_LOOKAHEAD(258 +3 +1))
302/* In order to simplify the code, particularly on 16 bit machines, match
303 * distances are limited to MAX_DIST instead of WSIZE.
304 */
305
306#define WIN_INIT258 MAX_MATCH258
307/* Number of bytes after end of data in window to initialize in order to avoid
308 memory checker errors from longest match routines */
309
310 /* in trees.c */
311void ZLIB_INTERNAL _tr_initMOZ_Z__tr_init(deflate_state *s);
312int ZLIB_INTERNAL _tr_tallyMOZ_Z__tr_tally(deflate_state *s, unsigned dist, unsigned lc);
313void ZLIB_INTERNAL _tr_flush_blockMOZ_Z__tr_flush_block(deflate_state *s, charf *buf,
314 ulg stored_len, int last);
315void ZLIB_INTERNAL _tr_flush_bitsMOZ_Z__tr_flush_bits(deflate_state *s);
316void ZLIB_INTERNAL _tr_alignMOZ_Z__tr_align(deflate_state *s);
317void ZLIB_INTERNAL _tr_stored_blockMOZ_Z__tr_stored_block(deflate_state *s, charf *buf,
318 ulg stored_len, int last);
319
320#define d_code(dist)((dist) < 256 ? MOZ_Z__dist_code[dist] : MOZ_Z__dist_code[
256+((dist)>>7)])
\
321 ((dist) < 256 ? _dist_codeMOZ_Z__dist_code[dist] : _dist_codeMOZ_Z__dist_code[256+((dist)>>7)])
322/* Mapping from a distance to a distance code. dist is the distance - 1 and
323 * must not have side effects. _dist_code[256] and _dist_code[257] are never
324 * used.
325 */
326
327#ifndef ZLIB_DEBUG
328/* Inline versions of _tr_tally for speed: */
329
330#if defined(GEN_TREES_H) || !defined(STDC)
331 extern uch ZLIB_INTERNAL _length_codeMOZ_Z__length_code[];
332 extern uch ZLIB_INTERNAL _dist_codeMOZ_Z__dist_code[];
333#else
334 extern const uch ZLIB_INTERNAL _length_codeMOZ_Z__length_code[];
335 extern const uch ZLIB_INTERNAL _dist_codeMOZ_Z__dist_code[];
336#endif
337
338#ifdef LIT_MEM
339# define _tr_tally_lit(s, c, flush){ uch cc = (c); s->sym_buf[s->sym_next++] = 0; s->sym_buf
[s->sym_next++] = 0; s->sym_buf[s->sym_next++] = cc;
s->dyn_ltree[cc].fc.freq++; flush = (s->sym_next == s->
sym_end); }
\
340 { uch cc = (c); \
341 s->d_buf[s->sym_next] = 0; \
342 s->l_buf[s->sym_next++] = cc; \
343 s->dyn_ltree[cc].Freqfc.freq++; \
344 flush = (s->sym_next == s->sym_end); \
345 }
346# define _tr_tally_dist(s, distance, length, flush){ uch len = (uch)(length); ush dist = (ush)(distance); s->
sym_buf[s->sym_next++] = (uch)dist; s->sym_buf[s->sym_next
++] = (uch)(dist >> 8); s->sym_buf[s->sym_next++]
= len; dist--; s->dyn_ltree[MOZ_Z__length_code[len]+256 +
1].fc.freq++; s->dyn_dtree[((dist) < 256 ? MOZ_Z__dist_code
[dist] : MOZ_Z__dist_code[256+((dist)>>7)])].fc.freq++;
flush = (s->sym_next == s->sym_end); }
\
347 { uch len = (uch)(length); \
348 ush dist = (ush)(distance); \
349 s->d_buf[s->sym_next] = dist; \
350 s->l_buf[s->sym_next++] = len; \
351 dist--; \
352 s->dyn_ltree[_length_codeMOZ_Z__length_code[len]+LITERALS256+1].Freqfc.freq++; \
353 s->dyn_dtree[d_code(dist)((dist) < 256 ? MOZ_Z__dist_code[dist] : MOZ_Z__dist_code[
256+((dist)>>7)])
].Freqfc.freq++; \
354 flush = (s->sym_next == s->sym_end); \
355 }
356#else
357# define _tr_tally_lit(s, c, flush){ uch cc = (c); s->sym_buf[s->sym_next++] = 0; s->sym_buf
[s->sym_next++] = 0; s->sym_buf[s->sym_next++] = cc;
s->dyn_ltree[cc].fc.freq++; flush = (s->sym_next == s->
sym_end); }
\
358 { uch cc = (c); \
359 s->sym_buf[s->sym_next++] = 0; \
360 s->sym_buf[s->sym_next++] = 0; \
361 s->sym_buf[s->sym_next++] = cc; \
362 s->dyn_ltree[cc].Freqfc.freq++; \
363 flush = (s->sym_next == s->sym_end); \
364 }
365# define _tr_tally_dist(s, distance, length, flush){ uch len = (uch)(length); ush dist = (ush)(distance); s->
sym_buf[s->sym_next++] = (uch)dist; s->sym_buf[s->sym_next
++] = (uch)(dist >> 8); s->sym_buf[s->sym_next++]
= len; dist--; s->dyn_ltree[MOZ_Z__length_code[len]+256 +
1].fc.freq++; s->dyn_dtree[((dist) < 256 ? MOZ_Z__dist_code
[dist] : MOZ_Z__dist_code[256+((dist)>>7)])].fc.freq++;
flush = (s->sym_next == s->sym_end); }
\
366 { uch len = (uch)(length); \
367 ush dist = (ush)(distance); \
368 s->sym_buf[s->sym_next++] = (uch)dist; \
369 s->sym_buf[s->sym_next++] = (uch)(dist >> 8); \
370 s->sym_buf[s->sym_next++] = len; \
371 dist--; \
372 s->dyn_ltree[_length_codeMOZ_Z__length_code[len]+LITERALS256+1].Freqfc.freq++; \
373 s->dyn_dtree[d_code(dist)((dist) < 256 ? MOZ_Z__dist_code[dist] : MOZ_Z__dist_code[
256+((dist)>>7)])
].Freqfc.freq++; \
374 flush = (s->sym_next == s->sym_end); \
375 }
376#endif
377#else
378# define _tr_tally_lit(s, c, flush){ uch cc = (c); s->sym_buf[s->sym_next++] = 0; s->sym_buf
[s->sym_next++] = 0; s->sym_buf[s->sym_next++] = cc;
s->dyn_ltree[cc].fc.freq++; flush = (s->sym_next == s->
sym_end); }
flush = _tr_tallyMOZ_Z__tr_tally(s, 0, c)
379# define _tr_tally_dist(s, distance, length, flush){ uch len = (uch)(length); ush dist = (ush)(distance); s->
sym_buf[s->sym_next++] = (uch)dist; s->sym_buf[s->sym_next
++] = (uch)(dist >> 8); s->sym_buf[s->sym_next++]
= len; dist--; s->dyn_ltree[MOZ_Z__length_code[len]+256 +
1].fc.freq++; s->dyn_dtree[((dist) < 256 ? MOZ_Z__dist_code
[dist] : MOZ_Z__dist_code[256+((dist)>>7)])].fc.freq++;
flush = (s->sym_next == s->sym_end); }
\
380 flush = _tr_tallyMOZ_Z__tr_tally(s, distance, length)
381#endif
382
383#endif /* DEFLATE_H */