From 62d6112a7981ad7c34f3b43cffdf00d4662a4f25 Mon Sep 17 00:00:00 2001 From: Mark Adler Date: Sun, 12 Aug 2012 18:08:52 -0700 Subject: [PATCH] Clean up the usage of z_const and respect const usage within zlib. This patch allows zlib to compile cleanly with the -Wcast-qual gcc warning enabled, but only if ZLIB_CONST is defined, which adds const to next_in and msg in z_stream and in the in_func prototype. A --const option is added to ./configure which adds -DZLIB_CONST to the compile flags, and adds -Wcast-qual to the compile flags when ZLIBGCCWARN is set in the environment. --- compress.c | 2 +- configure | 10 +++++++-- contrib/infback9/infback9.c | 2 +- deflate.c | 6 +++--- gzlib.c | 10 ++++----- gzread.c | 3 ++- gzwrite.c | 33 ++++++++++++++++------------- infback.c | 2 +- inffast.c | 4 ++-- inflate.c | 41 +++++++++++++++---------------------- test/example.c | 8 ++++---- trees.c | 14 +++++++------ uncompr.c | 2 +- zlib.h | 3 ++- zutil.c | 2 +- zutil.h | 4 ++-- 16 files changed, 76 insertions(+), 70 deletions(-) diff --git a/compress.c b/compress.c index ea4dfbe..6e97626 100644 --- a/compress.c +++ b/compress.c @@ -29,7 +29,7 @@ int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) z_stream stream; int err; - stream.next_in = (Bytef*)source; + stream.next_in = (z_const Bytef *)source; stream.avail_in = (uInt)sourceLen; #ifdef MAXSEG_64K /* Check for source > 64K on 16-bit machine: */ diff --git a/configure b/configure index a69d7bf..bc39fd7 100755 --- a/configure +++ b/configure @@ -70,6 +70,7 @@ shared=1 solo=0 cover=0 zprefix=0 +zconst=0 build64=0 gcc=0 old_cc="$CC" @@ -96,7 +97,7 @@ do case "$1" in -h* | --help) echo 'usage:' | tee -a configure.log - echo ' configure [--zprefix] [--prefix=PREFIX] [--eprefix=EXPREFIX]' | tee -a configure.log + echo ' configure [--const] [--zprefix] [--prefix=PREFIX] [--eprefix=EXPREFIX]' | tee -a configure.log echo ' [--static] [--64] [--libdir=LIBDIR] [--sharedlibdir=LIBDIR]' | tee -a configure.log echo ' [--includedir=INCLUDEDIR] [--archs="-arch i386 -arch x86_64"]' | tee -a configure.log exit 0 ;; @@ -119,6 +120,7 @@ case "$1" in -a*=* | --archs=*) ARCHS=`echo $1 | sed 's/.*=//'`; shift ;; --sysconfdir=*) echo "ignored option: --sysconfdir" | tee -a configure.log; shift ;; --localstatedir=*) echo "ignored option: --localstatedir" | tee -a configure.log; shift ;; + -c* | --const) zconst=1; shift ;; *) echo "unknown option: $1" | tee -a configure.log echo "$0 --help for help" | tee -a configure.log @@ -171,7 +173,11 @@ if test "$gcc" -eq 1 && ($cc -c $test.c) >> configure.log 2>&1; then SFLAGS="${SFLAGS} -m64" fi if test "${ZLIBGCCWARN}" = "YES"; then - CFLAGS="${CFLAGS} -Wall -Wextra -pedantic" + if test "$zconst" -eq 1; then + CFLAGS="${CFLAGS} -Wall -Wextra -Wcast-qual -pedantic -DZLIB_CONST" + else + CFLAGS="${CFLAGS} -Wall -Wextra -pedantic" + fi fi if test -z "$uname"; then uname=`(uname -s || echo unknown) 2>/dev/null` diff --git a/contrib/infback9/infback9.c b/contrib/infback9/infback9.c index 3691d4a..05fb3e3 100644 --- a/contrib/infback9/infback9.c +++ b/contrib/infback9/infback9.c @@ -222,7 +222,7 @@ out_func out; void FAR *out_desc; { struct inflate_state FAR *state; - unsigned char FAR *next; /* next input */ + z_const unsigned char FAR *next; /* next input */ unsigned char FAR *put; /* next output */ unsigned have; /* available input */ unsigned long left; /* available output */ diff --git a/deflate.c b/deflate.c index 4792345..4aa5afb 100644 --- a/deflate.c +++ b/deflate.c @@ -305,7 +305,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || s->pending_buf == Z_NULL) { s->status = FINISH_STATE; - strm->msg = (char*)ERR_MSG(Z_MEM_ERROR); + strm->msg = ERR_MSG(Z_MEM_ERROR); deflateEnd (strm); return Z_MEM_ERROR; } @@ -329,7 +329,7 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) uInt str, n; int wrap; unsigned avail; - unsigned char *next; + z_const unsigned char *next; if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) return Z_STREAM_ERROR; @@ -359,7 +359,7 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) avail = strm->avail_in; next = strm->next_in; strm->avail_in = dictLength; - strm->next_in = (Bytef *)dictionary; + strm->next_in = (z_const Bytef *)dictionary; fill_window(s); while (s->lookahead >= MIN_MATCH) { str = s->strstart; diff --git a/gzlib.c b/gzlib.c index c10fabb..e4ca576 100644 --- a/gzlib.c +++ b/gzlib.c @@ -541,7 +541,8 @@ const char * ZEXPORT gzerror(file, errnum) /* return error information */ if (errnum != NULL) *errnum = state->err; - return state->msg == NULL ? "" : state->msg; + return state->err == Z_MEM_ERROR ? "out of memory" : + (state->msg == NULL ? "" : state->msg); } /* -- see zlib.h -- */ @@ -592,16 +593,13 @@ void ZLIB_INTERNAL gz_error(state, err, msg) if (msg == NULL) return; - /* for an out of memory error, save as static string */ - if (err == Z_MEM_ERROR) { - state->msg = (char *)msg; + /* for an out of memory error, return literal string when requested */ + if (err == Z_MEM_ERROR) return; - } /* construct error message with path */ if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { state->err = Z_MEM_ERROR; - state->msg = (char *)"out of memory"; return; } #if !defined(NO_snprintf) && !defined(NO_vsnprintf) diff --git a/gzread.c b/gzread.c index 8ace830..52985c9 100644 --- a/gzread.c +++ b/gzread.c @@ -58,7 +58,8 @@ local int gz_avail(state) return -1; if (state->eof == 0) { if (strm->avail_in) { /* copy what's there to the start */ - unsigned char *p = state->in, *q = strm->next_in; + unsigned char *p = state->in; + unsigned const char *q = strm->next_in; unsigned n = strm->avail_in; do { *p++ = *q++; diff --git a/gzwrite.c b/gzwrite.c index 27cb342..bf57913 100644 --- a/gzwrite.c +++ b/gzwrite.c @@ -168,7 +168,6 @@ int ZEXPORT gzwrite(file, buf, len) unsigned len; { unsigned put = len; - unsigned n; gz_statep state; z_streamp strm; @@ -208,16 +207,19 @@ int ZEXPORT gzwrite(file, buf, len) if (len < state->size) { /* copy to input buffer, compress when full */ do { + unsigned have, copy; + if (strm->avail_in == 0) strm->next_in = state->in; - n = state->size - strm->avail_in; - if (n > len) - n = len; - memcpy(strm->next_in + strm->avail_in, buf, n); - strm->avail_in += n; - state->x.pos += n; - buf = (char *)buf + n; - len -= n; + have = strm->next_in + strm->avail_in - state->in; + copy = state->size - have; + if (copy > len) + copy = len; + memcpy(state->in + have, buf, copy); + strm->avail_in += copy; + state->x.pos += copy; + buf = (const char *)buf + copy; + len -= copy; if (len && gz_comp(state, Z_NO_FLUSH) == -1) return 0; } while (len); @@ -229,7 +231,7 @@ int ZEXPORT gzwrite(file, buf, len) /* directly compress user buffer to file */ strm->avail_in = len; - strm->next_in = (voidp)buf; + strm->next_in = (z_const Bytef *)buf; state->x.pos += len; if (gz_comp(state, Z_NO_FLUSH) == -1) return 0; @@ -244,6 +246,7 @@ int ZEXPORT gzputc(file, c) gzFile file; int c; { + unsigned have; unsigned char buf[1]; gz_statep state; z_streamp strm; @@ -267,10 +270,12 @@ int ZEXPORT gzputc(file, c) /* try writing to input buffer for speed (state->size == 0 if buffer not initialized) */ - if (strm->avail_in < state->size) { - if (strm->avail_in == 0) - strm->next_in = state->in; - strm->next_in[strm->avail_in++] = c; + if (strm->avail_in == 0) + strm->next_in = state->in; + have = strm->next_in + strm->avail_in - state->in; + if (have < state->size) { + state->in[have] = c; + strm->avail_in++; state->x.pos++; return c & 0xff; } diff --git a/infback.c b/infback.c index 981aff1..f3833c2 100644 --- a/infback.c +++ b/infback.c @@ -255,7 +255,7 @@ out_func out; void FAR *out_desc; { struct inflate_state FAR *state; - unsigned char FAR *next; /* next input */ + z_const unsigned char FAR *next; /* next input */ unsigned char FAR *put; /* next output */ unsigned have, left; /* available input and output */ unsigned long hold; /* bit buffer */ diff --git a/inffast.c b/inffast.c index 2f1d60b..0d78f23 100644 --- a/inffast.c +++ b/inffast.c @@ -69,8 +69,8 @@ z_streamp strm; unsigned start; /* inflate()'s starting value for strm->avail_out */ { struct inflate_state FAR *state; - unsigned char FAR *in; /* local strm->next_in */ - unsigned char FAR *last; /* while in < last, enough input available */ + z_const unsigned char FAR *in; /* local strm->next_in */ + z_const unsigned char FAR *last; /* while in < last, enough input available */ unsigned char FAR *out; /* local strm->next_out */ unsigned char FAR *beg; /* inflate()'s initial strm->next_out */ unsigned char FAR *end; /* while out < end, enough space available */ diff --git a/inflate.c b/inflate.c index d1efdb8..870f89b 100644 --- a/inflate.c +++ b/inflate.c @@ -93,11 +93,12 @@ /* function prototypes */ local void fixedtables OF((struct inflate_state FAR *state)); -local int updatewindow OF((z_streamp strm, unsigned out)); +local int updatewindow OF((z_streamp strm, const unsigned char FAR *end, + unsigned copy)); #ifdef BUILDFIXED void makefixed OF((void)); #endif -local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf, +local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf, unsigned len)); int ZEXPORT inflateResetKeep(strm) @@ -375,12 +376,13 @@ void makefixed() output will fall in the output data, making match copies simpler and faster. The advantage may be dependent on the size of the processor's data caches. */ -local int updatewindow(strm, out) +local int updatewindow(strm, end, copy) z_streamp strm; -unsigned out; +const Bytef *end; +unsigned copy; { struct inflate_state FAR *state; - unsigned copy, dist; + unsigned dist; state = (struct inflate_state FAR *)strm->state; @@ -400,19 +402,18 @@ unsigned out; } /* copy state->wsize or less output bytes into the circular window */ - copy = out - strm->avail_out; if (copy >= state->wsize) { - zmemcpy(state->window, strm->next_out - state->wsize, state->wsize); + zmemcpy(state->window, end - state->wsize, state->wsize); state->wnext = 0; state->whave = state->wsize; } else { dist = state->wsize - state->wnext; if (dist > copy) dist = copy; - zmemcpy(state->window + state->wnext, strm->next_out - copy, dist); + zmemcpy(state->window + state->wnext, end - copy, dist); copy -= dist; if (copy) { - zmemcpy(state->window, strm->next_out - copy, copy); + zmemcpy(state->window, end - copy, copy); state->wnext = copy; state->whave = state->wsize; } @@ -606,7 +607,7 @@ z_streamp strm; int flush; { struct inflate_state FAR *state; - unsigned char FAR *next; /* next input */ + z_const unsigned char FAR *next; /* next input */ unsigned char FAR *put; /* next output */ unsigned have, left; /* available input and output */ unsigned long hold; /* bit buffer */ @@ -920,7 +921,7 @@ int flush; while (state->have < 19) state->lens[order[state->have++]] = 0; state->next = state->codes; - state->lencode = (code const FAR *)(state->next); + state->lencode = (const code FAR *)(state->next); state->lenbits = 7; ret = inflate_table(CODES, state->lens, 19, &(state->next), &(state->lenbits), state->work); @@ -994,7 +995,7 @@ int flush; values here (9 and 6) without reading the comments in inftrees.h concerning the ENOUGH constants, which depend on those values */ state->next = state->codes; - state->lencode = (code const FAR *)(state->next); + state->lencode = (const code FAR *)(state->next); state->lenbits = 9; ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), &(state->lenbits), state->work); @@ -1003,7 +1004,7 @@ int flush; state->mode = BAD; break; } - state->distcode = (code const FAR *)(state->next); + state->distcode = (const code FAR *)(state->next); state->distbits = 6; ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, &(state->next), &(state->distbits), state->work); @@ -1230,7 +1231,7 @@ int flush; RESTORE(); if (state->wsize || (out != strm->avail_out && state->mode < BAD && (state->mode < CHECK || flush != Z_FINISH))) - if (updatewindow(strm, out)) { + if (updatewindow(strm, strm->next_out, out - strm->avail_out)) { state->mode = MEM; return Z_MEM_ERROR; } @@ -1294,8 +1295,6 @@ uInt dictLength; { struct inflate_state FAR *state; unsigned long dictid; - unsigned char *next; - unsigned avail; int ret; /* check state */ @@ -1314,13 +1313,7 @@ uInt dictLength; /* copy dictionary to window using updatewindow(), which will amend the existing dictionary if appropriate */ - next = strm->next_out; - avail = strm->avail_out; - strm->next_out = (Bytef *)dictionary + dictLength; - strm->avail_out = 0; - ret = updatewindow(strm, dictLength); - strm->avail_out = avail; - strm->next_out = next; + ret = updatewindow(strm, dictionary + dictLength, dictLength); if (ret) { state->mode = MEM; return Z_MEM_ERROR; @@ -1360,7 +1353,7 @@ gz_headerp head; */ local unsigned syncsearch(have, buf, len) unsigned FAR *have; -unsigned char FAR *buf; +const unsigned char FAR *buf; unsigned len; { unsigned got; diff --git a/test/example.c b/test/example.c index f515a48..138a699 100644 --- a/test/example.c +++ b/test/example.c @@ -26,7 +26,7 @@ } \ } -const char hello[] = "hello, hello!"; +z_const char hello[] = "hello, hello!"; /* "hello world" would be more standard, but the repeated "hello" * stresses the compression code better, sorry... */ @@ -212,7 +212,7 @@ void test_deflate(compr, comprLen) err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION); CHECK_ERR(err, "deflateInit"); - c_stream.next_in = (Bytef*)hello; + c_stream.next_in = (z_const unsigned char *)hello; c_stream.next_out = compr; while (c_stream.total_in != len && c_stream.total_out < comprLen) { @@ -387,7 +387,7 @@ void test_flush(compr, comprLen) err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION); CHECK_ERR(err, "deflateInit"); - c_stream.next_in = (Bytef*)hello; + c_stream.next_in = (z_const unsigned char *)hello; c_stream.next_out = compr; c_stream.avail_in = 3; c_stream.avail_out = (uInt)*comprLen; @@ -476,7 +476,7 @@ void test_dict_deflate(compr, comprLen) c_stream.next_out = compr; c_stream.avail_out = (uInt)comprLen; - c_stream.next_in = (Bytef*)hello; + c_stream.next_in = (z_const unsigned char *)hello; c_stream.avail_in = (uInt)strlen(hello)+1; err = deflate(&c_stream, Z_FINISH); diff --git a/trees.c b/trees.c index 8c32b21..1fd7759 100644 --- a/trees.c +++ b/trees.c @@ -146,8 +146,8 @@ local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); local int build_bl_tree OF((deflate_state *s)); local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, int blcodes)); -local void compress_block OF((deflate_state *s, ct_data *ltree, - ct_data *dtree)); +local void compress_block OF((deflate_state *s, const ct_data *ltree, + const ct_data *dtree)); local int detect_data_type OF((deflate_state *s)); local unsigned bi_reverse OF((unsigned value, int length)); local void bi_windup OF((deflate_state *s)); @@ -972,7 +972,8 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) { #endif send_bits(s, (STATIC_TREES<<1)+last, 3); - compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); + compress_block(s, (const ct_data *)static_ltree, + (const ct_data *)static_dtree); #ifdef DEBUG s->compressed_len += 3 + s->static_len; #endif @@ -980,7 +981,8 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) send_bits(s, (DYN_TREES<<1)+last, 3); send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, max_blindex+1); - compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); + compress_block(s, (const ct_data *)s->dyn_ltree, + (const ct_data *)s->dyn_dtree); #ifdef DEBUG s->compressed_len += 3 + s->opt_len; #endif @@ -1057,8 +1059,8 @@ int ZLIB_INTERNAL _tr_tally (s, dist, lc) */ local void compress_block(s, ltree, dtree) deflate_state *s; - ct_data *ltree; /* literal tree */ - ct_data *dtree; /* distance tree */ + const ct_data *ltree; /* literal tree */ + const ct_data *dtree; /* distance tree */ { unsigned dist; /* distance of matched string */ int lc; /* match length or unmatched char (if dist == 0) */ diff --git a/uncompr.c b/uncompr.c index ad98be3..242e949 100644 --- a/uncompr.c +++ b/uncompr.c @@ -30,7 +30,7 @@ int ZEXPORT uncompress (dest, destLen, source, sourceLen) z_stream stream; int err; - stream.next_in = (Bytef*)source; + stream.next_in = (z_const Bytef *)source; stream.avail_in = (uInt)sourceLen; /* Check for source > 64K on 16-bit machine: */ if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; diff --git a/zlib.h b/zlib.h index cd47df5..55e3c2c 100644 --- a/zlib.h +++ b/zlib.h @@ -1022,7 +1022,8 @@ ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, the version of the header file. */ -typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); +typedef unsigned (*in_func) OF((void FAR *, + z_const unsigned char FAR * FAR *)); typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, diff --git a/zutil.c b/zutil.c index 65e0d3b..23d2ebe 100644 --- a/zutil.c +++ b/zutil.c @@ -14,7 +14,7 @@ struct internal_state {int dummy;}; /* for buggy compilers */ #endif -const char * const z_errmsg[10] = { +z_const char * const z_errmsg[10] = { "need dictionary", /* Z_NEED_DICT 2 */ "stream end", /* Z_STREAM_END 1 */ "", /* Z_OK 0 */ diff --git a/zutil.h b/zutil.h index 4e3dcc6..0f02cbe 100644 --- a/zutil.h +++ b/zutil.h @@ -44,13 +44,13 @@ typedef unsigned short ush; typedef ush FAR ushf; typedef unsigned long ulg; -extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */ +extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */ /* (size given to avoid silly warnings with Visual C++) */ #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] #define ERR_RETURN(strm,err) \ - return (strm->msg = (char*)ERR_MSG(err), (err)) + return (strm->msg = ERR_MSG(err), (err)) /* To be used only when the state is known to be valid */ /* common constants */ -- GitLab