[libpng16] Removed one of the GCC-7.1.0 'strict-overflow' warnings that

result when integers appear on both sides of a compare.  Worked around the
  others by forcing the strict-overflow setting in the relevant functions to
  a level where they are not reported.
Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
  the space.
Worked around some C-style casts from (void*) because g++ 5.4.0 objects
  to them.
Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
  overflow' check that is on by default with -Wall -Wextra.
This commit is contained in:
John Bowler 2017-07-11 07:50:35 -05:00 committed by Glenn Randers-Pehrson
parent ecea632c4c
commit 72d07d3202
13 changed files with 124 additions and 60 deletions

10
CHANGES
View File

@ -5877,6 +5877,16 @@ Version 1.6.31beta03 [July 9, 2017]
Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
Version 1.6.31beta04 [July 9, 2017]
Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
integers appear on both sides of a compare. Worked around the others by
forcing the strict-overflow setting in the relevant functions to a level
where they are not reported (John Bowler).
Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
the space.
Worked around some C-style casts from (void*) because g++ 5.4.0 objects
to them.
Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
overflow' check that is on by default with -Wall -Wextra.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

View File

@ -1,8 +1,8 @@
/* contrib/arm-neon/linux.c
*
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by John Bowler, 2014.
* Last changed in libpng 1.6.16 [December 22, 2014]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 2014, 2017 Glenn Randers-Pehrson
* Written by John Bowler, 2014, 2017.
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -62,7 +62,7 @@ png_have_neon(png_structp png_ptr)
counter=0;
state = Feature;
/* FALL THROUGH */
/* FALLTHROUGH */
case Feature:
/* Match 'FEATURE', ASCII case insensitive. */
@ -75,7 +75,7 @@ png_have_neon(png_structp png_ptr)
/* did not match 'feature' */
state = SkipLine;
/* FALL THROUGH */
/* FALLTHROUGH */
case SkipLine:
skipLine:
@ -110,7 +110,7 @@ png_have_neon(png_structp png_ptr)
state = Neon;
counter = 0;
/* FALL THROUGH */
/* FALLTHROUGH */
case Neon:
/* Look for 'neon' tag */
@ -122,7 +122,7 @@ png_have_neon(png_structp png_ptr)
}
state = SkipTag;
/* FALL THROUGH */
/* FALLTHROUGH */
case SkipTag:
/* Skip non-space characters */

View File

@ -1,9 +1,8 @@
/*-
* pngstest.c
*
* Copyright (c) 2013-2016 John Cunningham Bowler
*
* Last changed in libpng 1.6.24 [August 4, 2016]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 2013-2017 John Cunningham Bowler
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -2746,22 +2745,27 @@ compare_two_images(Image *a, Image *b, int via_linear,
*/
else if ((a->opts & ACCUMULATE) == 0)
{
# ifdef __GNUC__
# define BYTE_CHARS 20 /* 2^32: GCC sprintf warning */
# else
# define BYTE_CHARS 3 /* 2^8: real maximum value */
# endif
/* Check the original image first,
* TODO: deal with input images with bad pixel values?
*/
if (amax >= a->image.colormap_entries)
{
char pindex[9];
sprintf(pindex, "%d[%lu]", amax,
(unsigned long)a->image.colormap_entries);
char pindex[3+2*BYTE_CHARS];
sprintf(pindex, "%d[%u]", amax,
(png_byte)/*SAFE*/a->image.colormap_entries);
return logerror(a, a->file_name, ": bad pixel index: ", pindex);
}
else if (bmax >= b->image.colormap_entries)
{
char pindex[9];
sprintf(pindex, "%d[%lu]", bmax,
(unsigned long)b->image.colormap_entries);
char pindex[3+2*BYTE_CHARS];
sprintf(pindex, "%d[%u]", bmax,
(png_byte)/*SAFE*/b->image.colormap_entries);
return logerror(b, b->file_name, ": bad pixel index: ", pindex);
}
}
@ -2881,10 +2885,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
{
case 4:
if (pua[btoa[3]] != pub[3]) break;
/* FALLTHROUGH */
case 3:
if (pua[btoa[2]] != pub[2]) break;
/* FALLTHROUGH */
case 2:
if (pua[btoa[1]] != pub[1]) break;
/* FALLTHROUGH */
case 1:
if (pua[btoa[0]] != pub[0]) break;
if (alpha_added != 4 && pub[alpha_added] != 65535) break;
@ -2900,10 +2907,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
{
case 4:
if (psa[btoa[3]] != psb[3]) break;
/* FALLTHROUGH */
case 3:
if (psa[btoa[2]] != psb[2]) break;
/* FALLTHROUGH */
case 2:
if (psa[btoa[1]] != psb[1]) break;
/* FALLTHROUGH */
case 1:
if (psa[btoa[0]] != psb[0]) break;
if (alpha_added != 4 && psb[alpha_added] != 255) break;

View File

@ -1,8 +1,8 @@
/* pngunknown.c - test the read side unknown chunk handling
*
* Last changed in libpng 1.6.26 [October 20, 2016]
* Copyright (c) 2015,2016 Glenn Randers-Pehrson
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 2015,2017 Glenn Randers-Pehrson
* Written by John Cunningham Bowler
*
* This code is released under the libpng license.
@ -614,7 +614,7 @@ get_unknown(display *d, png_infop info_ptr, int after_IDAT)
++(d->error_count);
break;
}
/* FALL THROUGH (safe) */
/* FALLTHROUGH */ /* (safe) */
case PNG_HANDLE_CHUNK_ALWAYS:
break;
}

View File

@ -1,7 +1,7 @@
/* pngvalid.c - validate libpng by constructing then reading png files.
*
* Last changed in libpng 1.6.29 [March 16, 2017]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 2014-2017 John Cunningham Bowler
*
* This code is released under the libpng license.
@ -6584,16 +6584,16 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
{
case PNG_COLOR_TYPE_PALETTE:
if (dp->output_bit_depth > 8) goto error;
/*FALL THROUGH*/
/* FALLTHROUGH */
case PNG_COLOR_TYPE_GRAY:
if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 ||
dp->output_bit_depth == 4)
break;
/*FALL THROUGH*/
/* FALLTHROUGH */
default:
if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16)
break;
/*FALL THROUGH*/
/* FALLTHROUGH */
error:
{
char message[128];
@ -9994,9 +9994,9 @@ gamma_component_validate(const char *name, const validate_info *vi,
case PNG_BACKGROUND_GAMMA_FILE:
case PNG_BACKGROUND_GAMMA_UNIQUE:
use_background = (alpha >= 0 && alpha < 1);
/*FALL THROUGH*/
# endif
# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
/* FALLTHROUGH */
case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:

View File

@ -1,8 +1,7 @@
/* pngfix.c
*
* Copyright (c) 2014-2016 John Cunningham Bowler
*
* Last changed in libpng 1.6.26 [October 20, 2016]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 2014-2017 John Cunningham Bowler
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -2416,7 +2415,7 @@ zlib_advance(struct zlib *zlib, png_uint_32 nbytes)
endrc = ZLIB_TOO_FAR_BACK;
break;
}
/* FALL THROUGH */
/* FALLTHROUGH */
default:
zlib_message(zlib, 0/*stream error*/);
@ -2570,7 +2569,7 @@ zlib_run(struct zlib *zlib)
list->lengths[i] -= zlib->extra_bytes;
list->count = i+1;
zlib->idat->idat_list_tail = list;
/* FALL THROUGH */
/* FALLTHROUGH */
default:
return rc;
@ -2673,7 +2672,7 @@ zlib_check(struct file *file, png_uint_32 offset)
/* Truncated stream; unrecoverable, gets converted to ZLIB_FATAL */
zlib.z.msg = PNGZ_MSG_CAST("[truncated]");
zlib_message(&zlib, 0/*expected*/);
/* FALL THROUGH */
/* FALLTHROUGH */
default:
/* Unrecoverable error; skip the chunk; a zlib_message has already
@ -3341,7 +3340,7 @@ read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
if (file->state != STATE_IDAT && length > 0)
setpos(chunk);
}
/* FALL THROUGH */
/* FALLTHROUGH */
default:
assert(chunk != NULL);

View File

@ -40,7 +40,7 @@ static __m128i load3(const void* p) {
/* We'll load 2 bytes, then 1 byte,
* then mask them together, and finally load into SSE.
*/
const png_uint_16* p01 = p;
const png_uint_16* p01 = (png_const_uint_16p)p;
const png_byte* p2 = (const png_byte*)(p01+1);
png_uint_32 v012 = (png_uint_32)(*p01)
@ -58,7 +58,7 @@ static void store3(void* p, __m128i v) {
store4(&v012, v);
p01 = p;
p01 = (png_uint_16p)p;
p2 = (png_byte*)(p01+1);
*p01 = (png_uint_16)v012;
*p2 = (png_byte)(v012 >> 16);

55
png.c
View File

@ -1,7 +1,7 @@
/* png.c - location for general purpose libpng functions
*
* Last changed in libpng 1.6.30 [June 28, 2017]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@ -16,6 +16,26 @@
/* Generate a compiler error if there is an old png.h in the search path. */
typedef png_libpng_version_1_6_31beta04 Your_png_h_is_not_version_1_6_31beta04;
#ifdef __GNUC__
/* The version tests may need to be added to, but the problem warning has
* consistently been fixed in GCC versions which obtain wide-spread release.
* The problem is that many versions of GCC rearrange comparison expressions in
* the optimizer in such a way that the results of the comparison will change
* if signed integer overflow occurs. Such comparisons are not permitted in
* ANSI C90, however GCC isn't clever enough to work out that that do not occur
* below in png_ascii_from_fp and png_muldiv, so it produces a warning with
* -Wextra. Unfortunately this is highly dependent on the optimizer and the
* machine architecture so the warning comes and goes unpredictably and is
* impossible to "fix", even were that a good idea.
*/
#if __GNUC__ == 7 && __GNUC_MINOR__ == 1
#define GCC_STRICT_OVERFLOW 1
#endif /* GNU 7.1.x */
#endif /* GNU */
#ifndef GCC_STRICT_OVERFLOW
#define GCC_STRICT_OVERFLOW 0
#endif
/* Tells libpng that we have already handled the first "num_bytes" bytes
* of the PNG file signature. If the PNG data is embedded into another
* stream we can set num_bytes = 8 so that libpng will not attempt to read
@ -2857,6 +2877,14 @@ png_pow10(int power)
/* Function to format a floating point value in ASCII with a given
* precision.
*/
#if GCC_STRICT_OVERFLOW
#pragma GCC diagnostic push
/* The problem arises below with exp_b10, which can never overflow because it
* comes, originally, from frexp and is therefore limited to a range which is
* typically +/-710 (log2(DBL_MAX)/log2(DBL_MIN)).
*/
#pragma GCC diagnostic warning "-Wstrict-overflow=2"
#endif /* GCC_STRICT_OVERFLOW */
void /* PRIVATE */
png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
double fp, unsigned int precision)
@ -2946,7 +2974,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
*/
if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
{
czero = (unsigned int)(-exp_b10); /* PLUS 2 digits: TOTAL 3 */
czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */
exp_b10 = 0; /* Dot added below before first output. */
}
else
@ -3087,7 +3115,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
/* Check for an exponent, if we don't need one we are
* done and just need to terminate the string. At
* this point exp_b10==(-1) is effectively if flag - it got
* this point exp_b10==(-1) is effectively a flag - it got
* to '-1' because of the decrement after outputting
* the decimal point above (the exponent required is
* *not* -1!)
@ -3101,7 +3129,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
* zeros were *not* output, so this doesn't increase
* the output count.
*/
while (--exp_b10 >= 0) *ascii++ = 48;
while (exp_b10-- > 0) *ascii++ = 48;
*ascii = 0;
@ -3131,11 +3159,11 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
if (exp_b10 < 0)
{
*ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */
uexp_b10 = (unsigned int)(-exp_b10);
uexp_b10 = 0U-exp_b10;
}
else
uexp_b10 = (unsigned int)exp_b10;
uexp_b10 = 0U+exp_b10;
cdigits = 0;
@ -3178,6 +3206,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
/* Here on buffer too small. */
png_error(png_ptr, "ASCII conversion buffer too small");
}
#if GCC_STRICT_OVERFLOW
#pragma GCC diagnostic pop
#endif /* GCC_STRICT_OVERFLOW */
# endif /* FLOATING_POINT */
@ -3291,6 +3322,15 @@ png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
* the nearest .00001). Overflow and divide by zero are signalled in
* the result, a boolean - true on success, false on overflow.
*/
#if GCC_STRICT_OVERFLOW /* from above */
/* It is not obvious which comparison below gets optimized in such a way that
* signed overflow would change the result; looking through the code does not
* reveal any tests which have the form GCC complains about, so presumably the
* optimizer is moving an add or subtract into the 'if' somewhere.
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic warning "-Wstrict-overflow=2"
#endif /* GCC_STRICT_OVERFLOW */
int
png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
png_int_32 divisor)
@ -3405,6 +3445,9 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
return 0;
}
#if GCC_STRICT_OVERFLOW
#pragma GCC diagnostic pop
#endif /* GCC_STRICT_OVERFLOW */
#endif /* READ_GAMMA || INCH_CONVERSIONS */
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)

View File

@ -1,8 +1,8 @@
/* pngerror.c - stub functions for i/o and memory allocation
*
* Last changed in libpng 1.6.26 [October 20, 2016]
* Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
@ -163,7 +163,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
case PNG_NUMBER_FORMAT_02u:
/* Expects at least 2 digits. */
mincount = 2;
/* FALL THROUGH */
/* FALLTHROUGH */
case PNG_NUMBER_FORMAT_u:
*--end = digits[number % 10];
@ -173,7 +173,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
case PNG_NUMBER_FORMAT_02x:
/* This format expects at least two digits */
mincount = 2;
/* FALL THROUGH */
/* FALLTHROUGH */
case PNG_NUMBER_FORMAT_x:
*--end = digits[number & 0xf];

View File

@ -1,8 +1,8 @@
/* pngread.c - read a PNG file
*
* Last changed in libpng 1.6.26 [October 20, 2016]
* Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
@ -1883,7 +1883,7 @@ png_create_colormap_entry(png_image_read_control *display,
{
case 4:
entry[afirst ? 0 : 3] = (png_uint_16)alpha;
/* FALL THROUGH */
/* FALLTHROUGH */
case 3:
if (alpha < 65535)
@ -1905,7 +1905,7 @@ png_create_colormap_entry(png_image_read_control *display,
case 2:
entry[1 ^ afirst] = (png_uint_16)alpha;
/* FALL THROUGH */
/* FALLTHROUGH */
case 1:
if (alpha < 65535)
@ -1934,6 +1934,7 @@ png_create_colormap_entry(png_image_read_control *display,
{
case 4:
entry[afirst ? 0 : 3] = (png_byte)alpha;
/* FALLTHROUGH */
case 3:
entry[afirst + (2 ^ bgr)] = (png_byte)blue;
entry[afirst + 1] = (png_byte)green;
@ -1942,6 +1943,7 @@ png_create_colormap_entry(png_image_read_control *display,
case 2:
entry[1 ^ afirst] = (png_byte)alpha;
/* FALLTHROUGH */
case 1:
entry[afirst] = (png_byte)green;
break;
@ -2861,7 +2863,7 @@ png_image_read_colormap(png_voidp argument)
case P_sRGB:
/* Change to 8-bit sRGB */
png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
/* FALL THROUGH */
/* FALLTHROUGH */
case P_FILE:
if (png_ptr->bit_depth > 8)
@ -3179,8 +3181,7 @@ png_image_read_colormapped(png_voidp argument)
image->colormap_entries == 244 /* 216 + 1 + 27 */)
break;
/* goto bad_output; */
/* FALL THROUGH */
goto bad_output;
default:
bad_output:

View File

@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* Last changed in libpng 1.6.30 [June 28, 2017]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@ -49,6 +49,7 @@ png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
png_warning(png_ptr,
"Can't discard critical data on CRC error");
/* FALLTHROUGH */
case PNG_CRC_ERROR_QUIT: /* Error/quit */
case PNG_CRC_DEFAULT:
@ -1253,7 +1254,7 @@ png_init_rgb_transformations(png_structrp png_ptr)
default:
case 8:
/* FALL THROUGH (Already 8 bits) */
/* FALLTHROUGH */ /* (Already 8 bits) */
case 16:
/* Already a full 16 bits */

View File

@ -1,7 +1,7 @@
/* pngrutil.c - utilities to read a PNG file
*
* Last changed in libpng 1.6.30 [June 28, 2017]
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@ -2978,7 +2978,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
case 2:
png_ptr->user_chunk_cache_max = 1;
png_chunk_benign_error(png_ptr, "no space in chunk cache");
/* FALL THROUGH */
/* FALLTHROUGH */
case 1:
/* NOTE: prior to 1.6.0 this case resulted in an unknown critical
* chunk being skipped, now there will be a hard error below.
@ -2987,7 +2987,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
default: /* not at limit */
--(png_ptr->user_chunk_cache_max);
/* FALL THROUGH */
/* FALLTHROUGH */
case 0: /* no limit */
# endif /* USER_LIMITS */
/* Here when the limit isn't reached or when limits are compiled

View File

@ -1,8 +1,8 @@
/* pngwrite.c - general routines to write a PNG file
*
* Last changed in libpng 1.6.26 [October 20, 2016]
* Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
* Last changed in libpng 1.6.31 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
@ -1007,8 +1007,8 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
case 5:
case 6:
case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
/* FALL THROUGH */
#endif /* WRITE_FILTER */
/* FALLTHROUGH */
case PNG_FILTER_VALUE_NONE:
png_ptr->do_filter = PNG_FILTER_NONE; break;
@ -1875,7 +1875,7 @@ png_image_set_PLTE(png_image_write_control *display)
tRNS[i] = entry[afirst ? 0 : 3];
if (tRNS[i] < 255)
num_trans = i+1;
/* FALL THROUGH */
/* FALLTHROUGH */
case 3:
palette[i].blue = entry[afirst + (2 ^ bgr)];
palette[i].green = entry[afirst + 1];
@ -1886,7 +1886,7 @@ png_image_set_PLTE(png_image_write_control *display)
tRNS[i] = entry[1 ^ afirst];
if (tRNS[i] < 255)
num_trans = i+1;
/* FALL THROUGH */
/* FALLTHROUGH */
case 1:
palette[i].blue = palette[i].red = palette[i].green =
entry[afirst];