DRC [Sat, 18 Mar 2017 18:24:50 +0000 (13:24 -0500)]
AppVeyor: Fix CI build
Something changed in the CI build environment, and our previous trick of
setting the Git URL to file://c:/projects/libjpeg-turbo no longer works.
Using cygpath to translate the Windows path to a MinGW-friendly format
is a better solution anyhow.
DRC [Sat, 18 Mar 2017 17:56:36 +0000 (12:56 -0500)]
TurboJPEG: Fix potential memory leaks
Referring to https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=746,
it seems that the values of local buffer pointers in TurboJPEG API
functions aren't always preserved if longjmp() returns control to a
point prior to the allocation of the local buffers. This is known to
be an issue with GCC 4.x and clang with -O1 and higher optimization
levels but not with GCC 5.x and later. It is unknown why GCC 5.x and
6.x do not suffer from the issue, but possibly the local buffer pointers
are not allocated on the stack when using those more recent compilers.
In any case, this commit modifies the TurboJPEG API library code such
that the jump buffer is always updated after any local buffer pointers
are allocated but before any subsequent libjpeg API functions are
called.
DRC [Fri, 20 Jan 2017 00:51:41 +0000 (18:51 -0600)]
Always tweak EXIF w/h tags w/ lossless transforms
... even if using libjpeg v6b emulation. Previously
adjust_exif_parameters() was only called with libjpeg v7/v8 emulation,
but due to a bug (which this commit also fixes), it only worked properly
with libjpeg v8 emulation.
DRC [Thu, 19 Jan 2017 23:50:59 +0000 (17:50 -0600)]
Fix error w/ lossless crop & libjpeg v7 emulation
The JPEG_LIB_VERSION #ifdef in jtransform_adjust_parameters() was
incorrect, which caused a "Bogus virtual array access" error when
attempting to use the lossless crop feature.
DRC [Sat, 10 Dec 2016 15:32:23 +0000 (09:32 -0600)]
LICENSE.md: Include text of BSD/zlib licenses
LICENSE.md is included in the binary distributions as well, so it
doesn't make much sense to refer to license headers in source files that
aren't necessarily going to be there.
DRC [Mon, 5 Dec 2016 20:02:59 +0000 (14:02 -0600)]
Fix build when CFLAGS contains -std=c89 (or -ansi)
This is a subtle point, but AC_C_INLINE defines "inline" to be either
"inline", "__inline__", or "__inline". The subsequent test for
"inline __attribute__((always_inline))" uses this definition. The
attribute is irrespective of the inline keyword, so whereas
"__inline__ __attribute__((always_inline))" works under C89,
"inline __attribute__((always_inline))" doesn't, and defining INLINE to
the latter causes the build to fail. The easiest way around this is
simply to define "inline" ahead of "INLINE" in jconfigint.h,
which causes the inline keyword detected by AC_C_INLINE to modify the
INLINE macro if necessary.
DRC [Mon, 5 Dec 2016 18:39:49 +0000 (12:39 -0600)]
Reorg AltiVec detection code
+ advertise that full AltiVec SIMD acceleration is now available on
OpenBSD.
The relevant compilers probably all support C99 or GNU's variation of
C90 that allows variables to be declared anywhere, but our policy is to
conform to the C90 standard, if for no other reason than that it
improves code readability.
Colin Cross [Fri, 2 Dec 2016 00:56:18 +0000 (16:56 -0800)]
Fix sign mismatch comparison warnings
Fixes:
rdppm.c:257:14: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
if (temp > maxval)
~~~~ ^ ~~~~~~
rdppm.c:284:14: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
if (temp > maxval)
~~~~ ^ ~~~~~~
rdppm.c:289:14: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
if (temp > maxval)
~~~~ ^ ~~~~~~
rdppm.c:294:14: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
if (temp > maxval)
DRC [Thu, 1 Dec 2016 07:58:34 +0000 (01:58 -0600)]
Travis: Use xcode7.3 image
The xcode7.2 image is verfallen, verlumpt, verblunget, verkackt
This also ensures that the build scripts are checked out from a
branch matching the libjpeg-turbo repository branch (not strictly
necessary when building from master, but it keeps the code in sync with
dev.)
DRC [Tue, 22 Nov 2016 04:58:18 +0000 (22:58 -0600)]
AppVeyor: Use built-in MSYS2 MinGW compilers
AppVeyor already has MinGW32 and MinGW64 flavors of GCC 5.3.0
installed under MSYS2, so there is no need to install our own builds of
MinGW. MinGW-builds is no longer an active project, and we were getting
occasional timeouts while wgetting those files from SourceForge.
Furthermore, GCC 5.3.0 should produce faster code than GCC 4.8.1.
DRC [Mon, 21 Nov 2016 02:59:55 +0000 (20:59 -0600)]
BUILDING.md: Clarifications and wordsmithing
Updated out-of-date information, wordsmithed and clarified many
sections, and generally cleaned up the build recipes (including a
complete overhaul of the iOS recipes.)
DRC [Fri, 18 Nov 2016 15:09:41 +0000 (09:09 -0600)]
BUILDING.md/README.md: Increment libjpeg SO age
Documentation buglet. This should have been changed in 6ed4d9d11085acd04dc7f2f899848693976dc010 to reflect the addition of
libjpeg API functions in libjpeg-turbo 1.5.
This commit also makes the "testclean" target clean up the 4:1:1 test
images. This was implemented in the autotools build system in 1f3635c4969f2319a01c9fe561958815b733227f but was left out of the CMake
build system due to an oversight.
DRC [Thu, 20 Oct 2016 22:55:55 +0000 (17:55 -0500)]
Travis: Deploy to S3 rather than SourceForge
This has the following advantages:
-- It doesn't require checking a private SSH key into the repository.
(With SourceForge, an SSH key is the "keys to the kingdom".)
-- If the S3 key is compromised, it is very easy to revoke it and
generate a new one.
-- The S3 bucket is isolated, so even if it becomes compromised, then
the damage that one could do is limited.
-- It's much easier to manage files through S3's web interface than
through SourceForge.
-- The files are served via HTTPS.
-- Travis fully supports S3 as a deployment target, so this simplifies
.travis.yml somewhat.
DRC [Thu, 20 Oct 2016 06:01:27 +0000 (01:01 -0500)]
Travis: GPG sign Linux binaries/source tarballs
Since we're still deploying our Linux/macOS CI artifacts to a web server
(specifically SourceForge Project Web Services) that doesn't support
HTTPS, it's a good idea to sign them. But since the private key has to
be checked into the repository, we use a different key for signing the
pre-releases (per project policy, the private signing keys for our
release binaries are never made available on any public server.)
DRC [Tue, 11 Oct 2016 16:58:20 +0000 (11:58 -0500)]
Win: Use YASM if it is in the PATH and NASM isn't
Previously, simd/CMakeLists.txt was hard-coded to use NASM, and it was
necessary to override the NASM variable in order to use YASM. This
commit changes the behavior such that NASM is still preferred, but YASM
will be used if it is in the PATH and NASM isn't available. This brings
the actual behavior in line with the behavior described in BUILDING.md.
DRC [Wed, 5 Oct 2016 19:36:46 +0000 (14:36 -0500)]
Travis: use correct repo/branch for off. builds
Pass the actual repository and branch that Travis is using into the
builtljt script, so the official builds it generates will come from
the same code base as the other tested builds.
DRC [Tue, 4 Oct 2016 18:41:48 +0000 (13:41 -0500)]
Fix 32-bit non-SIMD FP regression tests
- Introduce a new FLOATTEST value ("387") on Un*x systems that will
compare the floating point DCT/IDCT algorithms against the expected
results from the C algorithms when built using 32-bit code and
-mfpmath=387.
- Extend the Windows regression tests so that they work properly when
building libjpeg-turbo with 32-bit code and without SIMD, using either
Visual C++ (tested with 2008, 2010, 2015) or MinGW.
In the AArch64 ABI, as in many others, it's forbidden to read/store data
below the stack pointer. Some SIMD functions were doing just that
(stack pointer misuse) when trying to preserve callee-saved registers,
and this resulted in those registers being restored with incorrect
contents under certain circumstances.
This patch fixes that behavior, and callee-saved registers are now
stored above the stack pointer throughout the function call. The patch
also removes register saving in places where it is unnecessary for this
ABI, or it makes use of unused scratch regiters instead of callee-saved
registers.
Fixes #97. Closes #101.
Refer also to https://bugzilla.redhat.com/show_bug.cgi?id=1368569
The last iDevice to require ARMv6 was the iPhone 3G, which required iOS
4.2.1 or older. Our binaries have always required iOS 4.3 or newer,
so I'm not sure if the ARMv6 fork of our binaries was ever useful to
begin with. In any case, if it ever was useful, it no longer is. Fat
binaries can still be generated with ARMv6 support by invoking
{build_directory}/pkgscripts/makemacpkg manually.
Fix out-of-bounds write in partial decomp. feature
Reported by Clang UBSan (refer to
https://bugzilla.mozilla.org/show_bug.cgi?id=1301252 for test image.)
This appears to be a legitimate bug introduced by 3ab68cf563f6edc2608c085f5c8b2d5d5c61157e. Any component array, such
as first_MCU_col and last_MCU_col, should always be able to accommodate
MAX_COMPONENTS values. The aforementioned test image had 8 components,
which was not enough to make the out-of-bounds write bust out of the
jpeg_decomp_master struct (and fortunately the memory after last_MCU_col
is an integer used as a boolean, so stomping on it will do nothing other
than change the decoder state.) I crafted another special image that
has 10 components (the maximum allowable), but that was apparently not
enough to bust out of the allocated memory, either. Thus, it is
posited that the security threat posed by this bug is either extremely
minimal or non-existent.
NOTE: The jdhuff.c/jdphuff.c warnings should have already been silenced
by 8e9cef2e6f5156c4b055a04a8f979b7291fc6b7a, but apparently I need to
be REALLY clear that I'm trying to do pointer arithmetic rather than
dereference an array. Grrr...
Refer to:
https://bugzilla.mozilla.org/show_bug.cgi?id=1301250
https://bugzilla.mozilla.org/show_bug.cgi?id=1301256
When attempting to decode a malformed JPEG image (refer to
https://bugzilla.mozilla.org/show_bug.cgi?id=1295044) with dimensions
61472 x 32800, the maximum_space variable within the
realize_virt_arrays() function will exceed the maximum value of a 32-bit
integer and will wrap around. The memory manager subsequently fails
with an "Insufficient memory" error (case 4, in alloc_large()), so this
commit simply causes that error to be triggered earlier, before UBSan
has a chance to complain.
Note that this issue did not ever represent an exploitable security
threat, because the POSIX-based memory manager that we use doesn't ever
do anything meaningful with the value of maximum_space.
jpeg_mem_available() simply sets avail_mem = maximum_space, so the
subsequent behavior of the memory manager is the same regardless of
whether maximum_space is correct or not. This commit simply removes a
UBSan warning in order to make it easier to detect actual security
issues.
Normally, 4:2:2 JPEGs have horizontal x vertical luminance,chrominance
sampling factors of 2x1,1x1, and 4:4:0 JPEGs have horizontal x vertical
luminance,chrominance sampling factors of 1x2,1x1. However, it is
technically legal to create 4:2:2 JPEGs with sampling factors of
2x2,1x2 and 4:4:0 JPEGs with sampling factors of 2x2,2x1, since the
sums of the products of those sampling factors (2x2 + 1x2 + 1x2 and
2x2 + 2x1 + 2x1) are still <= 10. The libjpeg API correctly decodes
such images, so the TurboJPEG API should as well.
Currently, this only affects ARM, since it is the only platform that
accelerates YCbCr-to-RGB conversion but not merged upsampling. Even if
"plain" upsampling isn't accelerated, the combination of accelerated
color conversion + unaccelerated plain upsampling is still faster than
the unaccelerated merged upsampling algorithms.
In the AArch64 ABI, the high (unused) DWORD of a 32-bit argument's
register is undefined, so it was incorrect to use 64-bit
instructions to transfer a JDIMENSION argument in the 64-bit NEON SIMD
functions. The code worked thus far only because the existing compiler
optimizers weren't smart enough to do anything else with the register in
question, so the upper 32 bits happened to be all zeroes.
The latest builds of Clang/LLVM have a smarter optimizer, and under
certain circumstances, it will attempt to load-combine adjacent 32-bit
integers from one of the libjpeg structures into a single 64-bit integer
and pass that 64-bit integer as a 32-bit argument to one of the SIMD
functions (which is allowed by the ABI, since the upper 32 bits of the
32-bit argument's register are undefined.) This caused the
libjpeg-turbo regression tests to crash.
This patch tries to use the Wn registers whenever possible. Otherwise,
it uses a zero-extend instruction to avoid using the upper 32 bits of
the 64-bit registers, which are not guaranteed to be valid for 32-bit
arguments.
This eliminates "illegal instruction" errors when running libjpeg-turbo
under Linux on PowerPC chips that lack AltiVec support (e.g. the old
7XX/G3 models but also the newer e5500 series.)
The JSIMD_FORCE* environment variables previously meant "force the use
of this instruction set if it is available but others are available as
well", but that did nothing on ARM platforms, since there is only ever
one instruction set available. Since the ARM and MIPS CPU feature
detection code is less than bulletproof, and since there is only one
SIMD instruction set (currently) supported on those platforms, it makes
sense for the JSIMD_FORCE* environment variables on those platforms to
actually force the use of the SIMD instruction set, thus bypassing the
CPU feature detection code.
This addresses a concern raised in #88 whereby parsing /proc/cpuinfo
didn't work within a QEMU environment. This at least provides a
workaround, allowing users to force-enable or force-disable SIMD
instructions for ARM and MIPS builds of libjpeg-turbo.
DRC [Tue, 24 May 2016 15:23:56 +0000 (10:23 -0500)]
Format copyright headers more consistently
The IJG convention is to format copyright notices as:
Copyright (C) YYYY, Owner.
We try to maintain this convention for any code that is part of the
libjpeg API library (with the exception of preserving the copyright
notices from Cendio's code verbatim, since those predate
libjpeg-turbo.)
Note that the phrase "All Rights Reserved" is no longer necessary, since
all Buenos Aires Convention signatories signed onto the Berne Convention
in 2000. However, our convention is to retain this phrase for any files
that have a self-contained copyright header but to leave it off of any
files that refer to another file for conditions of distribution and use.
For instance, all of the non-SIMD files in the libjpeg API library refer
to README.ijg, and the copyright message in that file contains "All
Rights Reserved", so it is unnecessary to add it to the individual
files.
The TurboJPEG code retains my preferred formatting convention for
copyright notices, which is based on that of VirtualGL (where the
TurboJPEG API originated.)
DRC [Wed, 11 May 2016 02:04:02 +0000 (21:04 -0500)]
Don't allow opaque source/dest mgrs to be swapped
Calling jpeg_stdio_dest() followed by jpeg_mem_dest(), or jpeg_mem_src()
followed by jpeg_stdio_src(), is dangerous, because the existing opaque
structure would not be big enough to accommodate the new source/dest
manager. This issue was non-obvious to libjpeg-turbo consumers, since
it was only documented in code comments. Furthermore, the issue could
also occur if the source/dest manager was allocated by the calling
program, but it was not allocated with enough space to accommodate the
opaque stdio or memory source/dest manager structs. The safest thing to
do is to throw an error if one of these functions is called when there
is already a source/dest manager assigned to the object and it was
allocated elsewhere.
DRC [Tue, 10 May 2016 01:00:46 +0000 (20:00 -0500)]
Build: Don't allow jpeg-7+ emul. w/o arith coding
The jpeg-7/jpeg-8 APIs/ABIs require arithmetic coding, and the jpeg-8
API/ABI requires the memory source/destination manager, so this commit
causes the build system to ignore --with-arith-enc/--without-arith-enc
and --with-arith-dec/--without-arith-dec (and the equivalent CMake
variables-- WITH_ARITH_ENC and WITH_ARITH_DEC) when v7/v8 API/ABI
emulation is enabled. Furthermore, the CMake build system now ignores
WITH_MEM_SRCDST whenever WITH_JPEG8 is specified (the autotools build
system already did that.)
mattsarett [Tue, 3 May 2016 14:33:43 +0000 (10:33 -0400)]
ARMv7 SIMD: Fix clang compatibility (Part 2)
GCC does support UAL syntax (strbeq) if the ".syntax unified" directive
is supplied. This directive is supported by all versions of GCC and
clang going back to 2003, so it should not create any backward
compatibility issues.
mattsarett [Mon, 2 May 2016 16:31:51 +0000 (12:31 -0400)]
ARMv7 SIMD: Fix clang compatibility
By design, clang only supports Unified Assembler Language (and not
pre-UAL syntax):
https://llvm.org/bugs/show_bug.cgi?id=23507
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0473c/BABJIHGJ.html
Thus, clang only supports the strbeq instruction and not streqb, but
unfortunately some versions of GCC only support streqb. Go, go
Gadget #ifdef...
DRC [Sun, 1 May 2016 16:42:15 +0000 (11:42 -0500)]
Fix CMake fallback BUILD var on non-U.S. machines
If wmic.exe wasn't available, then CMakeLists.txt would call
"cmd /C date /T" and parse the result in order to set the BUILD
variable. However, the parser assumed that the date was in MM/DD/YYYY
format, which is not generally the case unless the user's locale is U.S.
English with the default region/language settings for that locale.
This commit modifies CMakeLists.txt such that it uses the
string(TIMESTAMP) function available in CMake 2.8.11 and later to set
the BUILD variable, thus eliminating the need to use wmic.exe or any
other platform-specific hack.
This commit also modifies the build instructions to remove any reference
to CMake 2.6 (which hasn't been supported by our build system since
libjpeg-turbo 1.3.x.)
At one time, it was possible to use CMake to build under Cygwin, but
that hasn't worked since 1.4.1 (due to the Huffman codec changes that
now require SIZEOF_SIZE_T to be defined for non-WIN32 platforms) and may
have even been broken before that. Originally, we used the "date"
command under MSYS in order to obtain the default build number, but that
was rendered unnecessary by 5e3bb3e9 (v1.3 beta.) 9fe22dac (1.4 beta)
further modified CMakeLists.txt so that the "date" command was only used
on Cygwin, but for unexplained reasons, that commit also applied the
(now vestigial) code to all non-WIN32 platforms. This prevented
CMakeLists.txt from displaying an error if someone attempted to use the
CMake build system on Un*x platforms, and that may have been behind the
flurry of pull requests and issues-- including #21, #29, #37, #58, #73--
complaining that the CMake build system didn't work on Un*x platforms
(although it was not until #73 that this bug came to light.)
This commit removes all vestiges of Un*x support from the CMake build
system and makes it clear that CMake cannot be used to build
libjpeg-turbo on non-WIN32 platforms. It is our position that CMake
will not be supported on non-WIN32 platforms until/unless the autotools
build system is removed, and this will not happen without broad support
from the community (including major O/S vendors.) If you are in favor
of migrating the entire build system to CMake, then please make your
voice heard by commenting on #56.
Even though tjDecompressToYUV2() is mostly just a wrapper for
tjDecompressToYUVPlanes(), tjDecompressToYUV2() still calls
jpeg_read_header(), so it needs to properly set up the libjpeg error
handler prior to making this call. Otherwise, under very esoteric (and
arguably incorrect) use cases, a program could call tjDecompressToYUV2()
without first checking the JPEG header using tjDecompressHeader3(), and
if the header was corrupt, then the libjpeg API would invoke
my_error_exit(). my_error_exit() would in turn call longjmp() on the
previous value of myerr->setjmp_buffer, which was probably set in a
previous TurboJPEG function, such as tjInitDecompress(). Thus, when a
libjpeg error was triggered within the body of tjDecompressToYUV2(), the
PC would jump to the error handler of the previous TurboJPEG function,
and this usually caused stack corruption in the calling program (because
the signature and return type of the previous TurboJPEG function
probably wasn't the same as that of tjDecompressToYUV2().)
Increase severity of tjDecompressToYUV2() bug desc
Actually, what happened was that the longjmp() call within
my_error_exit() acted on the previous value of myerr->setjmp_buffer,
which was probably set in a previous TurboJPEG function, such as
tjInitDecompress(). Thus, when a libjpeg error was triggered within
the body of tjDecompressToYUV2(), the PC jumped to the error handler
of the previous TurboJPEG function, and this usually caused stack
corruption in the calling program (because the signature and return
type of the previous TurboJPEG function probably wasn't the same.)
Even though tjDecompressToYUV2() is mostly just a wrapper for
tjDecompressToYUVPlanes(), tjDecompressToYUV2() still calls
jpeg_read_header(), so it needs to properly set up the libjpeg error
handler prior to making this call. Otherwise, under very esoteric (and
arguably incorrect) use cases, a program can call tjDecompressToYUV2()
without first checking the JPEG header using tjDecompressHeader3(), and
if the header is corrupt, tjDecompressToYUV2() will abort without
triggering an error.
<sigh> GitHub doesn't render indented text the same as my local MarkDown
viewer (MacDown), so it's necessary to indent "... OR ..." by 3 spaces
so both will display it on the same indentation level as "Visual C++
2005 or later" and "MinGW".
Indent "... OR ..." to make it clear that the choice is between Visual
C++ and MinGW, not Visual C++ and MinGW + NASM. Move NASM to the top of
the list to make that even more clear. Make it clear that nasm.exe
should be in the PATH.
DRC [Thu, 31 Mar 2016 14:49:49 +0000 (09:49 -0500)]
cjpeg: Fix buf overrun caused by bad bin PPM input
This extends the fix in 6709e4a0cfa44d4f54ee8ad05753d4aa9260cb91 to
include binary PPM/PGM files, thus preventing a malformed binary
PPM/PGM input file from triggering an overrun of the rescale array and
potentially crashing cjpeg.
Note that this issue affected only cjpeg and not the underlying
libjpeg-turbo libraries, and thus it did not represent a security
threat.
DRC [Wed, 16 Mar 2016 12:10:35 +0000 (07:10 -0500)]
Add version/build info to global string table
This is a common practice in other infrastructure libraries, such as
OpenSSL and libpng, because it makes it easy to examine an application
binary and determine which version of the library the application was
linked against.
DRC [Sun, 6 Mar 2016 14:15:04 +0000 (08:15 -0600)]
Ensure that default Huffman tables are initialized
This prevents a malformed motion-JPEG frame (MJPEG frames lack Huffman
tables) from causing the "fast path" of the Huffman decoder to read
uninitialized memory. Essentially, this is doing the same thing for
MJPEG frames as 43d8cf4d4572fa50a37cccadbe71b9bee37de55d did for regular
images.
DRC [Wed, 2 Mar 2016 15:53:11 +0000 (09:53 -0600)]
Java: Fix parallel make with autotools
Running 'make -j{jobs}' on a build that was configured with Java
(--with-java) would previously cause an error:
make: *** No rule to make target `TJExample.class', needed by
`turbojpeg.jar'.
It seems that parallel make doesn't understand that the files in
$(JAVA_CLASSES) are all generated from the same invocation of javac, so
it tries to parallelize the building of those files (which of course
doesn't work.) This patch instead makes turbojpeg.jar depend on
classnoinst.stamp. This effectively creates a synchronization fence,
since that file is only created when all of the class files have been
built.
DRC [Mon, 29 Feb 2016 23:21:02 +0000 (17:21 -0600)]
Win/x64: Fix improper callee save of xmm8-xmm11
The x86-64 SIMD accelerations for Huffman encoding used incorrect
stack math to save xmm8-xmm11 on Windows. This caused TJBench to
always report 1 Mpixel/sec for the compression performance, and it
likely would have caused other application issues as well.
DRC [Mon, 29 Feb 2016 19:18:01 +0000 (13:18 -0600)]
Bump TurboJPEG C API revision to 1.5
The changes relative to 1.4.x are only cosmetic (using const pointers)
and should not affect API/ABI compatibility, but our practice is to
synchronize the API revision with the most recent release that provides
user-visible changes to the API.
DRC [Sat, 20 Feb 2016 00:32:10 +0000 (18:32 -0600)]
libjpeg API: Partial scanline decompression
This, in combination with the existing jpeg_skip_scanlines() function,
provides the ability to crop the image both horizontally and vertically
while decompressing (certain restrictions apply-- see libjpeg.txt.)
This also cleans up the documentation of the line skipping feature and
removes the "strip decompression" feature from djpeg, since the new
cropping feature is a superset of it.
DRC [Fri, 19 Feb 2016 19:16:56 +0000 (13:16 -0600)]
Build: Make the NASM autoconf variable persistent
Previously, if a custom value of this variable was specified when
running configure, then that value would be lost if configure was
automatically re-run (as a result of changes to configure.ac, for
instance.)
As a bonus, the NASM variable is now also listed when running
'configure --help', so it is obvious how to override the default
NASM command.
projects / libjpeg-turbo / log