We can still avoid modifying the contents of this file during
configuration to simplify the build systems. Gnulib added replacements
for inclusions guards for Cygwin. Cygwin should not need getopt_long
replacement so this feature can be omitted.
<unistd.h> is conditionally included to avoid MSVC since it is not
available.
The definition for _GL_ARG_NONNULL was also copied into this file from
Gnulib since this stage is usually done during gnulib-tool.
The code maintains the prior modifications of conditionally including
config.h and disabling NLS support.
_GL_UNUSED is repalced with the simple cast to void trick. _GL_UNUSED
is only used for these two parameters so its simpler than having to
define it.
This was modified slightly from Gnulib. In Gnulib, it expects the
@HAVE_SYS_CDEFS_H@ to be replaced. Instead, we can set HAVE_SYS_CDEFS_H
on systems that have it and avoid copying another file into the build
directory. Since we are not using gnulib-tool, copying extra files
requires extra build system updates (and special handling with CMake) so
we should avoid when possible.
The getopt related files have changed from Gnulib by splitting up
getopt.in.h into more modular header files. We could have kept
everything in just getopt.in.h, but this will help us continue to update
in the future.
Before this commit, the following writes "foo" to the
console and deletes the input file:
echo foo | xz > con_xz
xz --suffix=_xz --decompress con_xz
It cannot happen without --suffix because names like con.xz
are also special and so attempting to decompress con.xz
(or compress con to con.xz) will already fail when opening
the input file.
Similar thing is possible when compressing. The following
writes to "nul" and the input file "n" is deleted.
echo foo | xz > n
xz --suffix=ul n
Now xz checks if the destination is a special file before
continuing. DOS/DJGPP version had a check for this but
Windows (and OS/2) didn't.
xzdec might build with VS2013 but it hasn't been tested.
It was never supported before and VS2013 is old anyway
so for simplicity only liblzma is supported with VS2013.
Building the command line tools xz and xzdec with the combination
of CMake + Visual Studio 2015/2017/2019/2022 works now.
VS2013 update 2 should still be able to build liblzma.
VS2013 cannot build the xz command line tool because xz
needs snprintf() that roughly conforms to C99.
VS2013 is old and no extra code will be added to support it.
Thanks to Kelvin Lee and Jia Tan for testing.
There are several new policies. CMP0149 may affect the Windows SDK
version that CMake will choose by default. The new behavior is more
predictable, always choosing the latest SDK version by default.
The other new policies shouldn't affect this package.
The CMake-based build doesn't use config.h.
Up-to-date getopt_long in Gnulib is LGPLv2 so at some
point it could be included in XZ Utils too but for now
this commit is enough to make CMake-based build possible.
For compatibility with C23's [[noreturn]], tuklib_attr_noreturn
must be at the beginning of declaration (before "extern" or
"static", and even before any GNU C's __attribute__).
This commit also moves all other function attributes to
the beginning of function declarations. "extern" is kept
at the beginning of a line so the attributes are listed on
separate lines before "extern" or "static".
xrealloc() is obviously incorrect, modern GCC docs even
mention realloc() as an example where this attribute
cannot be used.
liblzma's lzma_alloc() and lzma_alloc_zero() would be
correct uses most of the time but custom allocators
may use a memory pool or otherwise hold the pointer
so aliasing issues could happen in theory.
The xstrdup() case likely was correct but I removed it anyway.
Now there are no __malloc__ attributes left in the code.
The allocations aren't in hot paths so this should make
no practical difference.
This makes no difference for GCC or Clang as they support
GNU C's __attribute__((__noreturn__)) but this helps with MSVC:
- VS 2019 version 16.7 and later support _Noreturn if the
options /std:c11 or /std:c17 are used. This gets handled
with the check for __STDC_VERSION__ >= 201112.
- When MSVC isn't in C11/C17 mode, __declspec(noreturn) is used.
C23 will deprecate _Noreturn (and <stdnoreturn.h>)
for [[noreturn]]. This commit anticipates that but
the final __STDC_VERSION__ value isn't known yet.
If CMake was configured more than once, HAVE_CLOCK_GETTIME and
HAVE_CLOCK_MONOTONIC would not be set as compile definitions. The check
for librt being needed to provide HAVE_CLOCK_GETTIME was also
simplified.
Jia Tan
Lasse Collin
Kelvin Lee