All modern assemblers have this capability. Older NASM versions
that lack the capability produce code that crashes at runtime,
so it's better to error out during the build process instead.
CC: libav-stable@libav.org
Some awk versions do not treat the result of unary + on a (numeric)
string as numeric, giving wrong results when used in a boolean context
Using unary - instead is logically equivalent works as expected.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This isn't too useful as a normal codec, but can be used in
voip style applications. The decoder updates the noise
generator parameters when a packet is given to it for decoding,
but if called with an empty packet, it generates more noise
according to the last parameters.
Signed-off-by: Martin Storsjö <martin@martin.st>
This adds support for building on Plan 9 x86-32. The compat/plan9
directory contains these items:
- replacements for the 'head' and 'printf' shell commands
- wrapper for main() to disable FPU exceptions
Larger required changes to the system are described in the
documentation.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This allows targets to include special objects when linking
executables without including them in (shared) libraries.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The absence of this function will only give a less informative
string back from our fallback implementation of getnameinfo().
Signed-off-by: Mans Rullgard <mans@mansr.com>
This requires the makedef perl script by Derek, from the
c89-to-c99 repo. That scripts produces a .def file, listing
the symbols to be exported, based on the gcc version scripts
and the built object files.
To properly load non-function symbols from DLL files, the
data symbol declarations need to have the attribute
__declspec(dllimport) when building the calling code. (On mingw,
the linker can fix this up automatically, which is why it has not
been an issue so far. If this attribute is omitted, linking
actually succeeds, but reads from the table will not produce the
desired results at runtime.)
MSVC seems to manage to link DLLs (and run properly) even if
this attribute is present while building the library itself
(which normally isn't recommended) - other object files in the
same library manage to link to the symbol (with a small warning
at link time, like "warning LNK4049: locally defined symbol
_avpriv_mpa_bitrate_tab imported" - it doesn't seem to be possible
to squelch this warning), and the definition of the tables
themselves produce a warning that can be squelched ("warning C4273:
'avpriv_mpa_bitrate_tab' : inconsistent dll linkage, see previous
definition of 'avpriv_mpa_bitrate_tab').
In this setup, mingw isn't able to link object files that refer to
data symbols with __declspec(dllimport) without those symbols
actually being linked via a DLL (linking avcodec.dll ends up with
errors like "undefined reference to `__imp__avpriv_mpa_freq_tab'").
The dllimport declspec isn't needed at all in mingw, so we simply
choose not to declare it for other compilers than MSVC that requires
it. (If ICL support later requires it, the condition can be extended
later to include both of them.)
This also implies that code that is built to link to a certain
library as a DLL can't link to the same library as a static library.
Therefore, we only allow building either static or shared but not
both at the same time. (That is, static libraries as such can be,
and actually are, built - this is used for linking the test tools to
internal symbols in the libraries - but e.g. libavformat built to
link to libavcodec as a DLL cannot link statically to libavcodec.)
Also, linking to DLLs is slightly different from linking to shared
libraries on other platforms. DLLs use a thing called import
libraries, which is basically a stub library allowing the linker
to know which symbols exist in the DLL and what name the DLL will
have at runtime.
In mingw/gcc, the import library is usually named libfoo.dll.a,
which goes next to a static library named libfoo.a. This allows
gcc to pick the dynamic one, if available, from the normal -lfoo
switches, just as it does for libfoo.a vs libfoo.so on Unix. On
MSVC however, you need to literally specify the name of the import
library instead of the static library.
Signed-off-by: Martin Storsjö <martin@martin.st>
The name mingw32 as target OS is both misleading, and very little
of the target OS specific settings actually match.
Since the target OS default is set based on uname, the default
(which on MSYS is set to mingw) is overridden by --toolchain=msvc.
Signed-off-by: Martin Storsjö <martin@martin.st>
Add a configure function to pull in a compat object and set up
redirects in one operation. This avoids duplicating conditions
across configure and makefiles.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The glibc definitions of INFINITY and NAN do not work with the
tms470 compiler, nor do our usual fallbacks.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Apply flags to work around glibc quirks only if glibc is detected,
and add a few more such flags.
Do not mess with as/ld settings in probe_cc. This is not the
proper place.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Solaris defaults to non-standard utilities (grep, sed, ...) with
proper ones being in /usr/xpg4/bin. Prefixing PATH with this
directory when it exists ensures we get correct variants.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Enable dead store elimination. The last few releases work no worse
with this flag than without. Older versions failed to build some
source files when using this flag.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Now that there is CPU detection in YASM, there will always be one of
inline or external assembly enabled, which obviates the need to fall
back on CPU detection through compiler intrinsics.
v5.0 of the TI ARM compiler changes the version string.
This updates the detection to check for both the old and
the new strings.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This simplifies ensuring proper flags are used when the default
is overridden by the system or on the command line.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Some compilers are extra strict about register usage in main(),
disallowing ebp in inline asm there while allowing it elsewhere.
This change makes the test better reflect actual usage.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The 64 bit cl.exe version 16.00.30319.01 crashes with an internal
compiler error on the current check (and thus deduces it isn't
supported, even if the actual usage in libavuil/x86/cpu.c works
fine), but by assigning the value from the intrinsic to a variable,
or returning it, it works fine.
This error is fixed in cl.exe version 16.00.40219.01.
Signed-off-by: Martin Storsjö <martin@martin.st>
Some msvcrt versions (the static 64 bit libc in MSVC 10) have
a log2 function, but there is no declaration for it in the headers.
Therefore, the normal configure check might find it, but it can fail
during build or at runtime, depending on whether implicit function
declarations are an error or not.
Therefore simply ignore this function on this platform.
Signed-off-by: Martin Storsjö <martin@martin.st>
This disables the following warnings:
C4100: unreferenced formal parameter
(1035 occurrances)
C4214: nonstandard extension used : bit field types other than int
(609 occurances)
C4996: 'avpriv_snprintf': This function or variable may be unsafe.
Consider using _snprintf_s instead. To disable deprecation,
use _CRT_SECURE_NO_WARNINGS. See online help for details.
(351 occurrances)
Signed-off-by: Martin Storsjö <martin@martin.st>
Using ranlib is not required but prevents using the libraries with
msvc.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
This is necessary to avoid spuriously enabling _external or _inline
variants of arch extensions when they should be disabled.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This enables replacing the -l and -L flags used to specify the
just-built libraries when linking the tools and shared libs with
non-standard syntaxes. System library flags are already handled
by the filtering mechanism in configure.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Some tools use different command line syntax for specifying output
when compiling and linking. To accomodate these, separate variables
must be used. No currently supported compilers/linkers are affected
by the change.
Signed-off-by: Mans Rullgard <mans@mansr.com>
There is no point in having the user disable any fastdiv macros.
Besides the condition implementation was broken and only disabled
the C implementation, but no platform specific assembly versions.
There used to be one test for Altivec intrinsics support and a
separate test to determine which of two possible syntaxes to use
for vector literals. Since 2008, we only support the more common
of these so the split test no longer makes sense.
This combines the tests into one and also changes the hard error on
failure to a warning. The test can reasonably fail if no --cpu flag
is provided (or is provided with an unknown CPU) and the compiler
default target does not support Altivec. Aborting in this case is
probably over-reacting.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This fixes build failures on debian/kfreebsd, which has the
sctp.h header, but it is currently broken (a cpp test succeeds,
but a compile test fails), see http://bugs.debian.org/684330 for
details.
Also remove the checked item from HAVE_LIST, since the corresponding
HAVE_* define isn't used by the source code.
Signed-off-by: Martin Storsjö <martin@martin.st>
