This makes sense and takes care of missing build dependencies.

-pie was added to C flags for ThreadSanitizer in commit
19f251a288. Under clang 3.8.0, the -pie
flag causes a compiler warning and a linker error when running configure
--toolchain=clang-tsan. Here is an excerpt from config.log:

clang ... -fsanitize=thread -pie -std=c11 -fomit-frame-pointer -pthread -c -o /tmp/ffconf.A8SsaoCF.o /tmp/ffconf.JdpujQlD.c
clang: warning: argument unused during compilation: '-pie'
clang -fsanitize=thread -pie -Wl,--as-needed -o /tmp/ffconf.2iYA4bsw /tmp/ffconf.A8SsaoCF.o -lm -lm -lbz2 -lz -pthread
/usr/bin/ld: /tmp/ffconf.A8SsaoCF.o: relocation R_X86_64_PC32 against undefined symbol `atan2f@@GLIBC_2.2.5' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
clang: error: linker command failed with exit code 1 (use -v to see invocation)

To be conservative, I changed -pie to -fPIE. But the documentation seems
to imply just -fsanitize=thread is enough:

http://clang.llvm.org/docs/ThreadSanitizer.html
https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual

Signed-off-by: Wan-Teh Chang <wtc@google.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

The generic parameter names used for CFLAGS in configure must be filtered
for each compiler and replaced by the equivalent flag for that compiler.

This simplifies the code.

This ensures that dependencies are resolved correctly. COMPONENT_LIST
can contain parts that depend on previous entries of CONFIG_LIST.

Handle extralibs in the standard way, add missing pthreads dependency.
Also globally check for -fobj-arc with Objective-C compilers since
that option is useful for other Objective-C code as well.

The unadorned package name is needed to derive package-related variable names.

Fixes standalone compilation of the libmp3lame encoder.

It is of doubtful utility, adds complexity and no known users exist.

Supporting the system was a nice joke for the 9 release, but it has
run its course. Nowadays Plan 9 receives no testing and has no
practical usefulness.

The libdc1394 API transition was finished close to a decade ago.

This allows filtering out some warning noise.

Also drop -Winline from set of warning flags as it only produces noise.

Be explicit about which options should be set.

GnuTLS in combination with gcrypt has been deprecated since 2010.

Also add a missing avcodec.h #include in the movie filter.

This disables warnings about potentially uninitialized local pointer
variables.  Disabling the warning is in line with what we do for gcc.

The code now does not depend on VA and will work on windows as well.

It uses the same code as the MPEG-2 decoder, so the file is renamed
to contain all "other" (that is, not H.26[45]) codecs.

The replacement code uses tempnam(), which is dangerous.
Such a fringe feature is not worth the trouble.

This will allow to error out immediately if incompatible options are
passed on the command line instead of running time-consuming tests.

This avoids unnecessarily linking against xlib.

Also drop a related and now redundant informative output line.

Also drop a redundant output line.

In recent lld-link versions, this command prints the version to
stdout, but also prints an error to stderr:

$ lld-link -flavor gnu --version
LLD 4.0.0 (trunk 285641)
lld-link: error: no input files
lld-link: error: target emulation unknown: -m or at least one .o file required

Signed-off-by: Martin Storsjö <martin@martin.st>

The four examples (audio/video encoding/decoding) are completely
independent so it makes little sense to have them all in one file.

The four examples (audio/video encoding/decoding) are completely
independent so it makes little sense to have them all in one file.

Avoid an underlink issue on recent distributions.

CC: libav-stable@libav.org

Further simplifications by Martin Storsjö, to minimize the
diff.

Signed-off-by: Martin Storsjö <martin@martin.st>

Unfortunately the xavs.h API header is not self-sufficient and relies
on manual stdint.h inclusion by its users.