qemu @2.12.0_0 +snappy configure fails with numerous errors in qemu-conf.c

[ShadSterling (Shad Sterling)]

A few of the errors seen:

config-temp/qemu-conf.c:2:2: error: __linux__ not defined
config-temp/qemu-conf.c:2:2: error: _WIN32 not defined
config-temp/qemu-conf.c:2:2: error: __OpenBSD__ not defined
config-temp/qemu-conf.c:3:8: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
} x = {0};
       ^
       {}
1 error generated.
config-temp/qemu-conf.c:2:10: fatal error: 'linux/ip.h' file not found
Undefined symbols for architecture x86_64:
  "std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
      std::__1::vector<snappy::SnappySinkAllocator::Datablock, std::__1::allocator<snappy::SnappySinkAllocator::Datablock> >::allocate(unsigned long) in libsnappy.a(snappy.cc.o)

[raimue (Rainer Müller)]

Thank you for the report. Many of the errors are just from other tests and can be ignored. Only the last error about missing symbols is relevant.

The problem seems to be in the snappy library. Basically, this is the test program that the qemu configure script wants to run:

$ echo -e "#include <snappy-c.h>\nint main(void) { snappy_max_compressed_length(4096); return 0; }" | clang -xc -I/opt/local/include -L/opt/local/lib - -lsnappy
Undefined symbols for architecture x86_64:
  "std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
      std::__1::vector<snappy::SnappySinkAllocator::Datablock, std::__1::allocator<snappy::SnappySinkAllocator::Datablock> >::allocate(unsigned long) in libsnappy.a(snappy.cc.o)
      void std::__1::vector<snappy::SnappySinkAllocator::Datablock, std::__1::allocator<snappy::SnappySinkAllocator::Datablock> >::__push_back_slow_path<snappy::SnappySinkAllocator::Datablock const>(snappy::SnappySinkAllocator::Datablock const&) in libsnappy.a(snappy.cc.o)
      void std::__1::vector<char*, std::__1::allocator<char*> >::__push_back_slow_path<char* const>(char* const&) in libsnappy.a(snappy.cc.o)
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::resize(unsigned long, char)", referenced from:
...

Note there is only a libsnappy.a and no dynamic library. I don't know why it references undefined C++ symbols. This problem might be related to #55583.

[raimue (Rainer Müller)]

Definitely caused by #55583. Will automatically be resolved once the snappy port provides a shared libary again instead of a static library.

[raimue (Rainer Müller)]

Fixed with [547e3c593e113338f7b524a79f679cc93e8a2af1/macports-ports].