check.py fails on macOS

[pepyakin]

Running check.py on macOS fails on gcc torture tests.

build:  /usr/bin/gcc /Users/pepyakin/dev/etc/binaryen/test/example/c-api-hello-world.c -c -o example.o -I/Users/pepyakin/dev/etc/binaryen/src -g -Lbin/../lib -pthread
clang: warning: argument unused during compilation: '-Lbin/../lib' [-Wunused-command-line-argument]
   c-api-hello-world.c /Users/pepyakin/dev/etc/binaryen/test/example/c-api-hello-world.c /Users/pepyakin/dev/etc/binaryen/test/example/c-api-hello-world.txt
link:  /usr/bin/g++ -std=c++11 example.o -lbinaryen -I/Users/pepyakin/dev/etc/binaryen/src -g -lasmjs -lsupport -Lbin/../lib -pthread -o bin/example -Wl,-rpath=$ORIGIN/../lib
clang: warning: argument unused during compilation: '-pthread' [-Wunused-command-line-argument]
ld: unknown option: -rpath=$ORIGIN/../lib
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Traceback (most recent call last):
  File "./check.py", line 740, in <module>
    run_gcc_torture_tests()
  File "./check.py", line 584, in run_gcc_torture_tests
    os.remove(output_file)
OSError: [Errno 2] No such file or directory: 'bin/example'

Seems like it happens because clang pretends to be gcc.

gcc --version                                                                                                                                                                           
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.1.0 (clang-802.0.42)
Target: x86_64-apple-darwin16.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[jayphelps]

I tried solving it by installing gcc via brew install gcc and using CC=gcc-8 CXX=g++-8 ./check.py however I still receive the same error:

Error details

build:  gcc-8 /Users/jayphelps/Projects/jayphelps/binaryen/test/example/c-api-hello-world.c -c -o example.o -I/Users/jayphelps/Projects/jayphelps/binaryen/src -g -Lbin/../lib -pthread
   c-api-hello-world.c /Users/jayphelps/Projects/jayphelps/binaryen/test/example/c-api-hello-world.c /Users/jayphelps/Projects/jayphelps/binaryen/test/example/c-api-hello-world.txt
link:  g++-8 -std=c++11 example.o -Lbin/../lib -lbinaryen -I/Users/jayphelps/Projects/jayphelps/binaryen/src -g -pthread -o bin/example -Wl,-rpath=$ORIGIN/../lib
ld: unknown option: -rpath=$ORIGIN/../lib
collect2: error: ld returned 1 exit status
Traceback (most recent call last):
  File "./check.py", line 675, in 
    sys.exit(main())
  File "./check.py", line 657, in main
    run_gcc_tests()
  File "./check.py", line 566, in run_gcc_tests
    os.remove(output_file)
OSError: [Errno 2] No such file or directory: 'bin/example'

--

I noted ld: unknown option: -rpath=$ORIGIN/../lib and some googling suggested it might need to be a comma instead -rpath,$ORIGIN/../lib so I change that line in check.py.

I also noticed that an old PR had the rpath stuff excluded on Mac though that change was later lost. I'm not sure what's right.

That resolved the error, but then I got fatal error: _stdio.h: No such file or directory

More googling suggested that I needed to update my xcode "command line tools" so I used:

sudo softwareupdate -i "Command Line Tools (macOS High Sierra version 10.13) for Xcode-9.4"

PHEW. Now it works!

Aside from the -rpath,$ORIGIN/../lib change, I wonder if there's anything that can be done to make this easier for Mac users, or if we just need to provide some additional instructions for setup.