Problems using cSHTOOLS on macOS

[MarkWieczorek]

I am able to get the SHTOOLS C wrapper functions to compile on macOS, and to run the test suite. However, I need to manually alter the LIB string in examples/cpp/Makefile in order to find the gfortran library. This is hindering me to find a common solution so that the tests can be run in github actions and travis on both the macOS and linux platforms.

When using g++-10 (installed via homebrew), I need to manually add the search path -L /usr/local/Cellar/gcc/10.2.0/lib/gcc/10. This is strange to me, because if I force verbose output when linking, the output says explicitly that this path is in the linker's search path. If I don't add this search path manually, I get errors like this:

Library search paths:
	/Users/lunokhod/SphericalHarmonics/shtools-git/lib
	/usr/local/lib
	/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/gcc/x86_64-apple-darwin19/10.2.0
	/usr/local/Cellar/gcc/10.2.0/lib/gcc/10
	/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/lib
Framework search paths:
	/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/
Undefined symbols for architecture x86_64:
  "__ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv", referenced from:
      _main in test.o

If I use g++-9, I get slightly different, but very similar errors, like this:

  "std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::size() const", referenced from:
      _main in test.o

In contrast, if I try to use Apple's clang, g++ or gcc (located in /usr/bin), I simply get an error that it can't find the gfortran library:

clang  -v -o test test.o -L /Users/lunokhod/SphericalHarmonics/shtools-git/lib -lSHTOOLS -lgfortran -ldl -L/usr/local/lib -lfftw3 -lm -llapack -lblas
Apple clang version 12.0.0 (clang-1200.0.32.2)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -lto_library /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/libLTO.dylib -dynamic -arch x86_64 -platform_version macos 10.15.0 10.15.6 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -o test -L/Users/lunokhod/SphericalHarmonics/shtools-git/lib -L/usr/local/lib -L/usr/local/lib test.o -lSHTOOLS -lgfortran -ldl -lfftw3 -lm -llapack -lblas -lSystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.osx.a
ld: library not found for -lgfortran
clang: error: linker command failed with exit code 1 (use -v to see invocation)

It is possible that there is something wrong with the homebrew g++ compiler, and I have opened a discussion here.

[nrsharan]

I faced exactly the same issue. I had to use:

export LIBRARY_PATH=/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/

in the terminal and then run it. Not very sure about MacOS environment so I don't know why.

[MarkWieczorek]

Thanks for the suggestion. I did try manually setting the Library path in the terminal, but that didn't help. All it did was to add a duplicate line to the "Library search paths" above.

[nrsharan]

This is what I see

g++ -v -o test test.o -L ../../lib -lSHTOOLS -lgfortran -ldl -lfftw3 -lm -llapack -lblas
Apple clang version 12.0.0 (clang-1200.0.32.2)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
 "/Library/Developer/CommandLineTools/usr/bin/ld" -demangle -lto_library /Library/Developer/CommandLineTools/usr/lib/libLTO.dylib -dynamic -arch x86_64 -platform_version macos 10.15.0 10.15.6 -syslibroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -o test -L../../lib -L/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/ -L/usr/local/lib test.o -lSHTOOLS -lgfortran -ldl -lfftw3 -lm -llapack -lblas -lc++ -lSystem /Library/Developer/CommandLineTools/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.osx.a
ld: warning: could not create compact unwind for _shlocalizedadmitcorr_: stack subq instruction is too different from dwarf stack size
ld: warning: could not create compact unwind for _shmultitapercse_: stack subq instruction is too different from dwarf stack size


./test
SHRead exit status: 0
SHCilmToVector exit status: 0
3.3895e+06 -1735.55 -101.157 -785.374 -5966.19 222.242 -1060.12 119.976 758.445 38.4194 -194.816 -342.892 511.429 -86.9805 364.977 817.819 224.66 -69.8116 341.698 -243.804 -87.1215 6.97955 -196.686 28.2134 -237.52 -320.209 88.5702 -253.118 172.202 -79.6469 -163.68 307.327 39.3193 287.852 -420.73 97.2752 165.879 -28.0242 -138.316 -116.889 81.548 192.149 213.362 -102.405 98.3138 -57.7808 157.829 7.80598 61.4912 196.075 -13.3636 237.226 80.0594 9.74285 4.31236 71.511 66.402 149.996 -142.289 -44.3155 -140.201 4.70634 -34.2314 -134.793 -67.2091 -22.236 42.5351 1.55548 64.8776 -20.8739 -111.288 20.3224 -75.9854 105.082 19.9492 -2.42083 98.658 47.9556 -97.8901 102.213 0.864672 -11.9803 89.3677 -25.984 -53.7882 -15.9483 -123.266 59.6355 10.7198 -50.9656 -73.4738 -170.113 50.4186 -85.9382 50.1499 -7.63339 128.141 -106.215 43.8414 -74.6382 67.5064 81.2152 -45.2571 89.4706 -29.8078 -26.9755 45.0903 -11.5297 14.6132 -84.0519 2.66982 -3.63675 -31.0422 38.7938 -76.5979 -36.9509 -31.2392 -64.2192 29.8505 -112.607 53.5939 -4.05732 -92.7094 -23.9419 -39.0728 -21.3454 74.5288 41.404 -3.37021 -4.39096 -29.1079 69.8436 13.8554 -21.339 15.34 -16.1854 10.095 7.10758 40.7832 -53.2634 58.8055 -15.0454 53.2568 0.960232 51.1805 -11.8935 17.0156 -39.0905 28.8603 69.7857 -27.1099 51.9374 -106.134 73.0624 76.1015 36.2783 15.4683 -23.2197 26.0424 19.1658 -14.3442 17.4707 -74.9058 36.7783 -51.1199 49.8693 75.1868 -14.7429 -2.65042 -40.629 10.6243 -33.715 55.7701 42.6923 -13.8285 -68.9542 -24.5572 -13.1048 89.2731 -32.0745 30.2635 -94.1571 -29.6095 82.1565 3.81127 47.7297 40.2637 0.123983 17.34 16.09 6.34955 60.2813 -40.602 -9.38463 -13.2503 21.4409 66.422 39.3972 30.0866 32.5331 -16.2176 -18.1671 -14.5634 -42.5146 7.18052 36.9935 20.8726 -78.9059 -37.7639 34.5835 16.0421 35.0734 -35.7935 -29.3046 -13.6777 -33.9394 15.3642 5.17005 -4.08783 79.8079 -65.2803 -21.4523 -34.7513 95.4417 -40.8202 36.3634 20.9318 9.14367 -33.5605 -32.1138 -54.1955 -5.67777 34.1548 68.8129 -78.4384 13.1078 -33.0131 104.506 21.1803 16.6879 25.396 -16.0698 -46.1332 -17.9785 -10.4984 -1.25681 26.7552 3.88778 -1.3352 -24.1547 -2.14799 23.4063 36.9053 19.1212 -77.1753 18.2875 
diff to python 0

this is after using the export library path to gfortran. As I see in your verbose output, the cellar path to gfortran is not there as it is in mine here. Maybe this will be of some help.

[MarkWieczorek]

Interesting. It looks like you are using the default Apple g++ compiler (/usr/bin/g++), which doesn't come with a gfortran library. Then, you link to the gfortran library supplied by homebrew's gcc installation.

This does indeed work, but, I would prefer to use homebrew's g++ compiler (/usr/local/bin/g++-10). If you find a way to get this to work, let me know!

[QuLogic]

the default Apple g++ compiler (/usr/bin/g++),

This default is clang; they just symlinked it to appear like gcc. So there wouldn't be a Fortran library, AFAIK.