Add libvips version number to shared library SONAME and filename

[lovell]

This should help improve support for multiple versions of sharp that use differing versions of libvips running within the same process by ensuring dlopen accesses the relevant shared library.

Before:

lrwxrwxrwx 1 root root       17 Oct  8 15:05 libvips-cpp.so -> libvips-cpp.so.42
lrwxrwxrwx 1 root root       22 Oct  8 15:05 libvips-cpp.so.42 -> libvips-cpp.so.42.17.5
-rwxr-xr-x 1 root root 16313040 Oct  8 15:05 libvips-cpp.so.42.17.5

-rwxr-xr-x   1 runner  staff  18178880 Oct  8 15:13 libvips-cpp.42.dylib
lrwxr-xr-x   1 runner  staff        20 Oct  8 15:13 libvips-cpp.dylib -> libvips-cpp.42.dylib

After:

lrwxrwxrwx 1 root root       21 Oct  8 18:18 libvips-cpp.so -> libvips-cpp.so.8.15.5
-rwxr-xr-x 1 root root 16313040 Oct  8 18:18 libvips-cpp.so.8.15.5

-rwxr-xr-x   1 runner  staff  18178880 Oct  8 18:26 libvips-cpp.8.15.5.dylib
lrwxr-xr-x   1 runner  staff        24 Oct  8 18:26 libvips-cpp.dylib -> libvips-cpp.8.15.5.dylib

Relates to lovell/sharp#4095

[kleisauke]

LGTM! Tested with:

Details

$ readelf -d node_modules/@img/sharp-libvips-linux-x64/lib/libvips-cpp.so.42 | grep SONAME
 0x000000000000000e (SONAME)             Library soname: [libvips-cpp.so.42]
$ patchelf --set-soname libvips-cpp.so.8.15.2 node_modules/@img/sharp-libvips-linux-x64/lib/libvips-cpp.so.42
$ mv node_modules/@img/sharp-libvips-linux-x64/lib/libvips-cpp.so.42 node_modules/@img/sharp-libvips-linux-x64/lib/libvips-cpp.so.8.15.2
$ readelf -d node_modules/@img/sharp-libvips-linux-x64/lib/libvips-cpp.so.8.15.2 | grep SONAME
 0x000000000000000e (SONAME)             Library soname: [libvips-cpp.so.8.15.2]
$ readelf -d node_modules/@img/sharp-linux-x64/lib/sharp-linux-x64.node | grep libvips-cpp.so
 0x0000000000000001 (NEEDED)             Shared library: [libvips-cpp.so.42]
$ patchelf --replace-needed libvips-cpp.so.42 libvips-cpp.so.8.15.2 node_modules/@img/sharp-linux-x64/lib/sharp-linux-x64.node
$ node index
8.15.2
{ semver: '8.15.2', isGlobal: false, isWasm: false }
$ LD_DEBUG=libs node index 2>&1 | grep "libvips-cpp.so"
     10200:	find library=libvips-cpp.so.42 [0]; searching
     10200:	  trying file=/redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v4/libvips-cpp.so.42
     10200:	  trying file=/redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v3/libvips-cpp.so.42
     10200:	  trying file=/redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v2/libvips-cpp.so.42
     10200:	  trying file=/redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.42
     10200:	calling init: /redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.42
     10200:	find library=libvips-cpp.so.8.15.2 [0]; searching
     10200:	  trying file=/redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v4/libvips-cpp.so.8.15.2
     10200:	  trying file=/redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v3/libvips-cpp.so.8.15.2
     10200:	  trying file=/redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/glibc-hwcaps/x86-64-v2/libvips-cpp.so.8.15.2
     10200:	  trying file=/redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.8.15.2
     10200:	calling init: /redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.8.15.2
     10200:	calling fini: /redacted/node_modules/fast-average-color-node/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.42 [0]
     10200:	calling fini: /redacted/node_modules/@img/sharp-linux-x64/lib/../../sharp-libvips-linux-x64/lib/libvips-cpp.so.8.15.2 [0]

Of course, running two (or more) instances of libvips in the same process might degrade performance, but that might be better than having version mismatches.

Note that I'm unsure if we should apply the same approach to Windows builds, as these C++ DLLs are also used by projects other than sharp.

[lovell]

Thanks Kleis, I agree we should not apply this to the Windows builds.

(For sharp the C++ DLL is built/named via gyp.)