-static-libstdc++ -static-libgcc does not work with MOSTLY STATIC linking #2840
Description
When the -static-libstdc++ -static-libgcc flags are supplied as linkopts to cc_binary and linkstatic = 1, the resulting binary is still dynamically linked against libgcc/libc++, witness:
(cd /usr/local/google/home/htuch/.cache/bazel/_bazel_htuch/89676793239ac96d94294e6c7a44597f/execroot/envoy && \
exec env - \
/google/src/files/151979262/depot/google3/third_party/crosstool/v18/stable/wrappers/x86_64-grtev4-linux-gnu/bin/gcc -o bazel-out/local-fastbuild/bin/source/exe/envoy-static -pthread '-Wl,--build-id=md5' '-Wl,--hash-style=gnu' -static-libstdc++ -static-libgcc '-fuse-ld=gold' -Wl,-no-as-needed -Wl,-z,relro,-z,now -B/g
oogle/src/files/151979262/depot/google3/third_party/crosstool/v18/stable/wrappers/x86_64-grtev4-linux-gnu/bin -B/usr/bin '-Wl,--build-id=md5' '-Wl,--hash-style=gnu' -pass-exit-codes -Wl,-S -Wl,@bazel-out/local-fastbuild/bin/source/exe/envoy-static-2.params)
Target //source/exe:envoy-static up-to-date:
bazel-bin/source/exe/envoy-static
INFO: Elapsed time: 168.321s, Critical Path: 50.97s
<static-link> htuch@htuch00:~/src/envoy ⊧ ldd bazel-bin/source/exe/envoy-static
linux-vdso.so.1 => (0x00007ffc0c3c7000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f60e820f000)
libstdc++.so.6 => /google/src/files/151979262/depot/google3/third_party/crosstool/v18/stable/toolchain/x86_64-grtev4-linux-gnu/lib64/libstdc++.so.6 (0x00007f60e80f0000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f60e7dea000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f60e7bcc000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f60e7804000)
/usr/grte/v4/lib64/ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2 (0x000055f7c0973000)
libgcc_s.so.1 => /google/src/files/151979262/depot/google3/third_party/crosstool/v18/stable/toolchain/x86_64-grtev4-linux-gnu/lib64/libgcc_s.so.1 (0x00007f60e75ed000)
From the compiler man page, it looks like these flags are only supposed to work under the g++ driver. Even manually rerunning the command under g++ doesn't fix this. I had to modify bazel-out/local-fastbuild/bin/source/exe/envoy-static-2.params to remove the -lstdc++.
The Envoy (https://github.com/lyft/envoy/) Bazel build needs this mostly static link, where the Envoy libraries, external deps and standard C/C++ libs are statically linked, but the rest of the system libs are dynamically linked.
Looks like this requires some additional Bazel implementation work to properly support (at least as far as CROSSTOOLS goes, maybe another kind of pseudo-static link type). Are there any suggested workarounds in the meanwhile?