Linker scripts in cc_library deps missing from sandbox

[claridge]

In #184, we added support for linker scripts (.ld and .lds files) to cc_library's "deps" attribute. However, these don't appear to be mounted to the sandbox.

As a short-term workaround, I put my linker scripts in a filegroup and included that in the linker_files attribute of the appropriate cc_toolchain.

[tjurkiewicz]

Since cc_toolchain is not officially docummented, could you please describe, how exactly you use the cc_toolchain rule ?

[philwo]

Is this still an issue? If yes, please kindly re-open this bug with a small example on how to reproduce this. :)

[jnewton-sx]

@philwo please re-open this issue, it is still an issue and I have an example that reproduces it. It prevents using -Wl,--version-script in linkopts.

Test case:

BUILD:
 
cc_library(
    name="test",
    srcs=["test.c"],
    deps=[':linker.lds'],
    linkopts = ["-Wl,--version-script", "$(location :linker.lds)"],
)

linker.lds:

 LIBTEST_1.0 {
  global:
    func;
 
  local:
    *;
};

test.c:
 
int func(){
  return 0;
}

Works with --spawn_strategy=standalone, otherwise produces:

ERROR: /home/user/bazel-ldscript-testcase/BUILD:1:1: Linking of rule '//:test' failed (Exit 1): linux-sandbox failed: error executing command 
  (cd /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/execroot/__main__ && \
  exec env - \
    LD_LIBRARY_PATH=.: \
    PATH=/home/user/bin:/home/user/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games \
    PWD=/proc/self/cwd \
    TMPDIR=/tmp \
  /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/execroot/__main__/_bin/linux-sandbox -t 15 -w /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/1558636619903579259/execroot/__main__ -w /tmp -w /dev/shm -D -- /usr/bin/gcc -shared -o bazel-out/k8-fastbuild/bin/libtest.so -Wl,--version-script linker.lds '-fuse-ld=gold' -Wl,-no-as-needed -Wl,-z,relro,-z,now -B/usr/bin -B/usr/bin -pass-exit-codes -Wl,-S -Wl,@bazel-out/k8-fastbuild/bin/libtest.so-2.params)
src/main/tools/linux-sandbox.cc:154: linux-sandbox-pid1 has PID 136963
src/main/tools/linux-sandbox-pid1.cc:175: working dir: /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/1558636619903579259/execroot/__main__
src/main/tools/linux-sandbox-pid1.cc:194: writable: /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/1558636619903579259/execroot/__main__
src/main/tools/linux-sandbox-pid1.cc:194: writable: /tmp
src/main/tools/linux-sandbox-pid1.cc:194: writable: /dev/shm
src/main/tools/linux-sandbox-pid1.cc:265: remount ro: /
src/main/tools/linux-sandbox-pid1.cc:265: remount ro: /dev
src/main/tools/linux-sandbox-pid1.cc:265: remount ro: /dev/pts
src/main/tools/linux-sandbox-pid1.cc:265: remount rw: /dev/shm
src/main/tools/linux-sandbox-pid1.cc:265: remount rw: /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/1558636619903579259/execroot/__main__
src/main/tools/linux-sandbox-pid1.cc:265: remount rw: /home/user/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/1558636619903579259/execroot/__main__
src/main/tools/linux-sandbox-pid1.cc:265: remount rw: /tmp
src/main/tools/linux-sandbox-pid1.cc:265: remount rw: /dev/shm
src/main/tools/process-tools.cc:118: sigaction(32, &sa, nullptr) failed
src/main/tools/process-tools.cc:118: sigaction(33, &sa, nullptr) failed
gcc: error: linker.lds: No such file or directory
src/main/tools/linux-sandbox-pid1.cc:437: waitpid returned 2
src/main/tools/linux-sandbox-pid1.cc:457: child exited with code 1
src/main/tools/linux-sandbox.cc:204: child exited normally with exitcode 1
Target //:test failed to build
INFO: Elapsed time: 0.447s, Critical Path: 0.08s
FAILED: Build did NOT complete successfully

Only the following symlinks exist under bazel 10.0’s link-time sandbox, under ~/.cache/bazel/_bazel_user/3f57239b7854dc2d2a7465a30e6c1cb3/bazel-sandbox/2101481633161564656/execroot/__main__$ :

./external/bazel_tools/tools/cpp/build_interface_so
./external/bazel_tools/tools/cpp/link_dynamic_library.sh
./bazel-out/k8-fastbuild/bin/_objs/test/test.pic.o
./bazel-out/k8-fastbuild/bin/libtest.so-2.params

There’s a few related issues, as well as several replies that indicate an expectation for this to work:
#184
#716 (note: this was filed about propagation to cc_binary)
#4440

[philwo]

@mhlopko Seems like these files are missing from the inputs of C++ link actions? WDYT?

[hlopko]

Looks like dup of #716, the workaround is to only use linker scripts on cc_binary, that's how this feature was intended to be used.

[philwo]

I'm closing this again and unassigning it from me. It is definitely not a sandbox issue, but it might be a C++ rules issue. If it's actually a problem (but I understand @mhlopko so that this is working as intended), then please reopen.

[hlopko]

cc @oquenchil

[keithwyss]

What's the reason that ldscripts should only work with cc_binary rules @mhlopko and not with cc_library rules? I'd like to understand this better and whether our team is holding it wrong.

[hlopko]

ldscripts were meant to be used to give more precise control into symbols visibility/stripping. And that makes sense for cc_binaries only. But I agree that #716 should be fixed somehow.