MacOS crosstool configures /usr/bin/strip with invalid flags

[jmillikin-stripe]

This report is against Bazel release 0.7.0.

tools/osx/crosstool/CROSSTOOL.tpl configures /usr/bin/strip with multiple -R flags. In the GNU toolchain this flag removes a named section, but Clang (installed by Apple's dev tools) has a different definition of the -R flag.

       -R filename
              Remove the symbol table entries for the global symbols listed in
              filename.  This file has the same  format  as  the  -s  filename
              option  above.   This option is usually used in combination with
              other options that save some symbols, -S, -x, etc.

This causes builds of stripped binaries to fail on MacOS:

$ ~/bin/bazel build -s //:hello.stripped
# [...]
>>>>> # //:hello [action 'Stripping hello.stripped for //:hello']
(cd /private/var/tmp/_bazel_jmillikin/6469710131e6db2fa36d059d1b1c2547/execroot/__main__ && \
  exec env - \
    PATH=/usr/local/bin:/usr/bin:/bin \
    TMPDIR=/var/folders/bd/0cbzdsgs2lq1dtg56xn8c07c0000gn/T/ \
  /usr/bin/strip -S -o bazel-out/local-fastbuild/bin/hello.stripped -R .gnu.switches.text.quote_paths -R .gnu.switches.text.bracket_paths -R .gnu.switches.text.system_paths -R .gnu.switches.text.cpp_defines -R .gnu.switches.text.cpp_includes -R .gnu.switches.text.cl_args -R .gnu.switches.text.lipo_info -R .gnu.switches.text.annotation bazel-out/local-fastbuild/bin/hello)
ERROR: /Users/jmillikin/src/hello_cc/BUILD:1:1: Stripping hello.stripped for //:hello failed (Exit 1).
fatal error: /Library/Developer/CommandLineTools/usr/bin/strip: only one -R option allowed
Target //:hello.stripped failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 1.491s, Critical Path: 0.19s

Here's the workspace content to reproduce:

$ cat BUILD 
cc_binary(
    name = "hello",
    srcs = ["hello.cc"],
)
$ cat hello.cc 
#include <cstdio>

int main() {
  printf("Hello world!\n");
  return 0;
}

[hlopko]

Hi John, internal reviewer asked for tests, could you add some to src/test/shell/bazel/apple/bazel_objc_test.sh please?

[jmillikin-stripe]

Test added, to cpp_darwin_integration_test.sh -- this isn't Objective-C, it's just regular C++.

I'm some trouble running the test (with changes or at HEAD) because Bazel gets into an infinite loop and consumes all my disk. I'll keep trying.