Make $(location) work for top-level executables

[jmmv]

Consider the following workspace:

cat >WORKSPACE <<EOF
workspace(name = 'test')
EOF

cat >BUILD <<EOF
genrule(
    name = 'the_test',
    cmd = "$(location :hello.sh) >$@",
    outs = ['test_output'],
    tools = [":hello.sh"],
)
EOF

cat >hello.sh <<EOF
#! /bin/sh
echo Hello
EOF
chmod +x hello.sh

Given the above, the_test is unbuildable because the execution of hello.sh fails. The problem is that $(location :hello.sh) expands to simply hello.sh which cannot be resolved given a sane PATH (where a "sane path" means a set of directories that does not include the current directory for security reasons; see #958).

A possible fix would be to prefix all relative paths emitted by $(location) with ./. A worse fix (because it wouldn't be consistent in all cases) would be to do so only for outputs composed of a single path component. I don't know what the implications of doing any of these two would be.

[bsilver8192]

Sounds like a duplicate of #347.

[jmmv]

Indeed. Closing as such. I forgot to search for duplicates before filing this particular report.