We really ought to support no_sanitize("coverage") in line with other
sanitizers. This came up again in discussions on the Linux-kernel
mailing lists, because we currently do workarounds using objtool to
remove coverage instrumentation. Since that support is only on x86, to
continue support coverage instrumentation on other architectures, we
must support selectively disabling coverage instrumentation via function
attributes.
Unfortunately, for SanitizeCoverage, it has not been implemented as a
sanitizer via fsanitize= and associated options in Sanitizers.def, but
rolls its own option fsanitize-coverage. This meant that we never got
"automatic" no_sanitize attribute support.
Implement no_sanitize attribute support by special-casing the string
"coverage" in the NoSanitizeAttr implementation. To keep the feature as
unintrusive to existing IR generation as possible, define a new negative
function attribute NoSanitizeCoverage to propagate the information
through to the instrumentation pass.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=49035
Reviewed By: vitalybuka, morehouse
Differential Revision: https://reviews.llvm.org/D102772
This change removes the XFAIL from the original test and duplicates the test into sanitize-coverage-old-pm.c
which uses the old pass manager and has the corresponding XFAIL.
This should fix the XPASS from this and similar runs:
http://lab.llvm.org:8011/#/builders/60/builds/1875
Summary:
Versions of LLVM built on {arm,thumb}v7 appear to have differently
configured pass managers, which causes restrictions on which sanitizers
we may use.
As such, expect failure of the recently added "sanitize-coverage.c" test
on these architectures until we can investigate armv7's restrictions.
Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=46117
Reviewers: vitalybuka, glider
Reviewed By: glider
Subscribers: glider, kristof.beyls, danielkiss, cfe-commits, vvereschaka
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80668
Marco Elver