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Differential D49264

[SanitizerCoverage] Add associated metadata to 8-bit counters.
ClosedPublic

Authored by morehouse on Jul 12 2018, 12:31 PM.

Details

Reviewers
eugenis
Commits
rG45438161503f: [SanitizerCoverage] Add associated metadata to 8-bit counters.
rL336941: [SanitizerCoverage] Add associated metadata to 8-bit counters.
rCRT336941: [SanitizerCoverage] Add associated metadata to 8-bit counters.
Summary

This allows counters associated with unused functions to be
dead-stripped along with their functions. This approach is the same one
we used for PC tables.

Fixes an issue where LLD removes an unused PC table but leaves the 8-bit
counter.

Diff Detail

Event Timeline

morehouse created this revision.Jul 12 2018, 12:31 PM
Herald added a subscriber: hiraditya. · View Herald TranscriptJul 12 2018, 12:31 PM
Harbormaster completed remote builds in B20320: Diff 155252.Jul 12 2018, 12:31 PM
eugenis accepted this revision.Jul 12 2018, 1:21 PM
This revision is now accepted and ready to land.Jul 12 2018, 1:21 PM
Closed by commit rCRT336941: [SanitizerCoverage] Add associated metadata to 8-bit counters. (authored by morehouse). · Explain WhyJul 12 2018, 1:29 PM
This revision was automatically updated to reflect the committed changes.
Herald added a subscriber: Restricted Project. · View Herald TranscriptJul 12 2018, 1:29 PM

Revision Contents

PathSize
test/
fuzzer/
4 lines

Diff 155256

test/fuzzer/gc-sections.test

REQUIRES: linux, lld-available REQUIRES: linux, lld-available
No gc-sections: No gc-sections:
RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t
RUN: nm %t | grep UnusedFunctionShouldBeRemovedByLinker | count 1 RUN: nm %t | grep UnusedFunctionShouldBeRemovedByLinker | count 1
With gc-sections. Currently, we can't remove unused code. With gc-sections. Currently, we can't remove unused code except with LLD.
RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t -fuse-ld=lld -ffunction-sections -Wl,-gc-sections RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t -fuse-ld=lld -ffunction-sections -Wl,-gc-sections
RUN: nm %t | not grep UnusedFunctionShouldBeRemovedByLinker RUN: nm %t | not grep UnusedFunctionShouldBeRemovedByLinker
RUN: %run %t -runs=0 2>&1 | FileCheck %s
CHECK-NOT: ERROR: The size of coverage PC tables does not match
With gc sections, with trace-pc. Unused code is removed. With gc sections, with trace-pc. Unused code is removed.
RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t -fsanitize-coverage=0 -fsanitize-coverage=trace-pc -ffunction-sections -Wl,-gc-sections RUN: %cpp_compiler %S/GcSectionsTest.cpp -o %t -fsanitize-coverage=0 -fsanitize-coverage=trace-pc -ffunction-sections -Wl,-gc-sections
RUN: nm %t | not grep UnusedFunctionShouldBeRemovedByLinker RUN: nm %t | not grep UnusedFunctionShouldBeRemovedByLinker