[llvm-dev] Understanding a failure from ESan

[Duncan P. N. Exon Smith via llvm-dev]

Hi Derek,

It looks like you committed the efficiency sanitizer a couple of months ago (cool project, BTW).  A bot with the efficiency sanitizer recently failed on one of my commits:
  http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-debian-fast/builds/39357

It's not exactly clear to me what the error is reporting (full text below).  Is it saying I broke the efficiency sanitizer, or that I made clang less efficient?

In either case, this test might be too flakey to be on by default.  My recent commits have been NFC (supposedly... could be a bug), so I'm surprised this caused a failure.  But if you think I actually broke something I could use some help figuring out which side to investigate.

Thanks for the advice!
Duncan

FAIL: EfficiencySanitizer-x86_64 :: TestCases/workingset-samples.cpp (12230 of 29483)
******************** TEST 'EfficiencySanitizer-x86_64 :: TestCases/workingset-samples.cpp' FAILED ********************
Script:
--
/home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.obj/./bin/clang -fsanitize=efficiency-working-set -m64 -gline-tables-only -O0 /home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.src/projects/compiler-rt/test/esan/TestCases/workingset-samples.cpp -o /home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.obj/projects/compiler-rt/test/esan/X86_64Config/TestCases/Output/workingset-samples.cpp.tmp 2>&1
/home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.obj/projects/compiler-rt/test/esan/X86_64Config/TestCases/Output/workingset-samples.cpp.tmp 2>&1 | FileCheck /home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.src/projects/compiler-rt/test/esan/TestCases/workingset-samples.cpp
--
Exit Code: 1

Command Output (stderr):
--
/home/llvmbb/llvm-build-dir/llvm-clang-lld-x86_64-debian-fast/llvm.src/projects/compiler-rt/test/esan/TestCases/workingset-samples.cpp:25:17: error: expected string not found in input
 // CHECK-NEXT: =={{[0-9]+}}==# 0: {{[ 0-9]+}} {{KB|Bytes}} ({{[ 0-9]+}} cache lines)
                ^
<stdin>:4:1: note: scanning from here
==7087== Samples array #1 at period 80 ms
^
<stdin>:11:35: note: possible intended match here
==7087== EfficiencySanitizer: the total working set size: 32 MB (524289 cache lines)
                                  ^

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