[
https://issues.apache.org/jira/browse/IMPALA-5031?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16772489#comment-16772489
]
ASF subversion and git services commented on IMPALA-5031:
---------------------------------------------------------
Commit 7bb5b03703538e88d83a413b9dc838e1eed7250a in impala's branch
refs/heads/master from Jim Apple
[ https://gitbox.apache.org/repos/asf?p=impala.git;h=7bb5b03 ]
IMPALA-5031: oversized signed shifts are undefined
Standard section [expr.shift] says that E1 << E2 is undefined if E1 is
of signed type and the result cannot be represented in the
corresponding unsigned type. We can't simply change 1 << bit_width to
1u << bit_width, though, becuase it is the second argument of the
modulo operator, and following [expr.mul], "If the second operand of /
or % is zero the behavior is undefined."
This expression is tripped in RleTest.ValueSkippingFuzzy, with the
following backtrace:
util/rle-test.cc:304:29: runtime error: shift exponent 32 is too large
for 32-bit type 'int'
#0 RleTest::MakeRandomSequence(unsigned int, int, int, int)::
{lambda(int)#1}::operator()(int) const util/rle-test.cc:304:29
#1 RleTest::MakeRandomSequence(unsigned int, int, int, int)
util/rle-test.cc:315:15
#2 RleTest_ValueSkippingFuzzy_Test::TestBody()
util/rle-test.cc:392:25
Change-Id: I7debbd1ca5bd3ae640701ce0e95a12c5059abfd7
Reviewed-on: http://gerrit.cloudera.org:8080/12514
Reviewed-by: Tim Armstrong <[email protected]>
Tested-by: Impala Public Jenkins <[email protected]>
> UBSAN clean and method for testing UBSAN cleanliness
> ----------------------------------------------------
>
> Key: IMPALA-5031
> URL: https://issues.apache.org/jira/browse/IMPALA-5031
> Project: IMPALA
> Issue Type: Task
> Components: Backend, Infrastructure
> Affects Versions: Impala 2.9.0
> Reporter: Jim Apple
> Assignee: Jim Apple
> Priority: Minor
>
> http://releases.llvm.org/3.8.0/tools/clang/docs/UndefinedBehaviorSanitizer.html
> builds are supported after https://gerrit.cloudera.org/#/c/6186/, but
> Impala's test suite triggers many errors under UBSAN. Those errors should be
> fixed and then there should be a way to run the test suite under UBSAN and
> fail if there were any errors detected.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
