Commit Graph

7 Commits

Author SHA1 Message Date
Weverything 9740f9f0b6 Add -Wtautological-compare to -Wall
Some warnings in -Wtautological-compare subgroups are DefaultIgnore.
Adding this group to -Wmost, which is part of -Wall, will aid in their
discoverability.

Differential Revision: https://reviews.llvm.org/D69292
2019-11-12 14:36:57 -08:00
Richard Trieu 4c05de8c1d Merge and improve code that detects same value in comparisons.
-Wtautological-overlap-compare and self-comparison from -Wtautological-compare
relay on detecting the same operand in different locations.  Previously, each
warning had it's own operand checker.  Now, both are merged together into
one function that each can call.  The function also now looks through member
access and array accesses.

Differential Revision: https://reviews.llvm.org/D66045

llvm-svn: 372453
2019-09-21 03:02:26 +00:00
Richard Trieu 6541c7988b Improve -Wtautological-overlap-compare
Allow this warning to detect a larger number of constant values, including
negative numbers, and handle non-int types better.

Differential Revision: https://reviews.llvm.org/D66044

llvm-svn: 372448
2019-09-21 02:37:10 +00:00
Richard Trieu 6a6af52ba6 Extend -Wtautological-overlap-compare to more cases.
Previously, -Wtautological-overlap-compare did not warn on cases where the
boolean expression was in an assignment or return statement.  This patch
should cause all boolean statements to be passed to the tautological compare
checks in the CFG analysis.

This is one of the issues from PR13101

llvm-svn: 290920
2017-01-04 00:46:30 +00:00
George Burgess IV ced56e6eca Teach -Wtautological-overlap-compare about enums
Prior to this patch, -Wtautological-overlap-compare would only warn us
if there was a sketchy logical comparison between variables and
IntegerLiterals. This patch makes -Wtautological-overlap-compare aware
of EnumConstantDecls, so it can apply the same logic to them.

llvm-svn: 249053
2015-10-01 18:47:52 +00:00
Richard Trieu e9fa266cba Fix a bad interaction between -Wtautological-overlap-compare and delayed
diagnostics which caused delayed diagnostics on dead paths to be emitted.

llvm-svn: 206232
2014-04-15 00:57:50 +00:00
Richard Trieu f935b562b9 Add a new subgroup to -Wtautological-compare, -Wtautological-overlap-compare,
which warns on compound conditionals that always evaluate to the same value.
For instance, (x > 5 && x < 3) will always be false since no value for x can
satisfy both conditions.

This patch also changes the CFG to use these tautological values for better
branch analysis.  The test for -Wunreachable-code shows how this change catches
additional dead code.

Patch by Anders Rönnholm.

llvm-svn: 205665
2014-04-05 05:17:01 +00:00