Commit Graph

4 Commits

Author SHA1 Message Date
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