[analyzer] Avoid unnecessary enum range check on LValueToRValue casts
Summary: EnumCastOutOfRangeChecker should not perform enum range checks on LValueToRValue casts, since this type of cast does not actually change the underlying type. Performing the unnecessary check actually triggered an assertion failure deeper in EnumCastOutOfRange for certain input (which is captured in the accompanying test code).
Reviewers: #clang, Szelethus, gamesh411, NoQ
Reviewed By: Szelethus, gamesh411, NoQ
Subscribers: NoQ, gamesh411, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy, dkrupp, Charusso, bjope, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66014
llvm-svn: 369760
diff --git a/clang/test/Analysis/enum-cast-out-of-range.cpp b/clang/test/Analysis/enum-cast-out-of-range.cpp
index e77339b..b600367 100644
--- a/clang/test/Analysis/enum-cast-out-of-range.cpp
+++ b/clang/test/Analysis/enum-cast-out-of-range.cpp
@@ -150,7 +150,15 @@
scoped_specified_t InvalidAfterRangeEnd = (scoped_specified_t)(5); // expected-warning {{The value provided to the cast expression is not in the valid range of values for the enum}}
}
-void rangeContstrained1(int input) {
+unscoped_unspecified_t unused;
+void unusedExpr() {
+ // following line is not something that EnumCastOutOfRangeChecker should evaluate. checker should either ignore this line
+ // or process it without producing any warnings. However, compilation will (and should) still generate a warning having
+ // nothing to do with this checker.
+ unused; // expected-warning {{expression result unused}}
+}
+
+void rangeConstrained1(int input) {
if (input > -5 && input < 5)
auto value = static_cast<scoped_specified_t>(input); // OK. Being conservative, this is a possibly good value.
}