Fix PR 2514: Do not flag dead initializations for variables initialized to a constant global variable.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64149 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CheckDeadStores.cpp b/lib/Analysis/CheckDeadStores.cpp
index d5e5f4c..504de3c 100644
--- a/lib/Analysis/CheckDeadStores.cpp
+++ b/lib/Analysis/CheckDeadStores.cpp
@@ -195,8 +195,21 @@
// If x is EVER assigned a new value later, don't issue
// a warning. This is because such initialization can be
// due to defensive programming.
- if (!E->isConstantInitializer(Ctx))
- Report(V, DeadInit, V->getLocation(), E->getSourceRange());
+ if (E->isConstantInitializer(Ctx))
+ return;
+
+ // Special case: check for initializations from constant
+ // variables.
+ //
+ // e.g. extern const int MyConstant;
+ // int x = MyConstant;
+ //
+ if (DeclRefExpr *DRE=dyn_cast<DeclRefExpr>(E->IgnoreParenCasts()))
+ if (VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
+ if (VD->hasGlobalStorage() &&
+ VD->getType().isConstQualified()) return;
+
+ Report(V, DeadInit, V->getLocation(), E->getSourceRange());
}
}
}