Tweak dead stores checker to not emit a warning when initialization
a scalar variable with a scalar parameter. This is a
form of defensive programming. If the variable is unused,
it will be caused by -Wunused-variable.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98795 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/CheckDeadStores.cpp b/lib/Checker/CheckDeadStores.cpp
index 31f9390..d6ea187 100644
--- a/lib/Checker/CheckDeadStores.cpp
+++ b/lib/Checker/CheckDeadStores.cpp
@@ -220,16 +220,25 @@
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 (VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
+ // Special case: check for initialization from constant
+ // variables.
+ //
+ // e.g. extern const int MyConstant;
+ // int x = MyConstant;
+ //
if (VD->hasGlobalStorage() &&
- VD->getType().isConstQualified()) return;
+ VD->getType().isConstQualified())
+ return;
+ // Special case: check for initialization from scalar
+ // parameters. This is often a form of defensive
+ // programming. Non-scalars are still an error since
+ // because it more likely represents an actual algorithmic
+ // bug.
+ if (isa<ParmVarDecl>(VD) && VD->getType()->isScalarType())
+ return;
+ }
Report(V, DeadInit, V->getLocation(), E->getSourceRange());
}