Analysis: Add a CFG successor to a SwitchStmt if it is both empty and fully covered

Consider the case where a SwitchStmt satisfied isAllEnumCasesCovered()
as well as having no cases at all (i.e. the enum it covers has no
enumerators).

In this case, we should add a successor to repair the CFG.

This fixes PR16212.

llvm-svn: 183237

1 files changed, 16 insertions, 0 deletions

diff --git a/clang/test/Analysis/cfg.cpp b/clang/test/Analysis/cfg.cpp
index 0587057d724..c2ec2e9bec2 100644
--- a/clang/test/Analysis/cfg.cpp
+++ b/clang/test/Analysis/cfg.cpp
@@ -66,3 +66,19 @@ void checkDeclStmts() {
 
   static_assert(1, "abc");
 }
+
+// CHECK: ENTRY
+// CHECK-NEXT: Succs (1): B1
+// CHECK: [B1]
+// CHECK-NEXT:   1: e
+// CHECK-NEXT:   2: [B1.1] (ImplicitCastExpr, LValueToRValue, enum EmptyE)
+// CHECK-NEXT:   3: [B1.2] (ImplicitCastExpr, IntegralCast, int)
+// CHECK-NEXT:   T: switch [B1.3]
+// CHECK-NEXT:   Preds (1): B2
+// CHECK-NEXT:   Succs (1): B0
+// CHECK: [B0 (EXIT)]
+// CHECK-NEXT:   Preds (1): B1
+enum EmptyE {};
+void F(EmptyE e) {
+  switch (e) {}
+}