Avoid undefined behaviour if somehow NUM_GRAPHS equals 2^32 (or
whatever the size of unsigned is), though this can't actually
occur for any integer value of NUM_NODES.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ADT/SCCIteratorTest.cpp b/unittests/ADT/SCCIteratorTest.cpp
index c3ffce5..00fa066 100644
--- a/unittests/ADT/SCCIteratorTest.cpp
+++ b/unittests/ADT/SCCIteratorTest.cpp
@@ -249,14 +249,12 @@
// create graphs for which every node has a self-edge.
#define NUM_NODES 4
#define NUM_GRAPHS (NUM_NODES * (NUM_NODES - 1))
+ typedef Graph<NUM_NODES> GT;
- /// GraphDescriptor - Enumerate all graphs using NUM_GRAPHS bits.
- unsigned GraphDescriptor = 0;
- assert(NUM_GRAPHS <= sizeof(unsigned) * CHAR_BIT && "Too many graphs!");
-
- do {
- typedef Graph<NUM_NODES> GT;
-
+ /// Enumerate all graphs using NUM_GRAPHS bits.
+ assert(NUM_GRAPHS < sizeof(unsigned) * CHAR_BIT && "Too many graphs!");
+ for (unsigned GraphDescriptor = 0; GraphDescriptor < (1U << NUM_GRAPHS);
+ ++GraphDescriptor) {
GT G;
// Add edges as specified by the descriptor.
@@ -342,9 +340,7 @@
// Finally, check that the nodes in some SCC are exactly those that are
// reachable from the initial node.
EXPECT_EQ(NodesInSomeSCC, G.NodesReachableFrom(0));
-
- ++GraphDescriptor;
- } while (GraphDescriptor && GraphDescriptor < (1U << NUM_GRAPHS));
+ }
}
}