Add tests for invariant problem in cost analysis

Reviewed By: mbouaziz

Differential Revision: D8024696

fbshipit-source-id: 5c1e5e5

infer/tests/codetoanalyze/c/performance/invariant.c

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+/* We get quadratic bound for this example but we should get linear bound */
+void do_k_times(int n) {
+  int k = n;
+  for (int i = 0; i < k; i++) {
+  }
+}

infer/tests/codetoanalyze/c/performance/issues.exp

@@ -36,3 +36,5 @@ codetoanalyze/c/performance/instantiate.c, do_m2_times, 1, EXPENSIVE_EXECUTION_T
 codetoanalyze/c/performance/instantiate.c, do_m2_times, 2, EXPENSIVE_EXECUTION_TIME_CALL, ERROR, [with estimated cost 3 + 10 * s$1 + 6 * s$1^2]
 codetoanalyze/c/performance/instantiate.c, do_n_times, 1, EXPENSIVE_EXECUTION_TIME_CALL, ERROR, [with estimated cost 3 + 6 * s$1]
 codetoanalyze/c/performance/instantiate.c, do_n_times, 2, EXPENSIVE_EXECUTION_TIME_CALL, ERROR, [with estimated cost 3 + 6 * s$1]
+codetoanalyze/c/performance/invariant.c, do_k_times, 2, EXPENSIVE_EXECUTION_TIME_CALL, ERROR, [with estimated cost 5 + 5 * s$1^2]
+codetoanalyze/c/performance/invariant.c, do_k_times, 2, EXPENSIVE_EXECUTION_TIME_CALL, ERROR, [with estimated cost 5 + 5 * s$1^2]