From c7d6d904f7bbaa3d7bc83e59931bfb70286a2052 Mon Sep 17 00:00:00 2001
From: Andrzej Kotulski <akotulski@fb.com>
Date: Mon, 27 Jun 2016 10:41:33 -0700
Subject: [PATCH] Whitelist std::min and std::max

Summary: Those functions have simple enough implementations for infer to understand them

Reviewed By: jvillard

Differential Revision: D3463084

fbshipit-source-id: f84160f
---
 infer/src/backend/config.ml                   |  4 ++
 .../cpp/errors/numeric/min_max.cpp            | 50 ++++++++++++++
 .../tests/endtoend/cpp/MinMaxNumericTest.java | 66 +++++++++++++++++++
 3 files changed, 120 insertions(+)
 create mode 100644 infer/tests/codetoanalyze/cpp/errors/numeric/min_max.cpp
 create mode 100644 infer/tests/endtoend/cpp/MinMaxNumericTest.java

diff --git a/infer/src/backend/config.ml b/infer/src/backend/config.ml
index c706ee7fd..6e93ba193 100644
--- a/infer/src/backend/config.ml
+++ b/infer/src/backend/config.ml
@@ -54,6 +54,10 @@ type zip_library = {
 
 let whitelisted_cpp_methods = [
   ["std"; "move"];
+  ["std"; "forward"];
+  ["std"; "min"];
+  ["std"; "max"];
+  ["std"; "__less"];
   ["google"; "CheckNotNull"];
   ["google"; "GetReferenceableValue"];
   ["google"; "Check_NEImpl"];
diff --git a/infer/tests/codetoanalyze/cpp/errors/numeric/min_max.cpp b/infer/tests/codetoanalyze/cpp/errors/numeric/min_max.cpp
new file mode 100644
index 000000000..6f757cb50
--- /dev/null
+++ b/infer/tests/codetoanalyze/cpp/errors/numeric/min_max.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016 - 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.
+ */
+
+#include <algorithm>
+
+struct X {
+  X(int f) : f(f) {}
+  int f;
+};
+bool operator<(const X& x1, const X& x2) { return x1.f < x2.f; }
+
+struct X_inv {
+  X_inv(int f) : f(f) {}
+  int f;
+};
+bool operator<(const X_inv& x1, const X_inv& x2) { return x1.f > x2.f; }
+
+int min_int_div0() { return 1 / std::min(1, 0); }
+
+int min_int_div_1() { return 1 / std::min(-1, 0); }
+
+int max_int_div1() { return 1 / std::max(1, 0); }
+
+int max_int_div0() { return 1 / std::max(0, -1); }
+
+int min_X_div0() {
+  X x0(0), x1(1);
+  return 1 / std::min(x0, x1).f;
+}
+
+int max_X_div1() {
+  X x0(0), x1(1);
+  return 1 / std::max(x0, x1).f;
+}
+
+int min_X_inv_div1() {
+  X_inv x0(0), x1(1);
+  return 1 / std::min(x0, x1).f;
+}
+
+int max_X_inv_div0() {
+  X_inv x0(0), x1(1);
+  return 1 / std::max(x0, x1).f;
+}
diff --git a/infer/tests/endtoend/cpp/MinMaxNumericTest.java b/infer/tests/endtoend/cpp/MinMaxNumericTest.java
new file mode 100644
index 000000000..31129a98a
--- /dev/null
+++ b/infer/tests/endtoend/cpp/MinMaxNumericTest.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2016 - 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.
+ */
+
+package endtoend.cpp;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static utils.matchers.ResultContainsExactly.containsExactly;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import utils.DebuggableTemporaryFolder;
+import utils.InferException;
+import utils.InferResults;
+import utils.InferRunner;
+
+public class MinMaxNumericTest {
+
+  public static final String FILE =
+      "infer/tests/codetoanalyze/cpp/errors/numeric/min_max.cpp";
+
+  private static ImmutableList<String> inferCmd;
+
+  public static final String DIVIDE_BY_ZERO = "DIVIDE_BY_ZERO";
+
+  @ClassRule
+  public static DebuggableTemporaryFolder folder =
+      new DebuggableTemporaryFolder();
+
+  @BeforeClass
+  public static void runInfer() throws InterruptedException, IOException {
+    inferCmd = InferRunner.createCPPInferCommand(folder, FILE);
+  }
+
+  @Test
+  public void whenInferRunsOnDiv0MethodsErrorIsFound()
+      throws InterruptedException, IOException, InferException {
+    InferResults inferResults = InferRunner.runInferCPP(inferCmd);
+    String[] procedures = {
+        "min_int_div0",
+        "max_int_div0",
+        "min_X_div0",
+        "max_X_inv_div0",
+    };
+    assertThat(
+        "Results should contain the expected divide by zero",
+        inferResults,
+        containsExactly(
+            DIVIDE_BY_ZERO,
+            FILE,
+            procedures
+        )
+    );
+  }
+}