Bug 1283395 - add markup functions for static analysis builds. r=froydnj

MozReview-Commit-ID: 1F5GGpQtq4x

mfbt/Assertions.h

@@ -17,6 +17,7 @@
 #include "mozilla/Compiler.h"
 #include "mozilla/Likely.h"
 #include "mozilla/MacroArgs.h"
+#include "mozilla/StaticAnalysisFunctions.h"
 #ifdef MOZ_DUMP_ASSERTION_STACK
 #include "nsTraceRefcnt.h"
 #endif
@@ -368,7 +369,7 @@ struct AssertionConditionType
 #define MOZ_ASSERT_HELPER1(expr) \
   do { \
     MOZ_VALIDATE_ASSERT_CONDITION_TYPE(expr); \
-    if (MOZ_UNLIKELY(!(expr))) { \
+    if (MOZ_UNLIKELY(!MOZ_CHECK_ASSERT_ASSIGNMENT(expr))) { \
       MOZ_ReportAssertionFailure(#expr, __FILE__, __LINE__); \
       MOZ_CRASH_ANNOTATE("MOZ_RELEASE_ASSERT(" #expr ")"); \
       MOZ_REALLY_CRASH(); \
@@ -378,7 +379,7 @@ struct AssertionConditionType
 #define MOZ_ASSERT_HELPER2(expr, explain) \
   do { \
     MOZ_VALIDATE_ASSERT_CONDITION_TYPE(expr); \
-    if (MOZ_UNLIKELY(!(expr))) { \
+    if (MOZ_UNLIKELY(!MOZ_CHECK_ASSERT_ASSIGNMENT(expr))) { \
       MOZ_ReportAssertionFailure(#expr " (" explain ")", __FILE__, __LINE__); \
       MOZ_CRASH_ANNOTATE("MOZ_RELEASE_ASSERT(" #expr ") (" explain ")"); \
       MOZ_REALLY_CRASH(); \

mfbt/StaticAnalysisFunctions.h

@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_StaticAnalysisFunctions_h
+#define mozilla_StaticAnalysisFunctions_h
+
+#include <stdbool.h>
+
+/*
+ * Functions that are used as markers in Gecko code for static analysis. Their
+ * purpose is to have different AST nodes generated during compile time and to
+ * match them based on different checkers implemented in build/clang-plugin
+ */
+
+#ifdef MOZ_CLANG_PLUGIN
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * MOZ_AssertAssignmentTest - used in MOZ_ASSERT in order to test the possible
+ * presence of assignment instead of logical comparisons.
+ *
+ * Example:
+ * MOZ_ASSERT(retVal = true);
+ */
+static MOZ_ALWAYS_INLINE bool MOZ_AssertAssignmentTest(bool exprResult) {
+  return exprResult;
+}
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#define MOZ_CHECK_ASSERT_ASSIGNMENT(expr) MOZ_AssertAssignmentTest(!!(expr))
+
+#else
+
+#define MOZ_CHECK_ASSERT_ASSIGNMENT(expr) (!!(expr))
+
+#endif /* MOZ_CLANG_PLUGIN */
+#endif /* StaticAnalysisFunctions_h */

mfbt/moz.build

@@ -84,6 +84,7 @@ EXPORTS.mozilla = [
     'SizePrintfMacros.h',
     'Snprintf.h',
     'SplayTree.h',
+    'StaticAnalysisFunctions.h',
     'TaggedAnonymousMemory.h',
     'TemplateLib.h',
     'ThreadLocal.h',