Merge branch 'maint-0.2.9' into maint-0.3.3 (dff7d3d0) · Commits · Mike Perry / Tor

changes/bug27709

0 → 100644

+4 −0

Original line number	Diff line number	Diff line
		o Minor bugfixes (code safety):
		- Rewrite our assertion macros so that they no longer suppress
		the compiler's -Wparentheses warnings on their inputs. Fixes bug 27709;
		bugfix on 0.0.6.

src/common/util_bug.h

+44 −13

Original line number	Diff line number	Diff line
		@@ -55,6 +55,35 @@
		#error "Sorry; we don't support building with NDEBUG."
		#endif /* defined(NDEBUG) */

		#if defined(TOR_UNIT_TESTS) && defined(__GNUC__)
		/* We define this GCC macro as a replacement for PREDICT_UNLIKELY() in this
		* header, so that in our unit test builds, we'll get compiler warnings about
		* stuff like tor_assert(n = 5).
		*
		* The key here is that (e) is wrapped in exactly one layer of parentheses,
		* and then passed right to a conditional. If you do anything else to the
		* expression here, or introduce any more parentheses, the compiler won't
		* help you.
		*
		* We only do this for the unit-test build case because it interferes with
		* the likely-branch labeling. Note below that in the other case, we define
		* these macros to just be synonyms for PREDICT_(UN)LIKELY.
		*/
		#define ASSERT_PREDICT_UNLIKELY_(e) \
		({ \
		int tor__assert_tmp_value__; \
		if (e) \
		tor__assert_tmp_value__ = 1; \
		else \
		tor__assert_tmp_value__ = 0; \
		tor__assert_tmp_value__; \
		})
		#define ASSERT_PREDICT_LIKELY_(e) ASSERT_PREDICT_UNLIKELY_(e)
		#else
		#define ASSERT_PREDICT_UNLIKELY_(e) PREDICT_UNLIKELY(e)
		#define ASSERT_PREDICT_LIKELY_(e) PREDICT_LIKELY(e)
		#endif

		/* Sometimes we don't want to use assertions during branch coverage tests; it
		* leads to tons of unreached branches which in reality are only assertions we
		* didn't hit. */
		@@ -66,7 +95,8 @@
		/** Like assert(3), but send assertion failures to the log as well as to
		* stderr. */
		#define tor_assert(expr) STMT_BEGIN \
		if (PREDICT_UNLIKELY(!(expr))) { \
		if (ASSERT_PREDICT_LIKELY_(expr)) { \
		} else { \
		tor_assertion_failed_(SHORT_FILE__, __LINE__, __func__, #expr); \
		abort(); \
		} STMT_END
		@@ -106,7 +136,7 @@ extern int bug_macro_deadcode_dummy__;
		#define tor_assert_nonfatal_unreached_once() tor_assert(0)
		#define tor_assert_nonfatal_once(cond) tor_assert((cond))
		#define BUG(cond) \
		(PREDICT_UNLIKELY(cond) ? \
		(ASSERT_PREDICT_UNLIKELY_(cond) ? \
		(tor_assertion_failed_(SHORT_FILE__,__LINE__,__func__,"!("#cond")"), \
		abort(), 1) \
		: 0)
		@@ -115,13 +145,14 @@ extern int bug_macro_deadcode_dummy__;
		#define tor_assert_nonfatal(cond) ((void)(cond))
		#define tor_assert_nonfatal_unreached_once() STMT_NIL
		#define tor_assert_nonfatal_once(cond) ((void)(cond))
		#define BUG(cond) (PREDICT_UNLIKELY(cond) ? 1 : 0)
		#define BUG(cond) (ASSERT_PREDICT_UNLIKELY_(cond) ? 1 : 0)
		#else /* Normal case, !ALL_BUGS_ARE_FATAL, !DISABLE_ASSERTS_IN_UNIT_TESTS */
		#define tor_assert_nonfatal_unreached() STMT_BEGIN \
		tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, NULL, 0); \
		STMT_END
		#define tor_assert_nonfatal(cond) STMT_BEGIN \
		if (PREDICT_UNLIKELY(!(cond))) { \
		if (ASSERT_PREDICT_LIKELY_(cond)) { \
		} else { \
		tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, #cond, 0); \
		} \
		STMT_END
		@@ -134,13 +165,14 @@ extern int bug_macro_deadcode_dummy__;
		STMT_END
		#define tor_assert_nonfatal_once(cond) STMT_BEGIN \
		static int warning_logged__ = 0; \
		if (!warning_logged__ && PREDICT_UNLIKELY(!(cond))) { \
		if (ASSERT_PREDICT_LIKELY_(cond)) { \
		} else if (!warning_logged__) { \
		warning_logged__ = 1; \
		tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, #cond, 1); \
		} \
		STMT_END
		#define BUG(cond) \
		(PREDICT_UNLIKELY(cond) ? \
		(ASSERT_PREDICT_UNLIKELY_(cond) ? \
		(tor_bug_occurred_(SHORT_FILE__,__LINE__,__func__,"!("#cond")",0), 1) \
		: 0)
		#endif /* defined(ALL_BUGS_ARE_FATAL) \|\| ... */
		@@ -149,17 +181,17 @@ extern int bug_macro_deadcode_dummy__;
		#define IF_BUG_ONCE__(cond,var) \
		if (( { \
		static int var = 0; \
		int bool_result = (cond); \
		if (PREDICT_UNLIKELY(bool_result) && !var) { \
		int bool_result = !!(cond); \
		if (bool_result && !var) { \
		var = 1; \
		tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, \
		"!("#cond")", 1); \
		} \
		PREDICT_UNLIKELY(bool_result); } ))
		bool_result; } ))
		#else /* !(defined(__GNUC__)) */
		#define IF_BUG_ONCE__(cond,var) \
		static int var = 0; \
		if (PREDICT_UNLIKELY(cond) ? \
		if ((cond) ? \
		(var ? 1 : \
		(var=1, \
		tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, \
		@@ -177,7 +209,7 @@ extern int bug_macro_deadcode_dummy__;
		*/

		#define IF_BUG_ONCE(cond) \
		IF_BUG_ONCE__((cond), \
		IF_BUG_ONCE__(ASSERT_PREDICT_UNLIKELY_(cond), \
		IF_BUG_ONCE_VARNAME__(__LINE__))

		/** Define this if you want Tor to crash when any problem comes up,
		@@ -199,4 +231,3 @@ void tor_set_failed_assertion_callback(void (*fn)(void));
		#endif /* defined(TOR_UNIT_TESTS) */

		#endif /* !defined(TOR_UTIL_BUG_H) */