From: Michal Bloch <m.bloch@samsung.com>
Date: Wed, 2 Feb 2022 17:55:53 +0000 (+0100)
Subject: Fix shadowing in recursive ASSERT macros
X-Git-Tag: submit/tizen_6.5/20220314.044848~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bd5c802e12e339748a64085357df66a9e6c25698;p=platform%2Fkernel%2Flinux-tizen-modules-source.git

Fix shadowing in recursive ASSERT macros

Change-Id: I509e0e481ba147fa5a29a0e1e83e6458dea41d5e
(cherry picked from commit b95197f00d92114cd8ff1e3e44321f9f26927e1f)
---

diff --git a/tests/kdbus/kdbus-test.h b/tests/kdbus/kdbus-test.h
index 6d3034d..41f854e 100644
--- a/tests/kdbus/kdbus-test.h
+++ b/tests/kdbus/kdbus-test.h
@@ -38,23 +38,33 @@ enum {
 #define PRINTF_ARG(...) (_Generic((__VA_ARGS__),\
 	default: (__VA_ARGS__)))
 
-#define _ASSERT_REL_(val0, val0s, relop, val1, val1s, onfailure) do {\
-	__auto_type const _ASSERT_RETURN_VAL_val0_ = (val0);\
-	__auto_type const _ASSERT_RETURN_VAL_val1_ = (val1);\
-	if (!(_ASSERT_RETURN_VAL_val0_ relop _ASSERT_RETURN_VAL_val1_)) {			\
+/* Uses a counter to ensure unique var names and prevent shadowing,
+ * for when the macro is used recursively (e.g. inside the `onfailure` block) */
+#define _ASSERT_REL_COUNTER_(counter, val0, val0s, relop, val1, val1s, onfailure) do {\
+	__auto_type const _ASSERT_RETURN_VAL_val0_##counter = (val0);\
+	__auto_type const _ASSERT_RETURN_VAL_val1_##counter = (val1);\
+	if (!(_ASSERT_RETURN_VAL_val0_##counter relop _ASSERT_RETURN_VAL_val1_##counter)) {\
 		/* must assemble format string in runtime because _Generic does not play well with string constant concatenation */\
 		char _ASSERT_REL_fmt_[sizeof("[tid %u] Assertion '(")+4+sizeof("=%s) %s (")+4+sizeof("=%s)' failed in %s(), %s:%d\n")];\
 		strncpy(_ASSERT_REL_fmt_, "[tid %u] Assertion '(", 22);\
-		strncat(_ASSERT_REL_fmt_, PRINTF_FMT(_ASSERT_RETURN_VAL_val0_), 4);\
+		strncat(_ASSERT_REL_fmt_, PRINTF_FMT(_ASSERT_RETURN_VAL_val0_##counter), 4);\
 		strncat(_ASSERT_REL_fmt_, "=%s) %s (", 9);\
-		strncat(_ASSERT_REL_fmt_, PRINTF_FMT(_ASSERT_RETURN_VAL_val1_), 4);\
+		strncat(_ASSERT_REL_fmt_, PRINTF_FMT(_ASSERT_RETURN_VAL_val1_##counter), 4);\
 		strncat(_ASSERT_REL_fmt_, "=%s)' failed in %s(), %s:%d\n", 29);\
-		print(_ASSERT_REL_fmt_, syscall(SYS_gettid), PRINTF_ARG(_ASSERT_RETURN_VAL_val0_), val0s, #relop, PRINTF_ARG(_ASSERT_RETURN_VAL_val1_), val1s, __func__, __FILE__, __LINE__);\
+		print(_ASSERT_REL_fmt_, syscall(SYS_gettid), PRINTF_ARG(_ASSERT_RETURN_VAL_val0_##counter), val0s, #relop, PRINTF_ARG(_ASSERT_RETURN_VAL_val1_##counter), val1s, __func__, __FILE__, __LINE__);\
 		onfailure;\
 	}\
 		else print_assert_success("Assertion '%s' SUCCEEDED in %s(), %s:%d\n", val0s " " #relop " " val1s, __func__, __FILE__, __LINE__);\
 } while (0)
 
+/* Looks like a no-op, but expands macros (so that `val##counter`
+ * in the macro above becomes `val123` instead of `val__COUNTER__`). */
+#define _ASSERT_REL_COUNTER_EXPAND_MACROS_(a,b,c,d,e,f,g) \
+	_ASSERT_REL_COUNTER_(a,b,c,d,e,f,g)
+
+#define _ASSERT_REL_(val0, val0s, relop, val1, val1s, onfailure) \
+	_ASSERT_REL_COUNTER_EXPAND_MACROS_(__COUNTER__, val0, val0s, relop, val1, val1s, onfailure)
+
 #define ASSERT_RETURN_VAL(val0, relop, val1, retval) _ASSERT_REL_(val0, #val0, relop, val1, #val1, return retval)
 #define ASSERT_EXIT_VAL(val0, relop, val1, retval)   _ASSERT_REL_(val0, #val0, relop, val1, #val1, exit(retval))