selftests: do not macro-expand failed assertion expressions

I've stumbled over the current macro-expand behaviour of the test
harness:

$ gcc -Wall -xc - <<'__EOF__'
TEST(macro) {
int status = 0;
ASSERT_TRUE(WIFSIGNALED(status));
}
TEST_HARNESS_MAIN
__EOF__
$ ./a.out
[==========] Running 1 tests from 1 test cases.
[ RUN ] global.macro
<stdin>:4:global.macro:Expected 0 (0) != (((signed char) (((status) & 0x7f) + 1) >> 1) > 0) (0)
global.macro: Test terminated by assertion
[ FAIL ] global.macro
[==========] 0 / 1 tests passed.
[ FAILED ]

With this change the output of the same test looks much more
comprehensible:

[==========] Running 1 tests from 1 test cases.
[ RUN ] global.macro
<stdin>:4:global.macro:Expected 0 (0) != WIFSIGNALED(status) (0)
global.macro: Test terminated by assertion
[ FAIL ] global.macro
[==========] 0 / 1 tests passed.
[ FAILED ]

The issue is very similar to the bug fixed in glibc assert(3)
three years ago:
https://sourceware.org/bugzilla/show_bug.cgi?id=18604

Cc: Shuah Khan <[e-mail]>
Cc: Kees Cook <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Will Drewry <[e-mail]>
Cc: [e-mail]
Signed-off-by: Dmitry V. Levin <[e-mail]>
Acked-by: Kees Cook <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/kselftest_harness.h

···
  * ASSERT_EQ(expected, measured): expected == measured
  */
 #define ASSERT_EQ(expected, seen) \
-	__EXPECT(expected, seen, ==, 1)
+	__EXPECT(expected, #expected, seen, #seen, ==, 1)
 
 /**
  * ASSERT_NE(expected, seen)
···
  * ASSERT_NE(expected, measured): expected != measured
  */
 #define ASSERT_NE(expected, seen) \
-	__EXPECT(expected, seen, !=, 1)
+	__EXPECT(expected, #expected, seen, #seen, !=, 1)
 
 /**
  * ASSERT_LT(expected, seen)
···
  * ASSERT_LT(expected, measured): expected < measured
  */
 #define ASSERT_LT(expected, seen) \
-	__EXPECT(expected, seen, <, 1)
+	__EXPECT(expected, #expected, seen, #seen, <, 1)
 
 /**
  * ASSERT_LE(expected, seen)
···
  * ASSERT_LE(expected, measured): expected <= measured
  */
 #define ASSERT_LE(expected, seen) \
-	__EXPECT(expected, seen, <=, 1)
+	__EXPECT(expected, #expected, seen, #seen, <=, 1)
 
 /**
  * ASSERT_GT(expected, seen)
···
  * ASSERT_GT(expected, measured): expected > measured
  */
 #define ASSERT_GT(expected, seen) \
-	__EXPECT(expected, seen, >, 1)
+	__EXPECT(expected, #expected, seen, #seen, >, 1)
 
 /**
  * ASSERT_GE(expected, seen)
···
  * ASSERT_GE(expected, measured): expected >= measured
  */
 #define ASSERT_GE(expected, seen) \
-	__EXPECT(expected, seen, >=, 1)
+	__EXPECT(expected, #expected, seen, #seen, >=, 1)
 
 /**
  * ASSERT_NULL(seen)
···
  * ASSERT_NULL(measured): NULL == measured
  */
 #define ASSERT_NULL(seen) \
-	__EXPECT(NULL, seen, ==, 1)
+	__EXPECT(NULL, "NULL", seen, #seen, ==, 1)
 
 /**
  * ASSERT_TRUE(seen)
···
  * ASSERT_TRUE(measured): measured != 0
  */
 #define ASSERT_TRUE(seen) \
-	ASSERT_NE(0, seen)
+	__EXPECT(0, "0", seen, #seen, !=, 1)
 
 /**
  * ASSERT_FALSE(seen)
···
  * ASSERT_FALSE(measured): measured == 0
  */
 #define ASSERT_FALSE(seen) \
-	ASSERT_EQ(0, seen)
+	__EXPECT(0, "0", seen, #seen, ==, 1)
 
 /**
  * ASSERT_STREQ(expected, seen)
···
  * EXPECT_EQ(expected, measured): expected == measured
  */
 #define EXPECT_EQ(expected, seen) \
-	__EXPECT(expected, seen, ==, 0)
+	__EXPECT(expected, #expected, seen, #seen, ==, 0)
 
 /**
  * EXPECT_NE(expected, seen)
···
  * EXPECT_NE(expected, measured): expected != measured
  */
 #define EXPECT_NE(expected, seen) \
-	__EXPECT(expected, seen, !=, 0)
+	__EXPECT(expected, #expected, seen, #seen, !=, 0)
 
 /**
  * EXPECT_LT(expected, seen)
···
  * EXPECT_LT(expected, measured): expected < measured
  */
 #define EXPECT_LT(expected, seen) \
-	__EXPECT(expected, seen, <, 0)
+	__EXPECT(expected, #expected, seen, #seen, <, 0)
 
 /**
  * EXPECT_LE(expected, seen)
···
  * EXPECT_LE(expected, measured): expected <= measured
  */
 #define EXPECT_LE(expected, seen) \
-	__EXPECT(expected, seen, <=, 0)
+	__EXPECT(expected, #expected, seen, #seen, <=, 0)
 
 /**
  * EXPECT_GT(expected, seen)
···
  * EXPECT_GT(expected, measured): expected > measured
  */
 #define EXPECT_GT(expected, seen) \
-	__EXPECT(expected, seen, >, 0)
+	__EXPECT(expected, #expected, seen, #seen, >, 0)
 
 /**
  * EXPECT_GE(expected, seen)
···
  * EXPECT_GE(expected, measured): expected >= measured
  */
 #define EXPECT_GE(expected, seen) \
-	__EXPECT(expected, seen, >=, 0)
+	__EXPECT(expected, #expected, seen, #seen, >=, 0)
 
 /**
  * EXPECT_NULL(seen)
···
  * EXPECT_NULL(measured): NULL == measured
  */
 #define EXPECT_NULL(seen) \
-	__EXPECT(NULL, seen, ==, 0)
+	__EXPECT(NULL, "NULL", seen, #seen, ==, 0)
 
 /**
  * EXPECT_TRUE(seen)
···
  * EXPECT_TRUE(measured): 0 != measured
  */
 #define EXPECT_TRUE(seen) \
-	EXPECT_NE(0, seen)
+	__EXPECT(0, "0", seen, #seen, !=, 0)
 
 /**
  * EXPECT_FALSE(seen)
···
  * EXPECT_FALSE(measured): 0 == measured
  */
 #define EXPECT_FALSE(seen) \
-	EXPECT_EQ(0, seen)
+	__EXPECT(0, "0", seen, #seen, ==, 0)
 
 /**
  * EXPECT_STREQ(expected, seen)
···
 	if (_metadata->passed && _metadata->step < 255) \
 		_metadata->step++;
 
-#define __EXPECT(_expected, _seen, _t, _assert) do { \
+#define __EXPECT(_expected, _expected_str, _seen, _seen_str, _t, _assert) do { \
 	/* Avoid multiple evaluation of the cases */ \
 	__typeof__(_expected) __exp = (_expected); \
 	__typeof__(_seen) __seen = (_seen); \
···
 		unsigned long long __exp_print = (uintptr_t)__exp; \
 		unsigned long long __seen_print = (uintptr_t)__seen; \
 		__TH_LOG("Expected %s (%llu) %s %s (%llu)", \
-			 #_expected, __exp_print, #_t, \
-			 #_seen, __seen_print); \
+			 _expected_str, __exp_print, #_t, \
+			 _seen_str, __seen_print); \
 		_metadata->passed = 0; \
 		/* Ensure the optional handler is triggered */ \
 		_metadata->trigger = 1; \