selftests: improve reported failure locations

selftests: improve reported failure locations

This patch introduce a selftest::location struct to wrap up __FILE__
and __LINE__ information (and __FUNCTION__) throughout the selftests,
allowing location information to be passed around.

It updates the helper functions in pretty-print.c to pass through
the precise location of each test, so that if a failure occurs, the
correct line number is printed, rather than a line within a helper
function.

gcc/ChangeLog:
	* input.c (test_reading_source_line): Use SELFTEST_LOCATION.
	* pretty-print.c (assert_pp_format_va): Add location param and use
	it with ASSERT_STREQ_AT.
	(assert_pp_format): Add location param and pass it to
	assert_pp_format_va.
	(assert_pp_format_colored): Likewise.
	(ASSERT_PP_FORMAT_1): New.
	(ASSERT_PP_FORMAT_2): New.
	(ASSERT_PP_FORMAT_3): New.
	(test_pp_format): Provide SELFTEST_LOCATION throughout, either
	explicitly, or implicitly via the above macros.
	* selftest.c (selftest::pass): Use a selftest::location rather
	than file and line.
	(selftest::fail): Likewise.  Print the function name.
	(selftest::fail_formatted): Likewise.
	(selftest::assert_streq): Use a selftest::location rather than
	file and line.
	* selftest.h (selftest::location): New struct.
	(SELFTEST_LOCATION): New macro.
	(selftest::pass): Accept a const location & rather than file
	and line.
	(selftest::fail): Likewise.
	(selftest::fail_formatted): Likewise.
	(selftest::assert_streq): Likewise.
	(ASSERT_TRUE): Update for above changes, using SELFTEST_LOCATION.
	(ASSERT_FALSE): Likewise.
	(ASSERT_EQ): Likewise.
	(ASSERT_NE): Likewise.
	(ASSERT_STREQ): Likewise.
	(ASSERT_PRED1): Likewise.
	(ASSERT_STREQ_AT): New macro.

From-SVN: r237410