* For `-###`, `-o %t.o` is unnecessary if we don't specifically test the
output filename.
* --target= is the canonical spelling. -target is a legacy spelling which
unfortunately cannot be removed because there are too many uses.
* -no-canonical-prefixes uses the dereferenced absolute path for the cc1
command. For most tests "-cc1" is sufficient to identify the command line, no
need to specifically test the "clang" command, and -no-canonical-prefixes can
removed.
* --unwindlib= is the preferred spelling. -u is a short option taking a value,
which means a -uwindlib= typo cannot be detected.
I recommend that you take a look at linux-cross.cpp. Testing include paths and
library paths in one RUN line is sometimes more readable than having separate
include/library tests.
Having separate RUN lines for misc features like -fdata-sections
(`aix-data-sections.c`) is wasteful. It may be better testing multiple
options in a single RUN command.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D119309
Clang diagnostics should not start with a capital letter or use
trailing punctuation (https://clang.llvm.org/docs/InternalsManual.html#the-format-string),
but quite a few driver diagnostics were not following this advice. This
corrects the grammar and punctuation to improve consistency, but does
not change the circumstances under which the diagnostics are produced.
Fangrui Song