options: Add EnumBitSet property support [PR104158]

On Sat, Jan 22, 2022 at 01:47:08AM +0100, Jakub Jelinek via Gcc-patches wrote:
> I think with the 2) patch I achieve what we want for Fortran, for 1)
> the only behavior from gcc 11 is that
> -fsanitize-coverage=trace-cmp,trace-cmp is now rejected.
> This is mainly from the desire to disallow
> -fconvert=big-endian,little-endian or -Wbidi-chars=bidirectional,any
> etc. where it would be confusing to users what exactly it means.
> But it is the only from these options that actually acts as an Enum
> bit set, each enumerator can be specified with all the others.
> So one option would be stop requiring the EnumSet implies Set properties
> must be specified and just require that either they are specified on all
> EnumValues, or on none of them; the latter case would be for
> -fsanitize-coverage= and the non-Set case would mean that all the
> EnumValues need to have disjoint Value bitmasks and that they can
> be all specified and unlike the Set case also repeated.
> Thoughts on this?

Here is an incremental patch to the first two patches of the series
that implements EnumBitSet that fully restores the -fsanitize-coverage
GCC 11 behavior.

2022-01-24  Jakub Jelinek  <jakub@redhat.com>

	PR sanitizer/104158
	* opt-functions.awk (var_set): Handle EnumBitSet property.
	* optc-gen.awk: Don't disallow RejectNegative if EnumBitSet is
	specified.
	* opts.h (enum cl_enum_var_value): New type.
	* opts-common.cc (decode_cmdline_option): Use CLEV_* values.
	Handle CLEV_BITSET.
	(cmdline_handle_error): Handle CLEV_BITSET.
	* opts.cc (test_enum_sets): Also test EnumBitSet requirements.
	* doc/options.texi (EnumBitSet): Document.
	* common.opt (fsanitize-coverage=): Use EnumBitSet instead of
	EnumSet.
	(trace-pc, trace-cmp): Drop Set properties.

	* gcc.dg/sancov/pr104158-7.c: Adjust for repeating of arguments
	being allowed.

1 files changed, 8 insertions, 0 deletions

diff --git a/gcc/doc/options.texi b/gcc/doc/options.texi
index 9387c82..50674938 100644
--- a/gcc/doc/options.texi
+++ b/gcc/doc/options.texi
@@ -421,6 +421,14 @@ enumeration values with the same set bitwise ored together.
 Or option's argument can be a comma separated list of strings where
 each string is from a different @code{Set(@var{number})}.
 
+@item EnumBitSet
+Must be used together with the @code{Enum(@var{name})} property.
+Similar to @samp{EnumSet}, but corresponding @samp{Enum} record must
+not use @code{Set} properties, each @code{EnumValue} should have
+@code{Value} that is a power of 2, each value is treated as its own
+set and its value as the set's mask, so there are no mutually
+exclusive arguments.
+
 @item Defer
 The option should be stored in a vector, specified with @code{Var},
 for later processing.