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.

8 files changed, 81 insertions, 22 deletions

diff --git a/gcc/common.opt b/gcc/common.opt
index 985e6ab6f81..d9233279a16 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1072,17 +1072,17 @@ Common Driver Joined
 Select what to sanitize.
 
 fsanitize-coverage=
-Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumSet
+Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
 Select type of coverage sanitization.
 
 Enum
 Name(sanitize_coverage) Type(int)
 
 EnumValue
-Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC) Set(1)
+Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
 
 EnumValue
-Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP) Set(2)
+Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
 
 fasan-shadow-offset=
 Common Joined RejectNegative Var(common_deferred_options) Defer
diff --git a/gcc/doc/options.texi b/gcc/doc/options.texi
index 9387c82cd3d..50674938e3d 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.
diff --git a/gcc/opt-functions.awk b/gcc/opt-functions.awk
index b2b11bee25e..5b0bc6634f5 100644
--- a/gcc/opt-functions.awk
+++ b/gcc/opt-functions.awk
@@ -298,9 +298,11 @@ function var_set(flags)
 	if (flag_set_p("Enum.*", flags)) {
 		en = opt_args("Enum", flags);
 		if (flag_set_p("EnumSet", flags))
-			return enum_index[en] ", CLVC_ENUM, 1"
+			return enum_index[en] ", CLVC_ENUM, CLEV_SET"
+		else if (flag_set_p("EnumBitSet", flags))
+			return enum_index[en] ", CLVC_ENUM, CLEV_BITSET"
 		else
-			return enum_index[en] ", CLVC_ENUM, 0"
+			return enum_index[en] ", CLVC_ENUM, CLEV_NORMAL"
 	}
 	if (var_type(flags) == "const char *")
 		return "0, CLVC_STRING, 0"
diff --git a/gcc/optc-gen.awk b/gcc/optc-gen.awk
index d7c8e2b80a7..5f7946cf49b 100644
--- a/gcc/optc-gen.awk
+++ b/gcc/optc-gen.awk
@@ -349,6 +349,7 @@ for (i = 0; i < n_opts; i++) {
 		if (flag_set_p("Enum.*", flags[i])) {
 			if (!flag_set_p("RejectNegative", flags[i]) \
 			    && !flag_set_p("EnumSet", flags[i]) \
+			    && !flag_set_p("EnumBitSet", flags[i]) \
 			    && opts[i] ~ "^[Wfgm]")
 				print "#error Enum allowing negative form"
 		}
diff --git a/gcc/opts-common.cc b/gcc/opts-common.cc
index fb5d953968c..1663be1f602 100644
--- a/gcc/opts-common.cc
+++ b/gcc/opts-common.cc
@@ -811,8 +811,8 @@ decode_cmdline_option (const char *const *argv, unsigned int lang_mask,
     {
       const struct cl_enum *e = &cl_enums[option->var_enum];
 
-      gcc_assert (option->var_value || value == 1);
-      if (option->var_value)
+      gcc_assert (option->var_value != CLEV_NORMAL || value == 1);
+      if (option->var_value != CLEV_NORMAL)
 	{
 	  const char *p = arg;
 	  HOST_WIDE_INT sum_value = 0;
@@ -834,19 +834,30 @@ decode_cmdline_option (const char *const *argv, unsigned int lang_mask,
 		  break;
 		}
 
-	      unsigned set = e->values[idx].flags >> CL_ENUM_SET_SHIFT;
-	      gcc_checking_assert (set >= 1 && set <= HOST_BITS_PER_WIDE_INT);
-	      if ((used_sets & (HOST_WIDE_INT_1U << (set - 1))) != 0)
+	      HOST_WIDE_INT this_mask = 0;
+	      if (option->var_value == CLEV_SET)
 		{
-		  errors |= CL_ERR_ENUM_SET_ARG;
-		  break;
+		  unsigned set = e->values[idx].flags >> CL_ENUM_SET_SHIFT;
+		  gcc_checking_assert (set >= 1
+				       && set <= HOST_BITS_PER_WIDE_INT);
+		  if ((used_sets & (HOST_WIDE_INT_1U << (set - 1))) != 0)
+		    {
+		      errors |= CL_ERR_ENUM_SET_ARG;
+		      break;
+		    }
+		  used_sets |= HOST_WIDE_INT_1U << (set - 1);
+
+		  for (int i = 0; e->values[i].arg != NULL; i++)
+		    if (set == (e->values[i].flags >> CL_ENUM_SET_SHIFT))
+		      this_mask |= e->values[i].value;
+		}
+	      else
+		{
+		  gcc_assert (option->var_value == CLEV_BITSET
+			      && ((e->values[idx].flags >> CL_ENUM_SET_SHIFT)
+				  == 0));
+		  this_mask = this_value;
 		}
-	      used_sets |= HOST_WIDE_INT_1U << (set - 1);
-
-	      HOST_WIDE_INT this_mask = 0;
-	      for (int i = 0; e->values[i].arg != NULL; i++)
-		if (set == (e->values[i].flags >> CL_ENUM_SET_SHIFT))
-		  this_mask |= e->values[i].value;
 
 	      sum_value |= this_value;
 	      mask |= this_mask;
@@ -1430,6 +1441,14 @@ cmdline_handle_error (location_t loc, const struct cl_option *option,
 	      break;
 	    }
 
+	  if (option->var_value == CLEV_BITSET)
+	    {
+	      if (q == NULL)
+		break;
+	      p = q + 1;
+	      continue;
+	    }
+
 	  unsigned set = e->values[idx].flags >> CL_ENUM_SET_SHIFT;
 	  gcc_checking_assert (set >= 1 && set <= HOST_BITS_PER_WIDE_INT);
 	  if ((used_sets & (HOST_WIDE_INT_1U << (set - 1))) != 0)
diff --git a/gcc/opts.cc b/gcc/opts.cc
index fb906fa0aea..f21c821ab2e 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -3705,13 +3705,14 @@ test_get_option_html_page ()
 #endif
 }
 
-/* Verify EnumSet requirements.  */
+/* Verify EnumSet and EnumBitSet requirements.  */
 
 static void
 test_enum_sets ()
 {
   for (unsigned i = 0; i < cl_options_count; ++i)
-    if (cl_options[i].var_type == CLVC_ENUM && cl_options[i].var_value)
+    if (cl_options[i].var_type == CLVC_ENUM
+	&& cl_options[i].var_value != CLEV_NORMAL)
       {
 	const struct cl_enum *e = &cl_enums[cl_options[i].var_enum];
 	unsigned HOST_WIDE_INT used_sets = 0;
@@ -3720,12 +3721,22 @@ test_enum_sets ()
 	for (unsigned j = 0; e->values[j].arg; ++j)
 	  {
 	    unsigned set = e->values[j].flags >> CL_ENUM_SET_SHIFT;
+	    if (cl_options[i].var_value == CLEV_BITSET)
+	      {
+		/* For EnumBitSet Set shouldn't be used and Value should
+		   be a power of two.  */
+		ASSERT_TRUE (set == 0);
+		ASSERT_TRUE (pow2p_hwi (e->values[j].value));
+		continue;
+	      }
 	    /* Test that enumerators referenced in EnumSet have all
 	       Set(n) on them within the valid range.  */
 	    ASSERT_TRUE (set >= 1 && set <= HOST_BITS_PER_WIDE_INT);
 	    highest_set = MAX (set, highest_set);
 	    used_sets |= HOST_WIDE_INT_1U << (set - 1);
 	  }
+	if (cl_options[i].var_value == CLEV_BITSET)
+	  continue;
 	/* If there is just one set, no point to using EnumSet.  */
 	ASSERT_TRUE (highest_set >= 2);
 	/* Test that there are no gaps in between the sets.  */
diff --git a/gcc/opts.h b/gcc/opts.h
index 88fabf9fddc..a43ce66cffe 100644
--- a/gcc/opts.h
+++ b/gcc/opts.h
@@ -52,6 +52,18 @@ enum cl_var_type {
   CLVC_DEFER
 };
 
+/* Values for var_value member of CLVC_ENUM.  */
+enum cl_enum_var_value {
+  /* Enum without EnumSet or EnumBitSet.  */
+  CLEV_NORMAL,
+
+  /* EnumSet.  */
+  CLEV_SET,
+
+  /* EnumBitSet.  */
+  CLEV_BITSET
+};
+
 struct cl_option
 {
   /* Text of the option, including initial '-'.  */
diff --git a/gcc/testsuite/gcc.dg/sancov/pr104158-7.c b/gcc/testsuite/gcc.dg/sancov/pr104158-7.c
index aacd23e9512..7fc5b73403a 100644
--- a/gcc/testsuite/gcc.dg/sancov/pr104158-7.c
+++ b/gcc/testsuite/gcc.dg/sancov/pr104158-7.c
@@ -1,5 +1,11 @@
 /* PR sanitizer/104158 */
 /* { dg-do compile } */
 /* { dg-options "-fsanitize-coverage=trace-cmp,trace-cmp -fdump-tree-optimized" } */
-/* { dg-error "invalid argument in option '-fsanitize-coverage=trace-cmp,trace-cmp'" "" { target *-*-* } 0 } */
-/* { dg-message "'trace-cmp' specified multiple times in the same option" "" { target *-*-* } 0 } */
+/* { dg-final { scan-tree-dump "__sanitizer_cov_trace_cmp" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "__sanitizer_cov_trace_pc" "optimized" } } */
+
+int
+foo (int a, int b)
+{
+  return a == b;
+}