[PATCH, i386] Spellcheck hints for the i386 backend option handling (PR middle-end/77475)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

While most of the i386.opt -m....= options have enum args and thus
cmdline_handle_error handles those, -march=/-mtune=/-m*-strategy= (and also
-mrecip=) don't use that, with the CPU strings being maintained inside of a
function rather than in some *.def file that could be also sourced into the
*.opt or something (and similarly for the strategies).

This patch adds inform calls that handle those similarly to what
cmdline_handle_error does for the options with enum values.
In addition, it adds %qs instead of %s in a couple of spaces, and
stops reporting incorrect attribute option("march=...") when it is
target("march=...") etc.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-09-05  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/77475
	* config/i386/i386.c: Include spellcheck.h.
	(ix86_parse_stringop_strategy_string): Simplify, use %qs instead of %s
	where desirable, use argument instead of arg in the diagnostic
	wording, add list of supported strategies and spellcheck hint.
	(ix86_option_override_internal): Emit target("m...") instead of
	option("m...") in the diagnostic.  Use %qs instead of %s in invalid
	-march/-mtune option diagnostic.  Add list of supported arches/tunings
	and spellcheck hint.

	* gcc.target/i386/pr65990.c: Adjust expected diagnostics.

--- gcc/config/i386/i386.c.jj	2016-09-05 12:41:03.000000000 +0200
+++ gcc/config/i386/i386.c	2016-09-05 16:44:45.184981211 +0200
@@ -76,6 +76,7 @@ along with GCC; see the file COPYING3.
 #include "case-cfn-macros.h"
 #include "regrename.h"
 #include "dojump.h"
+#include "spellcheck.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -4533,19 +4534,19 @@ ix86_parse_stringop_strategy_string (cha
       next_range_str = strchr (curr_range_str, ',');
       if (next_range_str)
         *next_range_str++ = '\0';
+      const char *opt
+	= is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=";
 
       if (3 != sscanf (curr_range_str, "%20[^:]:%d:%10s",
                        alg_name, &maxs, align))
         {
-          error ("wrong arg %s to option %s", curr_range_str,
-                 is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=");
+	  error ("wrong argument %qs to option %qs", curr_range_str, opt);
           return;
         }
 
       if (n > 0 && (maxs < (input_ranges[n - 1].max + 1) && maxs != -1))
         {
-          error ("size ranges of option %s should be increasing",
-                 is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=");
+	  error ("size ranges of option %qs should be increasing", opt);
           return;
         }
 
@@ -4555,9 +4556,35 @@ ix86_parse_stringop_strategy_string (cha
 
       if (i == last_alg)
         {
-          error ("wrong stringop strategy name %s specified for option %s",
-                 alg_name,
-                 is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=");
+	  error ("wrong stringop strategy name %qs specified for option %s",
+		 alg_name, opt);
+
+	  size_t len = 0;
+	  for (i = 0; i < last_alg; i++)
+	    len += strlen (stringop_alg_names[i]) + 1;
+
+	  char *s, *p;
+	  auto_vec <const char *> candidates;
+	  s = XALLOCAVEC (char, len);
+	  p = s;
+	  for (i = 0; i < last_alg; i++)
+	  if ((stringop_alg) i != rep_prefix_8_byte || TARGET_64BIT)
+	    {
+	      size_t arglen = strlen (stringop_alg_names[i]);
+	      memcpy (p, stringop_alg_names[i], arglen);
+	      p[arglen] = ' ';
+	      p += arglen + 1;
+	      candidates.safe_push (stringop_alg_names[i]);
+	    }
+	  p[-1] = 0;
+	  const char *hint = find_closest_string (alg_name, &candidates);
+	  if (hint)
+	    inform (input_location,
+		    "valid arguments to %qs are: %s; did you mean %qs?",
+		    opt, s, hint);
+	  else
+	    inform (input_location, "valid arguments to %qs are: %s",
+		    opt, s);
           return;
         }
 
@@ -4565,10 +4592,8 @@ ix86_parse_stringop_strategy_string (cha
 	  && !TARGET_64BIT)
 	{
 	  /* rep; movq isn't available in 32-bit code.  */
-	  error ("stringop strategy name %s specified for option %s "
-		 "not supported for 32-bit code",
-                 alg_name,
-                 is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=");
+	  error ("stringop strategy name %qs specified for option %qs "
+		 "not supported for 32-bit code", alg_name, opt);
 	  return;
 	}
 
@@ -4580,8 +4605,7 @@ ix86_parse_stringop_strategy_string (cha
         input_ranges[n].noalign = true;
       else
         {
-          error ("unknown alignment %s specified for option %s",
-                 align, is_memset ? "-mmemset_strategy=" : "-mmemcpy_strategy=");
+	  error ("unknown alignment %qs specified for option %qs", align, opt);
           return;
         }
       n++;
@@ -5041,7 +5065,7 @@ ix86_option_override_internal (bool main
     }
   else
     {
-      prefix = "option(\"";
+      prefix = "target(\"";
       suffix = "\")";
       sw = "attribute";
     }
@@ -5480,8 +5504,41 @@ ix86_option_override_internal (bool main
     error ("intel CPU can be used only for %stune=%s %s",
 	   prefix, suffix, sw);
   else if (i == pta_size)
-    error ("bad value (%s) for %sarch=%s %s",
-	   opts->x_ix86_arch_string, prefix, suffix, sw);
+    {
+      error ("bad value (%qs) for %<%sarch=%s%> %s",
+	     opts->x_ix86_arch_string, prefix, suffix, sw);
+
+      size_t len = 0;
+      for (i = 0; i < pta_size; i++)
+	len += strlen (processor_alias_table[i].name) + 1;
+
+      char *s, *p;
+      auto_vec <const char *> candidates;
+      s = XALLOCAVEC (char, len);
+      p = s;
+      for (i = 0; i < pta_size; i++)
+	if (strcmp (processor_alias_table[i].name, "generic")
+	    && strcmp (processor_alias_table[i].name, "intel")
+	    && (!TARGET_64BIT_P (opts->x_ix86_isa_flags)
+		|| (processor_alias_table[i].flags & PTA_64BIT)))
+	  {
+	    size_t arglen = strlen (processor_alias_table[i].name);
+	    memcpy (p, processor_alias_table[i].name, arglen);
+	    p[arglen] = ' ';
+	    p += arglen + 1;
+	    candidates.safe_push (processor_alias_table[i].name);
+	  }
+      p[-1] = 0;
+      const char *hint
+	= find_closest_string (opts->x_ix86_arch_string, &candidates);
+      if (hint)
+	inform (input_location,
+		"valid arguments to %<%sarch=%s%> %s are: %s; "
+		"did you mean %qs?", prefix, suffix, sw, s, hint);
+      else
+	inform (input_location, "valid arguments to %<%sarch=%s%> %s are: %s",
+		prefix, suffix, sw, s);
+    }
 
   ix86_arch_mask = 1u << ix86_arch;
   for (i = 0; i < X86_ARCH_LAST; ++i)
@@ -5523,8 +5580,40 @@ ix86_option_override_internal (bool main
       }
 
   if (ix86_tune_specified && i == pta_size)
-    error ("bad value (%s) for %stune=%s %s",
-	   opts->x_ix86_tune_string, prefix, suffix, sw);
+    {
+      error ("bad value (%qs) for %<%stune=%s%> %s",
+	     opts->x_ix86_tune_string, prefix, suffix, sw);
+
+      size_t len = 0;
+      for (i = 0; i < pta_size; i++)
+	len += strlen (processor_alias_table[i].name) + 1;
+
+      char *s, *p;
+      auto_vec <const char *> candidates;
+      s = XALLOCAVEC (char, len);
+      p = s;
+      for (i = 0; i < pta_size; i++)
+	if (!TARGET_64BIT_P (opts->x_ix86_isa_flags)
+	    || (processor_alias_table[i].flags & PTA_64BIT))
+	  {
+	    size_t arglen = strlen (processor_alias_table[i].name);
+	    memcpy (p, processor_alias_table[i].name, arglen);
+	    p[arglen] = ' ';
+	    p += arglen + 1;
+	    candidates.safe_push (processor_alias_table[i].name);
+	  }
+      p[-1] = 0;
+      const char *hint
+	= find_closest_string (opts->x_ix86_tune_string, &candidates);
+      if (hint)
+	inform (input_location,
+		"valid arguments to %<%stune=%s%> %s are: %s; "
+		"did you mean %qs?", prefix, suffix, sw, s, hint);
+      else
+	inform (input_location, "valid arguments to %<%stune=%s%> %s are: %s",
+		prefix, suffix, sw, s);
+
+    }
 
   set_ix86_tune_features (ix86_tune, opts->x_ix86_dump_tunes);
 
--- gcc/testsuite/gcc.target/i386/pr65990.c.jj	2016-05-22 12:20:14.000000000 +0200
+++ gcc/testsuite/gcc.target/i386/pr65990.c	2016-09-05 19:00:48.000000000 +0200
@@ -1,7 +1,7 @@
 /* { dg-do compile } */
 /* { dg-options "-mtune=btver2 -mmemcpy-strategy=rep_8byte:-1:noalign" }
 
-/* { dg-error "stringop strategy name rep_8byte specified for option -mmemcpy_strategy= not supported for 32-bit code" "" { target ia32 } 0 } */
+/* { dg-error "stringop strategy name 'rep_8byte' specified for option '-mmemcpy_strategy=' not supported for 32-bit code" "" { target ia32 } 0 } */
 
 struct U9
 {

	Jakub