Support printf format checking of FreeBSD kernel formats %[Dbrz].

This is enabled by the undocumented option -fformat-extensions.
This option should be named better and/or give more control over
the extensions.

Fixed a message - don't warn about the field width when it's the
precision that has the wrong type.  Didn't fix excessive checking
for the precision relative to the type - ANSI requires both to be
ints, but gcc permits the field width to be either int or unsigned
int.

3 files changed, 69 insertions, 2 deletions

diff --git a/contrib/gcc/c-common.c b/contrib/gcc/c-common.c
index eace598..c4ab381 100644
--- a/contrib/gcc/c-common.c
+++ b/contrib/gcc/c-common.c
@@ -713,6 +713,11 @@ typedef struct {
 } format_char_info;
 
 static format_char_info print_char_table[] = {
+/* FreeBSD kernel extensions.  */
+  { "D",	1,	T_C,	NULL,	NULL,	NULL,	NULL,	"-wp"		},
+  { "b",	1,	T_C,	NULL,	NULL,	NULL,	NULL,	"-wp"		},
+  { "rz",	0,	T_I,	T_I,	T_L,	NULL,	NULL,	"-wp0 +#"	},
+#define unextended_print_char_table	(print_char_table + 3)
   { "di",	0,	T_I,	T_I,	T_L,	T_LL,	T_LL,	"-wp0 +"	},
   { "oxX",	0,	T_UI,	T_UI,	T_UL,	T_ULL,	T_ULL,	"-wp0#"		},
   { "u",	0,	T_UI,	T_UI,	T_UL,	T_ULL,	T_ULL,	"-wp0"		},
@@ -1071,11 +1076,12 @@ check_format_info (info, params)
 		      cur_param = TREE_VALUE (params);
 		      params = TREE_CHAIN (params);
 		      ++arg_num;
+		      /* XXX should we allow unsigned ints here?  */
 		      if (TYPE_MAIN_VARIANT (TREE_TYPE (cur_param))
 			  != integer_type_node)
 		        {
 		          sprintf (message,
-				   "field width is not type int (arg %d)",
+				   "precision is not type int (arg %d)",
 				   arg_num);
 		          warning (message);
 		        }
@@ -1088,6 +1094,56 @@ check_format_info (info, params)
 		}
 	    }
 	}
+      if (*format_chars == 'b')
+	{
+	  /* There should be an int arg to control the string arg.  */
+	  if (params == 0)
+	    {
+	      warning (tfaff);
+	      return;
+	    }
+	    if (info->first_arg_num != 0)
+	    {
+	      cur_param = TREE_VALUE (params);
+	      params = TREE_CHAIN (params);
+	      ++arg_num;
+	      if ((TYPE_MAIN_VARIANT (TREE_TYPE (cur_param))
+		   != integer_type_node)
+		  &&
+		  (TYPE_MAIN_VARIANT (TREE_TYPE (cur_param))
+		   != unsigned_type_node))
+		{
+		  sprintf (message, "bitmap is not type int (arg %d)",
+			   arg_num);
+		  warning (message);
+		}
+	    }
+	}
+      if (*format_chars == 'D')
+	{
+	  /* There should be an unsigned char * arg before the string arg.  */
+	  if (params == 0)
+	    {
+	      warning (tfaff);
+	      return;
+	    }
+	    if (info->first_arg_num != 0)
+	    {
+	      cur_param = TREE_VALUE (params);
+	      params = TREE_CHAIN (params);
+	      ++arg_num;
+	      cur_type = TREE_TYPE (cur_param);
+	      if (TREE_CODE (cur_type) != POINTER_TYPE
+		  || TYPE_MAIN_VARIANT (TREE_TYPE (cur_type))
+		     != unsigned_char_type_node)
+		{
+		  sprintf (message,
+		      "ethernet address is not type unsigned char * (arg %d)",
+			   arg_num);
+		  warning (message);
+		}
+	    }
+	}
       if (*format_chars == 'h' || *format_chars == 'l' || *format_chars == 'q' ||
 	  *format_chars == 'L')
 	length_char = *format_chars++;
@@ -1115,7 +1171,9 @@ check_format_info (info, params)
 	  continue;
 	}
       format_chars++;
-      fci = info->is_scan ? scan_char_table : print_char_table;
+      fci = info->is_scan ? scan_char_table
+	    : flag_format_extensions ? print_char_table
+	    : unextended_print_char_table;
       while (fci->format_chars != 0
 	     && index (fci->format_chars, format_char) == 0)
 	  ++fci;
diff --git a/contrib/gcc/flags.h b/contrib/gcc/flags.h
index ed1cf57..3538549 100644
--- a/contrib/gcc/flags.h
+++ b/contrib/gcc/flags.h
@@ -338,6 +338,10 @@ extern int flag_gnu_linker;
 
 /* Tag all structures with __attribute__(packed) */
 extern int flag_pack_struct;
+
+/* Nonzero means that -Wformat accepts certain non-ANSI formats.  */
+
+extern int flag_format_extensions;
 
 /* Other basic status info about current function.  */
 
diff --git a/contrib/gcc/toplev.c b/contrib/gcc/toplev.c
index 1b6fccb..cf7ec18 100644
--- a/contrib/gcc/toplev.c
+++ b/contrib/gcc/toplev.c
@@ -521,6 +521,10 @@ int flag_gnu_linker = 1;
 /* Tag all structures with __attribute__(packed) */
 int flag_pack_struct = 0;
 
+/* Nonzero means that -Wformat accepts certain system-dependent formats.  */
+
+int flag_format_extensions = 0;
+
 /* Table of language-independent -f options.
    STRING is the option name.  VARIABLE is the address of the variable.
    ON_VALUE is the value to store in VARIABLE
@@ -567,6 +571,7 @@ struct { char *string; int *variable; int on_value;} f_options[] =
   {"verbose-asm", &flag_verbose_asm, 1},
   {"gnu-linker", &flag_gnu_linker, 1},
   {"pack-struct", &flag_pack_struct, 1},
+  {"format-extensions", &flag_format_extensions, 1},
   {"bytecode", &output_bytecode, 1}
 };