re PR c/6300 (sparc-sun-solaris2.7 gcc-3.1 C testsuite failure in gcc.dg/cpp/charconst.c)

	* c-lex.c (lex_charconst): Call convert to get constant in
	proper type; don't just smash the type field.
	Fixes PR c/6300.

	* config.gcc: Add list of obsolete configurations.  Disallow
	building these without --enable-obsolete.
	* doc/install.texi: Document --enable-obsolete and obsoletion
	policy.  Mention obsoletion of individual targets in
	appropriate places.

From-SVN: r52639

gcc/ChangeLog

+2002-04-22  Zack Weinberg  <zack@codesourcery.com>
+
+	* c-lex.c (lex_charconst): Call convert to get constant in
+	proper type; don't just smash the type field.
+	Fixes PR c/6300.
+
+	* config.gcc: Add list of obsolete configurations.  Disallow
+	building these without --enable-obsolete.
+	* doc/install.texi: Document --enable-obsolete and obsoletion
+	policy.  Mention obsoletion of individual targets in
+	appropriate places.
+
 2002-04-22  Richard Henderson  <rth@redhat.com>
 
 	* config/sparc/sol2-bi.h (ASM_DEBUG_SPEC): New.

gcc/c-lex.c

@@ -1338,7 +1338,7 @@ lex_charconst (token)
      const cpp_token *token;
 {
   HOST_WIDE_INT result;
-  tree value;
+  tree type, value;
   unsigned int chars_seen;
  
   result = cpp_interpret_charconst (parse_in, token, warn_multichar,
@@ -1346,7 +1346,7 @@ lex_charconst (token)
   if (token->type == CPP_WCHAR)
     {
       value = build_int_2 (result, 0);
-      TREE_TYPE (value) = wchar_type_node;
+      type = wchar_type_node;
     }
   else
     {
@@ -1358,10 +1358,24 @@ lex_charconst (token)
       /* In C, a character constant has type 'int'.
  	 In C++ 'char', but multi-char charconsts have type 'int'.  */
       if (c_language == clk_cplusplus && chars_seen <= 1)
- 	TREE_TYPE (value) = char_type_node;
+	type = char_type_node;
       else
- 	TREE_TYPE (value) = integer_type_node;
+	type = integer_type_node;
     }
- 
+
+  /* cpp_interpret_charconst issues a warning if the constant
+     overflows, but if the number fits in HOST_WIDE_INT anyway, it
+     will return it un-truncated, which may cause problems down the
+     line.  So set the type to widest_integer_literal_type, call
+     convert to truncate it to the proper type, then clear
+     TREE_OVERFLOW so we don't get a second warning.
+
+     FIXME: cpplib's assessment of overflow may not be accurate on a
+     platform where the final type can change at (compiler's) runtime.  */
+
+  TREE_TYPE (value) = widest_integer_literal_type_node;
+  value = convert (type, value);
+  TREE_OVERFLOW (value) = 0;
+
   return value;
 }

gcc/config.gcc

@@ -207,6 +207,81 @@ gas="$gas_flag"
 gnu_ld="$gnu_ld_flag"
 enable_threads=$enable_threads_flag
 
+# Obsolete configurations.
+# To avoid some tedious lists, we have a blacklist with a whitelist
+# embedded within it.
+case $machine in
+	  1750a-* \
+	| a29k-* \
+	| alpha*-*-osf[123]* \
+	| arm-*-riscix* \
+	| c*-convex-* \
+	| clipper-* \
+	| elxsi-* \
+	| i860-* \
+	| i?86-*-aix* \
+	| i?86-*-bsd* \
+	| i?86-*-chorusos* \
+	| i?86-*-dgux* \
+	| i?86-*-freebsd1.* \
+	| i?86-*-isc* \
+	| i?86-*-linux*oldld* \
+	| i?86-*-osf1* \
+	| i?86-*-osfrose* \
+	| i?86-*-rtemscoff* \
+	| i?86-*-sunos* \
+	| i?86-go32-rtems* \
+	| i?86-next-* \
+	| i?86-sequent-bsd* \
+	| i?86-sequent-ptx[12]* \
+	| i?86-sequent-sysv3* \
+	| m68[k0]*-*-lynxos* \
+	| m68[k0]*-*-rtemscoff* \
+	| m68[k0]*-*-sysv3* \
+	| m68[k0]*-altos-* \
+	| m68[k0]*-apollo-* \
+	| m68[k0]*-apple-* \
+	| m68[k0]*-bull-* \
+	| m68[k0]*-convergent-* \
+	| m68[k0]*-isi-* \
+	| m68[k0]*-next-* \
+	| m68[k0]*-sony-* \
+	| m88k-* \
+	| mips-*-bsd* \
+	| mips-*-riscos* \
+	| mips-*-sysv* \
+	| mips-*-ultrix* \
+	| mips-dec-* \
+	| mips-sgi-irix[1234]* \
+	| mips-sony-* \
+	| mips-tandem-* \
+	| ns32k-* \
+	| pj-* \
+	| pjl-* \
+	| romp-* \
+	| sparc-*-rtemsaout* \
+	| we32k-* \
+)
+  case $machine in
+	  a29k-*-udi | a29k-*-coff \
+	| mips-sni-sysv4 \
+	| m88k-*-aout* | m88k-*-openbsd* | m88k-*-sysv4* \
+	| ns32k-*-netbsd* | ns32k-*-openbsd* \
+	| romp-*-openbsd* \
+   )
+    # Whitelisted.
+    ;;
+  *)
+    if test "x$enable_obsolete" = x; then
+      echo "*** Configuration $machine is obsolete." >&2
+      echo "*** Specify --enable-obsolete to build it anyway." >&2
+      echo "*** Support will be REMOVED in the next major release of GCC," >&2
+      echo "*** unless a maintainer comes forward." >&2
+      exit 1
+    fi;;
+  esac
+esac
+
 # Set default cpu_type, tm_file, tm_p_file and xm_file so it can be
 # updated in each machine entry.  Also set default extra_headers for some
 # machines.