configure.in (ENUM_BITFIELDS_ARE_UNSIGNED): Added.

        * configure.in (ENUM_BITFIELDS_ARE_UNSIGNED): Added.  Check that
        bitfields of the host compiler are not signed quantities.
        * config.in: Regenerate.
        * configure: Regenerate.
        * system.h (USE_ENUM_BITFIELDS): Added.
        (ENUM_BITFIELDS): Added.
        * rtl.h (rtx_def): Members `code', `mode', now ENUM_BITFIELD.
        (SHORT_ENUM_BUG): Deleted.
        * tree.h (tree_common): Members `code', `mode', `built_in_class',
        now ENUM_BITFIELD.
        * config/i386/xm-sco.h (ONLY_INT_FIELDS): Deleted.
        (CODE_FIELD_BUG): Likewise.
        * config/m68k/x-apollo68 (CC): Deleted SHORT_ENUM_BUG.
        (OLD_CC): Likewise.
        * config/m68k/x-ccur (X_CFLAGS): Likewise.

From-SVN: r33233

gcc/ChangeLog

+2000-04-18  Robert Lipe  <robertlipe@usa.net>
+
+	* configure.in (ENUM_BITFIELDS_ARE_UNSIGNED): Added.  Check that
+	bitfields of the host compiler are not signed quantities.
+	* config.in: Regenerate.
+	* configure: Regenerate.
+	* system.h (USE_ENUM_BITFIELDS): Added.
+	(ENUM_BITFIELDS): Added.
+	* rtl.h (rtx_def): Members `code', `mode', now ENUM_BITFIELD.
+	(SHORT_ENUM_BUG): Deleted.
+	* tree.h (tree_common): Members `code', `mode', `built_in_class', 
+	now ENUM_BITFIELD.
+	* config/i386/xm-sco.h (ONLY_INT_FIELDS): Deleted.
+	(CODE_FIELD_BUG): Likewise.
+	* config/m68k/x-apollo68 (CC): Deleted SHORT_ENUM_BUG.
+	(OLD_CC): Likewise.
+	* config/m68k/x-ccur (X_CFLAGS): Likewise.
+
 Tue Apr 18 14:16:47 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 	* ggc-common.c: Add missing blanks.

gcc/config.in

@@ -419,6 +419,9 @@
 /* Define if you have the i library (-li).  */
 #undef HAVE_LIBI
 
+/* Define if enumerated bitfields are treated as unsigned values. */
+#undef ENUM_BITFIELDS_ARE_UNSIGNED
+
 /* Define if mmap can get us zeroed pages from /dev/zero. */
 #undef HAVE_MMAP_ANYWHERE
 

gcc/config/i386/xm-sco.h

@@ -3,11 +3,3 @@
 /* Big buffers improve performance.  */
 
 #define IO_BUFFER_SIZE (0x8000 - 1024)
-
-#ifndef __GNUC__
-/* The SCO compiler gets it wrong, and treats enumerated bitfields
-   as signed quantities, making it impossible to use an 8-bit enum
-   for compiling GNU C++.  */
-#define ONLY_INT_FIELDS 1
-#define CODE_FIELD_BUG 1
-#endif

gcc/config/m68k/x-apollo68

@@ -2,8 +2,8 @@
 
 # vasta@apollo.com says this is how to compile on an Apollo (SR10.x).
 # Use a Berkeley environment.
-CC=cc -g -A nansi -A cpu,3000 -A runtype,bsd4.3 -A systype,any -DSHORT_ENUM_BUG
-OLDCC=cc -g -A nansi -A cpu,3000 -A runtype,bsd4.3 -A systype,any -DSHORT_ENUM_BUG
+CC=cc -g -A nansi -A cpu,3000 -A runtype,bsd4.3 -A systype,any
+OLDCC=cc -g -A nansi -A cpu,3000 -A runtype,bsd4.3 -A systype,any
 
 # This used to redefine CFLAGS and LIBGCC2_CFLAGS to eliminate the unsupported
 # -g flag from both macros.  This gives an undebuggable stage1 compiler which

gcc/config/m68k/x-ccur

 # Specify the jobs library when building in the ATT universe. 
 CLIB = -ljobs
-X_CFLAGS = -O0 -DSHORT_ENUM_BUG -Dregister=
+X_CFLAGS = -O0 -Dregister=

gcc/configure.in

@@ -377,6 +377,27 @@ if test $gcc_cv_header_inttypes_h = yes; then
   AC_DEFINE(HAVE_INTTYPES_H)
 fi
 
+#
+# Determine if enumerated bitfields are unsigned.   ISO C says they can 
+# be either signed or unsigned.
+#
+AC_CACHE_CHECK(for unsigned enumerated bitfields, gcc_cv_enum_bf_unsigned,
+[AC_TRY_RUN(#include <stdlib.h>
+enum t { BLAH = 128 } ;
+struct s_t { enum t member : 8; } s ;
+int main(void)
+{            
+        s.member = BLAH;
+        if (s.member < 0) exit(1);
+        exit(0);
+
+}, gcc_cv_enum_bf_unsigned=yes, gcc_cv_enum_bf_unsigned=no, gcc_cv_enum_bf_unsigned=yes)])
+AC_MSG_RESULT($gcc_cv_enum_bf_unsigned)
+if test $gcc_cv_enum_bf_unsigned = yes; then
+  AC_DEFINE(ENUM_BITFIELDS_ARE_UNSIGNED, 1,
+    [Define if enumerated bitfields are treated as unsigned values.])
+fi
+
 AC_CHECK_FUNCS(strtoul bsearch putenv popen bcopy bzero bcmp \
 	index rindex strchr strrchr kill getrlimit setrlimit atoll atoq \
 	sysconf isascii gettimeofday strsignal putc_unlocked fputc_unlocked \

gcc/rtl.h

@@ -103,23 +103,12 @@ typedef union rtunion_def
 
 typedef struct rtx_def
 {
-#ifdef ONLY_INT_FIELDS
-#ifdef CODE_FIELD_BUG
-  unsigned int code : 16;
-#else
-  unsigned short code;
-#endif
-#else
   /* The kind of expression this is.  */
-  enum rtx_code code : 16;
-#endif
+  ENUM_BITFIELD(rtx_code) code: 16;
 
   /* The kind of value the expression has.  */
-#ifdef ONLY_INT_FIELDS
-  int mode : 8;
-#else
-  enum machine_mode mode : 8;
-#endif
+  ENUM_BITFIELD(machine_mode) mode : 8;
+
   /* 1 in an INSN if it can alter flow of control
      within this function.
      LINK_COST_ZERO in an INSN_LIST.  */
@@ -189,13 +178,8 @@ typedef struct rtx_def
 
 /* Define macros to access the `code' field of the rtx.  */
 
-#ifdef SHORT_ENUM_BUG
-#define GET_CODE(RTX)		((enum rtx_code) ((RTX)->code))
-#define PUT_CODE(RTX, CODE)	((RTX)->code = ((short) (CODE)))
-#else
 #define GET_CODE(RTX)		((RTX)->code)
 #define PUT_CODE(RTX, CODE)	((RTX)->code = (CODE))
-#endif
 
 #define GET_MODE(RTX)		((RTX)->mode)
 #define PUT_MODE(RTX, MODE)	((RTX)->mode = (MODE))

gcc/system.h

@@ -547,4 +547,16 @@ extern void abort PARAMS ((void));
 /* Get libiberty declarations. */
 #include "libiberty.h"
 
+/* Enumerated bitfields are safe to use unless we've been explictly told
+ * otherwise or if they are signed. */
+ 
+#define USE_ENUM_BITFIELDS __GNUC__ || (!ONLY_INT_FIELDS && ENUM_BTIFIELDS_ARE_UNSIGNED)
+
+#if USE_ENUM_BITFIELDS
+#define ENUM_BITFIELD(TYPE) enum TYPE
+#else
+#define ENUM_BITFIELD(TYPE) unsigned int
+#endif
+
+
 #endif /* __GCC_SYSTEM_H__ */

gcc/tree.h

@@ -126,12 +126,7 @@ struct tree_common
 {
   union tree_node *chain;
   union tree_node *type;
-#ifdef ONLY_INT_FIELDS
-  unsigned int code : 8;
-#else
-  enum tree_code code : 8;
-#endif
-
+  ENUM_BITFIELD(tree_code) code : 8;
   unsigned side_effects_flag : 1;
   unsigned constant_flag : 1;
   unsigned permanent_flag : 1;
@@ -906,11 +901,7 @@ struct tree_type
   unsigned int uid;
 
   unsigned int precision : 9;
-#ifdef ONLY_INT_FIELDS
-  unsigned int mode : 7;
-#else
-  enum machine_mode mode : 7;
-#endif
+  ENUM_BITFIELD(machine_mode) mode : 7;
 
   unsigned string_flag : 1;
   unsigned no_force_blk_flag : 1;
@@ -1394,11 +1385,7 @@ struct tree_decl
   unsigned malloc_flag : 1;
   unsigned no_limit_stack : 1;
   unsigned pure_flag : 1;
-#ifdef ONLY_INT_FIELDS
-  unsigned int built_in_class : 2;
-#else
-  enum built_in_class built_in_class : 2;
-#endif
+  ENUM_BITFIELD(built_in_class) built_in_class : 2;
 
   unsigned lang_flag_0 : 1;
   unsigned lang_flag_1 : 1;