* tree.c (build_range_type): Allow creation of ranges with no maximum.

	* dbxout.c (dbxout_range_type): Handle missing TYPE_MAX_VALUE.
	* dwarf2out.c (add_subscript_info): Likewise.
	* dwarfout.c (subscript_data_attribute, byte_size_attribute): Likewise.
	* sdbout.c (plain_type_1): Likewise.
	* stmt.c (pushcase_range, all_cases_count, node_has_high_bound):
	Likewise.
	* fold-const.c (int_const_binop, fold_convert, make_range, fold):
	Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@17142 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 89 insertions, 25 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8c2ce0453ca..c1add15087b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+Fri Dec 19 00:19:42 1997  Richard Henderson  <rth@cygnus.com>
+
+	* tree.c (build_range_type): Allow creation of ranges with no maximum.
+	* dbxout.c (dbxout_range_type): Handle missing TYPE_MAX_VALUE.
+	* dwarf2out.c (add_subscript_info): Likewise.
+	* dwarfout.c (subscript_data_attribute, byte_size_attribute): Likewise.
+	* sdbout.c (plain_type_1): Likewise.
+	* stmt.c (pushcase_range, all_cases_count, node_has_high_bound):
+	Likewise.
+	* fold-const.c (int_const_binop, fold_convert, make_range, fold):
+	Likewise.
+
 Thu Dec 18 17:05:10 1997  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
  
         * mips.c (fatal): Remove declaration.
diff --git a/gcc/dbxout.c b/gcc/dbxout.c
index 11af421106e..fcb5d86650e 100644
--- a/gcc/dbxout.c
+++ b/gcc/dbxout.c
@@ -954,7 +954,8 @@ dbxout_range_type (type)
 	     TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)));
   else
     fprintf (asmfile, ";0");
-  if (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
+  if (TYPE_MAX_VALUE (type) 
+      && TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
     fprintf (asmfile, ";%d;", 
 	     TREE_INT_CST_LOW (TYPE_MAX_VALUE (type)));
   else
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index d321e9f0f3a..f41cd5efeb0 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -7195,8 +7195,16 @@ add_subscript_info (type_die, type)
 				    type_die);
 	    }
 
+	  /* ??? If upper is NULL, the array has unspecified length,
+	     but it does have a lower bound.  This happens with Fortran
+	       dimension arr(N:*)
+       	     Since the debugger is definitely going to need to know N
+	     to produce useful results, go ahead and output the lower
+	     bound solo, and hope the debugger can cope.  */
+
 	  add_bound_info (subrange_die, DW_AT_lower_bound, lower);
-	  add_bound_info (subrange_die, DW_AT_upper_bound, upper);
+	  if (upper)
+	    add_bound_info (subrange_die, DW_AT_upper_bound, upper);
 	}
       else
 	/* We have an array type with an unspecified length.  The DWARF-2
diff --git a/gcc/dwarfout.c b/gcc/dwarfout.c
index a72ccac5c81..528886a34f8 100644
--- a/gcc/dwarfout.c
+++ b/gcc/dwarfout.c
@@ -2587,9 +2587,8 @@ subscript_data_attribute (type)
 	  /* Output the representation format byte for this dimension.  */
 
 	  ASM_OUTPUT_DWARF_FMT_BYTE (asm_out_file,
-				  FMT_CODE (1,
-					    TREE_CODE (lower) == INTEGER_CST,
-					    TREE_CODE (upper) == INTEGER_CST));
+		  FMT_CODE (1, TREE_CODE (lower) == INTEGER_CST,
+			    (upper && TREE_CODE (upper) == INTEGER_CST)));
 
 	  /* Output the index type for this dimension.	*/
 
@@ -2675,9 +2674,9 @@ byte_size_attribute (tree_node)
       case ARRAY_TYPE:
 	{
 	  /* The lower bound is zero, so the length is the upper bound + 1.  */
-	  register tree upper_bound;
-	  upper_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (tree_node));
-	  size = (unsigned) TREE_INT_CST_LOW (upper_bound) + 1;
+	  register tree upper;
+	  upper = TYPE_MAX_VALUE (TYPE_DOMAIN (tree_node));
+	  size = upper ? (unsigned) TREE_INT_CST_LOW (upper) + 1 : -1;
 	  break;
 	}
 
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 65a6d85efc0..adcb1877d83 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -1215,7 +1215,9 @@ int_const_binop (code, arg1, arg2, notrunc, forsize)
     }
 
   if (TREE_TYPE (arg1) == sizetype && hi == 0
-      && low >= 0 && low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype))
+      && low >= 0
+      && (TYPE_MAX_VALUE (sizetype) == NULL
+	  || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
       && ! overflow
       && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
     t = size_int (low);
@@ -1532,25 +1534,34 @@ fold_convert (t, arg1)
 	  REAL_VALUE_TYPE l;
 	  REAL_VALUE_TYPE u;
 	  tree type1 = TREE_TYPE (arg1);
+	  int no_upper_bound;
 
 	  x = TREE_REAL_CST (arg1);
 	  l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
-	  u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
+
+	  no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
+	  if (!no_upper_bound)
+	    u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
+
 	  /* See if X will be in range after truncation towards 0.
 	     To compensate for truncation, move the bounds away from 0,
 	     but reject if X exactly equals the adjusted bounds.  */
 #ifdef REAL_ARITHMETIC
 	  REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
-	  REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
+	  if (!no_upper_bound)
+	    REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
 #else
 	  l--;
-	  u++;
+	  if (!no_upper_bound)
+	    u++;
 #endif
 	  /* If X is a NaN, use zero instead and show we have an overflow.
 	     Otherwise, range check.  */
 	  if (REAL_VALUE_ISNAN (x))
 	    overflow = 1, x = dconst0;
-	  else if (! (REAL_VALUES_LESS (l, x) && REAL_VALUES_LESS (x, u)))
+	  else if (! (REAL_VALUES_LESS (l, x)
+		      && !no_upper_bound
+		      && REAL_VALUES_LESS (x, u)))
 	    overflow = 1;
 
 #ifndef REAL_ARITHMETIC
@@ -2922,11 +2933,22 @@ make_range (exp, pin_p, plow, phigh)
 	  if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
 	    {
 	      tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
-	      tree high_positive
-		= fold (build (RSHIFT_EXPR, type,
-			       convert (type,
-					TYPE_MAX_VALUE (equiv_type)),
-			       convert (type, integer_one_node)));
+	      tree high_positive;
+
+	      /* A range without an upper bound is, naturally, unbounded.
+		 Since convert would have cropped a very large value, use
+		  the max value for the destination type.  */
+
+	      high_positive = TYPE_MAX_VALUE (equiv_type);
+	      if (!high_positive)
+		{
+		  high_positive = TYPE_MAX_VALUE (type);
+		  if (!high_positive)
+		    abort();
+		}
+	      high_positive = fold (build (RSHIFT_EXPR, type,
+					   convert (type, high_positive),
+					   convert (type, integer_one_node)));
 			
 	      /* If the low bound is specified, "and" the range with the
 		 range for which the original unsigned value will be
@@ -4914,6 +4936,7 @@ fold (expr)
       if (operand_equal_p (arg0, arg1, 0))
 	return arg0;
       if (INTEGRAL_TYPE_P (type)
+	  && TYPE_MAX_VALUE (type)
 	  && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
 	return omit_one_operand (type, arg1, arg0);
       goto associate;
@@ -5397,6 +5420,8 @@ fold (expr)
 	      && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
 	      && TREE_TYPE (cval1) == TREE_TYPE (cval2)
 	      && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
+	      && TYPE_MAX_VALUE (TREE_TYPE (cval1))
+	      && TYPE_MAX_VALUE (TREE_TYPE (cval2))
 	      && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
 				    TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
 	    {
diff --git a/gcc/sdbout.c b/gcc/sdbout.c
index ef1ff29604d..14c5b40dc32 100644
--- a/gcc/sdbout.c
+++ b/gcc/sdbout.c
@@ -584,6 +584,7 @@ plain_type_1 (type, level)
 	if (sdb_n_dims < SDB_MAX_DIM)
 	  sdb_dims[sdb_n_dims++]
 	    = (TYPE_DOMAIN (type)
+	       && TYPE_MAX_VALUE (TYPE_DOMAIN (type))
 	       && TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
 	       && TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
 	       ? (TREE_INT_CST_LOW (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))
diff --git a/gcc/stmt.c b/gcc/stmt.c
index 32867482f21..9779015963b 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -4624,10 +4624,16 @@ pushcase_range (value1, value2, converter, label, duplicate)
 
   /* Fail if the range is empty.  Do this before any conversion since
      we want to allow out-of-range empty ranges.  */
-  if (tree_int_cst_lt (value2, value1))
+  if (value2 && tree_int_cst_lt (value2, value1))
     return 4;
 
   value1 = (*converter) (nominal_type, value1);
+
+  /* If the max was unbounded, use the max of the nominal_type we are 
+     converting to.  Do this after the < check above to suppress false
+     positives.  */
+  if (!value2)
+    value2 = TYPE_MAX_VALUE (nominal_type);
   value2 = (*converter) (nominal_type, value2);
 
   /* Fail if these values are out of range.  */
@@ -4955,6 +4961,7 @@ all_cases_count (type, spareness)
     default:
     case INTEGER_TYPE:
       if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
+	  || TYPE_MAX_VALUE (type) == NULL
 	  || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
 	return -1;
       else
@@ -6194,6 +6201,11 @@ node_has_high_bound (node, index_type)
   tree high_plus_one;
   case_node_ptr pnode;
 
+  /* If there is no upper bound, obviously no test is needed.  */
+
+  if (TYPE_MAX_VALUE (index_type) == NULL)
+    return 1;
+
   /* If the upper bound of this node is the highest value in the type
      of the index expression, we need not test against it.  */
 
diff --git a/gcc/tree.c b/gcc/tree.c
index 7b150ebf388..492b6734961 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4002,19 +4002,25 @@ build_range_type (type, lowval, highval)
 
   push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
   TYPE_MIN_VALUE (itype) = convert (type, lowval);
-  TYPE_MAX_VALUE (itype) = convert (type, highval);
+  TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
   pop_obstacks ();
 
   TYPE_PRECISION (itype) = TYPE_PRECISION (type);
   TYPE_MODE (itype) = TYPE_MODE (type);
   TYPE_SIZE (itype) = TYPE_SIZE (type);
   TYPE_ALIGN (itype) = TYPE_ALIGN (type);
-  if ((TREE_CODE (lowval) == INTEGER_CST)
-      && (TREE_CODE (highval) == INTEGER_CST))
+  if (TREE_CODE (lowval) == INTEGER_CST)
     {
-      HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
-      HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
-      int maxint = (int) (highint - lowint);
+      HOST_WIDE_INT lowint, highint;
+      int maxint;
+
+      lowint = TREE_INT_CST_LOW (lowval);
+      if (highval && TREE_CODE (highval) == INTEGER_CST)
+	highint = TREE_INT_CST_LOW (highval);
+      else
+	highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
+
+      maxint = (int) (highint - lowint);
       return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
     }
   else