parser.c (cp_parser_expression_stack): Clarify why it is an array of NUM_PREC_VALUES elements.

2004-09-24  Paolo Bonzini  <bonzini@gnu.org>

	* parser.c (cp_parser_expression_stack): Clarify why it is
	an array of NUM_PREC_VALUES elements.
	(cp_parser_binary_expression): Clarify why we do not need to
	handle stack overflow.

From-SVN: r88042

gcc/cp/ChangeLog

+2004-09-24  Paolo Bonzini  <bonzini@gnu.org>
+
+	* parser.c (cp_parser_expression_stack): Clarify why it is
+	an array of NUM_PREC_VALUES elements.
+	(cp_parser_binary_expression): Clarify why we do not need to
+	handle stack overflow.
+
 2004-09-24  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/16889

gcc/cp/parser.c

@@ -1106,6 +1106,9 @@ typedef struct cp_parser_expression_stack_entry
   int prec;
 } cp_parser_expression_stack_entry;
 
+/* The stack for storing partial expressions.  We only need NUM_PREC_VALUES
+   entries because precedence levels on the stack are monotonically
+   increasing.  */
 typedef struct cp_parser_expression_stack_entry
   cp_parser_expression_stack[NUM_PREC_VALUES];
 
@@ -5356,7 +5359,9 @@ cp_parser_binary_expression (cp_parser* parser)
       if (lookahead_prec > new_prec)
         {
           /* ... and prepare to parse the RHS of the new, higher priority
-             expression.  */
+             expression.  Since precedence levels on the stack are
+	     monotonically increasing, we do not have to care about
+	     stack overflows.  */
           sp->prec = prec;
           sp->tree_type = tree_type;
           sp->lhs = lhs;