| Compiling C and C++ Programs |
This
section introduces the extensions to the ISO/ANSI C language implemented in
Release 6.50 of the SAS/C Compiler. Library extensions are described in SAS/C Library Reference, Volume 1, SAS/C Library Reference,
Volume 2, and SAS/C Compiler and Library User's Guide.
Note:
Use of these extensions is likely to render a
program nonportable. ![[cautionend]](../common/images/cautend.gif)
The SAS/C Compiler now supports C++ style line comments.
A line comment starts with two forward slashes and goes to the end of the
line. An example of the new comment extension is:
// This is a comment line
Note:
This support is turned off if the
-Kstrict
compiler option is used.
Compiler support for the at
sign (@) has been extended. When the compiler
option -KAT is specified, @ is treated as a new operator. The @
operator can be used only in an argument to a function call. (The result of
using it in any other context is undefined.) The @
operator has the same syntax as &. In situations
where & can be used, @
has the same meaning as &.
In addition, @ can be
used on non-lvalues such as constants and expressions. In these cases, the
value of @expr is the address of a temporary
storage area to which the value of expr is
copied.
One special case for the @
operator is when its argument is an array name or a string literal. In this
case, @array is different from &array. While @array addresses
a pointer addressing the array, &array
still addresses the array.
The compiler continues to process the @ operator as in earlier releases when the @ is
in the context of a function call. Use of @ is nonportable. Its use should be restricted to programs
that call non-C routines using call-by-reference.
Release 6.50 introduces
A
and
E
qualifiers for character and string constants. The new qualifiers
cause the string to be either ASCII or EBCDIC.
A string literal prefixed with
A
is parsed and stored by the compiler as an
ASCII string. An example of its usage is:
A"this is an ASCII string"
A string literal prefixed with
E
is parsed and stored by the compiler as an
EBCDIC string. An example of its usage is:
E"this is an EBCDIC string"
Copyright © 2001
by SAS Institute Inc., Cary, NC, USA. All rights reserved.
