• Edward Diener (13/13) Aug 27 2010 The code:
• Walter Bright (10/22) Aug 28 2010 This is because WCHAR_MAX is defined as:
• Edward Diener (12/34) Aug 28 2010 I believe it is therefore clearly misdefined, as it is supposed to be a
• Walter Bright (3/10) Aug 28 2010 You're right. I took off the (wchar_t) casts in \dm\include\wchar.h and
• Cesar Rabak (4/14) Jan 12 2011 Were those changes reflected in any patch/update? v852 seems to be the
• Walter Bright (2/18) Jan 12 2011 No, but I'll email them to you.

Edward Diener <eddielee_no_spam_here tropicsoft.com> writes:

The code:

#include <wchar.h>
#include <limits.h>
#if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
#endif

as TestFile.cpp when compiled gives:

#if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
                                    ^
TestFile.cpp(3) : Error: ')' expected
#endif
      ^
TestFile.cpp(4) : Preprocessor error: '#endif' found without '#if'
--- errorlevel 1

Walter Bright <newshound2 digitalmars.com> writes:

Edward Diener wrote:
 The code:
 
 #include <wchar.h>
 #include <limits.h>
 #if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
 #endif
 
 as TestFile.cpp when compiled gives:
 
 #if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
                                    ^
 TestFile.cpp(3) : Error: ')' expected


This is because WCHAR_MAX is defined as:

     (wchar_t)0xFFFF

and casts are not allowed in preprocessor expressions.

You can tell this by compiling this way:

H:ztc>dmc -c test -e -l
#if defined(WCHAR_MAX) && ((wchar_t)0xFFFF
                                           ^
test.cpp(3) : Error: ')' expected

Using -e -l will show the line after macro expansion.

Edward Diener <eddielee_no_spam_here tropicsoft.com> writes:

On 8/28/2010 8:40 PM, Walter Bright wrote:
 Edward Diener wrote:
 The code:

 #include <wchar.h>
 #include <limits.h>
 #if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
 #endif

 as TestFile.cpp when compiled gives:

 #if defined(WCHAR_MAX) && (WCHAR_MAX <= USHRT_MAX)
 ^
 TestFile.cpp(3) : Error: ')' expected


 This is because WCHAR_MAX is defined as:

 (wchar_t)0xFFFF

 and casts are not allowed in preprocessor expressions.

 You can tell this by compiling this way:

 H:ztc>dmc -c test -e -l
 #if defined(WCHAR_MAX) && ((wchar_t)0xFFFF
 ^
 test.cpp(3) : Error: ')' expected

 Using -e -l will show the line after macro expansion.

I believe it is therefore clearly misdefined, as it is supposed to be a 
constant expression that one can use in preprocessor #if expressions. In 
the Ansi C standard we have in 7.18.3 "Limits of other integer types" in 
paragraph 2:

"Each instance of these macros shall be replaced by a constant 
expression suitable for use
in #if preprocessing directives, and this expression shall have the same 
type as would an
expression that is an object of the corresponding type converted 
according to the integer
promotions."

Walter Bright <newshound2 digitalmars.com> writes:

Edward Diener wrote:
 "Each instance of these macros shall be replaced by a constant 
 expression suitable for use
 in #if preprocessing directives, and this expression shall have the same 
 type as would an
 expression that is an object of the corresponding type converted 
 according to the integer
 promotions."

You're right. I took off the (wchar_t) casts in \dm\include\wchar.h and 
\dm\include\stdint.h.

Cesar Rabak <crabak acm.org> writes:

Em 29/8/2010 01:54, Walter Bright escreveu:
 Edward Diener wrote:
 "Each instance of these macros shall be replaced by a constant
 expression suitable for use
 in #if preprocessing directives, and this expression shall have the
 same type as would an
 expression that is an object of the corresponding type converted
 according to the integer
 promotions."

 You're right. I took off the (wchar_t) casts in \dm\include\wchar.h and
 \dm\include\stdint.h.

Were those changes reflected in any patch/update? v852 seems to be the 
last update available.  However, checking the mentioned header files 
don't show any modifications.

Walter Bright <newshound2 digitalmars.com> writes:

Cesar Rabak wrote:
 Em 29/8/2010 01:54, Walter Bright escreveu:
 Edward Diener wrote:
 "Each instance of these macros shall be replaced by a constant
 expression suitable for use
 in #if preprocessing directives, and this expression shall have the
 same type as would an
 expression that is an object of the corresponding type converted
 according to the integer
 promotions."

 You're right. I took off the (wchar_t) casts in \dm\include\wchar.h and
 \dm\include\stdint.h.

 
 Were those changes reflected in any patch/update? v852 seems to be the 
 last update available.  However, checking the mentioned header files 
 don't show any modifications.

No, but I'll email them to you.