Dominik Vogt wrote:
> To me that seems as if the preprocessor is broken. It issues a
> warning as if
>
> globals.managers[id].##field
>
> was expanded to tow separate tokens:
>
> globals.managers[id] .buttonState[context]
> ^^^
>
> and not to
>
> globals.managers[id].buttonState[context]
> ^^
>
> And even if it split the token into two it would hardly ever
> matter since C does not care for the additional space.
I don't think that the preprocessor is broken. It's just that it is more
strict ANSI conformant than it used to be. (Correct me if I'm wrong, I
don't have an exact Standards description handy.)
What the warning is trying to say is that you're not allowed to use ##
with non-identifier-characters (period in this case); at any rate, it
won't insert a white space in such a case. And, it is just a warning; the
preprocessor does the Right Thing.
Consider the following:
==================================================================
lorinder$ cat > example
#define PERIODLEFT(x) .##x
#define CHARLEFT(x) a##x
PERIODLEFT(foo)
#line 100
PERIODLEFT(;)
#line 1000
CHARLEFT(bar)
#line 10000
CHARLEFT(!)
lorinder$ /usr/bin/cpp --version
2.95.2
lorinder$ /usr/bin/cpp example
# 1 "example"
.foo
# 99 "example"
.;
# 999 "example"
abar
# 9999 "example"
a!
lorinder$ /usr/local/bin/cpp --version
3.0
lorinder$ /usr/local/bin/cpp example
example:4:1: warning: pasting "." and "foo" does not give a valid
preprocessing token
# 4 "example"
.foo
# 100 "example"
example:100:1: warning: pasting "." and ";" does not give a valid
preprocessing token
.;
# 1000 "example"
abar
# 10000 "example"
example:10000:1: warning: pasting "a" and "!" does not give a valid
preprocessing token
a!
lorinder$
==================================================================
Hence, the fix is to simply remove the ##. This certainly can't break
anything since, as you pointed out, even if some preprocessors (wrongly)
insert a white space there, this won't cause any problems.
Thus, the following patch, which solves these problems, can be safely
applied.
Cheers,
--Lorenz
--- readconfig.c.orig Thu Mar 29 00:36:11 2001
+++ readconfig.c Sat Jun 23 01:54:12 2001
@@ -1047,11 +1047,11 @@
int id = manager; \
if (id == -1) { \
for (id = 0; id < globals.num_managers; id++) { \
- globals.managers[id].##field = value; \
+ globals.managers[id].field = value; \
} \
} \
else if (id < globals.num_managers) { \
- globals.managers[id].##field = value; \
+ globals.managers[id].field = value; \
} \
else { \
ConsoleMessage ("Internal error in SET_MANAGER: %d\n", id); \
--
Visit the official FVWM web page at <URL:http://www.fvwm.org/>.
To unsubscribe from the list, send "unsubscribe fvwm-workers" in the
body of a message to [EMAIL PROTECTED]
To report problems, send mail to [EMAIL PROTECTED]
