gcc and command line symbols

[AB]

Hello All,

I've got code like this...

#ifdef SYMBOL
..
..
..

/* Do stuff */
..
..
..
#endif

I want to define SYMBOL on the command line. Which switch should I use
when compiling with gcc?

[Vladimir Oka]

AB wrote:

Hello All,

I've got code like this...

#ifdef SYMBOL
.
.
.

/* Do stuff */
.
.
.
#endif

I want to define SYMBOL on the command line. Which switch should I use
when compiling with gcc?

Off-topic, but: -D tends to worrk for most compilers I ever used.

[Clever Monkey]

AB wrote:

Hello All,

I've got code like this...

#ifdef SYMBOL
.
.
.

/* Do stuff */
.
.
.
#endif

I want to define SYMBOL on the command line. Which switch should I use
when compiling with gcc?

man gcc

[Keith Thompson]

"AB" <ab*****@gmail.com> writes:

Hello All,

I've got code like this...

#ifdef SYMBOL
.
.
.

/* Do stuff */
.
.
.
#endif

I want to define SYMBOL on the command line. Which switch should I use
when compiling with gcc?

"info gcc" should give you the gcc documentation on most systems.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[David Wade]

"Keith Thompson" <ks***@mib.org> wrote in message
news:ln************@nuthaus.mib.org...

"AB" <ab*****@gmail.com> writes:

Hello All,

I've got code like this...

#ifdef SYMBOL
.
.
.

/* Do stuff */
.
.
.
#endif

I want to define SYMBOL on the command line. Which switch should I use
when compiling with gcc?
"info gcc" should give you the gcc documentation on most systems.

On some systems, without "man" or "info" you may need to use "gcc -v --help"
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst> San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst> We must do something. This is something. Therefore, we must do this.

[SM Ryan]

Keith Thompson <ks***@mib.org> wrote:
# "AB" <ab*****@gmail.com> writes:
# > Hello All,
# >
# > I've got code like this...
# >
# > #ifdef SYMBOL

On the command line include -DSYMBOL to simulate
#define SYMBOL
and -DSYMBOL=VALUE for
#define SYMBOL VALUE

For example,
(cd /tmp
cat >t.c <<':eof'
#include <stdio.h>
int main(int n,char **p) {
#ifdef P
printf("P\n");
#endif
#ifdef Q
printf("Q\n");
#endif
printf("least random number %d\n",R);
return 0;
}
:eof
cc -DP -DR=17 t.c
a.out)

# "info gcc" should give you the gcc documentation on most systems.

Once again wasting more bandwidth not answerring the question then
a simple answer would've provided.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
No pleasure, no rapture, no exquisite sin greater than central air.

[Keith Thompson]

SM Ryan <wy*****@tango-sierra-oscar-foxtrot-tango.fake.org> writes:
[...]

Once again wasting more bandwidth not answerring the question then
a simple answer would've provided.

Somebody else had mentioned "-D" before I posted.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.