question on conditional compilation

Thread Tools Search this Thread
Top Forums Programming question on conditional compilation
# 1  
Old 09-17-2007
question on conditional compilation

Hey, can I #define something outside the source file ?

I have a C program which uses #ifdef..

#ifdef ABC
 ... do this..
 ... that ...

The usual way that I know of defining ABC is in the source/header file

#define ABC

But is there any other way to do that ? Maybe as an option to pass to the compiler ?

The reason is, I just want to run one script/makefile which will compile both versions of the progra, with ABC defined and without ABC defined.. without having to make changes in the source code.
# 2  
Old 09-17-2007
Indeed there are more options.

1. Put the define in a common include file, such as 'config.h'

2. Put the define in a compiler option, normally it's

$(CC) $(CFLAGS)  -DMYDEFINE[=myvalue] ....

3. Put the define in a makefile variable


# 3  
Old 09-18-2007
Thanks buddy !!
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Conditional IF Question

I trying to get a simple script to see if a directory contains any files in it. I am failing on the conditional IF statement. I am not sure if it because the command I am using is creating the variable as a string or if it is numeric or if I just have the syntax wrong. #!/usr/bin/ksh... (2 Replies)
Discussion started by: awkwardone
2 Replies

2. Programming

Compilation C program

Hi guys... Im trying to compile a program written in C.. I am able to compile it to X86, especifically Ubuntu.. But i cant compile it to mips ar71xx architecture.. im using mips-linux-uclibc-gcc cross compiler. this is the portion of code: //STAT: LOGIN INFO // 3. login info i =... (3 Replies)
Discussion started by: lordtrex
3 Replies

3. Shell Programming and Scripting


Hi All, Do we have a way to compile a shell program? I am using ksh/bash/sh and not CSH. Cheers Ravi (12 Replies)
Discussion started by: panyam
12 Replies

4. Shell Programming and Scripting

Easy if conditional question.

I'm just starting this whole scripting thing, and I'm trying to write a simple script which will ask the user to press a key between 3-7. If they press a key that's not between 3-7, it will tell the user such. Here's my script: #!/bin/bash blah=1 echo -n "Press a key from 3-7." read... (3 Replies)
Discussion started by: SlickStretch
3 Replies

5. Programming

C Compilation problem

Dear all I am new to C programming In response to the post cat get_time.c #include <stdlib.h> #include <sys/time.h> main() { struct timeval tv; struct timezone tz; struct tm *tm; gettimeofday(&tv, &tz); tm=localtime(&tv.tv_sec); printf("... (2 Replies)
Discussion started by: on9west
2 Replies

6. Programming

Conditional Compilation based on Environmental Variable in Unix

I want to be able to access an environment variable to control how a program is compiled. So: export MY_VERSN=9 Then ideally, within my C++ code, I would have #if MY_VERSN = 9 iret = FRED9() #else iret = FRED() #endif The way I thought I could do it is that in the script that... (2 Replies)
Discussion started by: BrighterLater
2 Replies

7. UNIX for Advanced & Expert Users

Makefile conditional compilation giving error

Hi , Please answer my query: I want to create a common make file for one of mylibrary such that it should work on both Sun as well as Linux on 32 and 64 bit system. The flow is sth like this: .............. .............. if$(OS) == solaris BINDIR= ../../lib/solaris/64 else BINDIR=... (1 Reply)
Discussion started by: unisuraj
1 Replies

8. UNIX for Dummies Questions & Answers


Hi All, We have a C program existing in one of the folders which I have to modify a lil bit, When I'm trying to compile the program using GCC or CC command its showing as ksh: gcc: not found is that mean there is no compiler or do I have to verify for something, please advice Thank... (2 Replies)
Discussion started by: diggermf
2 Replies

9. Programming

C Question compilation error

What does the following mean: state_field state_abvr = { "AL","ALABAMA", "AK","ALASKA", . . . }; extern state_field state_abvr; issues we I am facing following compilation issue bosdf9d1:root make CC -I/bto/bcs/shared/include -I/bto/sys/BCS/usr/include ... (1 Reply)
Discussion started by: jaganreddy
1 Replies

10. Programming

compilation problem

i have a class name 1.c in tht i am using function n wich has his body in 2.c and declaration in 2.h now how can i compile 1.c. ex; 1.c int main() { //some data n(10); //somedata } ***** 2.c int n(int k) { //some data } int main() { some data (2 Replies)
Discussion started by: phani_sree
2 Replies
Login or Register to Ask a Question