compile with -ansi -pedantic -Wall switches automatically with gcc

Question

We are required to compile C source codes using gcc in this manner:

gcc -ansi -pedantic -Wall program.c

I'm wondering how can I 'automate' this so when I enter:

gcc program.c

It will automatically compile with the 3 switches. Is this possible?

Answer 1

To automate the build of any number of build steps / complex parameters, you should use a makefile.

Once you have a makefile you simply need to type: make

Answer 2

alias gcc="gcc -ansi -pedantic -Wall"

But as @Brian said, you really should use a makefile, or better, a build system like CMake or SCons.

Answer 3

A makefile would be the traditional way, especially as part of a larger build process.

If you frequently want to build without a makefile, you could define an alias in your .bashrc or equivalent: alias gcc=gcc -ansi -pedantic -Wall.

Answer 4

You can also use the implicit rules of make, so that you don't have to write a makefile for every program. Make will automatically call the compiler if you say make foo and there exists a foo.c file in the current directory. To add flags to this define the variable CFLAGS in your environment, e.g. in bash add export CFLAGS="-Wall -pedantic -ansi" to .bashrc.

If your program depends on multiple files however you'll have to create a makefile, but for C compilation you can get away with just listing dependancies so long as one of them has the same base name as a target.

For example for this makefile:

# Makefile
foo:foo.o bar.o

running make will execute the commands

gcc $CFLAGS -c -o foo.o foo.c
gcc $CFLAGS -c -o bar.o bar.c
gcc -o foo foo.o bar.o

without you having to add any rules.

Answer 5

You can use a shell script that takes some cues by how its called and invokes make after setting CFLAGS appropriately for the occasional one-off build.

Lets say you have /usr/bin/compile , which is a shell script that looks at $0 to see what name actually invoked it. You then make symbolic links to it named pedantic, fullwarn, etc.

In the shell script itself, something like:

OLDCFLAGS=$CFLAGS
WHATAMI=$(basename $0)

case "$WHATAMI" in
    pedantic)
        export CFLAGS="-Wall -pedantic -ansi"
        make $@
        exit $?
    ;;
    c99)
        export CFLAGS="-std=c99 ... ... ..."
        ....

Then, to compile foo.c with the extra naggy flags:

pedantic foo

This is handy, as I said for one-off builds, e.g trying to compile code that someone posted in a question, or working out how to use a new library, etc.

For anything else, just use a makefile, as others have said.