Old Content:

asmParser – A Lesson In Research

May 7, 2009 by Kyle Brady
Tags: Assembly, Code, CS47, Inline Assembly
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In my CS47 class, we've just started working on using Inline Assembly (assembly code processing built into the gcc compiler), and I thought the way you do it is pretty ugly.  The assembly, which is put inside a C file, looks like this:

asm("command1\t\n","command2\t\n","command3\t\n");

Keep in mind that's wrapped inside a C file.  Assembly.  In a C file.

Naturally, I thought there was probably a more clever way to do this - I knew that asm() wasn't a true function, that it was a compiler instruction, but I assumed that it would pretend to be like a function and accept a variable as an argument.

Nope.

But I didn't discover that I was wrong until I got weird errors while compiling:

gcc -S -masm=intel ./asmParser.c

-> error: argument of 'asm' is not a constant string

This is when I jumped onto #c on irc.freenode.net, and was essentially laughed at.  I guess that's what I get for trying to be clever... too clever.

You can find the everything-works-but-the-asm()-part code here with the exampleCommands file, or download everything as a zip file.

Next time I'm going to do a little more research!

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