8

I have some C code that I want to insert in a LaTeX document using a listing. I also want to display its translation to assembly code. I don't know how to display those two kind of codes in a multicolumn view, so to give the reader the possibility to make a quick comparison between C code and assembly code. I don't need to have the lines of C aligned with their correspondent assembly instructions since I think this is not going to be easy to do. What I need is just to show the two codes side by side. Can you help me?

Thanks

lockstep
  • 250,273
Raffo
  • 305

2 Answers2

11

You may try parcolumns package.

See also other question: Of parallel texts, lists and display equations.

Example

\documentclass[12pt]{article}
\usepackage[a4paper,margin=1cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[scaled=0.82]{beramono}
\usepackage{pifont,calc,xcolor}
\usepackage{parcolumns}
\usepackage{listings}
\definecolor{verylightgray}{gray}{0.85}
\newlength\lsthorizontalpadding
\setlength\lsthorizontalpadding{3pt}
\newcommand*\lstnumberstyle{\ttfamily\scriptsize}
\newlength\lstnumbersep
\setlength\lstnumbersep{10pt}
\newlength\lstnumberwidth
\setlength\lstnumberwidth{\widthof{\lstnumberstyle00}+\lstnumbersep+\lsthorizontalpadding}
\lstset{
    ,basicstyle=\ttfamily%
    ,breaklines=true%
    ,tabsize=4%
    ,showstringspaces=false%
    ,numbers=left%
    ,numbersep=\lstnumbersep%
    ,numberstyle=\lstnumberstyle%
    ,framesep=0pt%
    ,xleftmargin=\lstnumberwidth%
    ,framexleftmargin=\lsthorizontalpadding%
    ,xrightmargin=\lsthorizontalpadding%
    ,framexrightmargin=\lsthorizontalpadding%
    ,backgroundcolor=\color{verylightgray}%
    ,postbreak=\ding{229}\space%
}
%% far from complete list of gasm-specific keywords and instructions in AT&T syntax
\lstdefinelanguage[x86gasm]{Assembler}[x86masm]{Assembler}{%
    ,morekeywords={rax,rbx,rcx,rdx,rip,rdi,rsi,rsp,subq,decl,movq,movl,xorl,imull,popq}%
    ,morekeywords=[2]{.file,.section,.string,.text,.globl,.cfi_startproc,.cfi_def_cfa_offset,.cfi_endproc,.size,.ident}%
}
\lstnewenvironment{ccol}[1][]{\lstset{language=c,#1}}{}
\lstnewenvironment{acol}[1][]{\lstset{language=[x86gasm]Assembler,#1}}{}
\pagestyle{empty}
\parindent=0pt
\begin{document}
\texttt{gcc} on \texttt{text.c} file (left side) [\texttt{gcc -S -Os text.c}] gives following assembler code (right side):
\begin{parcolumns}{2}
\colchunk[1]{\begin{ccol}
#include <stdio.h>

int main(int argc, char *argv[])
{
    int t;

    if (argc < 2) {
        fprintf(stderr, "Not enough arguments!\n");
        return 1;
    }

    t = atoi(argv[1]);
    printf("%d^2 = %d\n", t, t * t);

    return 0;
}
\end{ccol}}
\colchunk[2]{\begin{acol}
    .file   "test.c"
    .section    .rodata.str1.1,"aMS",@progbits,1
.LC0:
    .string "Not enough arguments!\n"
.LC1:
    .string "%d^2 = %d\n"
    .text
.globl main
    .type   main, @function
main:
.LFB0:
    .cfi_startproc
    subq    $8, %rsp
    .cfi_def_cfa_offset 16
    decl    %edi
    jg  .L2
    movq    stderr(%rip), %rsi
    movl    $.LC0, %edi
    call    fputs
    movl    $1, %eax
    jmp .L3
.L2:
    movq    8(%rsi), %rdi
    xorl    %eax, %eax
    call    atoi
    movl    %eax, %edx
    movl    %eax, %esi
    movl    $.LC1, %edi
    imull   %eax, %edx
    xorl    %eax, %eax
    call    printf
    xorl    %eax, %eax
.L3:
    popq    %rdx
    ret
    .cfi_endproc
.LFE0:
    .size   main, .-main
    .ident  "GCC: (Debian 4.4.5-8) 4.4.5"
    .section    .note.GNU-stack,"",@progbits
\end{acol}}
\end{parcolumns}
\end{document}

enter image description here

Community
  • 1
przemoc
  • 2,142
9

The code can be displayed using the listings package. The side by side effect I would do using two minipages as shown below. In general you have to be careful because the listings are verbatim material and don't work inside the arguments of other macros. (Using saveboxes helps here)

\documentclass{article}

\usepackage[T1]{fontenc}
\usepackage{lmodern}

\usepackage{listings}
\usepackage{lipsum}

\lstset{basicstyle=\ttfamily\scriptsize}
\begin{document}

\lipsum[1]

\par\noindent
\begin{minipage}[t]{.45\textwidth}
\begin{lstlisting}[language=C,frame=lrtb]
   int function test(int a) {
         return a;
   }
\end{lstlisting}%
\end{minipage}%
\hfill
\begin{minipage}[t]{.45\textwidth}
\begin{lstlisting}[frame=lrtb]
   TEST:
       goto SOMEWHERE
\end{lstlisting}%
\end{minipage}%

\lipsum[2]

\end{document}

Result

Martin Scharrer
  • 262,582