Re: [PATCH] styleguide: Expand on goal of new snippet scheme

[Akira Yokosawa <akiyks@gmail.com>]

On 2018/11/18 13:52, Paul E. McKenney wrote:
> On Sun, Nov 18, 2018 at 12:17:33AM +0900, Akira Yokosawa wrote:
>> >From 0590665e74862cbbe59a432313cb36d55f8cee92 Mon Sep 17 00:00:00 2001
>> From: Akira Yokosawa <akiyks@gmail.com>
>> Date: Sun, 18 Nov 2018 00:04:46 +0900
>> Subject: [PATCH] styleguide: Expand on goal of new snippet scheme
>>
>> Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
> 
> I applied both, thank you very much!
> 
> As usual, I could not resist a bit of editing.  Could you please check
> below to catch anything I might have messed up?

I checked the diff of both branches and your edit looks much easier
to follow!

        Thanks, Akira

> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> commit 201ccf123685542f759e66f053d09bce4ca1d0ff
> Author: Akira Yokosawa <akiyks@gmail.com>
> Date:   Sun Nov 18 00:04:46 2018 +0900
> 
>     styleguide: Expand on goal of new snippet scheme
>     
>     Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
>     Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
>     [ paulmck: Update flow and style. ]
> 
> diff --git a/appendix/styleguide/samplecodesnippetfcv.tex b/appendix/styleguide/samplecodesnippetfcv.tex
> index 4e03b2aaf3ca..b47b7f59c324 100644
> --- a/appendix/styleguide/samplecodesnippetfcv.tex
> +++ b/appendix/styleguide/samplecodesnippetfcv.tex
> @@ -1,5 +1,5 @@
>  \begin{listing}[tb]
> -\begin{linelabel}[ln:base1]			%lnlbl~linelabel^
> +\begin{linelabel}[ln:base1]			%lnlbl~beg:linelabel^
>  \begin{VerbatimL}[commandchars=\$\[\]]
>  /*
>   * Sample Code Snippet
> @@ -11,7 +11,7 @@ int main(void)
>  	return 0;			$lnlbl[return]
>  }
>  \end{VerbatimL}
> -\end{linelabel}
> +\end{linelabel}					%lnlbl~end:linelabel^
>  \caption{Sample Code Snippet}
>  \label{lst:app:styleguide:Sample Code Snippet}
>  \end{listing}
> diff --git a/appendix/styleguide/samplecodesnippetlst.tex b/appendix/styleguide/samplecodesnippetlst.tex
> index b18922e763b3..43638b6f3137 100644
> --- a/appendix/styleguide/samplecodesnippetlst.tex
> +++ b/appendix/styleguide/samplecodesnippetlst.tex
> @@ -1,4 +1,4 @@
> -\begin{listing}
> +\begin{listing}[tb]
>  { \scriptsize
>  \begin{verbbox}[\LstLineNo]
>  /*
> diff --git a/appendix/styleguide/samplecodesnippetlstlbl.tex b/appendix/styleguide/samplecodesnippetlstlbl.tex
> index d3e4a9533d89..c0558d8eb2cd 100644
> --- a/appendix/styleguide/samplecodesnippetlstlbl.tex
> +++ b/appendix/styleguide/samplecodesnippetlstlbl.tex
> @@ -1,4 +1,4 @@
> -\begin{listing}
> +\begin{listing}[tb]
>  { \scriptsize
>  \begin{verbbox}[\LstLineNo] %lnlbl@lineno$
>  /*				%lnlbl@b$
> diff --git a/appendix/styleguide/styleguide.tex b/appendix/styleguide/styleguide.tex
> index 058789803f59..3fe79ceb5b04 100644
> --- a/appendix/styleguide/styleguide.tex
> +++ b/appendix/styleguide/styleguide.tex
> @@ -322,13 +322,31 @@ This section explains the use cases of such macros and environments.
>  \subsubsection{Code Snippet}
>  \label{sec:app:styleguide:Code Snippet}
>  
> -Because the \qco{verbatim} environment is a primitve way to include
> +Because the \qco{verbatim} environment is a primitive way to include
>  listings, we are transitioning to a new scheme which uses
>  the \qco{fancyvrb} package for code snippets.
>  
> -Three customized environments of \qco{Verbatim} are defined
> -for perfbook.
> +The goal of the new scheme is to extract \LaTeX\ sources of
> +code snippets directly from code samples under \path{CodeSamples}
> +directory.
> +It also makes it possible to embed line labels in the code samples,
> +which can be referred from the text.
> +This reduces the burden of keeping line numbers
> +in the text consistent with those in code snippets.
>  
> +Code-snippet extraction is handled by a couple of
> +perl scripts and recipes in Makefile.
> +We use the \co{fancyvrb} package's escaping feature
> +to embed line labels in comments.
> +
> +We used to use the \qco{verbbox} environment provided
> +by the \qco{verbatimbox} package.
> +Section~\ref{sec:app:styleguide:Code Snippet (Obsolete)} describes how
> +\co{verbbox} can automatically generate line numbers,
> +but these line numbers cannot be referenced from the text.
> +
> +Let's start by looking at how code snippets are coded in the new scheme.
> +There are three customized environments of \qco{Verbatim}.
>  \qco{VerbatimL} is for floating snippets within the \qco{listing}
>  environment. \qco{VerbatimN} is for inline snippets with line count
>  enabled. \qco{VerbatimU} is for inline snippets without line count.
> @@ -349,20 +367,6 @@ They are defined in the preamble as shown below:
>      samepage=true,frame=single}
>  \end{VerbatimU}
>  
> -We used to use the \qco{verbbox} environment provided
> -by the \qco{verbatimbox} package. As will be described later in
> -Section~\ref{sec:app:styleguide:Code Snippet (Obsolete)},
> -\co{verbbox} has the capability of automatic
> -line numbering. However, it is not possible to embed labels on lines
> -in the snippet to refer from the text.
> -
> -The \co{fancyvrb} package allows us to do that by the help of
> -escaping feature.
> -And the \LaTeX\ sources of snippets can be extracted from code samples under
> -the \path{CodeSamples} directory of perfbook tree.
> -
> -Conversion to the new scheme is currently underway.
> -
>  % Another option would be the ``lstlisting'' environment provided
>  %  by the ``listings'' package. We are already using its ``lstinline''
>  %  command in the definition of \co{\\co\{\}} macro.
> @@ -410,13 +414,39 @@ to from text.
>  \end{lineref}
>  \end{quote}
>  
> -\LaTeX\ source shown in
> +Macros \qco{\\lnlbl\{\}} and \qco{\\lnref\{\}} are defined in
> +the preamble as follows:
> +
> +\begin{VerbatimU}
> +\newcommand{\lnlblbase}{}
> +\newcommand{\lnlbl}[1]{%
> +  \phantomsection\label{\lnlblbase:#1}}
> +\newcommand{\lnrefbase}{}
> +\newcommand{\lnref}[1]{\ref{\lnrefbase:#1}}
> +\end{VerbatimU}
> +
> +Environments \qco{linelabel} and \qco{lineref} are defined as
> +shown below:
> +
> +\begin{VerbatimU}
> +\newenvironment{linelabel}[1][]{%
> +  \renewcommand{\lnlblbase}{#1}%
> +  \ignorespaces}{\ignorespacesafterend}
> +\newenvironment{lineref}[1][]{%
> +  \renewcommand{\lnrefbase}{#1}%
> +  \ignorespaces}{\ignorespacesafterend}
> +\end{VerbatimU}
> +
> +\begin{lineref}[ln:app:styleguide:LaTeX Source of Sample Code Snippet (Current)]
> +The main part of \LaTeX\ source shown on
> +Lines~\lnref{beg:linelabel}-\lnref{end:linelabel} in
>  Listing~\ref{lst:app:styleguide:LaTeX Source of Sample Code Snippet (Current)}
>  can be extracted from a code sample of
>  Listing~\ref{lst:app:styleguide:Source of Code Sample} by a perl script
>  \path{utilities/fcvextract.pl}. All the relevant rules of extraction
>  are described as recipes in the top level \path{Makefile} and
>  a script to generate dependencies (\path{utilities/gen_snippet_d.pl}).
> +\end{lineref}
>  
>  \begin{listing}[tb]
>  \fvset{fontsize=\scriptsize,numbers=left,numbersep=5pt,xleftmargin=9pt,obeytabs=true,tabsize=8}
> @@ -427,7 +457,7 @@ a script to generate dependencies (\path{utilities/gen_snippet_d.pl}).
>  \end{listing}
>  
>  As you can see, Listing ~\ref{lst:app:styleguide:Source of Code Sample}
> -has meta commands in comments of C (C++ style). These meta commands
> +has meta commands in comments of C (C++ style). Those meta commands
>  are interpreted by \path{utilities/fcvextract.pl}, which distinguishes
>  the type of comment style by the suffix of code sample's file name.
>  
> @@ -446,15 +476,17 @@ labelbase=<label base string>
>  commandchars=\X\Y\Z
>  \end{VerbatimU}
>  
> -The string given to \qco{labelbase} will be converted to
> +The string given to \qco{labelbase} will be passed to
>  ``\co{\\begin\{linelabel\}[<label base string>]}'' command as shown on
> -line~\ref{ln:app:styleguide:LaTeX Source of Sample Code Snippet (Current):linelabel} of
> +line~\ref{ln:app:styleguide:LaTeX Source of Sample Code Snippet (Current):beg:linelabel} of
>  Listing~\ref{lst:app:styleguide:LaTeX Source of Sample Code Snippet (Current)}.
>  \qco{commandchars} option is given to the \co{VerbatimL} environment as is.
>  Other types of options, if any, are also passed to the \co{VerbatimL}
>  environment.
> -The \qco{lnlbl} commands are converted to reflect the escape-character choice
> -along the way.
> +The \qco{lnlbl} commands are converted along the way to reflect
> +the escape-character choice.\footnote{
> +	Characters forming comments are also gobbled up.
> +}
>  
>  There can be multiple pairs of \co{\\begin\{snippet\}} and \co{\\end\{snippet\}}
>  as long as they have unique \qco{labelbase} strings.
> @@ -492,7 +524,7 @@ Comments in this part should be of the form \qco{(* ... *)}.
>  
>  You can't use \qco{\{} and \qco{\}} in comments in litmus tests, either.
>  
> -Example of disallowed comments in a litmus test are shown below:
> +Examples of disallowed comments in a litmus test are shown below:
>  
>  \begin{linelabel}[ln:app:styleguide:Bad comments in Litmus Test]
>  \begin{VerbatimN}[tabsize=8]
>