Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/altsrcs/1/1952

Internet Message Format | 1990-12-28 | 7KB

From: [e-mail] (Jean-Pierre Radley)
Newsgroups: alt.sources
Subject: [comp.lang.c] Re: Converting long variable names to names <8 characters
Message-ID: <[e-mail]>
Date: 14 Oct 90 20:28:26 GMT

Archive-name: unique-nms/13-Oct-90
Original-posting-by: [e-mail] (Jean-Pierre Radley)
Original-subject: Re: Converting long variable names to names <8 characters
Reposted-by: [e-mail] (Edward Vielmetti)

[Reposted from comp.lang.c.
Comments on this service to [e-mail] (Edward Vielmetti).]

In article <[e-mail]> [e-mail] (Peter Marshall) writes:
>
>Most code these days uses variables that have more than 8 significant
>characters.  I recently purchased a system (a convergent CG1000
>Miniframe -- a Motorola 68010 based system) that has a compiler that
>has the original 8 character limit on variable names.  I haven't been
>able to find a conversion routine that would systematically convert
>long names to shorter ones.  Is there such a beast?
>
>One of the primary candidates for conversion would be the gcc
>compiler.  Once it is running, I suspect that file name problems would
>be either eliminated or at least reduced (I have not yet determined
>the limitations of the linker).  Is there either a version of gcc that
>has been hand converted to 8 character names or a binary that would be
>compatible with my machine available?


By our late friend Fred Buck:


:
# Name: unique_nms
#
# Usage: unique_nms [ -y ] [ -v ] [ tagfilename ]
#
# Description: from the set of C source files in the current directory
# (i.e., *.c and *.h), detects function names that aren't unique within
# their first seven characters, and rewrites each reference to such
# functions (including their definitions) with a unique prefix.
#
# If a tagfilename is specified, then the specified tagfilename is
# taken to be a file created by 'ctags', representing the contents of
# the C source files in the current directory, and up to date.  If no
# tagfilename is specified, "tags" is assumed to be the tagfilename.
# The script prompts for whether to restrict the edit to the files
# specifically mentioned in the tagfile, regardless of whether a
# tagfilename is specified on the command line.
#
# If the "-y" (for "yes" or "affirmative") switch is present, no
# prompting will occur; the responses to all ordinary prompts will be
# assumed to be "yes".
#
# If the "-v" (for "void") switch is present, then if a tags file must
# be built, it will be built from copies of the specified source files
# with references to the "void" type removed.  This is for versions of
# 'ctags' that don't know about the "void" data type.  The implementation
# is crude, requiring a physical copy of each source file so as not to
# disturb the original.  The Tandy 6000 requires this switch for any
# source fileset that contains "void" functions.
#
# Notes: this script generates a 'sed' scriptfile called "sedfile$$"
# where "$$" is the current process number.  This file can be referred
# to to keep track of changes made in the original source files; it's
# pretty easy to reverse the changes made by this script with simple
# massaging of the sedfile and re-running 'sed'.
#
# Copyright: this script was written by Fred Buck, who hereby releases
# it into the public domain and expressly waives all copyright or
# similar rights with respect to it.  This script is public property.
# However, liability is disclaimed for any consequences of use of
# this script.

trap "rm -f TEMP$$ *@ tags$$ /tmp/tag$$; exit 1" 1 2 15

# affirmative mode?
if [ $# -gt 0 -a "$1" = "-y" ]
then
    AFFIRM="yes"
    shift
else
    AFFIRM="no"
fi

# anti-void mode?
if [ $# -gt 0 -a "$1" = "-v" ]
then
    VOID="yes"
    shift
else
    VOID="no"
fi


# usage section
case $# in
0)
    TAGFILE="tags"                ;;
1)    if [ ! -r $1 ]
    then
        echo "$0: can't open $1"
        exit 1
    else
        TAGFILE="$1"
    fi                    ;;
*)    echo "usage: $0 [ -y ] [ -v ] [ tagfilename ]"
    exit 1                    ;;
esac

# check for readability of specified tags file
if [ ! -r "$TAGFILE" ]
then
    if [ "$AFFIRM" = "no" ]
    then
        echo -n "'tags' file doesn't exist; generate it? "
        read yesno
        case $yesno in
            [Yy]*)                    ;;
            *)    echo "can't work without a tags file"
            exit 1                    ;;
        esac
    fi
    echo "calling 'ctags'....."
    if [ "$VOID" = "no" ]
    then
        ctags *.c *.h
    else
        for SFILE in *.c *.h
        do
            0<$SFILE sed \
                -e 's/^void//'\
                -e 's/^static void/static/'\
            1>$SFILE@
        done
        ctags *.c@ *.h@
        mv tags tags$$
        TAGFILE=/tmp/tag$$
        0<tags$$ sed 's/@//' 1>$TAGFILE
        rm tags$$
    fi
else
    echo "The tags file is stamped as follows:"
    echo
    ls -l ./$TAGFILE
    echo
    if [ "$AFFIRM" = "no" ]
    then
        echo -n "Use it? "
        read yesno
        case $yesno in
        [Yy]*)        echo "OK."                ;;
        *)        echo "can't work without a tags file"
                exit 1                    ;;
        esac
    fi
fi

# get to work

                # first, find names ambiguous in 1st 7 chars;
                # and build a sed scriptfile to disambiguate 'em
                # (scriptfile will be sedfile$$).  This logic
                # will accommodate up to about seventeen
                # thousand ambiguous function names, with
                # gradually increasing probability that
                # some "[A-Z][A-Z][A-Z]_*" names may become
                # ambiguous.
echo "Building edit scriptfile for ambiguous function names....."
0<$TAGFILE awk '
    BEGIN {
        a = "ABCDEFGFHIJKLMNOPQRSTUVWXYZ"
        i1 = 1
        i2 = 0
        i3 = 0
        l1 = 1
        l2 = 0
        l3 = 0
    }
    { if (substr($1,1,7) == prevsub) {
        prefix = substr(a,i3,l3) substr(a,i2,l2) substr(a,i1,l1)
        printf "s/^%s(/%s_&/\n", $1, prefix
        printf "s/\\([^_]\\)\\(%s(\\)/\\1%s_\\2/g\n", $1, prefix
        printf "s/\\([, \t]\\)\\(%s[^A-Za-z0-9_]\\)/\\1%s_\\2/g\n", \
            $1, prefix
        ++i1
        if (i1 > 26) {
            i1 = 1
            ++i2
            l2 = 1
        }
        if (i2 > 26) {
            i2 = 1
            ++i3
            l3 = 1
        }
        if (i3 > 26) exit(1)
      }
    }
    { prevsub = substr($1,1,7)
    }'                1>sedfile$$

    if [ $? -gt 0 ]
    then
        echo "Fatal error: 'awk' failure" 1>&2
        exit 1
    fi

                # if the sedfile is empty, bail out
if [ ! -s sedfile$$ ]
then
    echo "All names in '$TAGFILE' are unique within the first 7 characters."
    rm -f sedfile$$ /tmp/tag$$
    exit 0
fi

                # let the user look over the sedfile first
if [ "$AFFIRM" = "no" ]
then
    echo "Sed command file contains:"
    /usr/bin/less sedfile$$
    echo -n " -- go ahead with edit? "
    read yesno
    case $yesno in
        [Yy]*) echo ;;
        *)     exit 1 ;;
    esac
    echo -n "Restrict edit to files mentioned in '$TAGFILE'? "
    read yesno
    case $yesno in
        [Yy]*) TARGETS=`0<$TAGFILE awk '{ print $2 }' | sort -u` ;;
        *)     TARGETS=`echo *.c *.h`                 ;;
    esac
else
    echo "Restricting edit to files mentioned in '$TAGFILE'."
    TARGETS=`0<$TAGFILE awk '{ print $2 }' | sort -u`
fi
echo "About to edit: $TARGETS" | tr '\012' ' '
echo

                # finally, run the 'sed' commandfile on
                # the files mentioned in $TAGFILE
for FILE in $TARGETS
do
    echo "Editing $FILE:"
    0<$FILE sed -f sedfile$$ 1>TEMP$$
    if [ $? -eq 0 ]
    then
        mv TEMP$$ $FILE
        echo "    $FILE successfully edited"
    else
        echo "  Can't edit $FILE!"
    fi
done
rm -f TEMP$$
--
 Jean-Pierre Radley          HIGH-Q         jpr@jpradley    CIS: 72160,1341