path: root/library/auto.tcl

# auto.tcl --
#
# utility procs formerly in init.tcl dealing with auto execution
# of commands and can be auto loaded themselves.
#
# RCS: @(#) $Id: auto.tcl,v 1.25 2005/06/24 15:06:23 dgp Exp $
#
# Copyright (c) 1991-1993 The Regents of the University of California.
# Copyright (c) 1994-1998 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#

# auto_reset --
#
# Destroy all cached information for auto-loading and auto-execution,
# so that the information gets recomputed the next time it's needed.
# Also delete any commands that are listed in the auto-load index.
#
# Arguments: 
# None.

proc auto_reset {} {
    if {[array exists ::auto_index]} {
	foreach cmdName [array names ::auto_index] {
	    set fqcn [namespace which $cmdName]
	    if {$fqcn eq ""} {continue}
	    rename $fqcn {}
	}
    }
    unset -nocomplain ::auto_execs ::auto_index ::tcl::auto_oldpath
    if {[catch {llength $::auto_path}]} {
	set ::auto_path [list [info library]]
    } else {
	if {[info library] ni $::auto_path} {
	    lappend ::auto_path [info library]
	}
    }
}

# tcl_findLibrary --
#
#	This is a utility for extensions that searches for a library directory
#	using a canonical searching algorithm. A side effect is to source
#	the initialization script and set a global library variable.
#
# Arguments:
# 	basename	Prefix of the directory name, (e.g., "tk")
#	version		Version number of the package, (e.g., "8.0")
#	patch		Patchlevel of the package, (e.g., "8.0.3")
#	initScript	Initialization script to source (e.g., tk.tcl)
#	enVarName	environment variable to honor (e.g., TK_LIBRARY)
#	varName		Global variable to set when done (e.g., tk_library)

proc tcl_findLibrary {basename version patch initScript enVarName varName} {
    upvar #0 $varName the_library
    global env

    set dirs {}
    set errors {}

    # The C application may have hardwired a path, which we honor

    set variableSet [info exists the_library]
    if {$variableSet && $the_library ne ""} {
	lappend dirs $the_library
    } else {

	# Do the canonical search

	# 1. From an environment variable, if it exists.
	#    Placing this first gives the end-user ultimate control
	#    to work-around any bugs, or to customize.

        if {[info exists env($enVarName)]} {
            lappend dirs $env($enVarName)
        }

	# 2. In the package script directory registered within
	#    the configuration of the package itself.

	if {[catch {
	    ::${basename}::pkgconfig get scriptdir,runtime
	} value] == 0} {
	    lappend dirs $value
	}

	# 3. Relative to auto_path directories.  This checks relative to the
	# Tcl library as well as allowing loading of libraries added to the
	# auto_path that is not relative to the core library or binary paths.
	foreach d $::auto_path {
	    lappend dirs [file join $d $basename$version]
	    if {$::tcl_platform(platform) eq "unix"
		&& $::tcl_platform(os) eq "Darwin"} {
		# 4. On MacOSX, check the Resources/Scripts subdir too
		lappend dirs [file join $d $basename$version Resources Scripts]
	    }
	}

	# 3. Various locations relative to the executable
	# ../lib/foo1.0		(From bin directory in install hierarchy)
	# ../../lib/foo1.0	(From bin/arch directory in install hierarchy)
	# ../library		(From unix directory in build hierarchy)
	#
	# Remaining locations are out of date (when relevant, they ought
	# to be covered by the $::auto_path seach above) and disabled.
	#
	# ../../library		(From unix/arch directory in build hierarchy)
	# ../../foo1.0.1/library
	#		(From unix directory in parallel build hierarchy)
	# ../../../foo1.0.1/library
	#		(From unix/arch directory in parallel build hierarchy)

        set parentDir [file dirname [file dirname [info nameofexecutable]]]
        set grandParentDir [file dirname $parentDir]
        lappend dirs [file join $parentDir lib $basename$version]
        lappend dirs [file join $grandParentDir lib $basename$version]
        lappend dirs [file join $parentDir library]
	if {0} {
	    lappend dirs [file join $grandParentDir library]
	    lappend dirs [file join $grandParentDir $basename$patch library]
	    lappend dirs [file join [file dirname $grandParentDir] \
			      $basename$patch library]
	}
    }
    # uniquify $dirs in order
    array set seen {}
    foreach i $dirs {
	# Take note that the [file normalize] below has been noted to
	# cause difficulties for the freewrap utility.  See Bug 1072136.
	# Until freewrap resolves the matter, one might work around the
	# problem by disabling that branch.
	if {[interp issafe]} {
	    set norm $i
	} else {
	    set norm [file normalize $i]
	}
	if {[info exists seen($norm)]} { continue }
	set seen($norm) ""
	lappend uniqdirs $i
    }
    set dirs $uniqdirs
    foreach i $dirs {
        set the_library $i
        set file [file join $i $initScript]

	# source everything when in a safe interpreter because
	# we have a source command, but no file exists command

        if {[interp issafe] || [file exists $file]} {
            if {![catch {uplevel #0 [list source $file]} msg opts]} {
                return
            } else {
                append errors "$file: $msg\n"
		append errors [dict get $opts -errorinfo]\n
            }
        }
    }
    if {!$variableSet} {
	unset the_library
    }
    set msg "Can't find a usable $initScript in the following directories: \n"
    append msg "    $dirs\n\n"
    append msg "$errors\n\n"
    append msg "This probably means that $basename wasn't installed properly.\n"
    error $msg
}


# ----------------------------------------------------------------------
# auto_mkindex
# ----------------------------------------------------------------------
# The following procedures are used to generate the tclIndex file
# from Tcl source files.  They use a special safe interpreter to
# parse Tcl source files, writing out index entries as "proc"
# commands are encountered.  This implementation won't work in a
# safe interpreter, since a safe interpreter can't create the
# special parser and mess with its commands.  

if {[interp issafe]} {
    return	;# Stop sourcing the file here
}

# auto_mkindex --
# Regenerate a tclIndex file from Tcl source files.  Takes as argument
# the name of the directory in which the tclIndex file is to be placed,
# followed by any number of glob patterns to use in that directory to
# locate all of the relevant files.
#
# Arguments: 
# dir -		Name of the directory in which to create an index.
# args -	Any number of additional arguments giving the
#		names of files within dir.  If no additional
#		are given auto_mkindex will look for *.tcl.

proc auto_mkindex {dir args} {
    if {[interp issafe]} {
        error "can't generate index within safe interpreter"
    }

    set oldDir [pwd]
    cd $dir
    set dir [pwd]

    append index "# Tcl autoload index file, version 2.0\n"
    append index "# This file is generated by the \"auto_mkindex\" command\n"
    append index "# and sourced to set up indexing information for one or\n"
    append index "# more commands.  Typically each line is a command that\n"
    append index "# sets an element in the auto_index array, where the\n"
    append index "# element name is the name of a command and the value is\n"
    append index "# a script that loads the command.\n\n"
    if {[llength $args] == 0} {
	set args *.tcl
    }

    auto_mkindex_parser::init
    foreach file [glob {expand}$args] {
        if {[catch {auto_mkindex_parser::mkindex $file} msg opts] == 0} {
            append index $msg
        } else {
            cd $oldDir
	    return -options $opts $msg
        }
    }
    auto_mkindex_parser::cleanup

    set fid [open "tclIndex" w]
    puts -nonewline $fid $index
    close $fid
    cd $oldDir
}

# Original version of auto_mkindex that just searches the source
# code for "proc" at the beginning of the line.

proc auto_mkindex_old {dir args} {
    set oldDir [pwd]
    cd $dir
    set dir [pwd]
    append index "# Tcl autoload index file, version 2.0\n"
    append index "# This file is generated by the \"auto_mkindex\" command\n"
    append index "# and sourced to set up indexing information for one or\n"
    append index "# more commands.  Typically each line is a command that\n"
    append index "# sets an element in the auto_index array, where the\n"
    append index "# element name is the name of a command and the value is\n"
    append index "# a script that loads the command.\n\n"
    if {[llength $args] == 0} {
	set args *.tcl
    }
    foreach file [glob {expand}$args] {
	set f ""
	set error [catch {
	    set f [open $file]
	    while {[gets $f line] >= 0} {
		if {[regexp {^proc[ 	]+([^ 	]*)} $line match procName]} {
		    set procName [lindex [auto_qualify $procName "::"] 0]
		    append index "set [list auto_index($procName)]"
		    append index " \[list source \[file join \$dir [list $file]\]\]\n"
		}
	    }
	    close $f
	} msg opts]
	if {$error} {
	    catch {close $f}
	    cd $oldDir
	    return -options $opts $msg
	}
    }
    set f ""
    set error [catch {
	set f [open tclIndex w]
	puts -nonewline $f $index
	close $f
	cd $oldDir
    } msg opts]
    if {$error} {
	catch {close $f}
	cd $oldDir
	error $msg $info $code
	return -options $opts $msg
    }
}

# Create a safe interpreter that can be used to parse Tcl source files
# generate a tclIndex file for autoloading.  This interp contains
# commands for things that need index entries.  Each time a command
# is executed, it writes an entry out to the index file.

namespace eval auto_mkindex_parser {
    variable parser ""          ;# parser used to build index
    variable index ""           ;# maintains index as it is built
    variable scriptFile ""      ;# name of file being processed
    variable contextStack ""    ;# stack of namespace scopes
    variable imports ""         ;# keeps track of all imported cmds
    variable initCommands       ;# list of commands that create aliases
    if {![info exists initCommands]} {
	set initCommands [list]
    }

    proc init {} {
	variable parser
	variable initCommands

	if {![interp issafe]} {
	    set parser [interp create -safe]
	    $parser hide info
	    $parser hide rename
	    $parser hide proc
	    $parser hide namespace
	    $parser hide eval
	    $parser hide puts
	    $parser invokehidden namespace delete ::
	    $parser invokehidden proc unknown {args} {}

	    # We'll need access to the "namespace" command within the
	    # interp.  Put it back, but move it out of the way.

	    $parser expose namespace
	    $parser invokehidden rename namespace _%@namespace
	    $parser expose eval
	    $parser invokehidden rename eval _%@eval

	    # Install all the registered psuedo-command implementations

	    foreach cmd $initCommands {
		eval $cmd
	    }
	}
    }
    proc cleanup {} {
	variable parser
	interp delete $parser
	unset parser
    }
}

# auto_mkindex_parser::mkindex --
#
# Used by the "auto_mkindex" command to create a "tclIndex" file for
# the given Tcl source file.  Executes the commands in the file, and
# handles things like the "proc" command by adding an entry for the
# index file.  Returns a string that represents the index file.
#
# Arguments: 
#	file	Name of Tcl source file to be indexed.

proc auto_mkindex_parser::mkindex {file} {
    variable parser
    variable index
    variable scriptFile
    variable contextStack
    variable imports

    set scriptFile $file

    set fid [open $file]
    set contents [read $fid]
    close $fid

    # There is one problem with sourcing files into the safe
    # interpreter:  references like "$x" will fail since code is not
    # really being executed and variables do not really exist.
    # To avoid this, we replace all $ with \0 (literally, the null char)
    # later, when getting proc names we will have to reverse this replacement,
    # in case there were any $ in the proc name.  This will cause a problem
    # if somebody actually tries to have a \0 in their proc name.  Too bad
    # for them.
    set contents [string map [list \$ \0] $contents]

    set index ""
    set contextStack ""
    set imports ""

    $parser eval $contents

    foreach name $imports {
        catch {$parser eval [list _%@namespace forget $name]}
    }
    return $index
}

# auto_mkindex_parser::hook command
#
# Registers a Tcl command to evaluate when initializing the
# slave interpreter used by the mkindex parser.
# The command is evaluated in the master interpreter, and can
# use the variable auto_mkindex_parser::parser to get to the slave

proc auto_mkindex_parser::hook {cmd} {
    variable initCommands

    lappend initCommands $cmd
}

# auto_mkindex_parser::slavehook command
#
# Registers a Tcl command to evaluate when initializing the
# slave interpreter used by the mkindex parser.
# The command is evaluated in the slave interpreter.

proc auto_mkindex_parser::slavehook {cmd} {
    variable initCommands

    # The $parser variable is defined to be the name of the
    # slave interpreter when this command is used later.

    lappend initCommands "\$parser eval [list $cmd]"
}

# auto_mkindex_parser::command --
#
# Registers a new command with the "auto_mkindex_parser" interpreter
# that parses Tcl files.  These commands are fake versions of things
# like the "proc" command.  When you execute them, they simply write
# out an entry to a "tclIndex" file for auto-loading.
#
# This procedure allows extensions to register their own commands
# with the auto_mkindex facility.  For example, a package like
# [incr Tcl] might register a "class" command so that class definitions
# could be added to a "tclIndex" file for auto-loading.
#
# Arguments:
#	name 	Name of command recognized in Tcl files.
#	arglist	Argument list for command.
#	body 	Implementation of command to handle indexing.

proc auto_mkindex_parser::command {name arglist body} {
    hook [list auto_mkindex_parser::commandInit $name $arglist $body]
}

# auto_mkindex_parser::commandInit --
#
# This does the actual work set up by auto_mkindex_parser::command
# This is called when the interpreter used by the parser is created.
#
# Arguments:
#	name 	Name of command recognized in Tcl files.
#	arglist	Argument list for command.
#	body 	Implementation of command to handle indexing.

proc auto_mkindex_parser::commandInit {name arglist body} {
    variable parser

    set ns [namespace qualifiers $name]
    set tail [namespace tail $name]
    if {[string equal $ns ""]} {
        set fakeName "[namespace current]::_%@fake_$tail"
    } else {
	set fakeName [string map {:: _} "_%@fake_$name"]
        set fakeName "[namespace current]::$fakeName"
    }
    proc $fakeName $arglist $body

    # YUK!  Tcl won't let us alias fully qualified command names,
    # so we can't handle names like "::itcl::class".  Instead,
    # we have to build procs with the fully qualified names, and
    # have the procs point to the aliases.

    if {[string match "*::*" $name]} {
        set exportCmd [list _%@namespace export [namespace tail $name]]
        $parser eval [list _%@namespace eval $ns $exportCmd]
 
	# The following proc definition does not work if you
	# want to tolerate space or something else diabolical
	# in the procedure name, (i.e., space in $alias)
	# The following does not work:
	#   "_%@eval {$alias} \$args"
	# because $alias gets concat'ed to $args.
	# The following does not work because $cmd is somehow undefined
	#   "set cmd {$alias} \; _%@eval {\$cmd} \$args"
	# A gold star to someone that can make test
	# autoMkindex-3.3 work properly

        set alias [namespace tail $fakeName]
        $parser invokehidden proc $name {args} "_%@eval {$alias} \$args"
        $parser alias $alias $fakeName
    } else {
        $parser alias $name $fakeName
    }
    return
}

# auto_mkindex_parser::fullname --
# Used by commands like "proc" within the auto_mkindex parser.
# Returns the qualified namespace name for the "name" argument.
# If the "name" does not start with "::", elements are added from
# the current namespace stack to produce a qualified name.  Then,
# the name is examined to see whether or not it should really be
# qualified.  If the name has more than the leading "::", it is
# returned as a fully qualified name.  Otherwise, it is returned
# as a simple name.  That way, the Tcl autoloader will recognize
# it properly.
#
# Arguments:
# name -		Name that is being added to index.

proc auto_mkindex_parser::fullname {name} {
    variable contextStack

    if {![string match ::* $name]} {
        foreach ns $contextStack {
            set name "${ns}::$name"
            if {[string match ::* $name]} {
                break
            }
        }
    }

    if {[string equal [namespace qualifiers $name] ""]} {
        set name [namespace tail $name]
    } elseif {![string match ::* $name]} {
        set name "::$name"
    }

    # Earlier, mkindex replaced all $'s with \0.  Now, we have to reverse
    # that replacement.
    return [string map [list \0 \$] $name]
}

# Conditionally add support for Tcl byte code files.  There are some
# tricky details here.  First, we need to get the tbcload library
# initialized in the current interpreter.  We cannot load tbcload into the
# slave until we have done so because it needs access to the tcl_patchLevel
# variable.  Second, because the package index file may defer loading the
# library until we invoke a command, we need to explicitly invoke auto_load
# to force it to be loaded.  This should be a noop if the package has
# already been loaded

auto_mkindex_parser::hook {
    if {![catch {package require tbcload}]} {
	if {[llength [info commands tbcload::bcproc]] == 0} {
	    auto_load tbcload::bcproc
	}
	load {} tbcload $auto_mkindex_parser::parser

	# AUTO MKINDEX:  tbcload::bcproc name arglist body
	# Adds an entry to the auto index list for the given pre-compiled
	# procedure name.  

	auto_mkindex_parser::commandInit tbcload::bcproc {name args} {
	    variable index
	    variable scriptFile
	    # Do some nice reformatting of the "source" call, to get around
	    # path differences on different platforms.  We use the format
	    # command just so that the code is a little easier to read.
	    append index [list set auto_index([fullname $name])] \
		    [format { [list source [file join $dir %s]]} \
		    [file split $scriptFile]] "\n"
	}
    }
}

if {[llength $::auto_mkindex_parser::initCommands]} {
    return
}

# Register all of the procedures for the auto_mkindex parser that
# will build the "tclIndex" file.

# AUTO MKINDEX:  proc name arglist body
# Adds an entry to the auto index list for the given procedure name.

auto_mkindex_parser::command proc {name args} {
    variable index
    variable scriptFile
    # Do some fancy reformatting on the "source" call to handle platform
    # differences with respect to pathnames.  Use format just so that the
    # command is a little easier to read (otherwise it'd be full of 
    # backslashed dollar signs, etc.
    append index [list set auto_index([fullname $name])] \
	    [format { [list source [file join $dir %s]]} \
	    [file split $scriptFile]] "\n"
}

# AUTO MKINDEX:  namespace eval name command ?arg arg...?
# Adds the namespace name onto the context stack and evaluates the
# associated body of commands.
#
# AUTO MKINDEX:  namespace import ?-force? pattern ?pattern...?
# Performs the "import" action in the parser interpreter.  This is
# important for any commands contained in a namespace that affect
# the index.  For example, a script may say "itcl::class ...",
# or it may import "itcl::*" and then say "class ...".  This
# procedure does the import operation, but keeps track of imported
# patterns so we can remove the imports later.

auto_mkindex_parser::command namespace {op args} {
    switch -- $op {
        eval {
            variable parser
            variable contextStack

            set name [lindex $args 0]
            set args [lrange $args 1 end]

            set contextStack [linsert $contextStack 0 $name]
	    $parser eval [list _%@namespace eval $name] $args
            set contextStack [lrange $contextStack 1 end]
        }
        import {
            variable parser
            variable imports
            foreach pattern $args {
                if {[string compare $pattern "-force"]} {
                    lappend imports $pattern
                }
            }
            catch {$parser eval "_%@namespace import $args"}
        }
    }
}

return