source: data/trunk/tcl8.4/ldAout.tcl @ 5603

# ldAout.tcl --
#
#       This "tclldAout" procedure in this script acts as a replacement
#       for the "ld" command when linking an object file that will be
#       loaded dynamically into Tcl or Tk using pseudo-static linking.
#
# Parameters:
#       The arguments to the script are the command line options for
#       an "ld" command.
#
# Results:
#       The "ld" command is parsed, and the "-o" option determines the
#       module name.  ".a" and ".o" options are accumulated.
#       The input archives and object files are examined with the "nm"
#       command to determine whether the modules initialization
#       entry and safe initialization entry are present.  A trivial
#       C function that locates the entries is composed, compiled, and
#       its .o file placed before all others in the command; then
#       "ld" is executed to bind the objects together.
#
# RCS: @(#) $Id: ldAout.tcl,v 1.5 2001/09/28 01:21:53 dgp Exp $
#
# Copyright (c) 1995, by General Electric Company. All rights reserved.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# This work was supported in part by the ARPA Manufacturing Automation
# and Design Engineering (MADE) Initiative through ARPA contract
# F33615-94-C-4400.

proc tclLdAout {{cc {}} {shlib_suffix {}} {shlib_cflags none}} {
    global env
    global argv

    if {[string equal $cc ""]} {
        set cc $env(CC)
    }

    # if only two parameters are supplied there is assumed that the
    # only shlib_suffix is missing. This parameter is anyway available
    # as "info sharedlibextension" too, so there is no need to transfer
    # 3 parameters to the function tclLdAout. For compatibility, this
    # function now accepts both 2 and 3 parameters.

    if {[string equal $shlib_suffix ""]} {
        set shlib_cflags $env(SHLIB_CFLAGS)
    } elseif {[string equal $shlib_cflags "none"]} {
        set shlib_cflags $shlib_suffix
    }

    # seenDotO is nonzero if a .o or .a file has been seen
    set seenDotO 0

    # minusO is nonzero if the last command line argument was "-o".
    set minusO 0

    # head has command line arguments up to but not including the first
    # .o or .a file. tail has the rest of the arguments.
    set head {}
    set tail {}

    # nmCommand is the "nm" command that lists global symbols from the
    # object files.
    set nmCommand {|nm -g}

    # entryProtos is the table of _Init and _SafeInit prototypes found in the
    # module.
    set entryProtos {}

    # entryPoints is the table of _Init and _SafeInit entries found in the
    # module.
    set entryPoints {}

    # libraries is the list of -L and -l flags to the linker.
    set libraries {}
    set libdirs {}

    # Process command line arguments
    foreach a $argv {
        if {!$minusO && [regexp {\.[ao]$} $a]} {
            set seenDotO 1
            lappend nmCommand $a
        }
        if {$minusO} {
            set outputFile $a
            set minusO 0
        } elseif {![string compare $a -o]} {
            set minusO 1
        }
        if {[regexp {^-[lL]} $a]} {
            lappend libraries $a
            if {[regexp {^-L} $a]} {
                lappend libdirs [string range $a 2 end]
            }
        } elseif {$seenDotO} {
            lappend tail $a
        } else {
            lappend head $a
        }
    }
    lappend libdirs /lib /usr/lib

    # MIPS -- If there are corresponding G0 libraries, replace the
    # ordinary ones with the G0 ones.

    set libs {}
    foreach lib $libraries {
        if {[regexp {^-l} $lib]} {
            set lname [string range $lib 2 end]
            foreach dir $libdirs {
                if {[file exists [file join $dir lib${lname}_G0.a]]} {
                    set lname ${lname}_G0
                    break
                }
            }
            lappend libs -l$lname
        } else {
            lappend libs $lib
        }
    }
    set libraries $libs

    # Extract the module name from the "-o" option

    if {![info exists outputFile]} {
        error "-o option must be supplied to link a Tcl load module"
    }
    set m [file tail $outputFile]
    if {[regexp {\.a$} $outputFile]} {
        set shlib_suffix .a
    } else {
        set shlib_suffix ""
    }
    if {[regexp {\..*$} $outputFile match]} {
        set l [expr {[string length $m] - [string length $match]}]
    } else {
        error "Output file does not appear to have a suffix"
    }
    set modName [string tolower $m 0 [expr {$l-1}]]
    if {[regexp {^lib} $modName]} {
        set modName [string range $modName 3 end]
    }
    if {[regexp {[0-9\.]*(_g0)?$} $modName match]} {
        set modName [string range $modName 0 [expr {[string length $modName]-[string length $match]-1}]]
    }
    set modName [string totitle $modName]

    # Catalog initialization entry points found in the module

    set f [open $nmCommand r]
    while {[gets $f l] >= 0} {
        if {[regexp {T[         ]*_?([A-Z][a-z0-9_]*_(Safe)?Init(__FP10Tcl_Interp)?)$} $l trash symbol]} {
            if {![regexp {_?([A-Z][a-z0-9_]*_(Safe)?Init)} $symbol trash s]} {
                set s $symbol
            }
            append entryProtos {extern int } $symbol { (); } \n
            append entryPoints {  } \{ { "} $s {", } $symbol { } \} , \n
        }
    }
    close $f

    if {[string equal $entryPoints ""]} {
        error "No entry point found in objects"
    }

    # Compose a C function that resolves the initialization entry points and
    # embeds the required libraries in the object code.

    set C {#include <string.h>}
    append C \n
    append C {char TclLoadLibraries_} $modName { [] =} \n
    append C {  "@LIBS: } $libraries {";} \n
    append C $entryProtos
    append C {static struct } \{ \n
    append C {  char * name;} \n
    append C {  int (*value)();} \n
    append C \} {dictionary [] = } \{ \n
    append C $entryPoints
    append C {  0, 0 } \n \} \; \n
    append C {typedef struct Tcl_Interp Tcl_Interp;} \n
    append C {typedef int Tcl_PackageInitProc (Tcl_Interp *);} \n
    append C {Tcl_PackageInitProc *} \n
    append C TclLoadDictionary_ $modName { (symbol)} \n
    append C {    CONST char * symbol;} \n
    append C {
        {
            int i;
            for (i = 0; dictionary [i] . name != 0; ++i) {
                if (!strcmp (symbol, dictionary [i] . name)) {
                    return dictionary [i].value;
                }
            }
            return 0;
        }
    }
    append C \n


    # Write the C module and compile it

    set cFile tcl$modName.c
    set f [open $cFile w]
    puts -nonewline $f $C
    close $f
    set ccCommand "$cc -c $shlib_cflags $cFile"
    puts stderr $ccCommand
    eval exec $ccCommand

    # Now compose and execute the ld command that packages the module

    if {[string equal $shlib_suffix ".a"]} {
        set ldCommand "ar cr $outputFile"
        regsub { -o} $tail {} tail
    } else {
        set ldCommand ld
        foreach item $head {
            lappend ldCommand $item
        }
    }
    lappend ldCommand tcl$modName.o
    foreach item $tail {
        lappend ldCommand $item
    }
    puts stderr $ldCommand
    eval exec $ldCommand
    if {[string equal $shlib_suffix ".a"]} {
        exec ranlib $outputFile
    }

    # Clean up working files
    exec /bin/rm $cFile [file rootname $cFile].o
}