source: downloads/tcl8.5.2/library/platform/platform.tcl @ 25

# -*- tcl -*-
# ### ### ### ######### ######### #########
## Overview

# Heuristics to assemble a platform identifier from publicly available
# information. The identifier describes the platform of the currently
# running tcl shell. This is a mixture of the runtime environment and
# of build-time properties of the executable itself.
#
# Examples:
# <1> A tcl shell executing on a x86_64 processor, but having a
#   wordsize of 4 was compiled for the x86 environment, i.e. 32
#   bit, and loaded packages have to match that, and not the
#   actual cpu.
#
# <2> The hp/solaris 32/64 bit builds of the core cannot be
#   distinguished by looking at tcl_platform. As packages have to
#   match the 32/64 information we have to look in more places. In
#   this case we inspect the executable itself (magic numbers,
#   i.e. fileutil::magic::filetype).
#
# The basic information used comes out of the 'os' and 'machine'
# entries of the 'tcl_platform' array. A number of general and
# os/machine specific transformation are applied to get a canonical
# result.
#
# General
# Only the first element of 'os' is used - we don't care whether we
# are on "Windows NT" or "Windows XP" or whatever.
#
# Machine specific
# % arm*   -> arm
# % sun4*  -> sparc
# % intel  -> ix86
# % i*86*  -> ix86
# % Power* -> powerpc
# % x86_64 + wordSize 4 => x86 code
#
# OS specific
# % AIX are always powerpc machines
# % HP-UX 9000/800 etc means parisc
# % linux has to take glibc version into account
# % sunos -> solaris, and keep version number
#
# NOTE: A platform like linux glibc 2.3, which can use glibc 2.2 stuff
# has to provide all possible allowed platform identifiers when
# searching search. Ditto a solaris 2.8 platform can use solaris 2.6
# packages. Etc. This is handled by the other procedure, see below.

# ### ### ### ######### ######### #########
## Requirements

namespace eval ::platform {}

# ### ### ### ######### ######### #########
## Implementation

# -- platform::generic
#
# Assembles an identifier for the generic platform. It leaves out
# details like kernel version, libc version, etc.

proc ::platform::generic {} {
    global tcl_platform

    set plat [string tolower [lindex $tcl_platform(os) 0]]
    set cpu  $tcl_platform(machine)

    switch -glob -- $cpu {
        sun4* {
            set cpu sparc
        }
        intel -
        i*86* {
            set cpu ix86
        }
        x86_64 {
            if {$tcl_platform(wordSize) == 4} {
                # See Example <1> at the top of this file.
                set cpu ix86
            }
        }
        "Power*" {
            set cpu powerpc
        }
        "arm*" {
            set cpu arm
        }
        ia64 {
            if {$tcl_platform(wordSize) == 4} {
                append cpu _32
            }
        }
    }

    switch -- $plat {
        windows {
            set plat win32
            if {$cpu eq "amd64"} {
                # Do not check wordSize, win32-x64 is an IL32P64 platform.
                set cpu x86_64
            }
        }
        sunos {
            set plat solaris
            if {$cpu ne "ia64"} {
                if {$tcl_platform(wordSize) == 8} {
                    append cpu 64
                }
            }
        }
        darwin {
            set plat macosx
        }
        aix {
            set cpu powerpc
            if {$tcl_platform(wordSize) == 8} {
                append cpu 64
            }
        }
        hp-ux {
            set plat hpux
            if {$cpu ne "ia64"} {
                set cpu parisc
                if {$tcl_platform(wordSize) == 8} {
                    append cpu 64
                }
            }
        }
        osf1 {
            set plat tru64
        }
    }

    return "${plat}-${cpu}"
}

# -- platform::identify
#
# Assembles an identifier for the exact platform, by extending the
# generic identifier. I.e. it adds in details like kernel version,
# libc version, etc., if they are relevant for the loading of
# packages on the platform.

proc ::platform::identify {} {
    global tcl_platform

    set id [generic]
    regexp {^([^-]+)-([^-]+)$} $id -> plat cpu

    switch -- $plat {
        solaris {
            regsub {^5} $tcl_platform(osVersion) 2 text
            append plat $text
            return "${plat}-${cpu}"
        }
        linux {
            # Look for the libc*.so and determine its version
            # (libc5/6, libc6 further glibc 2.X)

            set v unknown

            if {[file exists /lib64] && [file isdirectory /lib64]} {
                set base /lib64
            } else {
                set base /lib
            }

            set libclist [lsort [glob -nocomplain -directory $base libc*]]
            if {[llength $libclist]} {
                set libc [lindex $libclist 0]

                # Try executing the library first. This should suceed
                # for a glibc library, and return the version
                # information.

                if {![catch {
                    set vdata [lindex [split [exec $libc] \n] 0]
                }]} {
                    regexp {([0-9]+(\.[0-9]+)*)} $vdata -> v
                    foreach {major minor} [split $v .] break
                    set v glibc${major}.${minor}
                } else {
                    # We had trouble executing the library. We are now
                    # inspecting its name to determine the version
                    # number. This code by Larry McVoy.

                    if {[regexp -- {libc-([0-9]+)\.([0-9]+)} $libc -> major minor]} {
                        set v glibc${major}.${minor}
                    }
                }
            }
            append plat -$v
            return "${plat}-${cpu}"
        }
    }

    return $id
}

# -- platform::patterns
#
# Given an exact platform identifier, i.e. _not_ the generic
# identifier it assembles a list of exact platform identifier
# describing platform which should be compatible with the
# input.
#
# I.e. packages for all platforms in the result list should be
# loadable on the specified platform.

# << Should we add the generic identifier to the list as well ? In
#    general it is not compatible I believe. So better not. In many
#    cases the exact identifier is identical to the generic one
#    anyway.
# >>

proc ::platform::patterns {id} {
    set res [list $id]
    if {$id eq "tcl"} {return $res}

    switch -glob --  $id {
        solaris*-* {
            if {[regexp {solaris([^-]*)-(.*)} $id -> v cpu]} {
                if {$v eq ""} {return $id}
                foreach {major minor} [split $v .] break
                incr minor -1
                for {set j $minor} {$j >= 6} {incr j -1} {
                    lappend res solaris${major}.${j}-${cpu}
                }
            }
        }
        linux*-* {
            if {[regexp {linux-glibc([^-]*)-(.*)} $id -> v cpu]} {
                foreach {major minor} [split $v .] break
                incr minor -1
                for {set j $minor} {$j >= 0} {incr j -1} {
                    lappend res linux-glibc${major}.${j}-${cpu}
                }
            }
        }
        macosx-powerpc -
        macosx-ix86    {
            lappend res macosx-universal
        }
    }
    lappend res tcl ; # Pure tcl packages are always compatible.
    return $res
}


# ### ### ### ######### ######### #########
## Ready

package provide platform 1.0.3

# ### ### ### ######### ######### #########
## Demo application

if {[info exists argv0] && ($argv0 eq [info script])} {
    puts ====================================
    parray tcl_platform
    puts ====================================
    puts Generic\ identification:\ [::platform::generic]
    puts Exact\ identification:\ \ \ [::platform::identify]
    puts ====================================
    puts Search\ patterns:
    puts *\ [join [::platform::patterns [::platform::identify]] \n*\ ]
    puts ====================================
    exit 0
}