#!/bin/sh
# This file is a part of Julia. License is MIT: https://julialang.org/license

# Run as: fixup-libgfortran.sh [--verbose] <$private_libdir>

# If we're invoked with "--verbose", create a `debug` function that prints stuff out
if test $1 == "--verbose" || test $1 == "-v" {
shift 1
proc debug { echo "$[join(ARGV)]"; }
} else {
proc debug { :; }
}

if test -z $1 {
    echo "Usage: $0 <private_libdir>"
    exit 1
}

setvar UNAME = "$(uname -s)"
if test $UNAME = "Linux" {
    setvar SHLIB_EXT = ""so""
} elif test $UNAME = "Darwin" {
    setvar SHLIB_EXT = ""dylib""
} else {
    echo "WARNING: Could not autodetect platform type ('uname -s' == $UNAME); assuming Linux" >&2
    setvar UNAME = ""Linux""
    setvar SHLIB_EXT = ""so""
}

setvar private_libdir = "$1"

if test ! -f "$private_libdir/libarpack.$SHLIB_EXT" {
    echo "ERROR: Could not open $private_libdir/libarpack.$SHLIB_EXT" >&2
    exit 2
}

proc find_shlib {
    setvar lib_path = "$1"
    if test -f $lib_path {
        if test $UNAME = "Linux" {
            ldd $lib_path | grep $2 | cut -d' ' -f3 | xargs
        } else { # $UNAME is "Darwin", we only have two options, see above
            otool -L $lib_path | grep $2 | cut -d' ' -f1 | xargs
        }
    }
}

proc private_libname {
    echo "$private_libdir/lib$1.$SHLIB_EXT"
}

# First, discover all the places where libgfortran/libgcc is, as well as their true SONAMES
for lib in arpack lapack {
    if test -f "$private_libdir/lib$lib.$SHLIB_EXT" {
        # Find the paths to the libraries we're interested in.  These are almost
        # always within the same directory, but we like to be general.
        setvar LIBGFORTRAN_PATH = $(find_shlib "$(private_libname $lib)" libgfortran)
        setvar LIBGCC_PATH = $(find_shlib "$(private_libname $lib)" libgcc_s)
        setvar LIBQUADMATH_PATH = $(find_shlib "$(private_libname $lib)" libquadmath)

        # Take the directories, add them onto LIBGFORTRAN_DIRS, which we use to
        # search for these libraries in the future.
        setvar LIBGFORTRAN_DIRS = ""$LIBGFORTRAN_DIRS $(dirname $LIBGFORTRAN_PATH)""
        setvar LIBGFORTRAN_DIRS = ""$LIBGFORTRAN_DIRS $(dirname $LIBGCC_PATH)""
        setvar LIBGFORTRAN_DIRS = ""$LIBGFORTRAN_DIRS $(dirname $LIBQUADMATH_PATH)""

        # Save the SONAMES
        setvar LIBGFORTRAN_SONAMES = ""$LIBGFORTRAN_SONAMES $(basename "$LIBGFORTRAN_PATH")""
        setvar LIBGCC_SONAMES = ""$LIBGCC_SONAMES $(basename "$LIBGCC_PATH")""
        setvar LIBQUADMATH_SONAMES = ""$LIBQUADMATH_SONAMES $(basename "$LIBQUADMATH_PATH")""
    }
}

# Take in a list of space-separated tokens, return a deduplicated list of the same
proc uniquify {
    echo $1 | tr " " "\n" | sort | uniq | grep -v '^$' | tr "\n" " "
}

setvar LIBGFORTRAN_DIRS = $(uniquify "$LIBGFORTRAN_DIRS")
setvar SONAMES = "$(uniquify "$LIBGFORTRAN_SONAMES $LIBGCC_SONAMES $LIBQUADMATH_SONAMES")"
debug "Discovered traces of libgfortran within $LIBGFORTRAN_DIRS"
debug "Got SONAMES of $SONAMES"

# Copy the SONAMEs we identified above into our private_libdir
for soname in $SONAMES {
    for dir in $LIBGFORTRAN_DIRS {
        if test ! -f "$private_libdir/$soname" && test -f "$dir/$soname" {
            cp -v "$dir/$soname" $private_libdir
            chmod 755 "$private_libdir/$soname"
            if test $UNAME = "Darwin" {
                install_name_tool -id "@rpath/$soname" "$private_libdir/$soname"
            }
        }
    }
}

# On OSX, we need to change the old link (which is usually a full path)
# to point to `@rpath/${soname}` explicitly, so we use `find_shlib()`
# to dynamically find the full path we want to change.  On Linux, we
# don't care about full paths, we just set the rpath to `$ORIGIN`.
proc change_linkage {
    # This is the path of the library we want to edit
    setvar lib_path = "$1"

    # If it doesn't exist, exit quietly
    if test ! -f $lib_path {
        debug "  $lib_path doesn't exist, skipping"
        return
    }

    # This is the soname of the dependency we want to swap out
    setvar soname = "$2"

    if test $UNAME = "Darwin" {
        setvar old_link = $(find_shlib "$lib_path" "$soname")
        echo " $old_link"
        install_name_tool -change $old_link "@rpath/$soname" $lib_path
    } else { # $UNAME is "Linux", we only have two options, see above
        patchelf --set-rpath '$'ORIGIN $lib_path
    }
}

# For every library that remotely touches libgfortran stuff (the libraries we
# have copied in ourselves as well as arpack, etc...) we must
# update the linkage to point to @rpath (on OSX) or $ORIGIN (on Linux) so
# that direct links to the old libgfortran directories are instead directed
# to the proper location, which is our $private_libdir.
for lib in libopenblas libarpack libcholmod liblapack $SONAMES {
    # Grab every incarnation of that library that exists within $private_libdir
    # (e.g. "libopenblas.so", and "libopenblas.so.0", etc...)
    for lib_path in $private_libdir/$lib* {
        # Iterate over dependency names that need to be changed
        for soname in $SONAMES {
            debug "changing linkage of $lib_path to $soname"
            change_linkage $lib_path $soname
        }
    }
}