loading.jl

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

using Test

# Tests for @__LINE__ inside and outside of macros
@test (@__LINE__) == 6

macro macro_caller_lineno()
    @test 9 == (@__LINE__) != __source__.line > 12
    return __source__.line
end

@test @macro_caller_lineno() == (@__LINE__) > 12

# @__LINE__ in a macro expands to the location of the macrocall in the source
# while __source__.line is the location of the macro caller
macro nested_LINE_expansion()
    return quote
        return (@emit_LINE, $(__source__.line))
    end
end
macro nested_LINE_expansion2()
    return :((@emit_LINE, $(__source__.line)))
end
macro emit_LINE()
    return quote
        (@__LINE__, $(__source__.line))
    end
end
@test (@emit_LINE) == ((@__LINE__) - 3, @__LINE__)
@test @nested_LINE_expansion() == ((@__LINE__() - 4, @__LINE__() - 12), @__LINE__())
@test @nested_LINE_expansion2() == ((@__LINE__() - 5, @__LINE__() - 9), @__LINE__())

loaded_files = String[]
push!(Base.include_callbacks, (mod::Module, fn::String) -> push!(loaded_files, fn))
include("test_sourcepath.jl")
@test length(loaded_files) == 1 && endswith(loaded_files[1], "test_sourcepath.jl")
pop!(Base.include_callbacks)
thefname = "the fname!//\\&\1*"
include_string_test_func = include_string(@__MODULE__, "include_string_test() = @__FILE__", thefname)
@test include_string_test_func() == thefname
@test include_string(@__MODULE__, "Base.source_path()", thefname) == Base.source_path()
@test basename(@__FILE__) == "loading.jl"
@test isabspath(@__FILE__)

@test isdir(@__DIR__)
@test @__DIR__() == dirname(@__FILE__)
@test !endswith(@__DIR__, Base.Filesystem.path_separator)
let exename = `$(Base.julia_cmd()) --compiled-modules=yes --startup-file=no`,
    wd = sprint(show, pwd())
    s_dir = sprint(show, realpath(tempdir()))
    @test wd != s_dir
    @test readchomp(`$exename -E "@__DIR__" -i`) == wd
    @test readchomp(`$exename -E "cd(()->eval(:(@__DIR__)), $s_dir)" -i`) == s_dir
    @test readchomp(`$exename -E "@__DIR__"`) == wd # non-interactive
    @test !endswith(wd, Base.Filesystem.path_separator)
    @test !endswith(s_dir, Base.Filesystem.path_separator)
end

# Issue #5789 and PR #13542:
mktempdir() do dir
    cd(dir) do
        let true_filename = "cAsEtEsT.jl", lowered_filename="casetest.jl"
            touch(true_filename)
            @test Base.isfile_casesensitive(true_filename)
            @test !Base.isfile_casesensitive(lowered_filename)

            # check that case-sensitivity only applies to basename of a path:
            if isfile(lowered_filename) # case-insensitive filesystem
                mkdir("cAsEtEsT")
                touch(joinpath("cAsEtEsT", true_filename))
                @test Base.isfile_casesensitive(joinpath("casetest", true_filename))
                @test !Base.isfile_casesensitive(joinpath("casetest", lowered_filename))
            end
        end

        # Test Unicode normalization; pertinent for OS X
        let nfc_name = "\U00F4.jl"
            touch(nfc_name)
            @test Base.isfile_casesensitive(nfc_name)
        end
    end
end

## unit tests of project parsing ##

import Base: SHA1, PkgId, load_path, identify_package, locate_package, version_slug, dummy_uuid
import UUIDs: UUID, uuid4, uuid_version
import Random: shuffle, randstring
using Test

let shastr = "ab"^20
    hash = SHA1(shastr)
    @test hash == eval(Meta.parse(repr(hash))) # check show method
    @test string(hash) == shastr
    @test "check $hash" == "check $shastr"
end

let shastr1 = "ab"^20, shastr2 = "ac"^20
    hash1 = SHA1(shastr1)
    hash2 = SHA1(shastr2)
    @test isless(hash1, hash2)
    @test !isless(hash2, hash1)
    @test !isless(hash1, hash1)
end

let uuidstr = "ab"^4 * "-" * "ab"^2 * "-" * "ab"^2 * "-" * "ab"^2 * "-" * "ab"^6
    uuid = UUID(uuidstr)
    @test uuid == eval(Meta.parse(repr(uuid))) # check show method
    @test string(uuid) == uuidstr == sprint(print, uuid)
    @test "check $uuid" == "check $uuidstr"
    @test UUID(UInt128(uuid)) == uuid
    @test UUID(convert(NTuple{2, UInt64}, uuid)) == uuid
    @test UUID(convert(NTuple{4, UInt32}, uuid)) == uuid

    uuidstr2 = "ba"^4 * "-" * "ba"^2 * "-" * "ba"^2 * "-" * "ba"^2 * "-" * "ba"^6
    uuid2 = UUID(uuidstr2)
    uuids = [uuid, uuid2]
    @test (uuids .== uuid) == [true, false]
end
@test_throws ArgumentError UUID("@"^4 * "-" * "@"^2 * "-" * "@"^2 * "-" * "@"^2 * "-" * "@"^6)

function subset(v::Vector{T}, m::Int) where T
    T[v[j] for j = 1:length(v) if ((m >>> (j - 1)) & 1) == 1]
end

function perm(p::Vector, i::Int)
    for j = length(p):-1:1
        i, k = divrem(i, j)
        p[j], p[k+1] = p[k+1], p[j]
    end
    return p
end

@testset "explicit_project_deps_get" begin
    mktempdir() do dir
        project_file = joinpath(dir, "Project.toml")
        touch(project_file) # dummy_uuid calls realpath
        # various UUIDs to work with
        proj_uuid = dummy_uuid(project_file)
        root_uuid = uuid4()
        this_uuid = uuid4()
        # project file to subset/permute
        lines = split("""
        name = "Root"
        uuid = "$root_uuid"
        [deps]
        This = "$this_uuid"
        """, '\n')
        N = length(lines)
        # test every permutation of every subset of lines
        for m = 0:2^N-1
            s = subset(lines, m) # each subset of lines
            for i = 1:factorial(count_ones(m))
                p = perm(s, i) # each permutation of the subset
                open(project_file, write=true) do io
                    for line in p
                        println(io, line)
                    end
                end
                # look at lines and their order
                n = findfirst(line -> startswith(line, "name"), p)
                u = findfirst(line -> startswith(line, "uuid"), p)
                d = findfirst(line -> line == "[deps]", p)
                t = findfirst(line -> startswith(line, "This"), p)
                # look up various packages by name
                root = Base.explicit_project_deps_get(project_file, "Root")
                this = Base.explicit_project_deps_get(project_file, "This")
                that = Base.explicit_project_deps_get(project_file, "That")
                # test that the correct answers are given
                @test root == (something(n, N+1) ≥ something(d, N+1) ? nothing :
                               something(u, N+1) < something(d, N+1) ? root_uuid : proj_uuid)
                @test this == (something(d, N+1) < something(t, N+1) ≤ N ? this_uuid : nothing)
                @test that == nothing
            end
        end
    end
end

## functional testing of package identification, location & loading ##

saved_load_path = copy(LOAD_PATH)
saved_depot_path = copy(DEPOT_PATH)
saved_home_project = Base.HOME_PROJECT[]
saved_active_project = Base.ACTIVE_PROJECT[]

push!(empty!(LOAD_PATH), "project")
push!(empty!(DEPOT_PATH), "depot")
Base.HOME_PROJECT[] = nothing
Base.ACTIVE_PROJECT[] = nothing

@test load_path() == [abspath("project","Project.toml")]

@testset "project & manifest identify_package & locate_package" begin
    local path
    for (names, uuid, path) in [
        ("Foo",     "767738be-2f1f-45a9-b806-0234f3164144", "project/deps/Foo1/src/Foo.jl"       ),
        ("Bar.Foo", "6f418443-bd2e-4783-b551-cdbac608adf2", "project/deps/Foo2.jl/src/Foo.jl"    ),
        ("Bar",     "2a550a13-6bab-4a91-a4ee-dff34d6b99d0", "project/deps/Bar/src/Bar.jl"        ),
        ("Foo.Baz", "6801f525-dc68-44e8-a4e8-cabd286279e7", "depot/packages/Baz/81oLe/src/Baz.jl"),
        ("Foo.Qux", "b5ec9b9c-e354-47fd-b367-a348bdc8f909", "project/deps/Qux.jl"                ),
    ]
        n = map(String, split(names, '.'))
        pkg = identify_package(n...)
        @test pkg == PkgId(UUID(uuid), n[end])
        @test joinpath(@__DIR__, normpath(path)) == locate_package(pkg)
    end
    @test identify_package("Baz") == nothing
    @test identify_package("Qux") == nothing
    @testset "equivalent package names" begin
        local classes = [
            ["Foo"],
            ["Bar", "Foo.Bar"],
            ["Foo.Baz", "Bar.Baz", "Foo.Bar.Baz"],
            ["Bar.Foo", "Foo.Bar.Foo", "Foo.Baz.Foo", "Bar.Baz.Foo"],
            ["Foo.Qux", "Foo.Baz.Qux", "Bar.Baz.Qux", "Foo.Bar.Foo.Qux",
             "Bar.Foo.Qux", "Foo.Baz.Foo.Qux", "Bar.Baz.Foo.Qux", "Foo.Bar.Baz.Foo.Qux"],
            ["Baz", "Qux", "Bar.Qux", "Bar.Baz.Bar", "Bar.Foo.Bar", "Bar.Foo.Baz",
             "Bar.Foo.Qux.Foo", "Bar.Foo.Qux.Bar", "Bar.Foo.Qux.Baz"],
        ]
        for i = 1:length(classes)
            A = classes[i]
            for x in A
                X = identify_package(map(String, split(x, '.'))...)
                for y in A
                    Y = identify_package(map(String, split(y, '.'))...)
                    @test X == Y
                end
                for j = i+1:length(classes)
                    B = classes[j]
                    for z in B
                        Z = identify_package(map(String, split(z, '.'))...)
                        @test X != Z
                    end
                end
            end
        end
    end
end

module NotPkgModule; end

@testset "project & manifest import" begin
    @test !@isdefined Foo
    @test !@isdefined Bar
    import Foo
    @test @isdefined Foo
    @test !@isdefined Bar
    import Bar
    @test @isdefined Foo
    @test @isdefined Bar

    @testset "module graph structure" begin
        local classes = Dict(
            "Foo1" => [Foo],
            "Bar"  => [Bar, Foo.Bar],
            "Baz"  => [Foo.Baz, Bar.Baz, Foo.Bar.Baz],
            "Foo2" => [Bar.Foo, Foo.Bar.Foo, Foo.Baz.Foo, Bar.Baz.Foo],
            "Qux"  => [Foo.Qux, Foo.Baz.Qux, Bar.Baz.Qux, Foo.Bar.Foo.Qux,
                       Bar.Foo.Qux, Foo.Baz.Foo.Qux, Bar.Baz.Foo.Qux,
                       Foo.Bar.Baz.Foo.Qux],
        )
        for (i, (this, mods)) in enumerate(classes)
            for x in mods
                @test x.this == this
                for y in mods
                    @test x === y
                end
                for (j, (that, mods′)) in enumerate(classes)
                    i == j && continue
                    for z in mods′
                        @test x !== z
                    end
                end
            end
        end
    end
    @test Foo.which == "path"

    @testset "pathof" begin
        @test pathof(Foo) == normpath(abspath(@__DIR__, "project/deps/Foo1/src/Foo.jl"))
        @test pathof(NotPkgModule) === nothing
    end

    @testset "pkgdir" begin
        @test pkgdir(Foo) == normpath(abspath(@__DIR__, "project/deps/Foo1"))
        @test pkgdir(Foo.SubFoo) == normpath(abspath(@__DIR__, "project/deps/Foo1"))
        @test pkgdir(NotPkgModule) === nothing
    end

end

## systematic generation of test environments ##

const M = 3 # number of node names
const N = 12 # different UUIDs per name
const NODES = 1:M*N
const NAMES = map(string, ('A':'Z')[1:M])
const UUIDS = [uuid4() for i = 1:M, j = 1:N]
const KIND = [(i + j) % 3 for i = 1:M, j = 1:N]
const KIND0 = filter(i -> KIND[i] == 0, NODES)
const KIND2 = filter(i -> KIND[i] == 2, NODES)

# kind 0: no project file
# kind 1: project file without name or uuid
# kind 2: project file with name and uuid

# explicit env: root can be anything, everything else kind 2
# implicit env: nodes can be anything, names must be unique

# allowed dependencies between kinds (explicit and implicit):
allowed(i::Int, j::Int) = KIND[i] ≤ KIND[j] && !(KIND[i] == KIND[j] == 1)

# node names/labels
L(i::Int) = NAMES[mod1(i, M)]

# first generate random dependency graphs

const graphs = Any[]

while length(graphs) < 100
    if (flat = rand(Bool))
        root = rand(KIND0)
        pool = root ∪ filter(i -> L(i) ≠ L(root), NODES)
        size = rand(1:N)
    else
        root = rand(NODES)
        pool = filter(i -> i ≠ root, KIND2)
        size = rand(1:length(NODES)÷2)
    end
    graph = Dict(root => Int[])
    KIND[root] ≠ 0 && push!(graph[root], root)
    for _ = 1:size
        i = rand(keys(graph))
        J = filter(pool) do j
            allowed(i, j) && all(L(j) ≠ L(k) for k in graph[i])
        end
        isempty(J) && continue
        j = rand(J)
        push!(graph[i], j)
        if j ∉ keys(graph)
            graph[j] = [j]
            flat && filter!(k -> L(k) ≠ L(j), pool)
            isempty(pool) && break
        end
    end
    roots = flat ? reduce(∪, values(graph)) : graph[root]
    for i in keys(graph)
        KIND[i] == 0 && delete!(graph, i)
    end
    t = (flat, root,
        Dict(L(i) => i for i in roots),
        Dict(i => Dict(L(j) => j for j in deps) for (i, deps) in graph))
    t in graphs || push!(graphs, t)
end

# materialize dependency graphs as explicit environments

function make_entry_point(path::String, name::String, uuid::UUID)
    mkpath(dirname(path))
    open(path, "w") do io
        print(io, """
        module $name
        name = $(repr(name))
        uuid = $(repr(string(uuid)))
        end
        """)
    end
end

function make_env(flat, root, roots, graph, paths, dummies)
    pkg(i::Int) = PkgId(KIND[i] == 2 ? UUIDS[i] : get(dummies, i, nothing), L(i))
    return (flat, pkg(root),
        Dict(n => pkg(i) for (n, i) in roots),
        Dict(pkg(i) => Dict(n => pkg(j) for (n, j) in d) for (i, d) in graph),
        Dict{PkgId,Union{Nothing,String}}(pkg(i) => path for (i, path) in paths),
    )
end

const depots = [mktempdir() for _ = 1:3]
const envs = Dict{String,Any}()

append!(empty!(DEPOT_PATH), depots)

for (flat, root, roots, graph) in graphs
    if flat
        all(KIND[i] == 2 for i in values(roots)) || continue
        all(KIND[i] == 2 for i in keys(graph)) || continue
    end
    dir = mktempdir()
    dummies = Dict{Int,UUID}()
    paths = Dict{Int,Union{Nothing,String}}()
    root_path = rand([false, true, joinpath("src", "$(randstring()).jl")])

    # generate project file
    project_file = joinpath(dir, "Project.toml")
    open(project_file, "w") do io
        name, uuid, kind = L(root), UUIDS[root], KIND[root]
        kind != 0 && println(io, "name = ", repr(name))
        kind == 2 && println(io, "uuid = ", repr(string(uuid)))
        kind == 1 && (dummies[root] = dummy_uuid(project_file))
        root_path isa String && println(io, "path = ", repr(root_path))
        println(io, "[deps]")
        for (n, i) in roots
            i == root && continue
            @assert KIND[i] == 2
            println(io, "$n = ", repr(string(UUIDS[i])))
        end
        kind == 0 && return
        # generate entry point
        if root_path == false
            kind == 2 && (paths[root] = nothing)
        else
            root_path == true && (root_path = joinpath("src", "$name.jl"))
            root_path = joinpath(dir, root_path)
            make_entry_point(root_path, name, uuid)
            paths[root] = root_path
        end
    end

    # count manifest entries
    counts = Dict(name => 0 for name in NAMES)
    for (i, _) in graph
        i == root && continue
        @assert KIND[i] == 2
        counts[L(i)] += 1
    end

    # generate manifest file
    open(joinpath(dir, "Manifest.toml"), "w") do io
        for (i, deps) in graph
            i == root && continue
            name, uuid = L(i), UUIDS[i]
            println(io, "[[$name]]")
            println(io, "uuid = ", repr(string(uuid)))
            if rand() < 2/3
                sha1 = SHA1(rand(UInt8, 20))
                println(io, "git-tree-sha1 = ", repr(string(sha1)))
                path = joinpath(
                    rand(depots), "packages",
                    name, version_slug(uuid, sha1),
                    "src", "$name.jl",
                )
                make_entry_point(path, name, uuid)
                paths[i] = path # may get overwritten below
            end
            if rand() < 1/4
                path = joinpath("deps", "$(randstring()).jl")
                println(io, "path = ", repr(path))
                path = joinpath(dir, path)
                make_entry_point(path, name, uuid)
                paths[i] = path # may overwrite path above
            end
            # neither can occur, i.e. no entry in paths
            deps = delete!(copy(deps), name)
            isempty(deps) && continue
            if all(counts[n] == 1 for n in keys(deps))
                println(io, "deps = ", repr(keys(deps)))
            else
                println(io, "  [$name.deps]")
                for (n, j) in deps
                    @assert KIND[j] == 2
                    println(io, "  $n = ", repr(string(UUIDS[j])))
                end
            end
        end
    end

    envs[dir] = make_env(flat, root, roots, graph, paths, dummies)
end

# materialize dependency graphs as implicit environments (if possible)

for (flat, root, roots, graph) in graphs
    flat || continue
    dir = mktempdir()
    dummies = Dict{Int,UUID}()
    paths = Dict{Int,Union{Nothing,String}}()

    for (name, i) in roots
        uuid, kind = UUIDS[i], KIND[i]
        # generate package entry point
        entry = joinpath(dir, name, "src", "$name.jl")
        make_entry_point(entry, name, uuid)
        paths[i] = entry
        kind == 0 && continue
        deps = delete!(copy(graph[i]), name)
        # generate project file
        project_file = joinpath(dir, name, "Project.toml")
        open(project_file, "w") do io
            kind != 0 && println(io, "name = ", repr(name))
            kind == 2 && println(io, "uuid = ", repr(string(uuid)))
            kind != 2 && (dummies[i] = dummy_uuid(project_file))
            isempty(deps) || println(io, "[deps]")
            for (n, j) in deps
                @assert KIND[j] == 2
                println(io, "  $n = ", repr(string(UUIDS[j])))
            end
        end
    end

    envs[dir] = make_env(flat, root, roots, graph, paths, dummies)
end

## use generated environments to test package loading ##

function test_find(
        roots::Dict{String,PkgId},
        graph::Dict{PkgId,Dict{String,PkgId}},
        paths::Dict{PkgId,Union{Nothing,String}},
    )
    # check direct dependencies
    for name in NAMES
        id = identify_package(name)
        @test id == get(roots, name, nothing)
        path = id === nothing ? nothing : locate_package(id)
        @test path == get(paths, id, nothing)
    end
    # check indirect dependencies
    for where in keys(graph)
        where.uuid === nothing && continue
        deps = get(graph, where, Dict(where.name => where))
        for name in NAMES
            id = identify_package(where, name)
            @test id == get(deps, name, nothing)
            path = id === nothing ? nothing : locate_package(id)
            @test path == get(paths, id, nothing)
        end
    end
end

@testset "find_package with one env in load path" begin
    for (env, (_, _, roots, graph, paths)) in envs
        push!(empty!(LOAD_PATH), env)
        test_find(roots, graph, paths)
    end
end

@testset "find_package with two envs in load path" begin
    for x = false:true,
        (env1, (_, _, roots1, graph1, paths1)) in (x ? envs : rand(envs, 10)),
        (env2, (_, _, roots2, graph2, paths2)) in (x ? rand(envs, 10) : envs)
        push!(empty!(LOAD_PATH), env1, env2)
        roots = merge(roots2, roots1)
        graph = merge(graph2, graph1)
        paths = merge(paths2, paths1)
        test_find(roots, graph, paths)
    end
end

@testset "find_package with three envs in load path" begin
    for (env1, (_, _, roots1, graph1, paths1)) in rand(envs, 10),
        (env2, (_, _, roots2, graph2, paths2)) in rand(envs, 10),
        (env3, (_, _, roots3, graph3, paths3)) in rand(envs, 10)
        push!(empty!(LOAD_PATH), env1, env2, env3)
        roots = merge(roots3, roots2, roots1)
        graph = merge(graph3, graph2, graph1)
        paths = merge(paths3, paths2, paths1)
        test_find(roots, graph, paths)
    end
end

# normalization of paths by include (#26424)
@test_throws ErrorException("could not open file $(joinpath(@__DIR__, "notarealfile.jl"))") include("./notarealfile.jl")

old_act_proj = Base.ACTIVE_PROJECT[]
pushfirst!(LOAD_PATH, "@")
try
    Base.ACTIVE_PROJECT[] = joinpath(@__DIR__, "TestPkg")
    @eval using TestPkg
finally
    Base.ACTIVE_PROJECT[] = old_act_proj
    popfirst!(LOAD_PATH)
end

@testset "--project and JULIA_PROJECT paths should be absolutified" begin
    mktempdir() do dir; cd(dir) do
        mkdir("foo")
        script = """
        using Test
        old = Base.active_project()
        cd("foo")
        @test Base.active_project() == old
        """
        @test success(`$(Base.julia_cmd()) --startup-file=no --project=foo -e $(script)`)
        withenv("JULIA_PROJECT" => "foo") do
            @test success(`$(Base.julia_cmd()) --startup-file=no -e $(script)`)
        end
    end; end
end

# Base.active_project when version directory exist in depot, but contains no project file
mktempdir() do dir
    vdir = Base.DEFAULT_LOAD_PATH[2]
    vdir = replace(vdir, "#" => VERSION.major, count = 1)
    vdir = replace(vdir, "#" => VERSION.minor, count = 1)
    vdir = replace(vdir, "#" => VERSION.patch, count = 1)
    vdir = vdir[2:end] # remove @
    vpath = joinpath(dir, "environments", vdir)
    mkpath(vpath)
    withenv("JULIA_DEPOT_PATH" => dir) do
        script = "@assert startswith(Base.active_project(), $(repr(vpath)))"
        @test success(`$(Base.julia_cmd()) --startup-file=no -e $(script)`)
    end
end

@testset "expansion of JULIA_LOAD_PATH" begin
    s = Sys.iswindows() ? ';' : ':'
    tmp = "/foo/bar"
    cases = Dict{Any,Vector{String}}(
        nothing => Base.DEFAULT_LOAD_PATH,
        "" => [],
        "$s" => Base.DEFAULT_LOAD_PATH,
        "$tmp$s" => [tmp; Base.DEFAULT_LOAD_PATH],
        "$s$tmp" => [Base.DEFAULT_LOAD_PATH; tmp],
        )
    for (env, result) in pairs(cases)
        withenv("JULIA_LOAD_PATH" => env) do
            script = "LOAD_PATH == $(repr(result)) || error()"
            @test success(`$(Base.julia_cmd()) --startup-file=no -e $script`)
        end
    end
end

@testset "expansion of JULIA_DEPOT_PATH" begin
    s = Sys.iswindows() ? ';' : ':'
    tmp = "/foo/bar"
    DEFAULT = Base.append_default_depot_path!(String[])
    cases = Dict{Any,Vector{String}}(
        nothing => DEFAULT,
        "" => [],
        "$s" => DEFAULT,
        "$tmp$s" => [tmp; DEFAULT],
        "$s$tmp" => [DEFAULT; tmp],
        )
    for (env, result) in pairs(cases)
        withenv("JULIA_DEPOT_PATH" => env) do
            script = "DEPOT_PATH == $(repr(result)) || error()"
            @test success(`$(Base.julia_cmd()) --startup-file=no -e $script`)
        end
    end
end

## cleanup after tests ##

for env in keys(envs)
    rm(env, force=true, recursive=true)
end
for depot in depots
    rm(depot, force=true, recursive=true)
end

append!(empty!(LOAD_PATH), saved_load_path)
append!(empty!(DEPOT_PATH), saved_depot_path)
Base.HOME_PROJECT[] = saved_home_project
Base.ACTIVE_PROJECT[] = saved_active_project

# issue #28190
module Foo; import Libdl; end
import .Foo.Libdl; import Libdl
@test Foo.Libdl === Libdl