Rewrite the CPAN generator to Perl

Also:

- It's now installable by doing "nix-env -i nix-generate-from-cpan".

- It maps dependencies to the correct attribute (e.g. HTML::HeadParser
  is mapped to HTMLParser).

- It automatically selects buildPerlPackage or buildPerlModule.

- It's documented in the manual.
This commit is contained in:
Eelco Dolstra 2013-06-13 15:39:08 +02:00
parent a79076b7aa
commit 629daa2102
6 changed files with 231 additions and 123 deletions

6
.gitignore vendored
View file

@ -2,6 +2,8 @@
,*
.*.swp
.*.swo
cpan-info
cpan_tmp/
result
doc/NEWS.html
doc/NEWS.txt
doc/manual.html
doc/manual.pdf

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@ -21,7 +21,7 @@ standard <varname>Makefile.PL</varname>. Its implemented in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.</para>
<para>Perl packages from CPAN are defined in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/perl-packages.nix</filename></link>,
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>,
rather than <filename>pkgs/all-packages.nix</filename>. Most Perl
packages are so straight-forward to build that they are defined here
directly, rather than having a separate function for each package
@ -151,6 +151,43 @@ ClassC3Componentised = buildPerlPackage rec {
</para>
<section><title>Generation from CPAN</title>
<para>Nix expressions for Perl packages can be generated (almost)
automatically from CPAN. This is done by the program
<command>nix-generate-from-cpan</command>, which can be installed
as follows:</para>
<screen>
$ nix-env -i nix-generate-from-cpan
</screen>
<para>This program takes a Perl module name, looks it up on CPAN,
fetches and unpacks the corresponding package, and prints a Nix
expression on standard output. For example:
<screen>
$ nix-generate-from-cpan XML::Simple
XMLSimple = buildPerlPackage {
name = "XML-Simple-2.20";
src = fetchurl {
url = mirror://cpan/authors/id/G/GR/GRANTM/XML-Simple-2.20.tar.gz;
sha256 = "5cff13d0802792da1eb45895ce1be461903d98ec97c9c953bc8406af7294434a";
};
propagatedBuildInputs = [ XMLNamespaceSupport XMLSAX XMLSAXExpat ];
meta = {
description = "Easily read/write XML (esp config files)";
license = "perl";
};
};
</screen>
The output can be pasted into
<filename>pkgs/top-level/perl-packages.nix</filename> or wherever else
you need it.</para>
</section>
</section>

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@ -1,120 +0,0 @@
#! /bin/sh -e
name="$1"
[ -n "$name" ] || { echo "no name"; exit 1; }
cpan -D "$name" > cpan-info
url="$(echo $(cat cpan-info | sed '6!d'))"
[ -n "$url" ] || { echo "no URL"; exit 1; }
url="mirror://cpan/authors/id/$url"
echo "URL = $url" >&2
version=$(cat cpan-info | grep 'CPAN: ' | awk '{ print $2 }')
echo "VERSION = $version"
declare -a xs=($(PRINT_PATH=1 nix-prefetch-url "$url"))
hash=${xs[0]}
path=${xs[1]}
echo "HASH = $hash" >&2
namedash="$(echo $name | sed s/::/-/g)-$version"
attr=$(echo $name | sed s/:://g)
rm -rf cpan_tmp
mkdir cpan_tmp
tar xf "$path" -C cpan_tmp
shopt -s nullglob
meta=$(echo cpan_tmp/*/META.json)
if [ -z "$meta" ]; then
yaml=$(echo cpan_tmp/*/META.yml)
[ -n "$yaml" ] || { echo "no meta file"; exit 1; }
meta=$(echo $yaml | sed s/\.yml$/.json/)
perl -e '
use YAML;
use JSON;
local $/;
$x = YAML::Load(<>);
print encode_json $x;
' < $yaml > $meta
fi
description="$(json abstract < $meta | perl -e '$x = <>; print uc(substr($x, 0, 1)), substr($x, 1);')"
homepage="$(json resources.homepage < $meta)"
if [ -z "$homepage" ]; then
#homepage="$(json meta-spec.url < $meta)"
true
fi
license="$(json license < $meta | json -a 2> /dev/null || true)"
if [ -z "$license" ]; then
license="$(json -a license < $meta)"
fi
license="$(echo $license | sed s/perl_5/perl5/)"
f() {
local type="$1"
perl -e '
use JSON;
local $/;
$x = decode_json <>;
if (defined $x->{prereqs}) {
$x2 = $x->{prereqs}->{'$type'}->{requires};
} elsif ("'$type'" eq "runtime") {
$x2 = $x->{requires};
} elsif ("'$type'" eq "configure") {
$x2 = $x->{configure_requires};
} elsif ("'$type'" eq "build") {
$x2 = $x->{build_requires};
}
foreach my $y (keys %{$x2}) {
next if $y eq "perl";
eval "use $y;";
if (!$@) {
print STDERR "skipping Perl-builtin module $y\n";
next;
}
print $y, "\n";
};
' < $meta | sed s/:://g
}
confdeps=$(f configure)
builddeps=$(f build)
testdeps=$(f test)
runtimedeps=$(f runtime)
buildInputs=$(echo $(for i in $confdeps $builddeps $testdeps; do echo $i; done | sort | uniq))
propagatedBuildInputs=$(echo $(for i in $runtimedeps; do echo $i; done | sort | uniq))
echo "===" >&2
cat <<EOF
$attr = buildPerlPackage {
name = "$namedash";
src = fetchurl {
url = $url;
sha256 = "$hash";
};
EOF
if [ -n "$buildInputs" ]; then
cat <<EOF
buildInputs = [ $buildInputs ];
EOF
fi
if [ -n "$propagatedBuildInputs" ]; then
cat <<EOF
propagatedBuildInputs = [ $propagatedBuildInputs ];
EOF
fi
cat <<EOF
meta = {
homepage = $homepage;
description = "$description";
license = "$license";
};
};
EOF

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@ -0,0 +1,22 @@
{ stdenv, makeWrapper, perl, perlPackages }:
stdenv.mkDerivation {
name = "nix-generate-from-cpan-1";
buildInputs = [ makeWrapper perl perlPackages.YAML perlPackages.JSON ];
unpackPhase = "true";
buildPhase = "true";
installPhase =
''
mkdir -p $out/bin
cp ${./nix-generate-from-cpan.pl} $out/bin/nix-generate-from-cpan
wrapProgram $out/bin/nix-generate-from-cpan --set PERL5LIB $PERL5LIB
'';
meta = {
maintainers = [ stdenv.lib.maintainers.eelco ];
description = "Utility to generate a Nix expression for a Perl package from CPAN";
};
}

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@ -0,0 +1,162 @@
#! /run/current-system/sw/bin/perl -w
use strict;
use CPANPLUS::Backend;
use YAML;
use JSON;
my $module_name = $ARGV[0];
die "syntax: $0 <MODULE-NAME>\n" unless defined $module_name;
my $cb = CPANPLUS::Backend->new;
my @modules = $cb->search(type => "name", allow => [$module_name]);
die "module $module_name not found\n" if scalar @modules == 0;
die "multiple packages that match module $module_name\n" if scalar @modules > 1;
my $module = $modules[0];
sub pkg_to_attr {
my ($pkg_name) = @_;
my $attr_name = $pkg_name;
$attr_name =~ s/-\d.*//; # strip version
return "LWP" if $attr_name eq "libwww-perl";
$attr_name =~ s/-//g;
return $attr_name;
}
sub get_pkg_name {
my ($module) = @_;
my $pkg_name = $module->package;
$pkg_name =~ s/\.tar.*//;
$pkg_name =~ s/\.zip//;
return $pkg_name;
}
my $pkg_name = get_pkg_name $module;
my $attr_name = pkg_to_attr $pkg_name;
print STDERR "attribute name: ", $attr_name, "\n";
print STDERR "module: ", $module->module, "\n";
print STDERR "version: ", $module->version, "\n";
print STDERR "package: ", $module->package, , " (", $pkg_name, ", ", $attr_name, ")\n";
print STDERR "path: ", $module->path, "\n";
my $tar_path = $module->fetch();
print STDERR "downloaded to: $tar_path\n";
print STDERR "sha-256: ", $module->status->checksum_value, "\n";
my $pkg_path = $module->extract();
print STDERR "unpacked to: $pkg_path\n";
my $meta;
if (-e "$pkg_path/META.yml") {
$meta = YAML::LoadFile("$pkg_path/META.yml");
}
print STDERR "metadata: ", encode_json($meta), "\n";
# Map a module to the attribute corresponding to its package
# (e.g. HTML::HeadParser will be mapped to HTMLParser, because that
# module is in the HTML-Parser package).
sub module_to_pkg {
my ($module_name) = @_;
my @modules = $cb->search(type => "name", allow => [$module_name]);
if (scalar @modules == 0) {
# Fallback.
$module_name =~ s/:://g;
return $module_name;
}
my $module = $modules[0];
my $attr_name = pkg_to_attr(get_pkg_name $module);
print STDERR "mapped dep $module_name to $attr_name\n";
return $attr_name;
}
sub get_deps {
my ($type) = @_;
my $deps;
if (defined $meta->{prereqs}) {
die "unimplemented";
} elsif ($type eq "runtime") {
$deps = $meta->{requires};
} elsif ($type eq "configure") {
$deps = $meta->{configure_requires};
} elsif ($type eq "build") {
$deps = $meta->{build_requires};
}
my @res;
foreach my $n (keys %{$deps}) {
next if $n eq "perl";
# Hacky way to figure out if this module is part of Perl.
if ($n !~ /^JSON/ && $n !~ /^YAML/) {
eval "use $n;";
if (!$@) {
print STDERR "skipping Perl-builtin module $n\n";
next;
}
}
push @res, module_to_pkg($n);
}
return @res;
}
sub uniq {
return keys %{{ map { $_ => 1 } @_ }};
}
my @build_deps = sort(uniq(get_deps("configure"), get_deps("build"), get_deps("test")));
print STDERR "build deps: @build_deps\n";
my @runtime_deps = sort(uniq(get_deps("runtime")));
print STDERR "runtime deps: @runtime_deps\n";
my $homepage = $meta->{resources}->{homepage};
print STDERR "homepage: $homepage\n" if defined $homepage;
my $description = $meta->{abstract};
$description = uc(substr($description, 0, 1)) . substr($description, 1); # capitalise first letter
$description =~ s/\.$//; # remove period at the end
$description =~ s/\s*$//;
$description =~ s/^\s*//;
print STDERR "description: $description\n";
my $license = $meta->{license};
if (defined $license) {
$license = "perl5" if $license eq "perl_5";
print STDERR "license: $license\n";
}
my $build_fun = -e "$pkg_path/Build.PL" && ! -e "$pkg_path/Makefile.PL" ? "buildPerlModule" : "buildPerlPackage";
print STDERR "===\n";
print <<EOF;
$attr_name = $build_fun {
name = "$pkg_name";
src = fetchurl {
url = mirror://cpan/${\$module->path}/${\$module->package};
sha256 = "${\$module->status->checksum_value}";
};
EOF
print <<EOF if scalar @build_deps > 0;
buildInputs = [ @build_deps ];
EOF
print <<EOF if scalar @runtime_deps > 0;
propagatedBuildInputs = [ @runtime_deps ];
EOF
print <<EOF;
meta = {
EOF
print <<EOF if defined $homepage;
homepage = $homepage;
EOF
print <<EOF;
description = "$description";
EOF
print <<EOF if defined $license;
license = "$license";
EOF
print <<EOF;
};
};
EOF

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@ -202,6 +202,11 @@ let
stringsWithDeps = lib.stringsWithDeps;
### Nixpkgs maintainer tools
nix-generate-from-cpan = callPackage ../../maintainers/scripts/nix-generate-from-cpan.nix { };
### STANDARD ENVIRONMENT