guix/nix/libstore/builtins.cc
Ludovic Courtès 94d92c7796
daemon: Add "builtin:download" derivation builder.
This ensures that 1) the derivation doesn't change when Guix changes;
2) the derivation closure doesn't contain Guix and its dependencies; 3)
we don't have to rely on ugly chroot hacks.

Adapted from Nix commit 0a2bee307b20411f5b0dda0c662b1f9bb9e0e131.

* nix/libstore/build.cc (DerivationGoal::runChild): Add special case for
'isBuiltin(drv)'.  Disable chroot when 'isBuiltin(drv)'.
* nix/libstore/builtins.cc, nix/libstore/builtins.hh,
nix/scripts/download.in, guix/scripts/perform-download.scm: New files.
* guix/ui.scm (show-guix-help)[internal?]: Add 'perform-download'.
* nix/local.mk (libstore_a_SOURCES): Add builtins.cc.
(libstore_headers): Add builtins.hh.
(nodist_pkglibexec_SCRIPTS): Add 'scripts/download'.
* config-daemon.ac: Emit 'scripts/download'.
* Makefile.am (MODULES): Add 'guix/scripts/perform-download.scm'.
* tests/derivations.scm ("unknown built-in builder")
("'download' built-in builder")
("'download' built-in builder, invalid hash")
("'download' built-in builder, not found")
("'download' built-in builder, not fixed-output"): New tests.

Co-authored-by: Eelco Dolstra <eelco.dolstra@logicblox.com>
2016-11-16 18:19:47 +01:00

69 lines
2 KiB
C++

/* GNU Guix --- Functional package management for GNU
Copyright (C) 2016 Ludovic Courtès <ludo@gnu.org>
This file is part of GNU Guix.
GNU Guix is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at
your option) any later version.
GNU Guix is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. */
#include <builtins.hh>
#include <util.hh>
#include <globals.hh>
#include <unistd.h>
namespace nix {
static void builtinDownload(const Derivation &drv,
const std::string &drvPath)
{
/* Invoke 'guix perform-download'. */
Strings args;
args.push_back("perform-download");
args.push_back(drvPath);
/* Close all other file descriptors. */
closeMostFDs(set<int>());
const char *const argv[] = { "download", drvPath.c_str(), NULL };
/* XXX: Hack our way to use the 'download' script from 'LIBEXECDIR/guix'
or just 'LIBEXECDIR', depending on whether we're running uninstalled or
not. */
const string subdir = getenv("GUIX_UNINSTALLED") != NULL
? "" : "/guix";
const string program = settings.nixLibexecDir + subdir + "/download";
execv(program.c_str(), (char *const *) argv);
throw SysError(format("failed to run download program '%1%'") % program);
}
static const std::map<std::string, derivationBuilder> builtins =
{
{ "download", builtinDownload }
};
derivationBuilder lookupBuiltinBuilder(const std::string & name)
{
if (name.substr(0, 8) == "builtin:")
{
auto realName = name.substr(8);
auto builder = builtins.find(realName);
return builder == builtins.end() ? NULL : builder->second;
}
else
return NULL;
}
}