#pragma once

#include "types.hh"
#include "hash.hh"

#include <map>


namespace nix {


/* Extension of derivations in the Nix store. */
const string drvExtension = ".drv";


/* Abstract syntax of derivations. */

struct DerivationOutput
{
    Path path;
    string hashAlgo; /* hash used for expected hash computation */
    string hash; /* expected hash, may be null */
    DerivationOutput()
    {
    }
    DerivationOutput(Path path, string hashAlgo, string hash)
    {
        this->path = path;
        this->hashAlgo = hashAlgo;
        this->hash = hash;
    }
    void parseHashInfo(bool & recursive, HashType & hashType, Hash & hash) const;
};

typedef std::map<string, DerivationOutput> DerivationOutputs;

/* For inputs that are sub-derivations, we specify exactly which
   output IDs we are interested in. */
typedef std::map<Path, StringSet> DerivationInputs;

typedef std::map<string, string> StringPairs;

struct Derivation
{
    DerivationOutputs outputs; /* keyed on symbolic IDs */
    DerivationInputs inputDrvs; /* inputs that are sub-derivations */
    PathSet inputSrcs; /* inputs that are sources */
    string platform;
    Path builder;
    Strings args;
    StringPairs env;
};


class StoreAPI;


/* Write a derivation to the Nix store, and return its path. */
Path writeDerivation(StoreAPI & store,
    const Derivation & drv, const string & name, bool repair = false);

/* Read a derivation from a file. */
Derivation readDerivation(const Path & drvPath);

/* Print a derivation. */
string unparseDerivation(const Derivation & drv);

/* Check whether a file name ends with the extensions for
   derivations. */
bool isDerivation(const string & fileName);

/* Return true iff this is a fixed-output derivation. */
bool isFixedOutputDrv(const Derivation & drv);

Hash hashDerivationModulo(StoreAPI & store, Derivation drv);

/* Memoisation of hashDerivationModulo(). */
typedef std::map<Path, Hash> DrvHashes;

extern DrvHashes drvHashes;

/* Split a string specifying a derivation and a set of outputs
   (/nix/store/hash-foo!out1,out2,...) into the derivation path and
   the outputs. */
typedef std::pair<string, std::set<string> > DrvPathWithOutputs;
DrvPathWithOutputs parseDrvPathWithOutputs(const string & s);

Path makeDrvPathWithOutputs(const Path & drvPath, const std::set<string> & outputs);

bool wantOutput(const string & output, const std::set<string> & wanted);

PathSet outputPaths(const Derivation & drv);

}
<table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/nix/libstore/builtins.hh?id=5005b6a1c98f840aaab78a04f883872bafad8d8e&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2017-01-11 17:06:31 +0100'>2017-01-11</span></td><td><a href='/guix/commit/nix/libstore/builtins.hh?id=9b5364a3afb03414bd6e3ded2fbfdacabe4e8870'>daemon: Allow check builds of 'builtin:download' derivations.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;http://bugs.gnu.org/25089&gt;.
Reported by Leo Famulari &lt;leo@famulari.name&gt;.

* nix/libstore/build.cc (DerivationGoal::runChild): In the 'isBuiltin'
case, check whether DRV's output is in 'redirectedOutputs', and pass an
'output' argument to the built-in builder.
(DerivationGoal::addHashRewrite): Add 'printMsg' call.
* nix/libstore/builtins.hh (derivationBuilder): Add 'output' parameter.
* nix/libstore/builtins.cc (builtinDownload): Likewise.
Add OUTPUT to ARGV.
* guix/scripts/perform-download.scm (perform-download): Add 'output'
parameter.
(guix-perform-download): Adjust 'match' clauses accordingly.
* tests/derivations.scm ("'download' built-in builder, check mode"): New
test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2016-11-16 18:19:54 +0100'>2016-11-16</span></td><td><a href='/guix/commit/nix/libstore/builtins.hh?id=f9aefa2d5fb3f6aad25a907939ee872c828b33d0'>daemon: Add 'built-in-builders' RPC.</a><span class='msg-avail'>...<span class='msg-tooltip'>* nix/libstore/builtins.cc (builtinBuilderNames): New function.
* nix/libstore/builtins.hh (builtinBuilderNames): New declaration.
* nix/libstore/worker-protocol.hh (PROTOCOL_VERSION): Bump to 0x160.
(WorkerOp)[wopBuiltinBuilders]: New value.
* nix/nix-daemon/nix-daemon.cc (performOp): Handle it.
* guix/store.scm (operation-id)[built-in-builders]: New value.
* guix/store.scm (read-arg): Add 'string-list'.
(built-in-builders): New procedure.
* tests/derivations.scm ("built-in-builders"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2016-11-16 18:19:47 +0100'>2016-11-16</span></td><td><a href='/guix/commit/nix/libstore/builtins.hh?id=94d92c7796a3dd50c27d532315f7d497ac99f08e'>daemon: Add "builtin:download" derivation builder.</a><span class='msg-avail'>...<span class='msg-tooltip'>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 &lt;eelco.dolstra@logicblox.com&gt;
</span></span></td><td>Ludovic Courtès</td></tr>