#include "misc.hh"
#include "store-api.hh"
#include "local-store.hh"
#include "globals.hh"


namespace nix {


Derivation derivationFromPath(StoreAPI & store, const Path & drvPath)
{
    assertStorePath(drvPath);
    store.ensurePath(drvPath);
    return readDerivation(drvPath);
}


void computeFSClosure(StoreAPI & store, const Path & path,
    PathSet & paths, bool flipDirection, bool includeOutputs, bool includeDerivers)
{
    if (paths.find(path) != paths.end()) return;
    paths.insert(path);

    PathSet edges;

    if (flipDirection) {
        store.queryReferrers(path, edges);

        if (includeOutputs) {
            PathSet derivers = store.queryValidDerivers(path);
            foreach (PathSet::iterator, i, derivers)
                edges.insert(*i);
        }

        if (includeDerivers && isDerivation(path)) {
            PathSet outputs = store.queryDerivationOutputs(path);
            foreach (PathSet::iterator, i, outputs)
                if (store.isValidPath(*i) && store.queryDeriver(*i) == path)
                    edges.insert(*i);
        }

    } else {
        store.queryReferences(path, edges);

        if (includeOutputs && isDerivation(path)) {
            PathSet outputs = store.queryDerivationOutputs(path);
            foreach (PathSet::iterator, i, outputs)
                if (store.isValidPath(*i)) edges.insert(*i);
        }

        if (includeDerivers) {
            Path deriver = store.queryDeriver(path);
            if (store.isValidPath(deriver)) edges.insert(deriver);
        }
    }

    foreach (PathSet::iterator, i, edges)
        computeFSClosure(store, *i, paths, flipDirection, includeOutputs, includeDerivers);
}


static void dfsVisit(StoreAPI & store, const PathSet & paths,
    const Path & path, PathSet & visited, Paths & sorted,
    PathSet & parents)
{
    if (parents.find(path) != parents.end())
        throw BuildError(format("cycle detected in the references of `%1%'") % path);

    if (visited.find(path) != visited.end()) return;
    visited.insert(path);
    parents.insert(path);

    PathSet references;
    if (store.isValidPath(path))
        store.queryReferences(path, references);

    foreach (PathSet::iterator, i, references)
        /* Don't traverse into paths that don't exist.  That can
           happen due to substitutes for non-existent paths. */
        if (*i != path && paths.find(*i) != paths.end())
            dfsVisit(store, paths, *i, visited, sorted, parents);

    sorted.push_front(path);
    parents.erase(path);
}


Paths topoSortPaths(StoreAPI & store, const PathSet & paths)
{
    Paths sorted;
    PathSet visited, parents;
    foreach (PathSet::const_iterator, i, paths)
        dfsVisit(store, paths, *i, visited, sorted, parents);
    return sorted;
}


}
'/guix/commit/gnu/packages/flex.scm?id=ee38d87c58aaf8f8c1b7599a598a56b94f09f711'>gnu: Remove flex@2.6.1.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/flex.scm (flex-2.6.1): Remove variable.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-07-09 21:07:13 +0200'>2019-07-09</span></td><td><a href='/guix/commit/gnu/packages/flex.scm?id=33f460addfcc737a7a80dab244211811283b77f7'>gnu: flex: Remove superfluous input.</a><span class='msg-avail'>...<span class='msg-tooltip'>The configure script will warn that "make indent" is unavailable, but
apart from that this input is not actually used for the build process.

* gnu/packages/flex.scm (flex)[inputs]: Remove INDENT.
* gnu/packages/commencement.scm (flex-boot0)[inputs]: Likewise.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-06-29 22:34:20 +0200'>2019-06-29</span></td><td><a href='/guix/commit/gnu/packages/flex.scm?id=06172df545f1253463bc51a9e2c39bf2133f3f23'>gnu: flex: Build bison-for-tests sequentially.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to b1593c1c4fd8f4fc6df4c43cab51334426e3aa76.

* gnu/packages/flex.scm (flex)[inputs](bison-for-tests): Use
'substitute-keyword-arguments' instead of overriding them altogether.
This ensures that #:parallel-build? and #:parallel-tests? are
preserved.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-08-25 16:23:36 +0200'>2018-08-25</span></td><td><a href='/guix/commit/gnu/packages/flex.scm?id=34f4c214b63c46ee609bbaa15b063e20bc739ce3'>gnu: flex: Update bison-for-tests to 3.0.5.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/flex.scm (flex)[inputs]: Make BISON-FOR-TESTS inherit source
from BISON, and disable tests on it since they require flex.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-05-23 13:59:46 +0200'>2018-05-23</span></td><td><a href='/guix/commit/gnu/packages/flex.scm?id=8efe2a22eaaf00d667c54968c025a3477cb3c3f7'>gnu: Use "code" instead of "indent".</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a follow-up to commit e470abf8b789e61ae918a80f141e3c06afd44832.

* gnu/packages/commencement.scm,
gnu/packages/flex.scm: Use module "code" instead of "indent".
</span></span></td><td>Ricardo Wurmus</td></tr>