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Merge pull request #14479 from lovesegfault/topo-sort-handle-cycles

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refactor(libutil/topo-sort): return variant instead of throwing
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John Ericson 2025-11-10 20:50:17 +00:00 • committed by GitHub
commit 750306234d
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6 changed files with 427 additions and 77 deletions
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29
src/libstore/local-store.cc
View file

@ -989,19 +989,22 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
error if a cycle is detected and roll back the
transaction. Cycles can only occur when a derivation
has multiple outputs. */
topoSort(
paths,
{[&](const StorePath & path) {
auto i = infos.find(path);
return i == infos.end() ? StorePathSet() : i->second.references;
}},
{[&](const StorePath & path, const StorePath & parent) {
return BuildError(
BuildResult::Failure::OutputRejected,
"cycle detected in the references of '%s' from '%s'",
printStorePath(path),
printStorePath(parent));
}});
auto topoSortResult = topoSort(paths, {[&](const StorePath & path) {
auto i = infos.find(path);
return i == infos.end() ? StorePathSet() : i->second.references;
}});
std::visit(
overloaded{
[&](const Cycle<StorePath> & cycle) {
throw BuildError(
BuildResult::Failure::OutputRejected,
"cycle detected in the references of '%s' from '%s'",
printStorePath(cycle.path),
printStorePath(cycle.parent));
},
[](auto &) { /* Success, continue */ }},
topoSortResult);
txn.commit();
});

35
src/libstore/misc.cc
View file

@ -311,22 +311,25 @@ MissingPaths Store::queryMissing(const std::vector<DerivedPath> & targets)
StorePaths Store::topoSortPaths(const StorePathSet & paths)
{
return topoSort(
paths,
{[&](const StorePath & path) {
try {
return queryPathInfo(path)->references;
} catch (InvalidPath &) {
return StorePathSet();
}
}},
{[&](const StorePath & path, const StorePath & parent) {
return BuildError(
BuildResult::Failure::OutputRejected,
"cycle detected in the references of '%s' from '%s'",
printStorePath(path),
printStorePath(parent));
}});
auto result = topoSort(paths, {[&](const StorePath & path) {
try {
return queryPathInfo(path)->references;
} catch (InvalidPath &) {
return StorePathSet();
}
}});
return std::visit(
overloaded{
[&](const Cycle<StorePath> & cycle) -> StorePaths {
throw BuildError(
BuildResult::Failure::OutputRejected,
"cycle detected in the references of '%s' from '%s'",
printStorePath(cycle.path),
printStorePath(cycle.parent));
},
[](const auto & sorted) { return sorted; }},
result);
}
std::map<DrvOutput, StorePath>

73
src/libstore/unix/build/derivation-builder.cc
View file

@ -1470,43 +1470,46 @@ SingleDrvOutputs DerivationBuilderImpl::registerOutputs()
outputStats.insert_or_assign(outputName, std::move(st));
}
auto sortedOutputNames = topoSort(
outputsToSort,
{[&](const std::string & name) {
auto orifu = get(outputReferencesIfUnregistered, name);
if (!orifu)
auto topoSortResult = topoSort(outputsToSort, {[&](const std::string & name) {
auto orifu = get(outputReferencesIfUnregistered, name);
if (!orifu)
throw BuildError(
BuildResult::Failure::OutputRejected,
"no output reference for '%s' in build of '%s'",
name,
store.printStorePath(drvPath));
return std::visit(
overloaded{
/* Since we'll use the already installed versions of these, we
can treat them as leaves and ignore any references they
have. */
[&](const AlreadyRegistered &) { return StringSet{}; },
[&](const PerhapsNeedToRegister & refs) {
StringSet referencedOutputs;
/* FIXME build inverted map up front so no quadratic waste here */
for (auto & r : refs.refs)
for (auto & [o, p] : scratchOutputs)
if (r == p)
referencedOutputs.insert(o);
return referencedOutputs;
},
},
*orifu);
}});
auto sortedOutputNames = std::visit(
overloaded{
[&](Cycle<std::string> & cycle) -> std::vector<std::string> {
// TODO with more -vvvv also show the temporary paths for manual inspection.
throw BuildError(
BuildResult::Failure::OutputRejected,
"no output reference for '%s' in build of '%s'",
name,
store.printStorePath(drvPath));
return std::visit(
overloaded{
/* Since we'll use the already installed versions of these, we
can treat them as leaves and ignore any references they
have. */
[&](const AlreadyRegistered &) { return StringSet{}; },
[&](const PerhapsNeedToRegister & refs) {
StringSet referencedOutputs;
/* FIXME build inverted map up front so no quadratic waste here */
for (auto & r : refs.refs)
for (auto & [o, p] : scratchOutputs)
if (r == p)
referencedOutputs.insert(o);
return referencedOutputs;
},
},
*orifu);
}},
{[&](const std::string & path, const std::string & parent) {
// TODO with more -vvvv also show the temporary paths for manual inspection.
return BuildError(
BuildResult::Failure::OutputRejected,
"cycle detected in build of '%s' in the references of output '%s' from output '%s'",
store.printStorePath(drvPath),
path,
parent);
}});
"cycle detected in build of '%s' in the references of output '%s' from output '%s'",
store.printStorePath(drvPath),
cycle.path,
cycle.parent);
},
[](auto & sorted) { return sorted; }},
topoSortResult);
std::reverse(sortedOutputNames.begin(), sortedOutputNames.end());