Improve path:// handling

In particular, doing 'nix build /path/to/dir' now works if
/path/to/dir is not a Git tree (it only has to contain a flake.nix
file).

Also, 'nix flake init' no longer requires a Git tree (but it will do a
'git add flake.nix' if it's a Git tree)
This commit is contained in:
Eelco Dolstra 2020-04-27 22:53:11 +02:00
parent 829dcb35d5
commit 6521c92ce8
6 changed files with 99 additions and 61 deletions

View file

@ -176,7 +176,7 @@ static FlakeInput parseFlakeInput(EvalState & state,
if (!attrs.empty())
throw Error("unexpected flake input attribute '%s', at %s", attrs.begin()->first, pos);
if (url)
input.ref = parseFlakeRef(*url);
input.ref = parseFlakeRef(*url, {}, true);
}
return input;
@ -630,7 +630,7 @@ void callFlake(EvalState & state,
static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto flakeRefS = state.forceStringNoCtx(*args[0], pos);
auto flakeRef = parseFlakeRef(flakeRefS);
auto flakeRef = parseFlakeRef(flakeRefS, {}, true);
if (evalSettings.pureEval && !flakeRef.input->isImmutable())
throw Error("cannot call 'getFlake' on mutable flake reference '%s', at %s (use --impure to override)", flakeRefS, pos);

View file

@ -47,9 +47,9 @@ FlakeRef FlakeRef::resolve(ref<Store> store) const
}
FlakeRef parseFlakeRef(
const std::string & url, const std::optional<Path> & baseDir)
const std::string & url, const std::optional<Path> & baseDir, bool allowMissing)
{
auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir);
auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir, allowMissing);
if (fragment != "")
throw Error("unexpected fragment '%s' in flake reference '%s'", fragment, url);
return flakeRef;
@ -66,7 +66,7 @@ std::optional<FlakeRef> maybeParseFlakeRef(
}
std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir)
const std::string & url, const std::optional<Path> & baseDir, bool allowMissing)
{
using namespace fetchers;
@ -115,17 +115,16 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
if (!S_ISDIR(lstat(path).st_mode))
throw BadURL("path '%s' is not a flake (because it's not a directory)", path);
if (!allowMissing && !pathExists(path + "/flake.nix"))
throw BadURL("path '%s' is not a flake (because it doesn't contain a 'flake.nix' file)", path);
auto fragment = percentDecode(std::string(match[3]));
auto flakeRoot = path;
std::string subdir;
while (true) {
if (pathExists(flakeRoot + "/.git")) break;
subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
flakeRoot = dirOf(flakeRoot);
if (flakeRoot == "/")
throw BadURL("path '%s' is not a flake (because it does not reference a Git repository)", path);
}
while (flakeRoot != "/") {
if (pathExists(flakeRoot + "/.git")) {
auto base = std::string("git+file://") + flakeRoot;
auto parsedURL = ParsedURL{
@ -137,8 +136,6 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
.query = decodeQuery(match[2]),
};
auto fragment = percentDecode(std::string(match[3]));
if (subdir != "") {
if (parsedURL.query.count("dir"))
throw Error("flake URL '%s' has an inconsistent 'dir' parameter", url);
@ -150,6 +147,17 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
fragment);
}
subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
flakeRoot = dirOf(flakeRoot);
}
fetchers::Attrs attrs;
attrs.insert_or_assign("type", "path");
attrs.insert_or_assign("path", path);
return std::make_pair(FlakeRef(inputFromAttrs(attrs), ""), fragment);
}
else {
auto parsedURL = parseURL(url);
std::string fragment;

View file

@ -41,13 +41,13 @@ struct FlakeRef
std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef);
FlakeRef parseFlakeRef(
const std::string & url, const std::optional<Path> & baseDir = {});
const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
std::optional<FlakeRef> maybeParseFlake(
const std::string & url, const std::optional<Path> & baseDir = {});
std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir = {});
const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir = {});

View file

@ -32,7 +32,7 @@ struct PathInput : Input
bool isImmutable() const override
{
return (bool) narHash;
return narHash || rev;
}
ParsedURL toURL() const override
@ -56,9 +56,20 @@ struct PathInput : Input
attrs.emplace("revCount", *revCount);
if (lastModified)
attrs.emplace("lastModified", *lastModified);
if (!rev && narHash)
attrs.emplace("narHash", narHash->to_string(SRI));
return attrs;
}
std::optional<Path> getSourcePath() const override
{
return path;
}
void markChangedFile(std::string_view file, std::optional<std::string> commitMsg) const override
{
}
std::pair<Tree, std::shared_ptr<const Input>> fetchTreeInternal(nix::ref<Store> store) const override
{
auto input = std::make_shared<PathInput>(*this);
@ -74,6 +85,8 @@ struct PathInput : Input
// FIXME: try to substitute storePath.
storePath = store->addToStore("source", path);
input->narHash = store->queryPathInfo(*storePath)->narHash;
return
{
Tree {
@ -99,6 +112,9 @@ struct PathInputScheme : InputScheme
auto input = std::make_unique<PathInput>();
input->path = url.path;
if (url.authority && *url.authority != "")
throw Error("path URL '%s' should not have an authority ('%s')", url.url, *url.authority);
for (auto & [name, value] : url.query)
if (name == "rev")
input->rev = Hash(value, htSHA1);
@ -114,6 +130,9 @@ struct PathInputScheme : InputScheme
throw Error("path URL '%s' has invalid parameter '%s'", url.to_string(), name);
input->lastModified = lastModified;
}
else if (name == "narHash")
// FIXME: require SRI hash.
input->narHash = Hash(value);
else
throw Error("path URL '%s' has unsupported parameter '%s'", url.to_string(), name);
@ -134,6 +153,9 @@ struct PathInputScheme : InputScheme
input->revCount = getIntAttr(attrs, "revCount");
else if (name == "lastModified")
input->lastModified = getIntAttr(attrs, "lastModified");
else if (name == "narHash")
// FIXME: require SRI hash.
input->narHash = Hash(getStrAttr(attrs, "narHash"));
else if (name == "type" || name == "path")
;
else

View file

@ -551,17 +551,18 @@ struct CmdFlakeInit : virtual Args, Command
{
Path flakeDir = absPath(".");
if (!pathExists(flakeDir + "/.git"))
throw Error("the directory '%s' is not a Git repository", flakeDir);
Path flakePath = flakeDir + "/flake.nix";
if (pathExists(flakePath))
throw Error("file '%s' already exists", flakePath);
writeFile(flakePath,
#include "flake-template.nix.gen.hh"
#include "flake-template.nix.gen.hh"
);
if (pathExists(flakeDir + "/.git"))
runProgram("git", true,
{ "-C", flakeDir, "add", "--intent-to-add", "flake.nix" });
}
};

View file

@ -438,14 +438,6 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
} else {
auto follow = [&](const std::string & s) -> std::optional<StorePath> {
try {
return store->followLinksToStorePath(s);
} catch (NotInStore &) {
return {};
}
};
for (auto & s : ss) {
if (hasPrefix(s, "nixpkgs.")) {
bool static warned;
@ -456,23 +448,38 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
}
else {
auto res = maybeParseFlakeRefWithFragment(s, absPath("."));
if (res) {
auto &[flakeRef, fragment] = *res;
std::exception_ptr ex;
try {
auto [flakeRef, fragment] = parseFlakeRefWithFragment(s, absPath("."));
result.push_back(std::make_shared<InstallableFlake>(
*this, std::move(flakeRef),
fragment == "" ? getDefaultFlakeAttrPaths() : Strings{fragment},
getDefaultFlakeAttrPathPrefixes()));
} else {
std::optional<StorePath> storePath;
if (s.find('/') != std::string::npos && (storePath = follow(s)))
result.push_back(std::make_shared<InstallableStorePath>(store, store->printStorePath(*storePath)));
else
continue;
} catch (...) {
ex = std::current_exception();
}
if (s.find('/') != std::string::npos) {
try {
result.push_back(std::make_shared<InstallableStorePath>(store, store->printStorePath(store->followLinksToStorePath(s))));
continue;
} catch (NotInStore &) {
} catch (...) {
if (!ex)
ex = std::current_exception();
}
}
std::rethrow_exception(ex);
/*
throw Error(
pathExists(s)
? "path '%s' is not a flake or a store path"
: "don't know how to handle argument '%s'", s);
}
*/
}
}
}