Make the search path lazier with non-fatal errors
Thus, -I / $NIX_PATH entries are now downloaded only when they are
needed for evaluation. An error to download an entry is a non-fatal
warning (just like non-existant paths).
This does change the semantics of builtins.nixPath, which now returns
the original, rather than resulting path. E.g., before we had
[ { path = "/nix/store/hgm3yxf1lrrwa3z14zpqaj5p9vs0qklk-nixexprs.tar.xz"; prefix = "nixpkgs"; } ... ]
but now
[ { path = "https://nixos.org/channels/nixos-16.03/nixexprs.tar.xz"; prefix = "nixpkgs"; } ... ]
Fixes #792.
(cherry picked from commit 363f37d084
)
This commit is contained in:
parent
dea9de79b7
commit
efa2e451fb
|
@ -273,7 +273,7 @@ EvalState::EvalState(const Strings & _searchPath)
|
|||
|
||||
/* Initialise the Nix expression search path. */
|
||||
Strings paths = parseNixPath(getEnv("NIX_PATH", ""));
|
||||
for (auto & i : _searchPath) addToSearchPath(i, true);
|
||||
for (auto & i : _searchPath) addToSearchPath(i);
|
||||
for (auto & i : paths) addToSearchPath(i);
|
||||
addToSearchPath("nix=" + settings.nixDataDir + "/nix/corepkgs");
|
||||
|
||||
|
@ -296,11 +296,15 @@ Path EvalState::checkSourcePath(const Path & path_)
|
|||
if (!restricted) return path_;
|
||||
|
||||
/* Resolve symlinks. */
|
||||
debug(format("checking access to ‘%s’") % path_);
|
||||
Path path = canonPath(path_, true);
|
||||
|
||||
for (auto & i : searchPath)
|
||||
if (path == i.second || isInDir(path, i.second))
|
||||
for (auto & i : searchPath) {
|
||||
auto r = resolveSearchPathElem(i);
|
||||
if (!r.first) continue;
|
||||
if (path == r.second || isInDir(path, r.second))
|
||||
return path;
|
||||
}
|
||||
|
||||
/* To support import-from-derivation, allow access to anything in
|
||||
the store. FIXME: only allow access to paths that have been
|
||||
|
|
|
@ -55,7 +55,8 @@ typedef std::map<Path, Path> SrcToStore;
|
|||
std::ostream & operator << (std::ostream & str, const Value & v);
|
||||
|
||||
|
||||
typedef list<std::pair<string, Path> > SearchPath;
|
||||
typedef std::pair<std::string, std::string> SearchPathElem;
|
||||
typedef std::list<SearchPathElem> SearchPath;
|
||||
|
||||
|
||||
/* Initialise the Boehm GC, if applicable. */
|
||||
|
@ -95,12 +96,14 @@ private:
|
|||
|
||||
SearchPath searchPath;
|
||||
|
||||
std::map<std::string, std::pair<bool, std::string>> searchPathResolved;
|
||||
|
||||
public:
|
||||
|
||||
EvalState(const Strings & _searchPath);
|
||||
~EvalState();
|
||||
|
||||
void addToSearchPath(const string & s, bool warn = false);
|
||||
void addToSearchPath(const string & s);
|
||||
|
||||
Path checkSourcePath(const Path & path);
|
||||
|
||||
|
@ -122,6 +125,9 @@ public:
|
|||
Path findFile(const string & path);
|
||||
Path findFile(SearchPath & searchPath, const string & path, const Pos & pos = noPos);
|
||||
|
||||
/* If the specified search path element is a URI, download it. */
|
||||
std::pair<bool, std::string> resolveSearchPathElem(const SearchPathElem & elem);
|
||||
|
||||
/* Evaluate an expression to normal form, storing the result in
|
||||
value `v'. */
|
||||
void eval(Expr * e, Value & v);
|
||||
|
|
|
@ -590,7 +590,7 @@ Expr * EvalState::parseExprFromString(const string & s, const Path & basePath)
|
|||
}
|
||||
|
||||
|
||||
void EvalState::addToSearchPath(const string & s, bool warn)
|
||||
void EvalState::addToSearchPath(const string & s)
|
||||
{
|
||||
size_t pos = s.find('=');
|
||||
string prefix;
|
||||
|
@ -602,16 +602,7 @@ void EvalState::addToSearchPath(const string & s, bool warn)
|
|||
path = string(s, pos + 1);
|
||||
}
|
||||
|
||||
if (isUri(path))
|
||||
path = downloadFileCached(path, true);
|
||||
|
||||
path = absPath(path);
|
||||
if (pathExists(path)) {
|
||||
debug(format("adding path ‘%1%’ to the search path") % path);
|
||||
/* Resolve symlinks in the path to support restricted mode. */
|
||||
searchPath.push_back(std::pair<string, Path>(prefix, canonPath(path, true)));
|
||||
} else if (warn)
|
||||
printMsg(lvlError, format("warning: Nix search path entry ‘%1%’ does not exist, ignoring") % path);
|
||||
searchPath.emplace_back(prefix, path);
|
||||
}
|
||||
|
||||
|
||||
|
@ -624,17 +615,19 @@ Path EvalState::findFile(const string & path)
|
|||
Path EvalState::findFile(SearchPath & searchPath, const string & path, const Pos & pos)
|
||||
{
|
||||
for (auto & i : searchPath) {
|
||||
assert(!isUri(i.second));
|
||||
Path res;
|
||||
std::string suffix;
|
||||
if (i.first.empty())
|
||||
res = i.second + "/" + path;
|
||||
suffix = "/" + path;
|
||||
else {
|
||||
if (path.compare(0, i.first.size(), i.first) != 0 ||
|
||||
(path.size() > i.first.size() && path[i.first.size()] != '/'))
|
||||
auto s = i.first.size();
|
||||
if (path.compare(0, s, i.first) != 0 ||
|
||||
(path.size() > s && path[s] != '/'))
|
||||
continue;
|
||||
res = i.second +
|
||||
(path.size() == i.first.size() ? "" : "/" + string(path, i.first.size()));
|
||||
suffix = path.size() == s ? "" : "/" + string(path, s);
|
||||
}
|
||||
auto r = resolveSearchPathElem(i);
|
||||
if (!r.first) continue;
|
||||
Path res = r.second + suffix;
|
||||
if (pathExists(res)) return canonPath(res);
|
||||
}
|
||||
format f = format(
|
||||
|
@ -645,4 +638,35 @@ Path EvalState::findFile(SearchPath & searchPath, const string & path, const Pos
|
|||
}
|
||||
|
||||
|
||||
std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathElem & elem)
|
||||
{
|
||||
auto i = searchPathResolved.find(elem.second);
|
||||
if (i != searchPathResolved.end()) return i->second;
|
||||
|
||||
std::pair<bool, std::string> res;
|
||||
|
||||
if (isUri(elem.second)) {
|
||||
try {
|
||||
res = { true, downloadFileCached(elem.second, true) };
|
||||
} catch (DownloadError & e) {
|
||||
printMsg(lvlError, format("warning: Nix search path entry ‘%1%’ cannot be downloaded, ignoring") % elem.second);
|
||||
res = { false, "" };
|
||||
}
|
||||
} else {
|
||||
auto path = absPath(elem.second);
|
||||
if (pathExists(path))
|
||||
res = { true, path };
|
||||
else {
|
||||
printMsg(lvlError, format("warning: Nix search path entry ‘%1%’ does not exist, ignoring") % elem.second);
|
||||
res = { false, "" };
|
||||
}
|
||||
}
|
||||
|
||||
debug(format("resolved search path element ‘%s’ to ‘%s’") % elem.second % res.second);
|
||||
|
||||
searchPathResolved[elem.second] = res;
|
||||
return res;
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
|
|
|
@ -765,7 +765,6 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va
|
|||
|
||||
SearchPath searchPath;
|
||||
|
||||
PathSet context;
|
||||
for (unsigned int n = 0; n < args[0]->listSize(); ++n) {
|
||||
Value & v2(*args[0]->listElems()[n]);
|
||||
state.forceAttrs(v2, pos);
|
||||
|
@ -778,21 +777,23 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va
|
|||
i = v2.attrs->find(state.symbols.create("path"));
|
||||
if (i == v2.attrs->end())
|
||||
throw EvalError(format("attribute ‘path’ missing, at %1%") % pos);
|
||||
string path = state.coerceToPath(pos, *i->value, context);
|
||||
|
||||
searchPath.push_back(std::pair<string, Path>(prefix, state.checkSourcePath(path)));
|
||||
PathSet context;
|
||||
string path = state.coerceToString(pos, *i->value, context, false, false);
|
||||
|
||||
try {
|
||||
realiseContext(context);
|
||||
} catch (InvalidPathError & e) {
|
||||
throw EvalError(format("cannot find ‘%1%’, since path ‘%2%’ is not valid, at %3%")
|
||||
% path % e.path % pos);
|
||||
}
|
||||
|
||||
searchPath.emplace_back(prefix, path);
|
||||
}
|
||||
|
||||
string path = state.forceStringNoCtx(*args[1], pos);
|
||||
|
||||
try {
|
||||
realiseContext(context);
|
||||
} catch (InvalidPathError & e) {
|
||||
throw EvalError(format("cannot find ‘%1%’, since path ‘%2%’ is not valid, at %3%")
|
||||
% path % e.path % pos);
|
||||
}
|
||||
|
||||
mkPath(v, state.findFile(searchPath, path, pos).c_str());
|
||||
mkPath(v, state.checkSourcePath(state.findFile(searchPath, path, pos)).c_str());
|
||||
}
|
||||
|
||||
/* Read a directory (without . or ..) */
|
||||
|
|
|
@ -20,4 +20,10 @@ nix-build file://$tarball
|
|||
|
||||
nix-build '<foo>' -I foo=file://$tarball
|
||||
|
||||
nix-build -E "import (fetchTarball file://$tarball)"
|
||||
nix-build -o $TMPDIR/result -E "import (fetchTarball file://$tarball)"
|
||||
|
||||
nix-instantiate --eval -E '1 + 2' -I fnord=file://no-such-tarball.tar.xz
|
||||
nix-instantiate --eval -E 'with <fnord/xyzzy>; 1 + 2' -I fnord=file://no-such-tarball.tar.xz
|
||||
(! nix-instantiate --eval -E '<fnord/xyzzy> 1' -I fnord=file://no-such-tarball.tar.xz)
|
||||
|
||||
nix-instantiate --eval -E '<fnord/config.nix>' -I fnord=file://no-such-tarball.tar.xz -I fnord=.
|
||||
|
|
Loading…
Reference in New Issue