allow flakes to trivially eval to attributes

flake.nix has historically been required to be a literal attribute set
expression. This commit relaxes that requirement that it must trivially
evaluate to an attribute set. Thunks are still not allowed, so imports,
most function applications, etc are all still disallowed, but things
like trivial let expressions are.

I love deleting code ^_^

Change-Id: I3b66e2bacb58d1deadfb4a768cc3a356638aeec3
This commit is contained in:
Qyriad 2024-05-24 20:53:21 -06:00
parent 5b4b216fac
commit 4982832dc3
3 changed files with 13 additions and 14 deletions

View file

@ -1099,7 +1099,7 @@ Value * ExprPath::maybeThunk(EvalState & state, Env & env)
}
void EvalState::evalFile(const SourcePath & path_, Value & v, bool mustBeTrivial)
void EvalState::evalFile(const SourcePath & path_, Value & v)
{
auto path = checkSourcePath(path_);
@ -1125,7 +1125,7 @@ void EvalState::evalFile(const SourcePath & path_, Value & v, bool mustBeTrivial
if (!e)
e = parseExprFromFile(checkSourcePath(resolvedPath));
cacheFile(path, resolvedPath, e, v, mustBeTrivial);
cacheFile(path, resolvedPath, e, v);
}
@ -1140,8 +1140,8 @@ void EvalState::cacheFile(
const SourcePath & path,
const SourcePath & resolvedPath,
Expr * e,
Value & v,
bool mustBeTrivial)
Value & v
)
{
fileParseCache[resolvedPath] = e;
@ -1154,12 +1154,6 @@ void EvalState::cacheFile(
e->getPos() ? std::make_shared<Pos>(positions[e->getPos()]) : nullptr,
"while evaluating the file '%1%':", resolvedPath.to_string())
: nullptr;
// Enforce that 'flake.nix' is a direct attrset, not a
// computation.
if (mustBeTrivial &&
!(dynamic_cast<ExprAttrs *>(e)))
error<EvalError>("file '%s' must be an attribute set", path).debugThrow();
eval(e, v);
} catch (Error & e) {
addErrorTrace(e, "while evaluating the file '%1%':", resolvedPath.to_string());

View file

@ -356,7 +356,7 @@ public:
* form. Optionally enforce that the top-level expression is
* trivial (i.e. doesn't require arbitrary computation).
*/
void evalFile(const SourcePath & path, Value & v, bool mustBeTrivial = false);
void evalFile(const SourcePath & path, Value & v);
/**
* Like `evalFile`, but with an already parsed expression.
@ -365,8 +365,8 @@ public:
const SourcePath & path,
const SourcePath & resolvedPath,
Expr * e,
Value & v,
bool mustBeTrivial = false);
Value & v
);
void resetFileCache();

View file

@ -234,7 +234,12 @@ static Flake getFlake(
// NOTE evalFile forces vInfo to be an attrset because mustBeTrivial is true.
Value vInfo;
state.evalFile(CanonPath(flakeFile), vInfo, true); // FIXME: symlink attack
state.evalFile(CanonPath(flakeFile), vInfo); // FIXME: symlink attack
if (vInfo.type() != nAttrs) {
state.error<EvalError>(
"file '%s' must be an attribute set, but is %s", flakeFile, showType(vInfo)
).debugThrow();
}
if (auto description = vInfo.attrs->get(state.sDescription)) {
expectType(state, nString, *description->value, description->pos);