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Always say which path component had trouble

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Chuck 2019-09-16 08:39:20 -07:00 committed by Linus Heckemann
parent 4ded9beea2
commit aa8e1d5f1e
1 changed files with 27 additions and 21 deletions
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48
nixos/modules/installer/tools/nixos-option/nixos-option.cc
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@ -31,6 +31,7 @@
using nix::absPath;
using nix::Bindings;
using nix::Error;
using nix::EvalError;
using nix::EvalState;
using nix::Path;
using nix::PathSet;
@ -465,12 +466,14 @@ bool optionTypeIs(Context * ctx, Value & v, const std::string & sought_type)
}
}
MakeError(OptionPathError, EvalError);
Value getSubOptions(Context * ctx, Value & option)
{
Value getSubOptions =
evaluateValue(ctx, findAlongAttrPath(*ctx->state, "type.getSubOptions", *ctx->autoArgs, option));
if (getSubOptions.type != tLambda) {
throw Error("Option's type.getSubOptions isn't a function");
throw OptionPathError("Option's type.getSubOptions isn't a function");
}
Value emptyString{};
nix::mkString(emptyString, "");
@ -486,28 +489,31 @@ Value findAlongOptionPath(Context * ctx, const std::string & path)
Strings tokens = parseAttrPath(path);
Value v = ctx->options_root;
for (auto i = tokens.begin(); i != tokens.end(); i++) {
bool last_attribute = std::next(i) == tokens.end();
const auto & attr = *i;
v = evaluateValue(ctx, &v);
if (attr.empty()) {
throw Error("empty attribute name in selection path '%s'", path);
}
if (isOption(ctx, v) && optionTypeIs(ctx, v, "submodule")) {
v = getSubOptions(ctx, v);
}
if (isOption(ctx, v) && optionTypeIs(ctx, v, "loaOf") && !last_attribute) {
v = getSubOptions(ctx, v);
// Note that we've consumed attr, but didn't actually use it. This is the path component that's looked up
// in the list or attribute set that doesn't name an option -- the "root" in "users.users.root.name".
} else if (v.type != tAttrs) {
throw Error("attribute '%s' in path '%s' attempts to index a value that should be a set but is %s", attr,
path, showType(v));
} else {
const auto & next = v.attrs->find(ctx->state->symbols.create(attr));
if (next == v.attrs->end()) {
throw Error("attribute '%s' in path '%s' not found", attr, path);
try {
bool last_attribute = std::next(i) == tokens.end();
v = evaluateValue(ctx, &v);
if (attr.empty()) {
throw OptionPathError("empty attribute name");
}
v = *next->value;
if (isOption(ctx, v) && optionTypeIs(ctx, v, "submodule")) {
v = getSubOptions(ctx, v);
}
if (isOption(ctx, v) && optionTypeIs(ctx, v, "loaOf") && !last_attribute) {
v = getSubOptions(ctx, v);
// Note that we've consumed attr, but didn't actually use it. This is the path component that's looked
// up in the list or attribute set that doesn't name an option -- the "root" in "users.users.root.name".
} else if (v.type != tAttrs) {
throw OptionPathError("Value is %s while a set was expected", showType(v));
} else {
const auto & next = v.attrs->find(ctx->state->symbols.create(attr));
if (next == v.attrs->end()) {
throw OptionPathError("Attribute not found", attr, path);
}
v = *next->value;
}
} catch (OptionPathError & e) {
throw OptionPathError("At '%s' in path '%s': %s", attr, path, e.msg());
}
}
return v;