Files
lix/lix/libexpr/primops/fetchMercurial.cc
T
skye d07bbb109e libexpr: Replace Value::mkAttrs with constructor calls
The pseudo-constructor `Value::mkAttrs` would previously be called on an
default-constructed (under-initialized) `Value` to create a properly
initialized `Value` that represents an attribute set. This change
removes mkAttrs and constructs attr `Value`s directly.

Change-Id: I11cd801eefecd454a7a5b6229d6770d06a6a6964
2026-02-23 03:54:35 +00:00

106 lines
4.0 KiB
C++

#include "lix/libexpr/primops.hh"
#include "lix/libexpr/eval-settings.hh"
#include "lix/libfetchers/fetchers.hh"
#include "lix/libutil/url-parts.hh"
namespace nix {
void prim_fetchMercurial(EvalState & state, Value ** args, Value & v)
{
std::string url;
std::optional<Hash> rev;
std::optional<std::string> ref;
std::string_view name = "source";
NixStringContext context;
state.forceValue(*args[0], noPos);
if (args[0]->type() == nAttrs) {
for (auto & attr : *args[0]->attrs()) {
std::string_view n(state.ctx.symbols[attr.name]);
if (n == "url")
url = state
.coerceToString(
attr.pos,
attr.value,
context,
"while evaluating the `url` attribute passed to "
"builtins.fetchMercurial",
StringCoercionMode::Strict,
false
)
.toOwned();
else if (n == "rev") {
// Ugly: unlike fetchGit, here the "rev" attribute can
// be both a revision or a branch/tag name.
auto value = state.forceStringNoCtx(
attr.value,
attr.pos,
"while evaluating the `rev` attribute passed to builtins.fetchMercurial"
);
if (std::regex_match(value.begin(), value.end(), revRegex)) {
rev = Hash::parseAny(value, HashType::SHA1);
} else
ref = value;
}
else if (n == "name")
name = state.forceStringNoCtx(
attr.value,
attr.pos,
"while evaluating the `name` attribute passed to builtins.fetchMercurial"
);
else {
state.ctx.errors
.make<EvalError>(
"unsupported argument '%s' to 'fetchMercurial'",
state.ctx.symbols[attr.name]
)
.atPos(attr.pos)
.debugThrow();
}
}
if (url.empty())
state.ctx.errors.make<EvalError>("'url' argument required").debugThrow();
} else
url = state.coerceToString(noPos, *args[0], context,
"while evaluating the first argument passed to builtins.fetchMercurial",
StringCoercionMode::Strict, false).toOwned();
// FIXME: git externals probably can be used to bypass the URI
// whitelist. Ah well.
state.ctx.paths.checkURI(url);
if (evalSettings.pureEval && !rev)
throw Error("in pure evaluation mode, 'fetchMercurial' requires a Mercurial revision");
fetchers::Attrs attrs;
attrs.insert_or_assign("type", "hg");
attrs.insert_or_assign("url", url.find("://") != std::string::npos ? url : "file://" + url);
attrs.insert_or_assign("name", std::string(name));
if (ref) attrs.insert_or_assign("ref", *ref);
if (rev) attrs.insert_or_assign("rev", rev->gitRev());
auto input = fetchers::Input::fromAttrs(std::move(attrs));
// FIXME: use name
auto [tree, input2] = state.aio.blockOn(input.fetch(state.ctx.store));
auto attrs2 = state.ctx.buildBindings(8);
state.ctx.paths.mkStorePathString(tree.storePath, attrs2.alloc(state.ctx.symbols.sym_outPath));
if (input2.getRef())
attrs2.alloc("branch").mkString(*input2.getRef());
// Backward compatibility: set 'rev' to
// 0000000000000000000000000000000000000000 for a dirty tree.
auto rev2 = input2.getRev().value_or(Hash(HashType::SHA1));
attrs2.alloc("rev").mkString(rev2.gitRev());
attrs2.alloc("shortRev").mkString(rev2.gitRev().substr(0, 12));
if (auto revCount = input2.getRevCount())
attrs2.alloc("revCount").mkInt(*revCount);
v = {NewValueAs::attrs, attrs2};
state.ctx.paths.allowPath(tree.storePath);
}
}