From bce47618bfdbb5b556ec663df8e4ba16f67ff870 Mon Sep 17 00:00:00 2001 From: Michael Baikov Date: Thu, 13 Jun 2024 08:46:30 -0400 Subject: [PATCH] local_def_path_hash_to_def_id can fail local_def_path_hash_to_def_id is used by Debug impl for DepNode and it looks for DefPathHash inside the current compilation. During incremental compilation we are going through nodes that belong to a previous compilation and might not be present and a simple attempt to print such node with tracing::debug (try_mark_parent_green does it for example) results in a otherwise avoidable panic Panic was added in https://github.com/rust-lang/rust/pull/82183, specifically in 2b60338ee9, with a comment "We only use this mapping for cases where we know that it must succeed.", but I'm not sure if this property holds when we traverse nodes from the old compilation in order to figure out if they are valid or not --- compiler/rustc_hir/src/definitions.rs | 12 +----------- compiler/rustc_middle/src/dep_graph/dep_node.rs | 12 ++---------- compiler/rustc_middle/src/query/on_disk_cache.rs | 8 ++++---- compiler/rustc_middle/src/ty/context.rs | 14 +++----------- 4 files changed, 10 insertions(+), 36 deletions(-) diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs index 35833e258d558..8aadcfa44c1b7 100644 --- a/compiler/rustc_hir/src/definitions.rs +++ b/compiler/rustc_hir/src/definitions.rs @@ -377,22 +377,12 @@ impl Definitions { } #[inline(always)] - pub fn local_def_path_hash_to_def_id( - &self, - hash: DefPathHash, - err_msg: &dyn std::fmt::Debug, - ) -> LocalDefId { + pub fn local_def_path_hash_to_def_id(&self, hash: DefPathHash) -> Option { debug_assert!(hash.stable_crate_id() == self.table.stable_crate_id); - #[cold] - #[inline(never)] - fn err(err_msg: &dyn std::fmt::Debug) -> ! { - panic!("{err_msg:?}") - } self.table .def_path_hash_to_index .get(&hash.local_hash()) .map(|local_def_index| LocalDefId { local_def_index }) - .unwrap_or_else(|| err(err_msg)) } pub fn def_path_hash_to_def_index_map(&self) -> &DefPathHashMap { diff --git a/compiler/rustc_middle/src/dep_graph/dep_node.rs b/compiler/rustc_middle/src/dep_graph/dep_node.rs index 3c5bf6eb82461..84b47a6ed447b 100644 --- a/compiler/rustc_middle/src/dep_graph/dep_node.rs +++ b/compiler/rustc_middle/src/dep_graph/dep_node.rs @@ -194,10 +194,7 @@ impl DepNodeExt for DepNode { /// has been removed. fn extract_def_id(&self, tcx: TyCtxt<'_>) -> Option { if tcx.fingerprint_style(self.kind) == FingerprintStyle::DefPathHash { - Some(tcx.def_path_hash_to_def_id( - DefPathHash(self.hash.into()), - &("Failed to extract DefId", self.kind, self.hash), - )) + tcx.def_path_hash_to_def_id(DefPathHash(self.hash.into())) } else { None } @@ -390,12 +387,7 @@ impl<'tcx> DepNodeParams> for HirId { if tcx.fingerprint_style(dep_node.kind) == FingerprintStyle::HirId { let (local_hash, local_id) = Fingerprint::from(dep_node.hash).split(); let def_path_hash = DefPathHash::new(tcx.stable_crate_id(LOCAL_CRATE), local_hash); - let def_id = tcx - .def_path_hash_to_def_id( - def_path_hash, - &("Failed to extract HirId", dep_node.kind, dep_node.hash), - ) - .expect_local(); + let def_id = tcx.def_path_hash_to_def_id(def_path_hash)?.expect_local(); let local_id = local_id .as_u64() .try_into() diff --git a/compiler/rustc_middle/src/query/on_disk_cache.rs b/compiler/rustc_middle/src/query/on_disk_cache.rs index ccd0c7cb10c49..924249bf37d6c 100644 --- a/compiler/rustc_middle/src/query/on_disk_cache.rs +++ b/compiler/rustc_middle/src/query/on_disk_cache.rs @@ -733,10 +733,10 @@ impl<'a, 'tcx> SpanDecoder for CacheDecoder<'a, 'tcx> { // If we get to this point, then all of the query inputs were green, // which means that the definition with this hash is guaranteed to // still exist in the current compilation session. - self.tcx.def_path_hash_to_def_id( - def_path_hash, - &("Failed to convert DefPathHash", def_path_hash), - ) + match self.tcx.def_path_hash_to_def_id(def_path_hash) { + Some(r) => r, + None => panic!("Failed to convert DefPathHash {def_path_hash:?}"), + } } fn decode_attr_id(&mut self) -> rustc_span::AttrId { diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 65d744239a6ab..1d010f43bf34c 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -1296,11 +1296,7 @@ impl<'tcx> TyCtxt<'tcx> { /// Converts a `DefPathHash` to its corresponding `DefId` in the current compilation /// session, if it still exists. This is used during incremental compilation to /// turn a deserialized `DefPathHash` into its current `DefId`. - pub fn def_path_hash_to_def_id( - self, - hash: DefPathHash, - err_msg: &dyn std::fmt::Debug, - ) -> DefId { + pub fn def_path_hash_to_def_id(self, hash: DefPathHash) -> Option { debug!("def_path_hash_to_def_id({:?})", hash); let stable_crate_id = hash.stable_crate_id(); @@ -1308,13 +1304,9 @@ impl<'tcx> TyCtxt<'tcx> { // If this is a DefPathHash from the local crate, we can look up the // DefId in the tcx's `Definitions`. if stable_crate_id == self.stable_crate_id(LOCAL_CRATE) { - self.untracked - .definitions - .read() - .local_def_path_hash_to_def_id(hash, err_msg) - .to_def_id() + Some(self.untracked.definitions.read().local_def_path_hash_to_def_id(hash)?.to_def_id()) } else { - self.def_path_hash_to_def_id_extern(hash, stable_crate_id) + Some(self.def_path_hash_to_def_id_extern(hash, stable_crate_id)) } }