handle edge-case of a recursion limit of 0

lqd · lqd · commit 0e1e964a3496 · 2023-08-29T19:20:22.000Z
diff --git a/compiler/rustc_trait_selection/src/solve/search_graph/mod.rs b/compiler/rustc_trait_selection/src/solve/search_graph/mod.rs
@@ -53,7 +53,7 @@ impl<'tcx> SearchGraph<'tcx> {
     pub(super) fn new(tcx: TyCtxt<'tcx>, mode: SolverMode) -> SearchGraph<'tcx> {
         Self {
             mode,
-            local_overflow_limit: tcx.recursion_limit().0.ilog2() as usize,
+            local_overflow_limit: tcx.recursion_limit().0.checked_ilog2().unwrap_or(0) as usize,
             stack: Default::default(),
             provisional_cache: ProvisionalCache::empty(),
         }

Original file line number	Diff line number	Diff line change
`@@ -53,7 +53,7 @@ impl<'tcx> SearchGraph<'tcx> {`
`53`	`53`	`pub(super) fn new(tcx: TyCtxt<'tcx>, mode: SolverMode) -> SearchGraph<'tcx> {`
`54`	`54`	`Self {`
`55`	`55`	`mode,`
`56`		`- local_overflow_limit: tcx.recursion_limit().0.ilog2() as usize,`
	`56`	`+ local_overflow_limit: tcx.recursion_limit().0.checked_ilog2().unwrap_or(0) as usize,`
`57`	`57`	`stack: Default::default(),`
`58`	`58`	`provisional_cache: ProvisionalCache::empty(),`
`59`	`59`	`}`