Auto merge of #55150 - pnkfelix:issues-47215-54797-fix-ice-from-moving-out-of-thread-local-under-ast-borrowck, r=nikomatsakis

Do not allow moving out of thread local under ast borrowck

AST borrowck failed to prevent moving out of a thread-local static.

This was broken. And it also (sometimes?) caused an ICE during drop elaboration.

Fix #47215
Fix #54797

6 files changed, 17 insertions, 1 deletions

diff --git a/src/librustc_borrowck/borrowck/check_loans.rs b/src/librustc_borrowck/borrowck/check_loans.rs
index d9b64527700..1fc9ee07a1a 100644
--- a/src/librustc_borrowck/borrowck/check_loans.rs
+++ b/src/librustc_borrowck/borrowck/check_loans.rs
@@ -377,6 +377,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
                 // by-move upvars, which is local data for generators
                 Categorization::Upvar(..) => true,
 
+                Categorization::ThreadLocal(region) |
                 Categorization::Rvalue(region) => {
                     // Rvalues promoted to 'static are no longer local
                     if let RegionKind::ReStatic = *region {
diff --git a/src/librustc_borrowck/borrowck/gather_loans/gather_moves.rs b/src/librustc_borrowck/borrowck/gather_loans/gather_moves.rs
index ffc4fbfb4c9..7bb5f411752 100644
--- a/src/librustc_borrowck/borrowck/gather_loans/gather_moves.rs
+++ b/src/librustc_borrowck/borrowck/gather_loans/gather_moves.rs
@@ -177,6 +177,7 @@ fn check_and_get_illegal_move_origin<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
     match cmt.cat {
         Categorization::Deref(_, mc::BorrowedPtr(..)) |
         Categorization::Deref(_, mc::UnsafePtr(..)) |
+        Categorization::ThreadLocal(..) |
         Categorization::StaticItem => {
             Some(cmt.clone())
         }
diff --git a/src/librustc_borrowck/borrowck/gather_loans/lifetime.rs b/src/librustc_borrowck/borrowck/gather_loans/lifetime.rs
index c9dcc0d9fa2..6ef5d65d10d 100644
--- a/src/librustc_borrowck/borrowck/gather_loans/lifetime.rs
+++ b/src/librustc_borrowck/borrowck/gather_loans/lifetime.rs
@@ -70,6 +70,7 @@ impl<'a, 'tcx> GuaranteeLifetimeContext<'a, 'tcx> {
 
         match cmt.cat {
             Categorization::Rvalue(..) |
+            Categorization::ThreadLocal(..) |
             Categorization::Local(..) |                     // L-Local
             Categorization::Upvar(..) |
             Categorization::Deref(_, mc::BorrowedPtr(..)) | // L-Deref-Borrowed
@@ -105,6 +106,7 @@ impl<'a, 'tcx> GuaranteeLifetimeContext<'a, 'tcx> {
         //! rooting etc, and presuming `cmt` is not mutated.
 
         match cmt.cat {
+            Categorization::ThreadLocal(temp_scope) |
             Categorization::Rvalue(temp_scope) => {
                 temp_scope
             }
diff --git a/src/librustc_borrowck/borrowck/gather_loans/move_error.rs b/src/librustc_borrowck/borrowck/gather_loans/move_error.rs
index b29ab55f9ba..e1a4473539c 100644
--- a/src/librustc_borrowck/borrowck/gather_loans/move_error.rs
+++ b/src/librustc_borrowck/borrowck/gather_loans/move_error.rs
@@ -145,6 +145,8 @@ fn report_cannot_move_out_of<'a, 'tcx>(bccx: &'a BorrowckCtxt<'a, 'tcx>,
     match move_from.cat {
         Categorization::Deref(_, mc::BorrowedPtr(..)) |
         Categorization::Deref(_, mc::UnsafePtr(..)) |
+        Categorization::Deref(_, mc::Unique) |
+        Categorization::ThreadLocal(..) |
         Categorization::StaticItem => {
             bccx.cannot_move_out_of(
                 move_from.span, &move_from.descriptive_string(bccx.tcx), Origin::Ast)
@@ -166,7 +168,10 @@ fn report_cannot_move_out_of<'a, 'tcx>(bccx: &'a BorrowckCtxt<'a, 'tcx>,
                 }
             }
         }
-        _ => {
+
+        Categorization::Rvalue(..) |
+        Categorization::Local(..) |
+        Categorization::Upvar(..) => {
             span_bug!(move_from.span, "this path should not cause illegal move");
         }
     }
diff --git a/src/librustc_borrowck/borrowck/gather_loans/restrictions.rs b/src/librustc_borrowck/borrowck/gather_loans/restrictions.rs
index d9784cc2177..52c7ebb4beb 100644
--- a/src/librustc_borrowck/borrowck/gather_loans/restrictions.rs
+++ b/src/librustc_borrowck/borrowck/gather_loans/restrictions.rs
@@ -70,6 +70,12 @@ impl<'a, 'tcx> RestrictionsContext<'a, 'tcx> {
                 RestrictionResult::Safe
             }
 
+            Categorization::ThreadLocal(..) => {
+                // Thread-locals are statics that have a scope, with
+                // no underlying structure to provide restrictions.
+                RestrictionResult::Safe
+            }
+
             Categorization::Local(local_id) => {
                 // R-Variable, locally declared
                 let lp = new_lp(LpVar(local_id));
diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs
index bf8d0231303..d52d78181b7 100644
--- a/src/librustc_borrowck/borrowck/mod.rs
+++ b/src/librustc_borrowck/borrowck/mod.rs
@@ -520,6 +520,7 @@ pub fn opt_loan_path_is_field<'tcx>(cmt: &mc::cmt_<'tcx>) -> (Option<Rc<LoanPath
 
     match cmt.cat {
         Categorization::Rvalue(..) |
+        Categorization::ThreadLocal(..) |
         Categorization::StaticItem => {
             (None, false)
         }