gccrs: fix ice when function is outside of context

Fixes #2477

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit):
	We need to check if a function context exists

gcc/testsuite/ChangeLog:

	* rust/compile/issue-2477.rs: New test.

Signed-off-by: Philip Herron <[email protected]>

Author: philberty

gcc/rust/typecheck/rust-hir-type-check-expr.cc

@@ -150,6 +150,14 @@ TypeCheckExpr::visit (HIR::TupleExpr &expr)
 void
 TypeCheckExpr::visit (HIR::ReturnExpr &expr)
 {
+  if (!context->have_function_context ())
+    {
+      rust_error_at (expr.get_locus (),
+		     "return statement outside of function body");
+      infered = new TyTy::ErrorType (expr.get_mappings ().get_hirid ());
+      return;
+    }
+
   auto fn_return_tyty = context->peek_return_type ();
   location_t expr_locus = expr.has_return_expr ()
 			    ? expr.get_expr ()->get_locus ()

gcc/testsuite/rust/compile/issue-2477.rs

@@ -0,0 +1,3 @@
+const FOO: u32 = return 0;
+// { dg-error "return statement outside of function body" "" { target *-*-* } .-1 }
+// { dg-error "expected .u32. got" "" { target *-*-* } .-2 }