From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 25 Apr 2022 02:59:00 +0000 (-0600)
Subject: catch existence_error exceptions from top-level calls to attribute_goals/3 (#1432)
X-Git-Tag: v0.9.1~47
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=ed89c43e484918a045ec7433292772346ca896bc;p=scryer-prolog.git

catch existence_error exceptions from top-level calls to attribute_goals/3 (#1432)
---

diff --git a/src/machine/machine_state_impl.rs b/src/machine/machine_state_impl.rs
index cbd8d602..5223dc92 100644
--- a/src/machine/machine_state_impl.rs
+++ b/src/machine/machine_state_impl.rs
@@ -1885,14 +1885,7 @@ impl MachineState {
                     }
                     (HeapCellValueTag::PStrLoc | HeapCellValueTag::PStrOffset, h) => {
                         let (focus, _) = pstr_loc_and_offset(&self.heap, h);
-                        let pstr_atom = read_heap_cell!(self.heap[focus],
-                            (HeapCellValueTag::CStr | HeapCellValueTag::PStr, pstr_atom) => {
-                                pstr_atom
-                            }
-                            _ => {
-                                unreachable!()
-                            }
-                        );
+                        let pstr_atom = cell_as_atom!(self.heap[focus]);
 
                         if has_tail {
                             self.s = HeapPtr::PStrLocation(focus, offset);
diff --git a/src/machine/project_attributes.pl b/src/machine/project_attributes.pl
index ae2054e3..b2f75007 100644
--- a/src/machine/project_attributes.pl
+++ b/src/machine/project_attributes.pl
@@ -32,6 +32,7 @@ call_attribute_goals([Module|Modules], GoalCaller, AttrVars) :-
 
 '$print_attribute_goals_exception'(Module, E) :-
     (  E = error(evaluation_error((Module:attribute_goals)/3), attribute_goals/3)
+    ;  E = error(existence_error(procedure, attribute_goals/3), attribute_goals/3)
     -> true
     ;  loader:write_error(E),
        nl