From: Markus Triska <triska@metalevel.at>
Date: Sat, 23 May 2020 17:14:29 +0000 (+0200)
Subject: ADDED: halt/1, halting with specified exit code
X-Git-Tag: v0.8.127~64^2
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=b0df981b01fad6898a00d6fe72407e0d75997437;p=scryer-prolog.git

ADDED: halt/1, halting with specified exit code
---

diff --git a/src/prolog/clause_types.rs b/src/prolog/clause_types.rs
index e685c65f..14c353b2 100644
--- a/src/prolog/clause_types.rs
+++ b/src/prolog/clause_types.rs
@@ -580,7 +580,7 @@ impl SystemClauseType {
             ("$get_lh_from_offset_diff", 3) => Some(SystemClauseType::GetLiftedHeapFromOffsetDiff),
             ("$get_double_quotes", 1) => Some(SystemClauseType::GetDoubleQuotes),
             ("$get_scc_cleaner", 1) => Some(SystemClauseType::GetSCCCleaner),
-            ("$halt", 0) => Some(SystemClauseType::Halt),
+            ("$halt", 1) => Some(SystemClauseType::Halt),
             ("$head_is_dynamic", 1) => Some(SystemClauseType::HeadIsDynamic),
             ("$install_scc_cleaner", 2) => Some(SystemClauseType::InstallSCCCleaner),
             ("$install_inference_counter", 3) => Some(SystemClauseType::InstallInferenceCounter),
diff --git a/src/prolog/lib/builtins.pl b/src/prolog/lib/builtins.pl
index a4bd6db8..3e1c8d28 100644
--- a/src/prolog/lib/builtins.pl
+++ b/src/prolog/lib/builtins.pl
@@ -52,7 +52,7 @@ user:term_expansion((:- op(Pred, Spec, [Op | OtherOps])), OpResults) :-
                      findall/3, findall/4, flush_output/0,
                      flush_output/1, get_byte/1, get_byte/2,
                      get_char/1, get_char/2, get_code/1, get_code/2,
-                     halt/0, max_arity/1, number_chars/2,
+                     halt/0, halt/1, max_arity/1, number_chars/2,
                      number_codes/2, once/1, op/3, open/3, open/4,
                      peek_byte/1, peek_byte/2, peek_char/1,
                      peek_char/2, peek_code/1, peek_code/2,
@@ -912,7 +912,14 @@ op(Priority, OpSpec, Op) :-
     ;  throw(error(type_error(list, Op), op/3)) % 8.14.3.3 f)
     ).
 
-halt :- '$halt'.
+
+halt :- halt(0).
+
+halt(N) :-
+        (   -2^31 =< N, N =< 2^31 - 1 ->
+            '$halt'(N)
+        ;   throw(error(domain_error(exit_code, N), halt/1))
+        ).
 
 atom_length(Atom, Length) :-
     (  var(Atom)  -> throw(error(instantiation_error, atom_length/2)) % 8.16.1.3 a)
diff --git a/src/prolog/machine/system_calls.rs b/src/prolog/machine/system_calls.rs
index 0fb224ad..dcc15bc1 100644
--- a/src/prolog/machine/system_calls.rs
+++ b/src/prolog/machine/system_calls.rs
@@ -3647,7 +3647,15 @@ impl MachineState {
                 self.fail = true;
             }
             &SystemClauseType::Halt => {
-                std::process::exit(0);
+                let code = self.store(self.deref(self[temp_v!(1)]));
+
+                let code = match Number::try_from((code, &self.heap)) {
+                    Ok(Number::Fixnum(n)) => n as i32,
+                    Ok(Number::Integer(n)) => n.to_i32().unwrap(),
+                    _ => { unreachable!() }
+                };
+
+                std::process::exit(code);
             }
             &SystemClauseType::InstallSCCCleaner => {
                 let addr = self[temp_v!(1)];