js vm: syscall 7 (exit) stops the run with its status, so a runtime fault no longer runs on past the fault (js vm trace check)

1 files changed, 4 insertions, 1 deletions

diff --git a/src/js/tinyvm.ts b/src/js/tinyvm.ts
index 51b390b..5ee29c7 100644
--- a/src/js/tinyvm.ts
+++ b/src/js/tinyvm.ts
@@ -179,6 +179,7 @@ export class TinyVM {
         should resume it after its event loop has run, whether or not input came. */
     public polling: boolean = false;
     private outputBuffer: number[] = [];
+    private exitCode: number | null = null;
     private onOutput?: (byte: number) => void;
     private onMessage?: (msg: string) => void;
 
@@ -439,7 +440,8 @@ export class TinyVM {
                 return -1n;
             case 6: // time
                 return BigInt(Math.floor(Date.now() / 1000));
-            case 7: // exit
+            case 7: // exit: the run stops here with this status, as the native core's exit() does
+                this.exitCode = Number(BigInt.asIntN(32, a)) & 255;
                 return 0n;
             case 8: // rand
                 return BigInt(Math.floor(Math.random() * 0x7FFFFFFF));
@@ -781,6 +783,7 @@ export class TinyVM {
                         mem = this.mem; bytes = this.bytes; view = this.view; mw = this.mw; // a grow may have moved them
                         mem[Number(a)] = result;
                         s = this.rs; r = this.rr;
+                        if (this.exitCode !== null) { const code = this.exitCode; this.exitCode = null; return code; }
                         break;
                     } else if (Number(a) >= 0 && Number(a) < mw) {
                         mem[Number(a)] = b;