duskos

commit 21cfece551c5285569588b624faba78018bd41dd
parent 634a95f34be1a8f164537b59fa889508b0e11792
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Thu, 15 Sep 2022 19:51:44 -0400

cc/vm/forth: fix PS corruption bug

The removal of the argframe introduced a bug not covered by tests.

Diffstat:
M
fs/cc/vm/forth.fs
 | 
11
+++++++----
M
fs/tests/cc/cc.fs
 | 
2
++

2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/cc/vm/forth.fs b/fs/cc/vm/forth.fs
@@ -87,16 +87,19 @@ struct+[ VMOp
 
 \ generate function prelude code by allocating "locsz" bytes on RS.
 : vmprelude, ( argsz locsz -- )
-  to locsz to argsz
+  to locsz to argsz 0 to psoff
   locsz if locsz neg r+, then ;
 
 \ deallocate locsz and argsz. If result is set, keep a 4b in here and push the
 \ result there.
 : vmret,
   selop2 noop# \ returning with a second operand? something's wrong
-  selop1 vmop loc if opCompile* opdeinit then
-  argsz ?dup if 4 / >r begin compile nip next then
-  locsz if locsz r+, then
+  selop1 vmop loc if
+    opCompile* opdeinit argsz ?dup if
+      p', compile ! argsz CELLSZ - ?dup if p+, then then
+  else
+    argsz ?dup if p+, then then
+  locsz ?dup if r+, then
   exit, ;
 
 \ Write op to args
diff --git a/fs/tests/cc/cc.fs b/fs/tests/cc/cc.fs
@@ -37,8 +37,10 @@ capture helloworld S" Hello World!" #s=
 42 5 forloop 47 #eq
 1 multret 1 #eq
 42 multret 32 #eq
+1234 \ test that void funcs with args don't mess with the PS underneath it.
 55 capture multretvoid S" Nope" #s=
 42 capture multretvoid S" Answer to the universe" #s=
+1234 #eq
 -1 0 lts #
 -1 0 ltu not #
 0 boolnot 1 #eq