643 - bug in use-before-set logic

Ran into this in color-repl.mu: I wasn't checking struct variables in
'get' operations.

Still no way to test for use-before-set logic. But we'll fix it when we
leave arc behind.

2 files changed, 10 insertions, 16 deletions

diff --git a/color-repl.mu b/color-repl.mu
index e6f52503..d733b8f8 100644
--- a/color-repl.mu
+++ b/color-repl.mu
@@ -96,13 +96,6 @@
     { begin
       (backspace?:boolean <- equal c:character ((#\backspace literal)))
       (break-unless backspace?:boolean)
-      (len:integer-address <- get-address result:buffer-address/deref length:offset)
-      ; but only if we need to
-      { begin
-        (zero?:boolean <- lesser-or-equal len:integer-address/deref 0:literal)
-        (break-if zero?:boolean)
-        (len:integer-address/deref <- subtract len:integer-address/deref 1:literal)
-      }
       (loop 2:blocks)
     }
     (newline?:boolean <- equal c:character ((#\newline literal)))
diff --git a/mu.arc b/mu.arc
index 5de3f75d..38dc0999 100644
--- a/mu.arc
+++ b/mu.arc
@@ -1250,7 +1250,7 @@
         (trace "cn0" instr " " canon.location " " canon.isa-field)
         (let (oargs op args)  (parse-instr instr)
 ;?           (tr "about to rename args: @op")
-          (if (in op 'get 'get-address)
+          (when (in op 'get 'get-address)
             ; special case: map field offset by looking up type table
             (with (basetype  (typeof args.0)
                    field  (v args.1))
@@ -1269,14 +1269,15 @@
                     (do (set isa-field.field)
                         (trace "cn0" "field location @idx")
                         (= location.field idx))
-                    (assert nil "couldn't find field in @instr")))))
-            ; map args to location indices
-            (each arg args
-              (trace "cn0" "checking arg " arg)
-              (when (and nondummy.arg not-raw-string.arg)
-                (assert (~isa-field v.arg) "arg @arg is also a field name")
-                (when (maybe-add arg location idx)
-                  (err "use before set: @arg")))))
+                    (assert nil "couldn't find field in @instr"))))))
+          ; map args to location indices
+          (each arg args
+            (trace "cn0" "checking arg " arg)
+            (when (and nondummy.arg not-raw-string.arg (~literal? arg))
+              (assert (~isa-field v.arg) "arg @arg is also a field name")
+              (when (maybe-add arg location idx)
+                ; todo: test this
+                (err "use before set: @arg"))))
 ;?           (tr "about to rename oargs")
           ; map oargs to location indices
           (each arg oargs