fix for issue #343

- the compiler now uses a temporary variable to hold the return
  value of a nested call across the restore-local-saves form to
  properly handle the case where the destination lvalue is an mref
  whose base and/or index is a local save.
    cpnanopass.ss,
    misc.ms

original commit: 835cbc2430be4f7381cee27133d42e77ace2b37f

LOG

@@ -991,3 +991,9 @@
     system.stex, release_notes.stex
 - fix boot_call and the invoke code object to handle multiple values
     scheme.c, cpnanopass.ss, 7.ms, release_notes.stex, system.stex
+- the compiler now uses a temporary variable to hold the return
+  value of a nested call across the restore-local-saves form to
+  properly handle the case where the destination lvalue is an mref
+  whose base and/or index is a local save.
+    cpnanopass.ss,
+    misc.ms

mats/misc.ms

@@ -272,6 +272,18 @@
        (case-lambda
          [() (q 0)]
          [(x) (q)])))
+   ; regression tests for non-tail-call mref lvalue destination
+   (begin
+     (define (c1-f a)
+       (let ([x (fxvector 0)])
+         (lambda (v) (fxvector-set! x 0 (modulo v a)) x)))
+     #t)
+   (equal? ((c1-f 7) 10) #vfx(3))
+   (begin
+     (define (c1-id x) x)
+     (define (c1-g x) (vector-set-fixnum! x 0 (c1-id 17)))
+     #t)
+   (equal? (let ([v (vector 3)]) (c1-g v) v) '#(17))
 )
 
 (mat compiler2 ; random tests

release_notes/release_notes.stex

@@ -2,7 +2,7 @@
 
 \thisversion{Version 9.5.1}
 \thatversion{Version 8.4}
-\pubmonth{January}
+\pubmonth{August}
 \pubyear{2018}
 
 \begin{document}
@@ -1592,12 +1592,21 @@ in fasl files does not generally make sense.
 %-----------------------------------------------------------------------------
 \section{Bug Fixes}\label{section:bugfixes}
 
-\subsection{Incorrect return code when \protect\scheme{exit} is called with multiple arguments}
+\subsection{Invalid memory reference from \protect\scheme{fxvector} calls (9.5)}
+
+A compiler bug that could result in an invalid memory reference or
+some other unpleasant behavior for calls to \scheme{fxvector} in
+which the nested subexpression to compute the new value to be stored
+is nontrivial has been fixed.
+This bug could also affect calls to \scheme{vector-set-fixnum!} and possibly
+other primitive operations.
+
+\subsection{Incorrect return code when \protect\scheme{exit} is called with multiple arguments (9.5)}
 
 A bug in the implementation of the default exit handler with multiple
 values has been fixed.
 
-\subsection{Boot files containing compiled library code fail to load}
+\subsection{Boot files containing compiled library code fail to load (9.5)}
 
 Compiled library code may now appear within fasl objects loaded during
 the boot process, provided that they are appended to the end of the base boot

s/cpnanopass.ss

@@ -11313,7 +11313,12 @@
         [(set! ,[lvalue] (mvcall ,info ,mdcl ,t0? ,t1* ... (,t* ...)))
          (build-nontail-call info mdcl t0? t1* t* '() #f #f
            (lambda (newframe-info)
-             (%seq (remove-frame ,newframe-info) (set! ,lvalue ,%ac0) (restore-local-saves ,newframe-info))))]
+             (let ([retval (make-tmp 'retval)])
+               (%seq
+                 (remove-frame ,newframe-info)
+                 (set! ,retval ,%ac0)
+                 (restore-local-saves ,newframe-info)
+                 (set! ,lvalue ,retval)))))]
         [(foreign-call ,info ,[t0] ,[t1*] ...)
          (build-foreign-call info t0 t1* #f #t)]
         [(set! ,[lvalue] (foreign-call ,info ,[t0] ,[t1*] ...))