cs: improve #%variable-reference-constant?

Repair constant detection for unmodified imports.

racket/src/cs/Makefile

@@ -5,7 +5,7 @@ RACKET = ../../bin/racket
 SCHEME = scheme
 
 # Controls whether Racket layers are built as unsafe:
-UNSAFE_COMP = --unsafe
+UNSAFE_COMP = # --unsafe
 
 # Controls whether Racket layers are built with expression-level debugging:
 DEBUG_COMP = # --debug

racket/src/cs/linklet.sls

@@ -176,6 +176,11 @@
   (define (compile-to-port* s o)
     (call-with-system-wind (lambda () (compile-to-port s o))))
 
+  (define (eval/foreign e mode)
+    (performance-region
+     mode
+     (compile* e)))
+
   (define primitives (make-hasheq))
   (define (install-linklet-primitive-tables! . tables)
     (for-each
@@ -827,6 +832,8 @@
     (generate-inspector-information (not omit-debugging?))
     (generate-procedure-source-information #t))
 
+  (set-foreign-eval! eval/foreign)
+
   (expand-omit-library-invocations #t)
 
   (install-linklet-bundle-write!))

racket/src/cs/linklet/read.ss

@@ -1,5 +1,7 @@
 (define (read-compiled-linklet in)
-  (read-compiled-linklet-or-directory in #t))
+  (performance-region
+   'read
+   (read-compiled-linklet-or-directory in #t)))
 
 (define (read-compiled-linklet-or-directory in initial?)
   ;; `#~` has already been read

racket/src/cs/rumble.sls

@@ -579,6 +579,7 @@
           set-ffi-get-lib-and-obj!        ; not exported to Racket
           poll-async-callbacks            ; not exported to Racket
           set-async-callback-poll-wakeup! ; not exported to Racket
+          set-foreign-eval!               ; not exported to racket
 
           unsafe-unbox
           unsafe-unbox*

racket/src/cs/rumble/foreign.ss

@@ -1279,6 +1279,13 @@
 
 ;; ----------------------------------------
 
+(define eval/foreign
+  (lambda (expr mode)
+    (call-with-system-wind (lambda () (eval expr)))))
+
+(define (set-foreign-eval! proc)
+  (set! eval/foreign proc))
+
 (define/who ffi-call
   (case-lambda
    [(p in-types out-type)
@@ -1385,7 +1392,7 @@
                                                (make-ftype-pointer ,id p))))
                                      ids)
                                 '())))])
-            (call-with-system-wind (lambda () (eval expr))))]
+            (eval/foreign expr (if call? 'comp-ffi 'comp-ffi-back)))]
          [gen-proc (car gen-proc+ret-maker+arg-makers)]
          [ret-maker (cadr gen-proc+ret-maker+arg-makers)]
          [arg-makers (cddr gen-proc+ret-maker+arg-makers)]

racket/src/schemify/schemify.rkt

@@ -152,10 +152,9 @@
         (define v (known-inline->export-known (hash-ref defn-info id #f)
                                               prim-knowns imports exports))
         (cond
-         [(and v
-               (not (set!ed-mutated-state? (hash-ref mutated id #f))))
+         [(not (set!ed-mutated-state? (hash-ref mutated id #f)))
           (define ext-id (ex-ext-id ex-id))
-          (hash-set knowns ext-id v)]
+          (hash-set knowns ext-id (or v a-known-constant))]
          [else knowns])))]))
 
 ;; ----------------------------------------