From d5bb22c2d97cab32c80fc303304967eb27bc250b Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sat, 30 Jun 2018 20:32:01 -0600
Subject: [PATCH] cs: improve `#%variable-reference-constant?`

Repair constant detection for unmodified imports.
---
 racket/src/cs/Makefile           | 2 +-
 racket/src/cs/linklet.sls        | 7 +++++++
 racket/src/cs/linklet/read.ss    | 4 +++-
 racket/src/cs/rumble.sls         | 5 +++--
 racket/src/cs/rumble/foreign.ss  | 9 ++++++++-
 racket/src/schemify/schemify.rkt | 5 ++---
 6 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/racket/src/cs/Makefile b/racket/src/cs/Makefile
index db44c75d8b..adc27acdb9 100644
--- a/racket/src/cs/Makefile
+++ b/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
diff --git a/racket/src/cs/linklet.sls b/racket/src/cs/linklet.sls
index bbaa92ead0..456cfdc112 100644
--- a/racket/src/cs/linklet.sls
+++ b/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!))
diff --git a/racket/src/cs/linklet/read.ss b/racket/src/cs/linklet/read.ss
index bea0ec04d4..11ac2711e9 100644
--- a/racket/src/cs/linklet/read.ss
+++ b/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
diff --git a/racket/src/cs/rumble.sls b/racket/src/cs/rumble.sls
index 1c4b8e6925..0ed6102385 100644
--- a/racket/src/cs/rumble.sls
+++ b/racket/src/cs/rumble.sls
@@ -576,9 +576,10 @@
           ptr-set! saved-errno set-cpointer-tag! set-ptr-offset! vector->cpointer
           unsafe-register-process-global
           (rename [ffi-lib* ffi-lib])
-          set-ffi-get-lib-and-obj! ; not exported to Racket
-          poll-async-callbacks ; not exported to Racket
+          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*
diff --git a/racket/src/cs/rumble/foreign.ss b/racket/src/cs/rumble/foreign.ss
index 698500ef98..aacb205aa0 100644
--- a/racket/src/cs/rumble/foreign.ss
+++ b/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)]
diff --git a/racket/src/schemify/schemify.rkt b/racket/src/schemify/schemify.rkt
index 3c44a7fb67..69793959d4 100644
--- a/racket/src/schemify/schemify.rkt
+++ b/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])))]))
 
 ;; ----------------------------------------