expander: add missing environment-prep for lifted requires

Also, add checking for a parse phase that must not trigger macros.

Author: mflatt

racket/src/expander/expand/context.rkt

@@ -64,7 +64,8 @@
           requires+provides ; enclosing module's requires+provides during `provide`
           * name       ; #f or identifier to name the expression
           observer   ; logging observer (for the macro debugger)
-          for-serializable?)) ; accumulate submodules as serializable?
+          for-serializable? ; accumulate submodules as serializable?
+          should-not-encounter-macros?)) ; #t when "expanding" to parse
 
 (define (make-expand-context ns
                              #:to-parsed? [to-parsed? #f]
@@ -107,7 +108,8 @@
                   #f   ; requires+provides
                   #f   ; name
                   (and observable? (current-expand-observe))
-                  for-serializable?))
+                  for-serializable?
+                  #f))
 
 (define (copy-root-expand-context ctx root-ctx)
   (struct*-copy expand-context ctx
@@ -192,4 +194,5 @@
 (define (as-to-parsed-context ctx)
   (struct*-copy expand-context ctx
                 [to-parsed? #t]
-                [observer #f]))
+                [observer #f]
+                [should-not-encounter-macros? #t]))

racket/src/expander/expand/local-expand.rkt

@@ -6,6 +6,7 @@
          "../syntax/scope.rkt"
          "../syntax/binding.rkt"
          "../namespace/core.rkt"
+         "../namespace/module.rkt"
          "context.rkt"
          "main.rkt"
          "syntax-local.rkt"
@@ -107,6 +108,8 @@
                                                 #:to-parsed-ok? to-parsed-ok?
                                                 #:track-to-be-defined? track-to-be-defined?))
 
+   (namespace-visit-available-modules! (expand-context-namespace ctx) phase)
+
    (log-expand local-ctx 'enter-local s)
    (define input-s (add-intdef-scopes (flip-introduction-scopes s ctx) intdefs))
 

racket/src/expander/expand/main.rkt

@@ -270,6 +270,10 @@
     (define adj-s (avoid-current-expand-context (substitute-alternate-id s id) t ctx))
     (log-expand ctx 'exit-macro s)
     (expand adj-s ctx)]
+   [(expand-context-should-not-encounter-macros? ctx)
+    (raise-syntax-error #f
+                        "encountered a macro binding in form that should be fully expanded"
+                        s)]
    [else
     (log-expand* ctx #:when (and (expand-context-only-immediate? ctx)
                                  (not (rename-transformer? t)))

racket/src/expander/expand/module.rkt

@@ -791,6 +791,10 @@
           (define-values (exp-rhs parsed-rhs vals)
             (expand+eval-for-syntaxes-binding (m 'rhs) ids
                                               (struct*-copy expand-context partial-body-ctx
+                                                            [lifts #f]
+                                                            ;; require lifts ok, others disallowed
+                                                            [module-lifts #f]
+                                                            [to-module-lifts #f]
                                                             [need-eventually-defined need-eventually-defined])
                                               #:log-next? #f))
           ;; Install transformers in the namespace for expansion:
@@ -1290,7 +1294,7 @@
                           #:modules-being-compiled modules-being-compiled)
   (unless is-star?
     (log-expand* ctx ['enter-prim s] [(if is-star? 'prim-submodule* 'prim-submodule)]))
-  
+
   ;; Register name and check for duplicates
   (define-match m s '(module name . _))
   (define name (syntax-e (m 'name)))

racket/src/expander/expand/syntax-local.rkt

@@ -212,6 +212,7 @@
   (check who exact-nonnegative-integer? n)
   (define ctx (get-current-expand-context who))
   (define lifts (expand-context-lifts ctx))
+  (unless lifts (raise-arguments-error who "no lift target"))
   (define counter (root-expand-context-counter ctx))
   (define ids (for/list ([i (in-range n)])
                 (set-box! counter (add1 (unbox counter)))
@@ -264,6 +265,7 @@
   (more-checks)
   (define ctx (get-current-expand-context who))
   (define lift-ctx (get-lift-ctx ctx))
+  (unless lift-ctx (raise-arguments-error who "no lift target"))
   (define phase (expand-context-phase ctx))   ; we're currently at this phase
   (define wrt-phase (get-wrt-phase lift-ctx)) ; lift context is at this phase
   (define added-s (if intro? (flip-introduction-scopes s ctx) s))
@@ -294,6 +296,8 @@
                              #:post-wrap
                              (lambda (s phase require-lift-ctx)
                                (wrap-form '#%require (add-scope s sc) phase))))
+  (namespace-visit-available-modules! (expand-context-namespace ctx)
+                                      (expand-context-phase ctx))
   (define result-s (add-scope use-s sc))
   (log-expand ctx 'lift-require added-s use-s result-s)
   result-s)