add support for indirect CM dependencies; use in lazy-require

If module M in package P imports module N from package Q,
and if N has a `lazy-require` for a module in R that is
triggered during the compilation of M, then P doesn't really
depend on R; P depends on Q, and Q depends on R, and P
shoudn't necessarily know anything about Q. At the same time,
a change to the file in R means that M must be recompiled.
So, continue to track the compilation dependency, but mark
it as "indirect" so that the package-dependency checker can
ignore the dependency.

pkgs/racket-doc/scribblings/raco/make.scrbl

@@ -550,25 +550,36 @@ field is a @racket[compile-event] as document in
 
 @defmodule[compiler/cm-accomplice]
 
-@defproc[(register-external-file [file (and path? complete-path?)]) void?]{
+@defproc[(register-external-file [file (and path? complete-path?)]
+                                 [#:indirect? indirect? any/c #f])
+         void?]{
 
-Logs a message (see @racket[log-message]) at level @racket['info] to 
+Logs a message (see @racket[log-message]) at level @racket['info] to a
-a logger named @racket['cm-accomplice]. The
+logger named @racket['cm-accomplice]. The message data is a
-message data is a @racketidfont{file-dependency} prefab structure type
+@racketidfont{file-dependency} prefab structure type with two fields;
-with two fields; the first field's value is @racket[file] and the second
+the first field's value is @racket[file] and the second field's value
-field's value is @racket[#f] (to indicate a non-module dependency).
+is @racket[#f] (to indicate a non-module dependency). If the
+@racket[indirect?] argument is true, the data is more specifically an
+instance of a @racketidfont{file-dependency/indirect} prefab structure
+type that is a subtype of @racketidfont{file-dependency} with no new
+fields.
 
 A compilation manager implemented by @racketmodname[compiler/cm] looks
-for such messages to register an external dependency. The compilation
+for such messages to register an external dependency. In response, the
-manager records (in a @filepath{.dep} file) the path as contributing
+compilation manager records (in a @filepath{.dep} file) the path as
-to the implementation of the module currently being
+contributing to the implementation of the module currently being
 compiled. Afterward, if the registered file is modified, the
-compilation manager will know to recompile the module.
+compilation manager will know to recompile the module. An ``indirect''
+dependency has no effect on recompilation, but it can signal to other
+tools, such as a package-dependency checker, that the dependency is
+indirect (and should not imply a direct package dependency).
 
 The @racket[include] macro, for example, calls this procedure with the
 path of an included file as it expands an @racket[include] form.}
 
-@defproc[(register-external-module [file (and path? complete-path?)]) void?]{
+@defproc[(register-external-module [file (and path? complete-path?)]
+                                   [#:indirect? indirect? any/c #f])
+         void?]{
 
 Like @racket[register-external-file], but logs a message with a
 @racketidfont{file-dependency} prefab structure type whose second

pkgs/racket-doc/scribblings/reference/syntax.scrbl

@@ -3005,10 +3005,10 @@ submodule). Introduced submodules have the names
 @racket[lazy-require-]@racket[_n]@racketidfont{-}@racket[_m], where
 @racket[_n] is a phase-level number and @racket[_m] is a number.
 
-When the use of a lazily-required function triggers module loading,
+When the use of a lazily-required function triggers module loading, it
-@racket[register-external-module] declares a potential compilation
+also triggers a use of @racket[register-external-module] to declare an
-dependency (in case the function is used in the process of compiling a
+indirect compilation dependency (in case the function is used in the
-module).
+process of compiling a module).
 
 @examples[#:eval lazy-require-eval
 (lazy-require

racket/collects/compiler/cm-accomplice.rkt

@@ -3,16 +3,18 @@
 (provide register-external-file
          register-external-module)
 
-(define (register-external-file f)
+(define (register-external-file f #:indirect? [indirect? #f])
-  (register-external 'register-external-file f #f))
+  (register-external 'register-external-file f #f indirect?))
-(define (register-external-module f)
+(define (register-external-module f #:indirect? [indirect? #f])
-  (register-external 'register-external-module f #t))
+  (register-external 'register-external-module f #t indirect?))
 
-(define (register-external who f module?)
+(define (register-external who f module? indirect?)
   (unless (and (path? f) (complete-path? f))
     (raise-type-error who "complete path" f))
   (log-message (current-logger)
                'info
                'cm-accomplice
                (format "file dependency: ~s" f)
-               `#s(file-dependency ,f ,module?)))
+               (if indirect?
+                   `#s((file-dependency/indirect file-dependency 2) ,f ,module?)
+                   `#s(file-dependency ,f ,module?))))

racket/collects/compiler/cm.rkt

@@ -231,9 +231,13 @@
 (define (get-dep-sha1s deps up-to-date collection-cache read-src-syntax mode roots must-exist? seen)
   (let ([l (for/fold ([l null]) ([dep (in-list deps)])
              (and l
+                  ;; (cons 'indirect dep) => indirect dependency (for pkg-dep checking)
                   ;; (cons 'ext rel-path) => a non-module file, check source
                   ;; rel-path => a module file name, check cache
-                  (let* ([ext? (and (pair? dep) (eq? 'ext (car dep)))]
+                  (let* ([dep (if (and (pair? dep) (eq? 'indirect (car dep)))
+                                  (cdr dep)
+                                  dep)]
+                         [ext? (and (pair? dep) (eq? 'ext (car dep)))]
                          [p (collects-relative*->path (if ext? (cdr dep) dep) collection-cache)])
                     (cond
                      [ext? (let ([v (get-source-sha1 p)])
@@ -273,12 +277,19 @@
                                          external-module-deps ; can create cycles if misused!
                                          reader-deps))]
         [external-deps (remove-duplicates external-deps)])
+    (define (path*->collects-relative/maybe-indirect dep)
+      (if (and (pair? dep) (eq? 'indirect (car dep)))
+          (cons 'indirect (path*->collects-relative (cdr dep)))
+          (path*->collects-relative dep)))
     (with-compile-output dep-path
       (lambda (op tmp-path)
         (let ([deps (append
-                     (map path*->collects-relative deps)
+                     (map path*->collects-relative/maybe-indirect deps)
                      (map (lambda (x)
-                            (cons 'ext (path*->collects-relative x)))
+                            (define d (path*->collects-relative/maybe-indirect x))
+                            (if (and (pair? d) (eq? 'indirect d))
+                                (cons 'indirect (cons 'ext (cdr d)))
+                                (cons 'ext d)))
                           external-deps))])
           (write (list* (version)
                         (cons (or src-sha1 (get-source-sha1 path))
@@ -311,6 +322,7 @@
 (define-struct ext-reader-guard (proc top)
   #:property prop:procedure (struct-field-index proc))
 (define-struct file-dependency (path module?) #:prefab)
+(define-struct (file-dependency/indirect file-dependency) () #:prefab)
 
 (define (compile-zo* mode roots path src-sha1 read-src-syntax zo-name up-to-date collection-cache)
   ;; The `path' argument has been converted to .rkt or .ss form,
@@ -322,10 +334,14 @@
   (define reader-deps null)
   (define deps-sema (make-semaphore 1))
   (define done-key (gensym))
-  (define (external-dep! p module?)
+  (define (external-dep! p module? indirect?)
+    (define bstr (path->bytes p))
+    (define dep (if indirect?
+                    (cons 'indirect bstr)
+                    bstr))
     (if module?
-        (set! external-module-deps (cons (path->bytes p) external-module-deps))
+        (set! external-module-deps (cons dep external-module-deps))
-        (set! external-deps (cons (path->bytes p) external-deps))))
+        (set! external-deps (cons dep external-deps))))
   (define (reader-dep! p)
     (call-with-semaphore
      deps-sema
@@ -386,7 +402,8 @@
                    (file-dependency? (vector-ref l 2))
                    (path? (file-dependency-path (vector-ref l 2))))
           (external-dep! (file-dependency-path (vector-ref l 2))
-                         (file-dependency-module? (vector-ref l 2))))
+                         (file-dependency-module? (vector-ref l 2))
+                         (file-dependency/indirect? (vector-ref l 2))))
         (loop))))
 
   ;; Write the code and dependencies:
@@ -627,9 +644,13 @@
               ;; If `sha1-only?', then `maybe-compile-zo' returns a #f or thunk:
               (maybe-compile-zo sha1-only? deps mode roots path orig-path read-src-syntax up-to-date collection-cache new-seen)]
              [(ormap
-               (lambda (p)
+               (lambda (raw-p)
+                 ;; (cons 'indirect dep) => indirect dependency (for pkg-dep checking)
                  ;; (cons 'ext rel-path) => a non-module file (check date)
                  ;; rel-path => a module file name (check transitive dates)
+                 (define p (if (and (pair? raw-p) (eq? 'indirect (car raw-p)))
+                               (cdr raw-p)
+                               raw-p))
                  (define ext? (and (pair? p) (eq? 'ext (car p))))
                  (define d (collects-relative*->path (if ext? (cdr p) p) collection-cache))
                  (define t

racket/collects/racket/lazy-require.rkt

@@ -110,4 +110,4 @@
                  modpath
                  (variable-reference->resolved-module-path vr))))])
     (when (path? path)
-      (register-external-module path))))
+      (register-external-module path #:indirect? #t))))

racket/collects/setup/private/pkg-deps.rkt

@@ -489,6 +489,7 @@
             ;; Treat everything in ".dep" as 'build mode...
             (define deps (cddr (call-with-input-file* (build-path dir f) read)))
             (for ([dep (in-list deps)])
+              ;; Note: indirect dependencies (which start with 'indirect) are ignored
               (when (and (pair? dep)
                          (eq? 'collects (car dep)))
                 (define path-strs (map bytes->string/utf-8 (cdr dep)))