~ chicken-core (chicken-5) d8c60219874deef3555b16e0b64581f2e97548b2

commit d8c60219874deef3555b16e0b64581f2e97548b2
Author:     Felix <bunny351@gmail.com>
AuthorDate: Sun Nov 8 00:59:33 2009 +0100
Commit:     felix <felix@call-with-current-continuation.org>
CommitDate: Mon Nov 23 17:47:20 2009 +0100

    import lib only generated if changed
    
    Signed-off-by: felix <felix@call-with-current-continuation.org>

diff --git a/compiler.scm b/compiler.scm
index 41258492..dd8a629f 100644
--- a/compiler.scm
+++ b/compiler.scm
@@ -486,21 +486,27 @@
        '() ) ))
 
   (define (emit-import-lib name il)
-    (let ((fname (if all-import-libraries
-		     (string-append (symbol->string name) ".import.scm")
-		     (cdr il))))
-      (when verbose-mode
-	(print "generating import library " fname " for module "
-	       name " ..."))
-      (with-output-to-file fname
-	(lambda ()
-	  (print ";;;; " fname " - GENERATED BY CHICKEN "
-		 (chicken-version) " -*- Scheme -*-\n")
-	  (for-each
-	   pretty-print
-	   (##sys#compiled-module-registration
-	    (##sys#current-module)))
-	  (print "\n;; END OF FILE")))))
+    (let* ((fname (if all-import-libraries
+		      (string-append (symbol->string name) ".import.scm")
+		      (cdr il)))
+	   (imps (##sys#compiled-module-registration (##sys#current-module)))
+	   (oldimps
+	    (and (file-exists? fname)
+		 (read-file fname) ) ) )
+      (cond ((equal? imps oldimps)
+	     (when verbose-mode
+	       (print "not generating import library `" fname "' for module `" 
+		      name "' because imports did not change")) )
+	    (else
+	     (when verbose-mode
+	       (print "generating import library `" fname "' for module `"
+		      name "' ..."))
+	     (with-output-to-file fname
+	       (lambda ()
+		 (print ";;;; " fname " - GENERATED BY CHICKEN "
+			(chicken-version) " -*- Scheme -*-\n")
+		 (for-each pretty-print imps)
+		 (print "\n;; END OF FILE"))))) ) )
 
   (define (walk x e se dest)
     (cond ((symbol? x)
diff --git a/manual/Declarations b/manual/Declarations
index e62a79ce..deabbeee 100644
--- a/manual/Declarations
+++ b/manual/Declarations
@@ -77,13 +77,6 @@ The opposite of {{hide}}. All given identifiers will be exported and all topleve
 not listed will be hidden and not be accessible outside of this compilation unit.
 
 
-=== emit-exports
-
- [declaration specifier] (emit-exports STRING)
-
-Write exported toplevel variables to file with name {{STRING}}.
-
-
 === emit-external-prototypes-first
 
  [declaration specifier] (emit-external-prototypes-first)
@@ -116,7 +109,10 @@ compiler option).
 
 Declares that any following definition of a module named {{MODULENAME}} should be written to
 an external file (either a specified one or a file named {{"MODULENAME.import.scm"}}).
-The compiler option {{-emit-import-library}} may also be used.
+The compiler option {{-emit-import-library}} may also be used instead.
+
+Note that the import library is only generated if it cannot be found in the current
+directory, or if it exists but is not equal to the one that would be generated.
 
 
 === inline