makefile-targets and some other meta info functions added

private/engine.rkt

@@ -2,7 +2,10 @@
 
 (require racket/list)
 
-(provide makefile-targets
+(provide makefile-prefixes
+         makefile-targets
+         makefile-target-exists?
+         makefile-target-procedure
          current-makefile-prefix
          begin-makefile!
          register-target!
@@ -18,8 +21,11 @@
 ;; Target procedures are registered globally per makefile prefix.  The value is
 ;; deliberately the real target procedure; `make` ultimately resolves a target
 ;; in this hash and calls that procedure.
-(define makefile-targets (make-hash))
+(define makefile-target-registry (make-hash))
 (define target-dependencies (make-hash))
+(define target-values (make-hash))
+(define makefile-prefix-values (make-hash))
+(define makefile-prefix-order '())
 (define phony-targets (make-hash))
 (define target-order (make-hash))
 (define default-targets (make-hash))
@@ -57,22 +63,33 @@
 
 (define (clear-prefix! prefix)
   (define pkey (prefix-key prefix))
-  (for ([key (in-list (hash-keys makefile-targets))])
+  (for ([key (in-list (hash-keys makefile-target-registry))])
     (when (equal? (car key) pkey)
-      (hash-remove! makefile-targets key)
+      (hash-remove! makefile-target-registry key)
       (hash-remove! target-dependencies key)
+      (hash-remove! target-values key)
       (hash-remove! phony-targets key)))
   (hash-remove! target-order pkey)
   (hash-remove! default-targets pkey)
   (void))
 
 (define (begin-makefile! prefix)
+  (define pkey (prefix-key prefix))
   (clear-prefix! prefix)
+  (hash-set! makefile-prefix-values pkey prefix)
+  (set! makefile-prefix-order
+        (append
+         (filter (λ (existing) (not (equal? existing pkey)))
+                 makefile-prefix-order)
+         (list pkey)))
   (void))
 
 (define (reset-makefiles!)
-  (hash-clear! makefile-targets)
+  (hash-clear! makefile-target-registry)
   (hash-clear! target-dependencies)
+  (hash-clear! target-values)
+  (hash-clear! makefile-prefix-values)
+  (set! makefile-prefix-order '())
   (hash-clear! phony-targets)
   (hash-clear! target-order)
   (hash-clear! default-targets)
@@ -84,12 +101,13 @@
   (define tkey (target-key name))
   (define key (cons pkey tkey))
 
-  (unless (hash-has-key? makefile-targets key)
+  (unless (hash-has-key? makefile-target-registry key)
     (hash-set! target-order
                pkey
                (append (hash-ref target-order pkey '()) (list tkey))))
 
-  (hash-set! makefile-targets key procedure)
+  (hash-set! makefile-target-registry key procedure)
+  (hash-set! target-values key name)
   (hash-set! target-dependencies key (append-map target-keys dependencies))
   (void))
 
@@ -103,8 +121,45 @@
   (hash-set! default-targets (prefix-key prefix) (target-key name))
   (void))
 
+(define (require-current-prefix who)
+  (define prefix (current-makefile-prefix))
+  (unless prefix
+    (error who "no current makefile prefix; evaluate a makefile definition first"))
+  prefix)
+
+(define (makefile-prefixes)
+  (for/list ([pkey (in-list makefile-prefix-order)])
+    (hash-ref makefile-prefix-values pkey)))
+
+(define makefile-targets
+  (case-lambda
+    [()
+     (makefile-targets (require-current-prefix 'makefile-targets))]
+    [(prefix)
+     (define pkey (prefix-key prefix))
+     (for/list ([tkey (in-list (hash-ref target-order pkey '()))])
+       (hash-ref target-values (cons pkey tkey) tkey))]))
+
+(define makefile-target-exists?
+  (case-lambda
+    [(name)
+     (makefile-target-exists?
+      (require-current-prefix 'makefile-target-exists?)
+      name)]
+    [(prefix name)
+     (hash-has-key? makefile-target-registry (registry-key prefix name))]))
+
+(define makefile-target-procedure
+  (case-lambda
+    [(name)
+     (makefile-target-procedure
+      (require-current-prefix 'makefile-target-procedure)
+      name)]
+    [(prefix name)
+     (target-procedure prefix name)]))
+
 (define (target-procedure prefix name)
-  (hash-ref makefile-targets
+  (hash-ref makefile-target-registry
             (registry-key prefix name)
             (λ ()
               (error 'racket-makefile
@@ -131,7 +186,7 @@
   (file-or-directory-modify-seconds path #f (λ () #f)))
 
 (define (registered-target? prefix name)
-  (hash-has-key? makefile-targets (registry-key prefix name)))
+  (hash-has-key? makefile-target-registry (registry-key prefix name)))
 
 (define (dependency-time prefix name built-results)
   (cond
@@ -159,7 +214,8 @@
           (and dep-time (> dep-time target-time)))])]))
 
 (define (execute-target! prefix name)
-  (printf "racket-makefile[~a]: ~a\n" prefix (target-key name))
+  (printf "racket-makefile[~a]: ~a
+" prefix (target-key name))
   ((target-procedure prefix name))
   (void))