(zilch ninja): resolve depfile and source overrides relative to zilch file

Change-Id: I6a6a6964b712289cfd408a02f3b6951e1de53e97

cli/zilch-ninja.scm

@@ -53,7 +53,7 @@
 (define source (and (assoc 'source options) (cdr (assoc 'source options))))
 
 (define config-path (if (assoc 'config-file options) (cdr (assoc 'config-file options)) "zilch.scm"))
-(define config (parse-ninja-config `(override-source: ,source ,@(call-with-input-file config-path read))))
+(define config (parse-ninja-config config-path `(override-source: ,(and source (vfs-from-directory source)) ,@(call-with-input-file config-path read))))
 
 (when (and (ninja-build-config-depfile-path config) (file-exists? (ninja-build-config-depfile-path config)))
   (set-ninja-build-config-depfile! config (alist->mapping (make-default-comparator) (call-with-input-file (ninja-build-config-depfile-path config) read))))

lang/ninja/src/config.sld

@@ -3,7 +3,7 @@
  (import
   (scheme base) (scheme eval)
   (zilch magic) (zilch nixpkgs) (zilch vfs)
-  (srfi 88)
+  (srfi 88) (srfi 152)
   (prefix (only scheme eval) scheme-))
 
  (export
@@ -39,7 +39,14 @@
     (disallow-elide ninja-build-config-disallow-elide set-ninja-build-config-disallow-elide!)
     (rewrites ninja-build-config-rewrites set-ninja-build-config-rewrites!))
 
-   (define (parse-config-inner conf data)
+   (define (relative-to-file path path2)
+    (if (string-prefix? "/" path2) path2
+     (let ((last-slash (string-contains-right path "/")))
+      (if last-slash
+        (string-append (string-copy path 0 last-slash) "/" path2)
+        path2))))
+
+   (define (parse-config-inner path conf data)
     (cond
      ((null? data) conf)
      ((null? (cdr data)) (error "Expected even list of directives in Zilch Ninja config"))
@@ -51,19 +58,19 @@
            (set-ninja-build-config-environment! conf (environment-for-derivation drv))
            (set-ninja-build-config-environment-drv! conf (store-path-drv drv)))
          (set-ninja-build-config-environment! conf (list-ref data 1)))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:root)
         (set-ninja-build-config-root-dir! conf (if (string? (list-ref data 1)) (vfs-from-directory (list-ref data 1)) (list-ref data 1)))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:override-source)
-        (set-ninja-build-config-override-source! conf (if (string? (list-ref data 1)) (vfs-from-directory (list-ref data 1)) (list-ref data 1)))
+        (set-ninja-build-config-override-source! conf (if (string? (list-ref data 1)) (vfs-from-directory (relative-to-file path (list-ref data 1))) (list-ref data 1)))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:depfile-path)
-        (set-ninja-build-config-depfile-path! conf (list-ref data 1))
+        (set-ninja-build-config-depfile-path! conf (relative-to-file path (list-ref data 1)))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:depfile)
         (set-ninja-build-config-depfile! conf (list-ref data 1))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:patch)
         (let*
          ((patch-base (list-ref data 1))
@@ -75,7 +82,7 @@
              (scheme-eval patch-base))
             (else patch-base))))
          (set-ninja-build-config-patches! conf (cons processed-patch (ninja-build-config-patches conf))))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:disallow-elide)
         (let*
          ((thunk (list-ref data 1))
@@ -85,7 +92,7 @@
              (scheme-eval thunk))
             (else thunk))))
          (set-ninja-build-config-disallow-elide! conf processed-thunk)) 
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:target #:targets)
         (when (eq? (ninja-build-config-targets conf) #f)
           (set-ninja-build-config-targets! conf '()))
@@ -93,12 +100,12 @@
          ((val (list-ref data 1))
           (list-val (if (list? val) val (list val))))
          (set-ninja-build-config-targets! conf (append list-val (ninja-build-config-targets conf))))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        ((#:rewrite)
         (let*
          ((val (list-ref data 1)))
-         (set-ninja-build-config-rewrites! conf (cons (cons (car val) (parse-ninja-config (cdr val))) (ninja-build-config-rewrites conf))))
+         (set-ninja-build-config-rewrites! conf (cons (cons (car val) (parse-ninja-config path (cdr val))) (ninja-build-config-rewrites conf))))
-        (parse-config-inner conf (cddr data)))
+        (parse-config-inner path conf (cddr data)))
        (else (error (string-append "Unknown directive " (keyword->string (car data)) " parsing Zilch Ninja config")))))))
   
    ;; Parses a Zilch Ninja configuration file.
@@ -132,10 +139,12 @@
    ;; - `rewrite: ("<derivation name>" . <nested config>): A nested Zilch
    ;;   Ninja configuration to swap out the input derivation with equivalent
    ;;   name.
-   (define (parse-ninja-config config)
+   ;;
+   ;; `path` is the path this file was located at, used to resolve relative paths for depfiles.
+   (define (parse-ninja-config path config)
     (unless (list? config)
      (error "expected Zilch Ninja config to be a list"))
-    (parse-config-inner (make-ninja-build-config #f #f #f '() #f #f #f #f #f '()) config))
+    (parse-config-inner path (make-ninja-build-config #f #f #f '() #f #f #f #f #f '()) config))
 
    ;; `source-paths`: mapping of original store path to virtual path.
    ;; `finalized-drv`: promise of a <finalized-drv>