>From d07fb2e8ae791f6e2846db942515d5a4de8f9de2 Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <address@hidden>
Date: Thu, 2 Jul 2009 11:17:35 +0200
Subject: [PATCH] Add backend warning/error switch for svg.  Fixes exit upon missing function.

This allows for easy backend testing doing something like

    lilypond -dbackend=svg -dwarning-as-error=#t input/typography-demo.ly
---
 lily/program-option-scheme.cc |    2 ++
 scm/lily.scm                  |    2 ++
 scm/output-svg.scm            |   29 ++++++++++++++++++++---------
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/lily/program-option-scheme.cc b/lily/program-option-scheme.cc
index 1e03c5f..5ea08fd 100644
--- a/lily/program-option-scheme.cc
+++ b/lily/program-option-scheme.cc
@@ -113,6 +113,8 @@ internal_set_option (SCM var,
       relative_includes = to_boolean (val);
       val = scm_from_bool (to_boolean (val));
     }
+  else if (var == ly_symbol2scm ("warning-as-error"))
+      val = scm_from_bool (to_boolean (val));
 
   scm_hashq_set_x (option_hash, var, val);
 }
diff --git a/scm/lily.scm b/scm/lily.scm
index d62c70b..7528a28 100644
--- a/scm/lily.scm
+++ b/scm/lily.scm
@@ -152,6 +152,8 @@ second.  Dump results to `FILE.stacks' and
 "List available font names.")
     (verbose ,(ly:command-line-verbose?)
 "Value of the --verbose flag (read-only).")
+    (warning-as-error #f
+"Exit upon warning.")
     ))
 
 ;; Need to do this in the beginning.  Other parts of the Scheme
diff --git a/scm/output-svg.scm b/scm/output-svg.scm
index 80199a1..278a804 100644
--- a/scm/output-svg.scm
+++ b/scm/output-svg.scm
@@ -24,6 +24,7 @@
  (guile)
  (ice-9 regex)
  (ice-9 format)
+ (ice-9 optargs)
  (lily)
  (srfi srfi-1)
  (srfi srfi-13))
@@ -173,14 +174,24 @@
 ;;; catch-all for missing stuff
 ;;; comment this out to see find out what functions you miss :-)
 
-(if #f
-    (begin
-      (define (dummy . foo) "")
-      (map (lambda (x) (module-define! this-module x dummy))
-	   (append
-	    (ly:all-stencil-expressions)
-	    (ly:all-output-backend-commands)))
-      ))
+  ;; FIXME: share with other output-* backends
+  (define (missing-function type name)
+    (apply
+     (if (ly:get-option 'warning-as-error) ly:error ly:warning)
+     (list (_ "missing: ~S: ~S") type name)))
+  (define (missing-stencil-expression name)
+    (missing-function 'stencil-expression name))
+  (define (missing-backend-command name)
+    (missing-function 'backend-command name))
+
+  (map (lambda (x) (module-define!
+		    (current-module)
+		    x (lambda* (#:optional y . z) (missing-stencil-expression x))))
+       (ly:all-stencil-expressions))
+  (map (lambda (x) (module-define!
+		    (current-module)
+		    x (lambda* (#:optional y . z) (missing-backend-command x))))
+       (ly:all-output-backend-commands))
 
 (define (url-link url x y)
   (string-append
@@ -259,7 +270,7 @@
 (define-public (comment s)
   (string-append "<!-- " s " !-->\n"))
 
-(define (draw-line thick x1 y1 x2 y2 . alist)
+(define (xdraw-line thick x1 y1 x2 y2 . alist)
   
   (apply entity 'line ""
 	 (append
-- 
1.6.0.rc1.49.g98a8