[vala] Add `do not modify' note at the top of generated C files

[Jürg Billeter <juergbi src gnome org>]

commit 728bb93c7fce2725413627a4012fe4a5230bec50
Author: Michael B. Trausch <mike trausch us>
Date:   Sun Sep 27 22:22:57 2009 +0200

    Add `do not modify' note at the top of generated C files
    
    Fixes bug 595797.

 ccode/valaccodewriter.vala       |   20 +++++++++++++++++++-
 codegen/valaccodebasemodule.vala |    2 +-
 2 files changed, 20 insertions(+), 2 deletions(-)
---
diff --git a/ccode/valaccodewriter.vala b/ccode/valaccodewriter.vala
index 11559cd..ff0677b 100644
--- a/ccode/valaccodewriter.vala
+++ b/ccode/valaccodewriter.vala
@@ -32,6 +32,11 @@ public class Vala.CCodeWriter {
 	public string filename { get; set; }
 
 	/**
+	 * Specifies the source file used to generate this one.
+	 */
+	private string source_filename;
+
+	/**
 	 * Specifies whether to emit line directives.
 	 */
 	public bool line_directives { get; set; }
@@ -55,8 +60,9 @@ public class Vala.CCodeWriter {
 	/* at begin of line */
 	private bool _bol = true;
 	
-	public CCodeWriter (string filename) {
+	public CCodeWriter (string filename, string? source_filename = null) {
 		this.filename = filename;
+		this.source_filename = source_filename;
 	}
 
 	/**
@@ -74,6 +80,18 @@ public class Vala.CCodeWriter {
 			stream = FileStream.open (filename, "w");
 		}
 
+		write_string ("/* %s generated by valac, the Vala compiler".printf (Path.get_basename (filename)));
+
+		// Write the file name if known
+		if (source_filename != null) {
+			write_newline ();
+			write_string (" * generated from %s".printf (Path.get_basename (source_filename)));
+		}
+
+		write_string (", do not modify */");
+		write_newline ();
+		write_newline ();
+
 		return (stream != null);
 	}
 
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 50fd405..38662ba 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -651,7 +651,7 @@ internal class Vala.CCodeBaseModule : CCodeModule {
 			source_type_member_definition.append (cfunc);
 		}
 		
-		var writer = new CCodeWriter (source_file.get_csource_filename ());
+		var writer = new CCodeWriter (source_file.get_csource_filename (), source_file.filename);
 		if (!writer.open ()) {
 			Report.error (null, "unable to open `%s' for writing".printf (writer.filename));
 			return;