add debug() facility to print to terminal stderr

src/modules/LibC.js

@@ -0,0 +1,85 @@
+/* -*- Mode: javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+
+var EXPORTED_SYMBOLS = ["LibC"];
+
+const LIB_C = "libc.so.6";
+
+const Cu = Components.utils;
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/ctypes.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyGetter(this, "libc", function() {
+  var libc = ctypes.open(LIB_C);
+  if (!libc)
+    throw "libc is unavailable";
+
+  return libc;
+});
+
+XPCOMUtils.defineLazyGetter(this, "FILE", function() {
+  return ctypes.StructType("FILE");
+});
+
+XPCOMUtils.defineLazyGetter(this, "fdopen", function() {
+  var fdopen = libc.declare(
+    "fdopen", ctypes.default_abi, FILE.ptr,
+    ctypes.int,
+    ctypes.char.ptr
+  );
+
+  if (!fdopen)
+    throw "fdopen is unavailable";
+
+  return fdopen;
+});
+
+
+XPCOMUtils.defineLazyGetter(this, "puts", function() {
+  var puts = libc.declare(
+    "puts", ctypes.default_abi, ctypes.int32_t,
+    ctypes.char.ptr
+  );
+
+  if (!puts)
+    throw "puts is unavailable";
+
+  return puts;
+});
+
+XPCOMUtils.defineLazyGetter(this, "fputs", function() {
+  var fputs = libc.declare(
+    "fputs", ctypes.default_abi, ctypes.int32_t,
+    ctypes.char.ptr,
+    FILE.ptr
+  );
+
+  if (!fputs)
+    throw "fputs is unavailable";
+
+  return fputs;
+});
+
+XPCOMUtils.defineLazyGetter(this, "fflush", function() {
+  var fflush = libc.declare(
+    "fflush", ctypes.default_abi, ctypes.int32_t,
+    FILE.ptr
+  );
+
+  if (!fflush)
+    throw "fflush is unavailable";
+
+  return fflush;
+});
+
+var LibC = {
+  stderr: this.fdopen(2, "a"),
+
+  FILE: FILE,
+  fdopen: fdopen,
+  puts: puts,
+  fputs: fputs,
+  fflush: fflush,
+}

src/modules/commons.js

@@ -10,6 +10,9 @@ var EXPORTED_SYMBOLS = [ "mozt", "Cc", "Ci" ];
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+Cu.import("resource://moztray/LibC.js");
 
 const FIREFOX_ID = "{ec8030f7-c20a-464f-9b0e-13a3a9e97384}";
 const THUNDERBIRD_ID = "{3550f703-e582-4d05-9a08-453d09bdfdc6}";
@@ -64,6 +67,11 @@ mozt.Debug = {
     this.dump(str);
   },
 
+  // dump to terminal (stderr)
+  debug: function(str) {
+    LibC.fputs(str + "\n", LibC.stderr);
+    LibC.fflush(LibC.stderr);
+  },
 };
 // build it !
 mozt.Debug.init();