1 files changed, 98 insertions, 0 deletions
diff --git a/widget/gtk/GfxInfoUtils.h b/widget/gtk/GfxInfoUtils.h
new file mode 100644
index 0000000000..f4d96604e3
--- /dev/null
+++ b/widget/gtk/GfxInfoUtils.h
@@ -0,0 +1,98 @@
+/* vim: se cin sw=2 ts=2 et : */
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WIDGET_GTK_GFXINFO_UTILS_h__
+#define WIDGET_GTK_GFXINFO_UTILS_h__
+
+// An alternative to mozilla::Unused for use in (a) C code and (b) code where
+// linking with unused.o is difficult.
+#define MOZ_UNUSED(expr) \
+  do {                   \
+    if (expr) {          \
+      (void)0;           \
+    }                    \
+  } while (0)
+
+#define LOG_PIPE 2
+
+static bool enable_logging = false;
+static void log(const char* format, ...) {
+  if (!enable_logging) {
+    return;
+  }
+  va_list args;
+  va_start(args, format);
+  vfprintf(stderr, format, args);
+  va_end(args);
+}
+
+static int output_pipe = 1;
+static void close_logging() {
+  // we want to redirect to /dev/null stdout, stderr, and while we're at it,
+  // any PR logging file descriptors. To that effect, we redirect all positive
+  // file descriptors up to what open() returns here. In particular, 1 is stdout
+  // and 2 is stderr.
+  int fd = open("/dev/null", O_WRONLY);
+  for (int i = 1; i < fd; i++) {
+    if (output_pipe != i) {
+      dup2(fd, i);
+    }
+  }
+  close(fd);
+}
+
+// C++ standard collides with C standard in that it doesn't allow casting void*
+// to function pointer types. So the work-around is to convert first to size_t.
+// http://www.trilithium.com/johan/2004/12/problem-with-dlsym/
+template <typename func_ptr_type>
+static func_ptr_type cast(void* ptr) {
+  return reinterpret_cast<func_ptr_type>(reinterpret_cast<size_t>(ptr));
+}
+
+#define BUFFER_SIZE_STEP 4000
+
+static char* test_buf = nullptr;
+static int test_bufsize = 0;
+static int test_length = 0;
+
+static void record_value(const char* format, ...) {
+  if (!test_buf || test_length + BUFFER_SIZE_STEP / 2 > test_bufsize) {
+    test_bufsize += BUFFER_SIZE_STEP;
+    test_buf = (char*)realloc(test_buf, test_bufsize);
+  }
+  int remaining = test_bufsize - test_length;
+
+  // Append the new values to the buffer, not to exceed the remaining space.
+  va_list args;
+  va_start(args, format);
+  int max_added = vsnprintf(test_buf + test_length, remaining, format, args);
+  va_end(args);
+
+  if (max_added >= remaining) {
+    test_length += remaining;
+  } else {
+    test_length += max_added;
+  }
+}
+
+#define record_error(str_, ...) record_value("ERROR\n" str_ "\n", ##__VA_ARGS__)
+#define record_warning(str_, ...) \
+  record_value("WARNING\n" str_ "\n", ##__VA_ARGS__)
+
+static void record_flush() {
+  if (!test_buf) {
+    return;
+  }
+  MOZ_UNUSED(write(output_pipe, test_buf, test_length));
+  if (enable_logging) {
+    MOZ_UNUSED(write(LOG_PIPE, test_buf, test_length));
+  }
+  free(test_buf);
+  test_buf = nullptr;
+}
+
+#endif /* WIDGET_GTK_GFXINFO_h__ */