1 files changed, 139 insertions, 0 deletions
diff --git a/gfx/thebes/gfxEnv.h b/gfx/thebes/gfxEnv.h
new file mode 100644
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+++ b/gfx/thebes/gfxEnv.h
@@ -0,0 +1,139 @@
+/* -*- Mode: C++; tab-width: 20; 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 GFX_ENV_H
+#define GFX_ENV_H
+
+#include "mozilla/Attributes.h"
+#include "nsDebug.h"
+#include "prenv.h"
+
+#include <sstream>
+#include <string_view>
+
+// To register the check for an environment variable existence (and not empty),
+// add a line in this file using the DECL_GFX_ENV macro.
+//
+// For example this line in the .h:
+//   DECL_GFX_ENV(MOZ_GL_SPEW);
+
+// means that you can call e.g.
+//   if (gfxEnv::MOZ_GL_SPEW()) { ... }
+//   if (gfxEnv::MOZ_GL_SPEW().as_str == "2") { ... }
+// and that the value will be checked only once, first time we call it, then
+// cached.
+
+struct EnvVal {
+  std::string_view as_str;
+
+  static auto From(const char* const raw) {
+    auto ret = EnvVal{};
+
+    ret.as_str = std::string_view{};
+    // Empty string counts as missing.
+    if (raw) {
+      ret.as_str = raw;
+    }
+
+    return ret;
+  }
+
+  MOZ_IMPLICIT operator bool() const {
+    return !as_str.empty();  // Warning, this means ENV=0" -> true!
+  }
+};
+
+class gfxEnv final {
+ public:
+  gfxEnv() = delete;
+
+  static EnvVal Uncached(const char* name) {
+    const auto raw = PR_GetEnv(name);
+    const auto ret = EnvVal::From(raw);
+    if (ret && ret.as_str == "0") {
+      auto msg = std::stringstream{};
+      msg << name << "=" << ret.as_str << " -> true!";
+      NS_WARNING(msg.str().c_str());
+    }
+    return ret;
+  }
+
+#define DECL_GFX_ENV(Name)                      \
+  static const EnvVal& Name() {                 \
+    static const auto cached = Uncached(#Name); \
+    return cached;                              \
+  }
+
+  // This is where DECL_GFX_ENV for each of the environment variables should go.
+  // We will keep these in an alphabetical order by the environment variable,
+  // to make it easier to see if a method accessing an entry already exists.
+  // Just insert yours in the list.
+
+  // OpenGL shader debugging in OGLShaderProgram, in DEBUG only
+  DECL_GFX_ENV(MOZ_DEBUG_SHADERS)
+
+  // Disabling the crash guard in DriverCrashGuard
+  DECL_GFX_ENV(MOZ_DISABLE_CRASH_GUARD)
+  DECL_GFX_ENV(MOZ_FORCE_CRASH_GUARD_NIGHTLY)
+
+  // We force present to work around some Windows bugs - disable that if this
+  // environment variable is set.
+  DECL_GFX_ENV(MOZ_DISABLE_FORCE_PRESENT)
+
+  // Together with paint dumping, only when MOZ_DUMP_PAINTING is defined.
+  // Dumping compositor textures is broken pretty badly. For example,
+  // on Linux it crashes TextureHost::GetAsSurface() returns null.
+  // Expect to have to fix things like this if you turn it on.
+  // Meanwhile, content-side texture dumping
+  // (conditioned on DebugDumpPainting()) is a good replacement.
+  DECL_GFX_ENV(MOZ_DUMP_COMPOSITOR_TEXTURES)
+
+  // Dump GLBlitHelper shader source text.
+  DECL_GFX_ENV(MOZ_DUMP_GLBLITHELPER)
+
+  // Paint dumping, only when MOZ_DUMP_PAINTING is defined.
+  DECL_GFX_ENV(MOZ_DUMP_PAINT)
+  DECL_GFX_ENV(MOZ_DUMP_PAINT_ITEMS)
+  DECL_GFX_ENV(MOZ_DUMP_PAINT_TO_FILE)
+
+  // Force gfxDevCrash to use MOZ_CRASH in Beta and Release
+  DECL_GFX_ENV(MOZ_GFX_CRASH_MOZ_CRASH)
+  // Force gfxDevCrash to use telemetry in Nightly and Aurora
+  DECL_GFX_ENV(MOZ_GFX_CRASH_TELEMETRY)
+
+  // Debugging in GLContext
+  DECL_GFX_ENV(MOZ_GL_DEBUG)
+  DECL_GFX_ENV(MOZ_GL_DEBUG_VERBOSE)
+  DECL_GFX_ENV(MOZ_GL_DEBUG_ABORT_ON_ERROR)
+  DECL_GFX_ENV(MOZ_GL_RELEASE_ASSERT_CONTEXT_OWNERSHIP)
+  DECL_GFX_ENV(MOZ_EGL_RELEASE_ASSERT_CONTEXT_OWNERSHIP)
+
+  // Count GL extensions
+  DECL_GFX_ENV(MOZ_GL_DUMP_EXTS)
+
+  // Very noisy GLContext and GLContextProviderEGL
+  DECL_GFX_ENV(MOZ_GL_SPEW)
+
+  // Do extra work before and after each GLX call in GLContextProviderGLX
+  DECL_GFX_ENV(MOZ_GLX_DEBUG)
+
+  // GL compositing on Windows
+  DECL_GFX_ENV(MOZ_LAYERS_PREFER_EGL)
+
+  // Offscreen GL context for main layer manager
+  DECL_GFX_ENV(MOZ_LAYERS_PREFER_OFFSCREEN)
+
+  // WebGL workarounds
+  DECL_GFX_ENV(MOZ_WEBGL_WORKAROUND_FIRST_AFFECTS_INSTANCE_ID)
+
+  // WARNING:
+  // For readability reasons, please make sure that you've added your new envvar
+  // to the list above in alphabetical order.
+  // Please do not just append it to the end of the list!
+
+#undef DECL_GFX_ENV
+};
+
+#endif /* GFX_ENV_H */