diff --git a/core/io/file_access_network.h b/core/io/file_access_network.h
index 7e4669ffd5..e32dcea990 100644
--- a/core/io/file_access_network.h
+++ b/core/io/file_access_network.h
@@ -47,8 +47,6 @@ class FileAccessNetworkClient {
 		int size;
 	};
 
-	int ml;
-
 	List<BlockRequest> block_requests;
 
 	Semaphore *sem;
diff --git a/core/io/file_access_zip.h b/core/io/file_access_zip.h
index 4fe0651a55..9bb1ad221a 100644
--- a/core/io/file_access_zip.h
+++ b/core/io/file_access_zip.h
@@ -90,8 +90,6 @@ class FileAccessZip : public FileAccess {
 
 	mutable bool at_eof;
 
-	ZipArchive *archive;
-
 public:
 	virtual Error _open(const String &p_path, int p_mode_flags); ///< open a file
 	virtual void close(); ///< close a file
diff --git a/core/io/resource_format_binary.h b/core/io/resource_format_binary.h
index 35d594f228..513252055f 100644
--- a/core/io/resource_format_binary.h
+++ b/core/io/resource_format_binary.h
@@ -119,7 +119,6 @@ class ResourceFormatSaverBinaryInstance {
 	bool skip_editor;
 	bool big_endian;
 	bool takeover_paths;
-	int bin_meta_idx;
 	FileAccess *f;
 	String magic;
 	Set<RES> resource_set;
diff --git a/core/message_queue.h b/core/message_queue.h
index f51da3c7a3..2083bb0639 100644
--- a/core/message_queue.h
+++ b/core/message_queue.h
@@ -32,7 +32,6 @@
 #define MESSAGE_QUEUE_H
 
 #include "core/object.h"
-#include "core/os/mutex.h"
 #include "core/os/thread_safe.h"
 
 class MessageQueue {
@@ -44,8 +43,6 @@ class MessageQueue {
 		DEFAULT_QUEUE_SIZE_KB = 1024
 	};
 
-	Mutex *mutex;
-
 	enum {
 		TYPE_CALL,
 		TYPE_NOTIFICATION,
diff --git a/core/object.h b/core/object.h
index f9e8755e06..b23160c1df 100644
--- a/core/object.h
+++ b/core/object.h
@@ -422,7 +422,7 @@ private:
 	};
 
 #ifdef DEBUG_ENABLED
-	friend class _ObjectDebugLock;
+	friend struct _ObjectDebugLock;
 #endif
 	friend bool predelete_handler(Object *);
 	friend void postinitialize_handler(Object *);
diff --git a/core/variant.h b/core/variant.h
index 2fffb31de6..8953217760 100644
--- a/core/variant.h
+++ b/core/variant.h
@@ -116,7 +116,7 @@ public:
 	};
 
 private:
-	friend class _VariantCall;
+	friend struct _VariantCall;
 	// Variant takes 20 bytes when real_t is float, and 36 if double
 	// it only allocates extra memory for aabb/matrix.
 
diff --git a/drivers/gles3/rasterizer_scene_gles3.cpp b/drivers/gles3/rasterizer_scene_gles3.cpp
index 1fcd4e02ac..7160668fe8 100644
--- a/drivers/gles3/rasterizer_scene_gles3.cpp
+++ b/drivers/gles3/rasterizer_scene_gles3.cpp
@@ -51,26 +51,6 @@ static const GLenum _cube_side_enum[6] = {
 
 };
 
-static _FORCE_INLINE_ void store_transform2d(const Transform2D &p_mtx, float *p_array) {
-
-	p_array[0] = p_mtx.elements[0][0];
-	p_array[1] = p_mtx.elements[0][1];
-	p_array[2] = 0;
-	p_array[3] = 0;
-	p_array[4] = p_mtx.elements[1][0];
-	p_array[5] = p_mtx.elements[1][1];
-	p_array[6] = 0;
-	p_array[7] = 0;
-	p_array[8] = 0;
-	p_array[9] = 0;
-	p_array[10] = 1;
-	p_array[11] = 0;
-	p_array[12] = p_mtx.elements[2][0];
-	p_array[13] = p_mtx.elements[2][1];
-	p_array[14] = 0;
-	p_array[15] = 1;
-}
-
 static _FORCE_INLINE_ void store_transform(const Transform &p_mtx, float *p_array) {
 	p_array[0] = p_mtx.basis.elements[0][0];
 	p_array[1] = p_mtx.basis.elements[1][0];
@@ -1202,7 +1182,7 @@ bool RasterizerSceneGLES3::_setup_material(RasterizerStorageGLES3::Material *p_m
 
 		glActiveTexture(GL_TEXTURE0 + i);
 
-		GLenum target;
+		GLenum target = GL_TEXTURE_2D;
 		GLuint tex = 0;
 
 		RasterizerStorageGLES3::Texture *t = storage->texture_owner.getptr(textures[i]);
diff --git a/drivers/gles3/rasterizer_storage_gles3.h b/drivers/gles3/rasterizer_storage_gles3.h
index b31c5ff7bb..9a4798ac2a 100644
--- a/drivers/gles3/rasterizer_storage_gles3.h
+++ b/drivers/gles3/rasterizer_storage_gles3.h
@@ -691,7 +691,7 @@ public:
 		}
 	};
 
-	class MultiMesh;
+	struct MultiMesh;
 
 	struct Mesh : public GeometryOwner {
 
diff --git a/editor/editor_export.h b/editor/editor_export.h
index 420f383f95..b4ee5b89e7 100644
--- a/editor/editor_export.h
+++ b/editor/editor_export.h
@@ -37,10 +37,10 @@
 #include "scene/main/timer.h"
 #include "scene/resources/texture.h"
 
-class EditorProgress;
 class FileAccess;
 class EditorExportPlatform;
 class EditorFileSystemDirectory;
+struct EditorProgress;
 
 class EditorExportPreset : public Reference {
 
diff --git a/editor/editor_properties.cpp b/editor/editor_properties.cpp
index 690fbd2c93..d336b84750 100644
--- a/editor/editor_properties.cpp
+++ b/editor/editor_properties.cpp
@@ -2638,7 +2638,7 @@ bool EditorInspectorDefaultPlugin::parse_property(Object *p_object, Variant::Typ
 
 			} else if (p_hint == PROPERTY_HINT_LAYERS_2D_PHYSICS || p_hint == PROPERTY_HINT_LAYERS_2D_RENDER || p_hint == PROPERTY_HINT_LAYERS_3D_PHYSICS || p_hint == PROPERTY_HINT_LAYERS_3D_RENDER) {
 
-				EditorPropertyLayers::LayerType lt;
+				EditorPropertyLayers::LayerType lt = EditorPropertyLayers::LAYER_RENDER_2D;
 				switch (p_hint) {
 					case PROPERTY_HINT_LAYERS_2D_RENDER:
 						lt = EditorPropertyLayers::LAYER_RENDER_2D;
diff --git a/editor/editor_properties_array_dict.cpp b/editor/editor_properties_array_dict.cpp
index 4e638cb4ac..24360813a2 100644
--- a/editor/editor_properties_array_dict.cpp
+++ b/editor/editor_properties_array_dict.cpp
@@ -969,7 +969,7 @@ void EditorPropertyDictionary::update_property() {
 				pc->add_child(add_vbox);
 			}
 			prop->set_object_and_property(object.ptr(), prop_name);
-			int change_index;
+			int change_index = 0;
 
 			if (i < amount) {
 				String cs = key.get_construct_string();
diff --git a/editor/plugins/curve_editor_plugin.cpp b/editor/plugins/curve_editor_plugin.cpp
index 79169d3183..8b7156dcee 100644
--- a/editor/plugins/curve_editor_plugin.cpp
+++ b/editor/plugins/curve_editor_plugin.cpp
@@ -205,13 +205,13 @@ void CurveEditor::on_gui_input(const Ref<InputEvent> &p_event) {
 						curve.set_point_left_tangent(_selected_point, tangent);
 
 						// Note: if a tangent is set to linear, it shouldn't be linked to the other
-						if (link && _selected_point != curve.get_point_count() - 1 && !curve.get_point_right_mode(_selected_point) != Curve::TANGENT_FREE)
+						if (link && _selected_point != (curve.get_point_count() - 1) && curve.get_point_right_mode(_selected_point) != Curve::TANGENT_LINEAR)
 							curve.set_point_right_tangent(_selected_point, tangent);
 
 					} else {
 						curve.set_point_right_tangent(_selected_point, tangent);
 
-						if (link && _selected_point != 0 && !curve.get_point_left_mode(_selected_point) != Curve::TANGENT_FREE)
+						if (link && _selected_point != 0 && curve.get_point_left_mode(_selected_point) != Curve::TANGENT_LINEAR)
 							curve.set_point_left_tangent(_selected_point, tangent);
 					}
 				}
diff --git a/editor/plugins/script_editor_plugin.cpp b/editor/plugins/script_editor_plugin.cpp
index 5e000ca6ef..d2a9830fe0 100644
--- a/editor/plugins/script_editor_plugin.cpp
+++ b/editor/plugins/script_editor_plugin.cpp
@@ -1414,21 +1414,6 @@ void ScriptEditor::notify_script_changed(const Ref<Script> &p_script) {
 	emit_signal("editor_script_changed", p_script);
 }
 
-static const Node *_find_node_with_script(const Node *p_node, const RefPtr &p_script) {
-
-	if (p_node->get_script() == p_script)
-		return p_node;
-
-	for (int i = 0; i < p_node->get_child_count(); i++) {
-
-		const Node *result = _find_node_with_script(p_node->get_child(i), p_script);
-		if (result)
-			return result;
-	}
-
-	return NULL;
-}
-
 void ScriptEditor::get_breakpoints(List<String> *p_breakpoints) {
 
 	for (int i = 0; i < tab_container->get_child_count(); i++) {
diff --git a/editor/scene_tree_dock.cpp b/editor/scene_tree_dock.cpp
index 18c9f6b784..6100a55d65 100644
--- a/editor/scene_tree_dock.cpp
+++ b/editor/scene_tree_dock.cpp
@@ -1860,32 +1860,6 @@ static bool _has_visible_children(Node *p_node) {
 	return false;
 }
 
-static Node *_find_last_visible(Node *p_node) {
-
-	Node *last = NULL;
-
-	bool collapsed = p_node->is_displayed_folded();
-
-	if (!collapsed) {
-		for (int i = 0; i < p_node->get_child_count(); i++) {
-			if (_is_node_visible(p_node->get_child(i))) {
-				last = p_node->get_child(i);
-			}
-		}
-	}
-
-	if (last) {
-		Node *lastc = _find_last_visible(last);
-		if (lastc)
-			last = lastc;
-
-	} else {
-		last = p_node;
-	}
-
-	return last;
-}
-
 void SceneTreeDock::_normalize_drop(Node *&to_node, int &to_pos, int p_type) {
 
 	to_pos = -1;
diff --git a/editor/settings_config_dialog.cpp b/editor/settings_config_dialog.cpp
index fe384da75b..537c9ac6b8 100644
--- a/editor/settings_config_dialog.cpp
+++ b/editor/settings_config_dialog.cpp
@@ -361,7 +361,7 @@ void EditorSettingsDialog::_tabs_tab_changed(int p_tab) {
 void EditorSettingsDialog::_focus_current_search_box() {
 
 	Control *tab = tabs->get_current_tab_control();
-	LineEdit *current_search_box;
+	LineEdit *current_search_box = NULL;
 	if (tab == tab_general)
 		current_search_box = search_box;
 	else if (tab == tab_shortcuts)
diff --git a/main/tests/test_gui.cpp b/main/tests/test_gui.cpp
index d25eedbf6f..271353f1dd 100644
--- a/main/tests/test_gui.cpp
+++ b/main/tests/test_gui.cpp
@@ -60,8 +60,6 @@ namespace TestGUI {
 
 class TestMainLoop : public SceneTree {
 
-	Control *control;
-
 public:
 	virtual void request_quit() {
 
diff --git a/modules/bullet/rigid_body_bullet.h b/modules/bullet/rigid_body_bullet.h
index cd2f215906..25dac30951 100644
--- a/modules/bullet/rigid_body_bullet.h
+++ b/modules/bullet/rigid_body_bullet.h
@@ -227,7 +227,7 @@ public:
 
 	void init_kinematic_utilities();
 	void destroy_kinematic_utilities();
-	_FORCE_INLINE_ class KinematicUtilities *get_kinematic_utilities() const { return kinematic_utilities; }
+	_FORCE_INLINE_ KinematicUtilities *get_kinematic_utilities() const { return kinematic_utilities; }
 
 	_FORCE_INLINE_ btRigidBody *get_bt_rigid_body() { return btBody; }
 
diff --git a/modules/bullet/space_bullet.h b/modules/bullet/space_bullet.h
index d815898ffd..c3d55cbbb1 100644
--- a/modules/bullet/space_bullet.h
+++ b/modules/bullet/space_bullet.h
@@ -57,7 +57,7 @@ class btDiscreteDynamicsWorld;
 class btEmptyShape;
 class btGhostPairCallback;
 class btSoftRigidDynamicsWorld;
-class btSoftBodyWorldInfo;
+struct btSoftBodyWorldInfo;
 class ConstraintBullet;
 class CollisionObjectBullet;
 class RigidBodyBullet;
diff --git a/modules/gdscript/gdscript_parser.cpp b/modules/gdscript/gdscript_parser.cpp
index 5facfe7869..2fa5084d84 100644
--- a/modules/gdscript/gdscript_parser.cpp
+++ b/modules/gdscript/gdscript_parser.cpp
@@ -7835,7 +7835,7 @@ void GDScriptParser::_check_block_types(BlockNode *p_block) {
 							// Figure out function name for warning
 							String func_name = _find_function_name(op);
 							if (func_name.empty()) {
-								func_name == "<undetected name>";
+								func_name = "<undetected name>";
 							}
 							_add_warning(GDScriptWarning::RETURN_VALUE_DISCARDED, op->line, func_name);
 						}
diff --git a/modules/gdscript/gdscript_parser.h b/modules/gdscript/gdscript_parser.h
index c7813a2144..8121fb7f85 100644
--- a/modules/gdscript/gdscript_parser.h
+++ b/modules/gdscript/gdscript_parser.h
@@ -555,7 +555,6 @@ private:
 
 	CompletionType completion_type;
 	StringName completion_cursor;
-	bool completion_static;
 	Variant::Type completion_built_in_constant;
 	Node *completion_node;
 	ClassNode *completion_class;
diff --git a/platform/x11/os_x11.h b/platform/x11/os_x11.h
index 47ff257455..bb8411e213 100644
--- a/platform/x11/os_x11.h
+++ b/platform/x11/os_x11.h
@@ -34,17 +34,17 @@
 #include "context_gl_x11.h"
 #include "core/os/input.h"
 #include "crash_handler_x11.h"
-#include "drivers/unix/os_unix.h"
-#include "servers/visual_server.h"
-//#include "servers/visual/visual_server_wrap_mt.h"
 #include "drivers/alsa/audio_driver_alsa.h"
 #include "drivers/alsamidi/alsa_midi.h"
 #include "drivers/pulseaudio/audio_driver_pulseaudio.h"
+#include "drivers/unix/os_unix.h"
 #include "joypad_linux.h"
 #include "main/input_default.h"
 #include "power_x11.h"
 #include "servers/audio_server.h"
 #include "servers/visual/rasterizer.h"
+#include "servers/visual_server.h"
+//#include "servers/visual/visual_server_wrap_mt.h"
 
 #include <X11/Xcursor/Xcursor.h>
 #include <X11/Xlib.h>
@@ -145,7 +145,6 @@ class OS_X11 : public OS_Unix {
 	void handle_key_event(XKeyEvent *p_event, bool p_echo = false);
 	void process_xevents();
 	virtual void delete_main_loop();
-	IP_Unix *ip_unix;
 
 	bool force_quit;
 	bool minimized;
@@ -177,8 +176,6 @@ class OS_X11 : public OS_Unix {
 	AudioDriverPulseAudio driver_pulseaudio;
 #endif
 
-	Atom net_wm_icon;
-
 	PowerX11 *power_manager;
 
 	bool layered_window;
@@ -186,8 +183,6 @@ class OS_X11 : public OS_Unix {
 	CrashHandler crash_handler;
 
 	int video_driver_index;
-	int audio_driver_index;
-	unsigned int capture_idle;
 	bool maximized;
 	//void set_wm_border(bool p_enabled);
 	void set_wm_fullscreen(bool p_enabled);
diff --git a/scene/resources/mesh.cpp b/scene/resources/mesh.cpp
index fa87623e38..6cd701eb9a 100644
--- a/scene/resources/mesh.cpp
+++ b/scene/resources/mesh.cpp
@@ -546,33 +546,6 @@ void Mesh::clear_cache() const {
 Mesh::Mesh() {
 }
 
-static const ArrayMesh::ArrayType _array_types[] = {
-
-	ArrayMesh::ARRAY_VERTEX,
-	ArrayMesh::ARRAY_NORMAL,
-	ArrayMesh::ARRAY_TANGENT,
-	ArrayMesh::ARRAY_COLOR,
-	ArrayMesh::ARRAY_TEX_UV,
-	ArrayMesh::ARRAY_TEX_UV2,
-	ArrayMesh::ARRAY_BONES,
-	ArrayMesh::ARRAY_WEIGHTS,
-	ArrayMesh::ARRAY_INDEX
-};
-
-/* compatibility */
-static const int _format_translate[] = {
-
-	ArrayMesh::ARRAY_FORMAT_VERTEX,
-	ArrayMesh::ARRAY_FORMAT_NORMAL,
-	ArrayMesh::ARRAY_FORMAT_TANGENT,
-	ArrayMesh::ARRAY_FORMAT_COLOR,
-	ArrayMesh::ARRAY_FORMAT_TEX_UV,
-	ArrayMesh::ARRAY_FORMAT_TEX_UV2,
-	ArrayMesh::ARRAY_FORMAT_BONES,
-	ArrayMesh::ARRAY_FORMAT_WEIGHTS,
-	ArrayMesh::ARRAY_FORMAT_INDEX,
-};
-
 bool ArrayMesh::_set(const StringName &p_name, const Variant &p_value) {
 
 	String sname = p_name;
diff --git a/scene/resources/world.h b/scene/resources/world.h
index 4c517323f3..4ba6b13476 100644
--- a/scene/resources/world.h
+++ b/scene/resources/world.h
@@ -36,9 +36,9 @@
 #include "servers/physics_server.h"
 #include "servers/visual_server.h"
 
-class SpatialIndexer;
 class Camera;
 class VisibilityNotifier;
+struct SpatialIndexer;
 
 class World : public Resource {
 	GDCLASS(World, Resource);
diff --git a/scene/resources/world_2d.cpp b/scene/resources/world_2d.cpp
index b390e74073..dd78d04104 100644
--- a/scene/resources/world_2d.cpp
+++ b/scene/resources/world_2d.cpp
@@ -29,13 +29,13 @@
 /*************************************************************************/
 
 #include "world_2d.h"
-#include "servers/physics_2d_server.h"
-#include "servers/visual_server.h"
-//#include "servers/spatial_sound_2d_server.h"
+
 #include "core/project_settings.h"
 #include "scene/2d/camera_2d.h"
 #include "scene/2d/visibility_notifier_2d.h"
 #include "scene/main/viewport.h"
+#include "servers/physics_2d_server.h"
+#include "servers/visual_server.h"
 
 struct SpatialIndexer2D {
 
diff --git a/scene/resources/world_2d.h b/scene/resources/world_2d.h
index 856e9dbf01..88ad392f85 100644
--- a/scene/resources/world_2d.h
+++ b/scene/resources/world_2d.h
@@ -35,9 +35,9 @@
 #include "core/resource.h"
 #include "servers/physics_2d_server.h"
 
-class SpatialIndexer2D;
 class VisibilityNotifier2D;
 class Viewport;
+struct SpatialIndexer2D;
 
 class World2D : public Resource {
 
diff --git a/servers/audio/reverb_sw.cpp b/servers/audio/reverb_sw.cpp
index 13742d5db5..d078da38b4 100644
--- a/servers/audio/reverb_sw.cpp
+++ b/servers/audio/reverb_sw.cpp
@@ -29,33 +29,21 @@
 /*************************************************************************/
 
 #include "reverb_sw.h"
+
 #include "core/print_string.h"
-#include "stdlib.h"
+
+#include <stdlib.h>
+
 #define SETMIN(x, y) (x) = MIN((x), (y))
+
 #define rangeloop(c, min, max) \
 	for ((c) = (min); (c) < (max); (c)++)
 
 #define ABSDIFF(x, y) \
 	(((x) < (y)) ? ((y) - (x)) : ((x) - (y)))
 
-#ifdef bleh_MSC_VER
-
-#if _MSC_VER >= 1400
-_FORCE_INLINE_ int32_tMULSHIFT_S32(
-		int32_t Factor1,
-		int32_t Factor2,
-		uint8_t Bits) {
-
-	return __ll_rshift(
-			__emul(Factor1, Factor2),
-			Bits);
-}
-#endif
-
-#else
 #define MULSHIFT_S32(Factor1, Factor2, Bits) \
 	((int)(((int64_t)(Factor1) * (Factor2)) >> (Bits)))
-#endif
 
 struct ReverbParamsSW {
 	unsigned int BufferSize; // Required buffer size
diff --git a/servers/audio/reverb_sw.h b/servers/audio/reverb_sw.h
index 26b3fa5166..01977d1f61 100644
--- a/servers/audio/reverb_sw.h
+++ b/servers/audio/reverb_sw.h
@@ -34,7 +34,7 @@
 #include "core/os/memory.h"
 #include "core/typedefs.h"
 
-class ReverbParamsSW;
+struct ReverbParamsSW;
 
 class ReverbSW {
 public:
diff --git a/servers/physics/body_pair_sw.h b/servers/physics/body_pair_sw.h
index fd85d77718..17ff9d6a88 100644
--- a/servers/physics/body_pair_sw.h
+++ b/servers/physics/body_pair_sw.h
@@ -76,7 +76,6 @@ class BodyPairSW : public ConstraintSW {
 	Contact contacts[MAX_CONTACTS];
 	int contact_count;
 	bool collided;
-	int cc;
 
 	static void _contact_added_callback(const Vector3 &p_point_A, const Vector3 &p_point_B, void *p_userdata);
 
diff --git a/servers/visual/visual_server_raster.h b/servers/visual/visual_server_raster.h
index ef2b767a8a..62ba2eab69 100644
--- a/servers/visual/visual_server_raster.h
+++ b/servers/visual/visual_server_raster.h
@@ -59,7 +59,6 @@ class VisualServerRaster : public VisualServer {
 	};
 
 	static int changes;
-	bool draw_extra_frame;
 	RID test_cube;
 
 	int black_margin[4];