Fix various warnings: [-Waddress], [-Wpointer-arith], [-Wwrite-strings], [-Wreturn-local-addr] and more

Fixes the following GCC 5 warnings:
```
core/os/file_access.cpp:49:19: warning: the address of 'FileAccess::create_func' will always evaluate as 'true' [-Waddress]
servers/audio_server.cpp:192:70: warning: comparison with string literal results in unspecified behaviour [-Waddress]

drivers/gles2/rasterizer_storage_gles2.cpp:4095:90: warning: NULL used in arithmetic [-Wpointer-arith]

modules/gdnative/register_types.cpp:237:3: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
platform/android/export/export.cpp:207:1: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

modules/gdscript/gdscript.h:150:67: warning: returning reference to temporary [-Wreturn-local-addr]
servers/physics_2d/collision_object_2d_sw.h:119:56: warning: returning reference to temporary [-Wreturn-local-addr]
servers/physics_2d/collision_object_2d_sw.h:123:56: warning: returning reference to temporary [-Wreturn-local-addr]
servers/physics_2d/collision_object_2d_sw.h:127:50: warning: returning reference to temporary [-Wreturn-local-addr]
servers/physics_2d/collision_object_2d_sw.h:131:52: warning: returning reference to temporary [-Wreturn-local-addr]

editor/plugins/skeleton_editor_plugin.cpp:34:36: warning: extra tokens at end of #include directive
modules/bullet/bullet_types_converter.cpp:31:9: warning: #pragma once in main file

editor/import/editor_scene_importer_gltf.cpp:1996:51: warning: name lookup of 'i' changed
modules/visual_script/visual_script_property_selector.cpp:402:45: warning: name lookup of 'E' changed
scene/gui/tree.cpp:1268:25: warning: name lookup of 'i' changed
scene/resources/visual_shader.cpp:808:32: warning: name lookup of 'i' changed
```

core/os/file_access.cpp

@@ -46,7 +46,6 @@ bool FileAccess::backup_save = false;
 
 FileAccess *FileAccess::create(AccessType p_access) {
 
-	ERR_FAIL_COND_V(!create_func, 0);
 	ERR_FAIL_INDEX_V(p_access, ACCESS_MAX, 0);
 
 	FileAccess *ret = create_func[p_access]();

drivers/gles2/rasterizer_storage_gles2.cpp

@@ -4089,15 +4089,14 @@ void RasterizerStorageGLES2::initialize() {
 	}
 
 	config.shrink_textures_x2 = false;
-	config.float_texture_supported = config.extensions.find("GL_ARB_texture_float") != NULL || config.extensions.find("GL_OES_texture_float") != NULL;
-	config.s3tc_supported = config.extensions.find("GL_EXT_texture_compression_s3tc") != NULL;
-	config.etc1_supported = config.extensions.has("GL_OES_compressed_ETC1_RGB8_texture") != NULL;
+	config.float_texture_supported = config.extensions.has("GL_ARB_texture_float") || config.extensions.has("GL_OES_texture_float");
+	config.s3tc_supported = config.extensions.has("GL_EXT_texture_compression_s3tc");
+	config.etc1_supported = config.extensions.has("GL_OES_compressed_ETC1_RGB8_texture");
 
 	frame.count = 0;
 	frame.delta = 0;
 	frame.current_rt = NULL;
 	frame.clear_request = false;
-	// config.keep_original_textures = false;
 
 	glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &config.max_texture_image_units);
 	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &config.max_texture_size);

editor/import/editor_scene_importer_gltf.cpp

@@ -1910,15 +1910,15 @@ void EditorSceneImporterGLTF::_import_animation(GLTFState &state, AnimationPlaye
 		NodePath node_path;
 
 		GLTFNode *node = state.nodes[E->key()];
-		for (int i = 0; i < node->godot_nodes.size(); i++) {
+		for (int n = 0; n < node->godot_nodes.size(); n++) {
 
 			if (node->joints.size()) {
-				Skeleton *sk = (Skeleton *)node->godot_nodes[i];
+				Skeleton *sk = (Skeleton *)node->godot_nodes[n];
 				String path = ap->get_parent()->get_path_to(sk);
-				String bone = sk->get_bone_name(node->joints[i].godot_bone_index);
+				String bone = sk->get_bone_name(node->joints[n].godot_bone_index);
 				node_path = path + ":" + bone;
 			} else {
-				node_path = ap->get_parent()->get_path_to(node->godot_nodes[i]);
+				node_path = ap->get_parent()->get_path_to(node->godot_nodes[n]);
 			}
 
 			for (int i = 0; i < track.rotation_track.times.size(); i++) {
@@ -1993,8 +1993,8 @@ void EditorSceneImporterGLTF::_import_animation(GLTFState &state, AnimationPlaye
 						xform.basis.set_quat_scale(rot, scale);
 						xform.origin = pos;
 
-						Skeleton *skeleton = skeletons[node->joints[i].skin];
-						int bone = node->joints[i].godot_bone_index;
+						Skeleton *skeleton = skeletons[node->joints[n].skin];
+						int bone = node->joints[n].godot_bone_index;
 						xform = skeleton->get_bone_rest(bone).affine_inverse() * xform;
 
 						rot = xform.basis.get_rotation_quat();

editor/plugins/skeleton_editor_plugin.cpp

@@ -29,9 +29,10 @@
 /*************************************************************************/
 
 #include "skeleton_editor_plugin.h"
+
 #include "scene/3d/collision_shape.h"
 #include "scene/3d/physics_body.h"
-#include "scene/3d/physics_joint.h";
+#include "scene/3d/physics_joint.h"
 #include "scene/resources/capsule_shape.h"
 #include "scene/resources/sphere_shape.h"
 #include "spatial_editor_plugin.h"

modules/bullet/bullet_types_converter.cpp

@@ -28,8 +28,6 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
 
-#pragma once
-
 #include "bullet_types_converter.h"
 
 /**

modules/gdnative/register_types.cpp

@@ -29,19 +29,19 @@
 /*************************************************************************/
 
 #include "register_types.h"
+
 #include "gdnative/gdnative.h"
 
 #include "gdnative.h"
 
-#include "core/io/resource_loader.h"
-#include "core/io/resource_saver.h"
-
 #include "arvr/register_types.h"
 #include "nativescript/register_types.h"
 #include "net/register_types.h"
 #include "pluginscript/register_types.h"
 
 #include "core/engine.h"
+#include "core/io/resource_loader.h"
+#include "core/io/resource_saver.h"
 #include "core/os/os.h"
 #include "core/project_settings.h"
 
@@ -148,7 +148,7 @@ protected:
 };
 
 struct LibrarySymbol {
-	char *name;
+	const char *name;
 	bool is_required;
 };
 

modules/gdscript/gdscript.h

@@ -147,7 +147,7 @@ public:
 	const Map<StringName, Variant> &get_constants() const { return constants; }
 	const Set<StringName> &get_members() const { return members; }
 	const GDScriptDataType &get_member_type(const StringName &p_member) const {
-		ERR_FAIL_COND_V(!member_indices.has(p_member), GDScriptDataType());
+		CRASH_COND(!member_indices.has(p_member));
 		return member_indices[p_member].data_type;
 	}
 	const Map<StringName, GDScriptFunction *> &get_member_functions() const { return member_functions; }

modules/visual_script/visual_script_property_selector.cpp

@@ -386,8 +386,8 @@ void VisualScriptPropertySelector::get_visual_node_names(const String &root_filt
 		}
 		Vector<String> path = E->get().split("/");
 		bool is_filter = false;
-		for (Set<String>::Element *E = filter.front(); E; E = E->next()) {
-			if (path.size() >= 2 && path[1].findn(E->get()) != -1) {
+		for (Set<String>::Element *F = filter.front(); F; F = F->next()) {
+			if (path.size() >= 2 && path[1].findn(F->get()) != -1) {
 				is_filter = true;
 				break;
 			}

platform/android/export/export.cpp

@@ -194,8 +194,8 @@ static const char *android_perms[] = {
 };
 
 struct LauncherIcon {
-	char *option_id;
-	char *export_path;
+	const char *option_id;
+	const char *export_path;
 };
 
 static const LauncherIcon launcher_icons[] = {

scene/gui/tree.cpp

@@ -1254,13 +1254,13 @@ int Tree::draw_item(const Point2i &p_pos, const Point2 &p_draw_ofs, const Size2
 
 						String s = RTR("(Other)");
 						Vector<String> strings = p_item->cells[i].text.split(",");
-						for (int i = 0; i < strings.size(); i++) {
-							int value = i;
-							if (!strings[i].get_slicec(':', 1).empty()) {
-								value = strings[i].get_slicec(':', 1).to_int();
+						for (int j = 0; j < strings.size(); j++) {
+							int value = j;
+							if (!strings[j].get_slicec(':', 1).empty()) {
+								value = strings[j].get_slicec(':', 1).to_int();
 							}
 							if (option == value) {
-								s = strings[i].get_slicec(':', 0);
+								s = strings[j].get_slicec(':', 0);
 								break;
 							}
 						}

scene/resources/visual_shader.cpp

@@ -796,10 +796,10 @@ Error VisualShader::_write_node(Type type, StringBuilder &global_code, StringBui
 				val.basis.transpose();
 				inputs[i] = "n_in" + itos(node) + "p" + itos(i);
 				Array values;
-				for (int i = 0; i < 3; i++) {
-					values.push_back(val.basis[i].x);
-					values.push_back(val.basis[i].y);
-					values.push_back(val.basis[i].z);
+				for (int j = 0; j < 3; j++) {
+					values.push_back(val.basis[j].x);
+					values.push_back(val.basis[j].y);
+					values.push_back(val.basis[j].z);
 				}
 				values.push_back(val.origin.x);
 				values.push_back(val.origin.y);

servers/audio_server.cpp

@@ -189,7 +189,7 @@ void AudioDriverManager::initialize(int p_driver) {
 		}
 	}
 
-	if (driver_count > 1 && AudioDriver::get_singleton()->get_name() == "Dummy") {
+	if (driver_count > 1 && String(AudioDriver::get_singleton()->get_name()) == "Dummy") {
 		WARN_PRINT("All audio drivers failed, falling back to the dummy driver.");
 	}
 }

servers/physics_2d/collision_object_2d_sw.h

@@ -112,23 +112,23 @@ public:
 
 	_FORCE_INLINE_ int get_shape_count() const { return shapes.size(); }
 	_FORCE_INLINE_ Shape2DSW *get_shape(int p_index) const {
-		ERR_FAIL_INDEX_V(p_index, shapes.size(), NULL);
+		CRASH_BAD_INDEX(p_index, shapes.size());
 		return shapes[p_index].shape;
 	}
 	_FORCE_INLINE_ const Transform2D &get_shape_transform(int p_index) const {
-		ERR_FAIL_INDEX_V(p_index, shapes.size(), Transform2D());
+		CRASH_BAD_INDEX(p_index, shapes.size());
 		return shapes[p_index].xform;
 	}
 	_FORCE_INLINE_ const Transform2D &get_shape_inv_transform(int p_index) const {
-		ERR_FAIL_INDEX_V(p_index, shapes.size(), Transform2D());
+		CRASH_BAD_INDEX(p_index, shapes.size());
 		return shapes[p_index].xform_inv;
 	}
 	_FORCE_INLINE_ const Rect2 &get_shape_aabb(int p_index) const {
-		ERR_FAIL_INDEX_V(p_index, shapes.size(), Rect2());
+		CRASH_BAD_INDEX(p_index, shapes.size());
 		return shapes[p_index].aabb_cache;
 	}
 	_FORCE_INLINE_ const Variant &get_shape_metadata(int p_index) const {
-		ERR_FAIL_INDEX_V(p_index, shapes.size(), Variant());
+		CRASH_BAD_INDEX(p_index, shapes.size());
 		return shapes[p_index].metadata;
 	}
 
@@ -138,16 +138,16 @@ public:
 
 	void set_shape_as_disabled(int p_idx, bool p_disabled);
 	_FORCE_INLINE_ bool is_shape_set_as_disabled(int p_idx) const {
-		ERR_FAIL_INDEX_V(p_idx, shapes.size(), false);
+		CRASH_BAD_INDEX(p_idx, shapes.size());
 		return shapes[p_idx].disabled;
 	}
 
 	_FORCE_INLINE_ void set_shape_as_one_way_collision(int p_idx, bool p_one_way_collision) {
-		ERR_FAIL_INDEX(p_idx, shapes.size());
+		CRASH_BAD_INDEX(p_idx, shapes.size());
 		shapes.write[p_idx].one_way_collision = p_one_way_collision;
 	}
 	_FORCE_INLINE_ bool is_shape_set_as_one_way_collision(int p_idx) const {
-		ERR_FAIL_INDEX_V(p_idx, shapes.size(), false);
+		CRASH_BAD_INDEX(p_idx, shapes.size());
 		return shapes[p_idx].one_way_collision;
 	}