Fix warnings about unhandled enum value in switch [-Wswitch]

Fixes GCC 5 warnings of the form:

core/io/http_client.cpp:288:9: warning: enumeration value 'STATUS_SSL_HANDSHAKE_ERROR' not handled in switch [-Wswitch]
core/io/marshalls.cpp:806:9: warning: enumeration value 'AABB' not handled in switch [-Wswitch]

Those can be trivial cases where adding a default fallback is the solution,
or more complex issues/hidden bugs where missed values are actually meant
to be handled.

4 files changed, 17 insertions, 2 deletions

diff --git a/modules/gdscript/gdscript.cpp b/modules/gdscript/gdscript.cpp
index b0d5422afe..48c1760662 100644
--- a/modules/gdscript/gdscript.cpp
+++ b/modules/gdscript/gdscript.cpp
@@ -1981,6 +1981,7 @@ String GDScriptWarning::get_message() const {
 			CHECK_SYMBOLS(2);
 			return "The '" + symbols[0] + "' keyword is deprecated and will be removed in a future release, please replace its uses by '" + symbols[1] + "'.";
 		} break;
+		case WARNING_MAX: break; // Can't happen, but silences warning
 	}
 	ERR_EXPLAIN("Invalid GDScript warning code: " + get_name_from_code(code));
 	ERR_FAIL_V(String());
diff --git a/modules/gdscript/gdscript_editor.cpp b/modules/gdscript/gdscript_editor.cpp
index 3194f19aa9..55bc3d2359 100644
--- a/modules/gdscript/gdscript_editor.cpp
+++ b/modules/gdscript/gdscript_editor.cpp
@@ -1110,6 +1110,7 @@ static bool _guess_expression_type(const GDScriptCompletionContext &p_context, c
 				} break;
 			}
 		} break;
+		default: {}
 	}
 
 	// It may have found a null, but that's never useful
@@ -3354,6 +3355,7 @@ Error GDScriptLanguage::lookup_code(const String &p_code, const String &p_symbol
 				return OK;
 			}
 		} break;
+		default: {}
 	}
 
 	return ERR_CANT_RESOLVE;
diff --git a/modules/gdscript/gdscript_parser.cpp b/modules/gdscript/gdscript_parser.cpp
index bff608e56b..5facfe7869 100644
--- a/modules/gdscript/gdscript_parser.cpp
+++ b/modules/gdscript/gdscript_parser.cpp
@@ -5219,6 +5219,8 @@ String GDScriptParser::DataType::to_string() const {
 			}
 			return class_type->name.operator String();
 		} break;
+		case UNRESOLVED: {
+		} break;
 	}
 
 	return "Unresolved";
@@ -5791,7 +5793,10 @@ bool GDScriptParser::_is_type_compatible(const DataType &p_container, const Data
 				expr_native = base->base_type.native_type;
 				expr_script = base->base_type.script_type;
 			}
-		}
+		} break;
+		case DataType::BUILTIN: // Already handled above
+		case DataType::UNRESOLVED: // Not allowed, see above
+			break;
 	}
 
 	switch (p_container.kind) {
@@ -5834,7 +5839,10 @@ bool GDScriptParser::_is_type_compatible(const DataType &p_container, const Data
 				expr_class = expr_class->base_type.class_type;
 			}
 			return false;
-		}
+		} break;
+		case DataType::BUILTIN: // Already handled above
+		case DataType::UNRESOLVED: // Not allowed, see above
+			break;
 	}
 
 	return false;
@@ -6228,6 +6236,7 @@ GDScriptParser::DataType GDScriptParser::_reduce_node_type(Node *p_node) {
 									case Variant::COLOR: {
 										error = index_type.builtin_type != Variant::INT && index_type.builtin_type != Variant::STRING;
 									} break;
+									default: {}
 								}
 							}
 							if (error) {
@@ -6345,6 +6354,7 @@ GDScriptParser::DataType GDScriptParser::_reduce_node_type(Node *p_node) {
 				}
 			}
 		} break;
+		default: {}
 	}
 
 	p_node->set_datatype(_resolve_type(node_type, p_node->line));
diff --git a/modules/gdscript/gdscript_parser.h b/modules/gdscript/gdscript_parser.h
index cd68072499..c7813a2144 100644
--- a/modules/gdscript/gdscript_parser.h
+++ b/modules/gdscript/gdscript_parser.h
@@ -88,6 +88,8 @@ public:
 				case CLASS: {
 					return class_type == other.class_type;
 				} break;
+				case UNRESOLVED: {
+				} break;
 			}
 			return false;
 		}