Merge pull request #49996 from Chaosus/shader_localvar_warning

Added a shader warning about unused local variable

4 files changed, 56 insertions, 4 deletions

diff --git a/servers/rendering/shader_language.cpp b/servers/rendering/shader_language.cpp
index 9b2ba36358..f771d6d0ef 100644
--- a/servers/rendering/shader_language.cpp
+++ b/servers/rendering/shader_language.cpp
@@ -918,6 +918,7 @@ void ShaderLanguage::clear() {
 	used_uniforms.clear();
 	used_functions.clear();
 	used_structs.clear();
+	used_local_vars.clear();
 	warnings.clear();
 #endif // DEBUG_ENABLED
 
@@ -936,7 +937,7 @@ void ShaderLanguage::clear() {
 }
 
 #ifdef DEBUG_ENABLED
-void ShaderLanguage::_parse_used_identifier(const StringName &p_identifier, IdentifierType p_type) {
+void ShaderLanguage::_parse_used_identifier(const StringName &p_identifier, IdentifierType p_type, const StringName &p_function) {
 	switch (p_type) {
 		case IdentifierType::IDENTIFIER_CONSTANT:
 			if (HAS_WARNING(ShaderWarning::UNUSED_CONSTANT_FLAG) && used_constants.has(p_identifier)) {
@@ -958,6 +959,11 @@ void ShaderLanguage::_parse_used_identifier(const StringName &p_identifier, Iden
 				used_functions[p_identifier].used = true;
 			}
 			break;
+		case IdentifierType::IDENTIFIER_LOCAL_VAR:
+			if (HAS_WARNING(ShaderWarning::UNUSED_LOCAL_VARIABLE_FLAG) && used_local_vars.has(p_function) && used_local_vars[p_function].has(p_identifier)) {
+				used_local_vars[p_function][p_identifier].used = true;
+			}
+			break;
 		default:
 			break;
 	}
@@ -4171,7 +4177,13 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 					expr = func;
 #ifdef DEBUG_ENABLED
 					if (check_warnings) {
-						_parse_used_identifier(name, IdentifierType::IDENTIFIER_FUNCTION);
+						StringName func_name;
+
+						if (p_block && p_block->parent_function) {
+							func_name = p_block->parent_function->name;
+						}
+
+						_parse_used_identifier(name, IdentifierType::IDENTIFIER_FUNCTION, func_name);
 					}
 #endif // DEBUG_ENABLED
 				}
@@ -4319,7 +4331,13 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 				}
 #ifdef DEBUG_ENABLED
 				if (check_warnings) {
-					_parse_used_identifier(identifier, ident_type);
+					StringName func_name;
+
+					if (p_block && p_block->parent_function) {
+						func_name = p_block->parent_function->name;
+					}
+
+					_parse_used_identifier(identifier, ident_type, func_name);
 				}
 #endif // DEBUG_ENABLED
 			}
@@ -5537,6 +5555,20 @@ Error ShaderLanguage::_parse_block(BlockNode *p_block, const FunctionInfo &p_fun
 					}
 				}
 
+#ifdef DEBUG_ENABLED
+				if (check_warnings && HAS_WARNING(ShaderWarning::UNUSED_LOCAL_VARIABLE_FLAG)) {
+					if (p_block && p_block->parent_function) {
+						StringName func_name = p_block->parent_function->name;
+
+						if (!used_local_vars.has(func_name)) {
+							used_local_vars.insert(func_name, Map<StringName, Usage>());
+						}
+
+						used_local_vars[func_name].insert(name, Usage(tk_line));
+					}
+				}
+#endif // DEBUG_ENABLED
+
 				BlockNode::Variable var;
 				var.type = type;
 				var.precision = precision;
@@ -7984,6 +8016,15 @@ String ShaderLanguage::get_shader_type(const String &p_code) {
 
 #ifdef DEBUG_ENABLED
 void ShaderLanguage::_check_warning_accums() {
+	for (Map<ShaderWarning::Code, Map<StringName, Map<StringName, Usage>> *>::Element *E = warnings_check_map2.front(); E; E = E->next()) {
+		for (Map<StringName, Map<StringName, Usage>>::Element *T = (*E->get()).front(); T; T = T->next()) {
+			for (const Map<StringName, Usage>::Element *U = T->get().front(); U; U = U->next()) {
+				if (!U->get().used) {
+					_add_warning(E->key(), U->get().decl_line, U->key());
+				}
+			}
+		}
+	}
 	for (Map<ShaderWarning::Code, Map<StringName, Usage> *>::Element *E = warnings_check_map.front(); E; E = E->next()) {
 		for (const Map<StringName, Usage>::Element *U = (*E->get()).front(); U; U = U->next()) {
 			if (!U->get().used) {
@@ -8456,6 +8497,8 @@ ShaderLanguage::ShaderLanguage() {
 	warnings_check_map.insert(ShaderWarning::UNUSED_STRUCT, &used_structs);
 	warnings_check_map.insert(ShaderWarning::UNUSED_UNIFORM, &used_uniforms);
 	warnings_check_map.insert(ShaderWarning::UNUSED_VARYING, &used_varyings);
+
+	warnings_check_map2.insert(ShaderWarning::UNUSED_LOCAL_VARIABLE, &used_local_vars);
 #endif // DEBUG_ENABLED
 }
 
diff --git a/servers/rendering/shader_language.h b/servers/rendering/shader_language.h
index 4120e04ee1..a91fa57a8e 100644
--- a/servers/rendering/shader_language.h
+++ b/servers/rendering/shader_language.h
@@ -848,6 +848,9 @@ private:
 	Map<StringName, Usage> used_structs;
 	Map<ShaderWarning::Code, Map<StringName, Usage> *> warnings_check_map;
 
+	Map<StringName, Map<StringName, Usage>> used_local_vars;
+	Map<ShaderWarning::Code, Map<StringName, Map<StringName, Usage>> *> warnings_check_map2;
+
 	List<ShaderWarning> warnings;
 
 	bool check_warnings = false;
@@ -917,7 +920,7 @@ private:
 
 	bool _find_identifier(const BlockNode *p_block, bool p_allow_reassign, const FunctionInfo &p_function_info, const StringName &p_identifier, DataType *r_data_type = nullptr, IdentifierType *r_type = nullptr, bool *r_is_const = nullptr, int *r_array_size = nullptr, StringName *r_struct_name = nullptr, ConstantNode::Value *r_constant_value = nullptr);
 #ifdef DEBUG_ENABLED
-	void _parse_used_identifier(const StringName &p_identifier, IdentifierType p_type);
+	void _parse_used_identifier(const StringName &p_identifier, IdentifierType p_type, const StringName &p_function);
 #endif // DEBUG_ENABLED
 	bool _is_operator_assign(Operator p_op) const;
 	bool _validate_assign(Node *p_node, const FunctionInfo &p_function_info, String *r_message = nullptr);
diff --git a/servers/rendering/shader_warnings.cpp b/servers/rendering/shader_warnings.cpp
index aa11b4e397..0c1d6408c9 100644
--- a/servers/rendering/shader_warnings.cpp
+++ b/servers/rendering/shader_warnings.cpp
@@ -59,6 +59,8 @@ String ShaderWarning::get_message() const {
 			return vformat("The uniform '%s' is declared but never used.", subject);
 		case UNUSED_VARYING:
 			return vformat("The varying '%s' is declared but never used.", subject);
+		case UNUSED_LOCAL_VARIABLE:
+			return vformat("The local variable '%s' is declared but never used.", subject);
 		default:
 			break;
 	}
@@ -79,6 +81,7 @@ String ShaderWarning::get_name_from_code(Code p_code) {
 		"UNUSED_STRUCT",
 		"UNUSED_UNIFORM",
 		"UNUSED_VARYING",
+		"UNUSED_LOCAL_VARIABLE",
 	};
 
 	static_assert((sizeof(names) / sizeof(*names)) == WARNING_MAX, "Amount of warning types don't match the amount of warning names.");
@@ -106,6 +109,7 @@ static void init_code_to_flags_map() {
 	code_to_flags_map->insert(ShaderWarning::UNUSED_STRUCT, ShaderWarning::UNUSED_STRUCT_FLAG);
 	code_to_flags_map->insert(ShaderWarning::UNUSED_UNIFORM, ShaderWarning::UNUSED_UNIFORM_FLAG);
 	code_to_flags_map->insert(ShaderWarning::UNUSED_VARYING, ShaderWarning::UNUSED_VARYING_FLAG);
+	code_to_flags_map->insert(ShaderWarning::UNUSED_LOCAL_VARIABLE, ShaderWarning::UNUSED_LOCAL_VARIABLE_FLAG);
 }
 
 ShaderWarning::CodeFlags ShaderWarning::get_flags_from_codemap(const Map<Code, bool> &p_map) {
diff --git a/servers/rendering/shader_warnings.h b/servers/rendering/shader_warnings.h
index c40aeefa2d..db872d8fb1 100644
--- a/servers/rendering/shader_warnings.h
+++ b/servers/rendering/shader_warnings.h
@@ -46,6 +46,7 @@ public:
 		UNUSED_STRUCT,
 		UNUSED_UNIFORM,
 		UNUSED_VARYING,
+		UNUSED_LOCAL_VARIABLE,
 		WARNING_MAX,
 	};
 
@@ -57,6 +58,7 @@ public:
 		UNUSED_STRUCT_FLAG = 8U,
 		UNUSED_UNIFORM_FLAG = 16U,
 		UNUSED_VARYING_FLAG = 32U,
+		UNUSED_LOCAL_VARIABLE_FLAG = 64U,
 	};
 
 private: