From e034d5f764ccd9a3d7b60414240dcc9a695d3ef7 Mon Sep 17 00:00:00 2001
From: Yuri Rubinsky <chaosus89@gmail.com>
Date: Wed, 1 Feb 2023 09:04:10 +0300
Subject: [PATCH] Fix shader failure when using non-const initializer on a
 constant

---
 servers/rendering/shader_language.cpp | 24 +++++++++++++++++++++++-
 servers/rendering/shader_language.h   |  2 +-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/servers/rendering/shader_language.cpp b/servers/rendering/shader_language.cpp
index 11a9303f119..a187057859f 100644
--- a/servers/rendering/shader_language.cpp
+++ b/servers/rendering/shader_language.cpp
@@ -1225,7 +1225,7 @@ void ShaderLanguage::clear() {
 	char_idx = 0;
 	error_set = false;
 	error_str = "";
-	last_const = false;
+	is_const_decl = false;
 	while (nodes) {
 		Node *n = nodes;
 		nodes = nodes->next;
@@ -3561,6 +3561,14 @@ bool ShaderLanguage::_parse_function_arguments(BlockNode *p_block, const Functio
 			return false;
 		}
 
+		if (is_const_decl && arg->type == Node::TYPE_VARIABLE) {
+			const VariableNode *var = static_cast<const VariableNode *>(arg);
+			if (!var->is_const) {
+				_set_error(RTR("Expected constant expression."));
+				return false;
+			}
+		}
+
 		p_func->arguments.push_back(arg);
 
 		tk = _get_token();
@@ -5184,6 +5192,12 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 					expr = func;
 
 				} else { //a function call
+					if (p_block == nullptr) { // Non-constructor function call in global space is forbidden.
+						if (is_const_decl) {
+							_set_error(RTR("Expected constant expression."));
+						}
+						return nullptr;
+					}
 
 					const StringName &name = identifier;
 
@@ -5460,6 +5474,10 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 						_set_error(vformat(RTR("Unknown identifier in expression: '%s'."), String(identifier)));
 						return nullptr;
 					}
+					if (is_const_decl && !is_const) {
+						_set_error(RTR("Expected constant expression."));
+						return nullptr;
+					}
 					if (ident_type == IDENTIFIER_VARYING) {
 						TkPos prev_pos = _get_tkpos();
 						Token next_token = _get_token();
@@ -6977,6 +6995,7 @@ Error ShaderLanguage::_parse_block(BlockNode *p_block, const FunctionInfo &p_fun
 					}
 				}
 #endif // DEBUG_ENABLED
+				is_const_decl = is_const;
 
 				BlockNode::Variable var;
 				var.type = type;
@@ -7233,6 +7252,7 @@ Error ShaderLanguage::_parse_block(BlockNode *p_block, const FunctionInfo &p_fun
 
 				vdnode->declarations.push_back(decl);
 				p_block->variables[name] = var;
+				is_const_decl = false;
 
 				if (!fixed_array_size) {
 					array_size = 0;
@@ -9101,6 +9121,7 @@ Error ShaderLanguage::_parse_shader(const HashMap<StringName, FunctionInfo> &p_f
 						constant.precision = precision;
 						constant.initializer = nullptr;
 						constant.array_size = array_size;
+						is_const_decl = true;
 
 						if (tk.type == TK_BRACKET_OPEN) {
 							Error error = _parse_array_size(nullptr, constants, false, nullptr, &constant.array_size, &unknown_size);
@@ -9360,6 +9381,7 @@ Error ShaderLanguage::_parse_shader(const HashMap<StringName, FunctionInfo> &p_f
 							unknown_size = false;
 
 						} else if (tk.type == TK_SEMICOLON) {
+							is_const_decl = false;
 							break;
 						} else {
 							_set_expected_error(",", ";");
diff --git a/servers/rendering/shader_language.h b/servers/rendering/shader_language.h
index 32e497aa46c..aea61e42c31 100644
--- a/servers/rendering/shader_language.h
+++ b/servers/rendering/shader_language.h
@@ -953,7 +953,7 @@ private:
 
 	StringName shader_type_identifier;
 	StringName current_function;
-	bool last_const = false;
+	bool is_const_decl = false;
 	StringName last_name;
 	bool is_shader_inc = false;