Improve detection of variable writing in shader, fixes #15177

2 files changed, 31 insertions, 33 deletions

diff --git a/drivers/gles3/shader_compiler_gles3.cpp b/drivers/gles3/shader_compiler_gles3.cpp
index ac43b3ce1b..875946f089 100644
--- a/drivers/gles3/shader_compiler_gles3.cpp
+++ b/drivers/gles3/shader_compiler_gles3.cpp
@@ -267,7 +267,7 @@ void ShaderCompilerGLES3::_dump_function_deps(SL::ShaderNode *p_node, const Stri
 	}
 }
 
-String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, GeneratedCode &r_gen_code, IdentifierActions &p_actions, const DefaultIdentifierActions &p_default_actions) {
+String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, GeneratedCode &r_gen_code, IdentifierActions &p_actions, const DefaultIdentifierActions &p_default_actions, bool p_assigning) {
 
 	String code;
 
@@ -407,7 +407,7 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 			//code for functions
 			for (int i = 0; i < pnode->functions.size(); i++) {
 				SL::FunctionNode *fnode = pnode->functions[i].function;
-				function_code[fnode->name] = _dump_node_code(fnode->body, p_level + 1, r_gen_code, p_actions, p_default_actions);
+				function_code[fnode->name] = _dump_node_code(fnode->body, p_level + 1, r_gen_code, p_actions, p_default_actions, p_assigning);
 			}
 
 			//place functions in actual code
@@ -455,7 +455,7 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 
 			for (int i = 0; i < bnode->statements.size(); i++) {
 
-				String scode = _dump_node_code(bnode->statements[i], p_level, r_gen_code, p_actions, p_default_actions);
+				String scode = _dump_node_code(bnode->statements[i], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 
 				if (bnode->statements[i]->type == SL::Node::TYPE_CONTROL_FLOW || bnode->single_statement) {
 					code += scode; //use directly
@@ -481,7 +481,7 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 				declaration += _mkid(vdnode->declarations[i].name);
 				if (vdnode->declarations[i].initializer) {
 					declaration += "=";
-					declaration += _dump_node_code(vdnode->declarations[i].initializer, p_level, r_gen_code, p_actions, p_default_actions);
+					declaration += _dump_node_code(vdnode->declarations[i].initializer, p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 				}
 			}
 
@@ -490,6 +490,10 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 		case SL::Node::TYPE_VARIABLE: {
 			SL::VariableNode *vnode = (SL::VariableNode *)p_node;
 
+			if (p_assigning && p_actions.write_flag_pointers.has(vnode->name)) {
+				*p_actions.write_flag_pointers[vnode->name] = true;
+			}
+
 			if (p_default_actions.usage_defines.has(vnode->name) && !used_name_defines.has(vnode->name)) {
 				String define = p_default_actions.usage_defines[vnode->name];
 				if (define.begins_with("@")) {
@@ -540,24 +544,18 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 				case SL::OP_ASSIGN_BIT_AND:
 				case SL::OP_ASSIGN_BIT_OR:
 				case SL::OP_ASSIGN_BIT_XOR:
-					if (onode->arguments[0]->type == SL::Node::TYPE_VARIABLE) {
-						SL::VariableNode *vnode = (SL::VariableNode *)onode->arguments[0];
-						if (p_actions.write_flag_pointers.has(vnode->name)) {
-							*p_actions.write_flag_pointers[vnode->name] = true;
-						}
-					}
-					code = _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions) + _opstr(onode->op) + _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions);
+					code = _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, true) + _opstr(onode->op) + _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					break;
 				case SL::OP_BIT_INVERT:
 				case SL::OP_NEGATE:
 				case SL::OP_NOT:
 				case SL::OP_DECREMENT:
 				case SL::OP_INCREMENT:
-					code = _opstr(onode->op) + _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions);
+					code = _opstr(onode->op) + _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					break;
 				case SL::OP_POST_DECREMENT:
 				case SL::OP_POST_INCREMENT:
-					code = _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions) + _opstr(onode->op);
+					code = _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + _opstr(onode->op);
 					break;
 				case SL::OP_CALL:
 				case SL::OP_CONSTRUCT: {
@@ -584,31 +582,31 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 					for (int i = 1; i < onode->arguments.size(); i++) {
 						if (i > 1)
 							code += ", ";
-						code += _dump_node_code(onode->arguments[i], p_level, r_gen_code, p_actions, p_default_actions);
+						code += _dump_node_code(onode->arguments[i], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					}
 					code += ")";
 				} break;
 				case SL::OP_INDEX: {
 
-					code += _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					code += "[";
-					code += _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					code += "]";
 
 				} break;
 				case SL::OP_SELECT_IF: {
 
-					code += _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					code += "?";
-					code += _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 					code += ":";
-					code += _dump_node_code(onode->arguments[2], p_level, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(onode->arguments[2], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 
 				} break;
 
 				default: {
 
-					code = "(" + _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions) + _opstr(onode->op) + _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions) + ")";
+					code = "(" + _dump_node_code(onode->arguments[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + _opstr(onode->op) + _dump_node_code(onode->arguments[1], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + ")";
 					break;
 				}
 			}
@@ -618,29 +616,29 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 			SL::ControlFlowNode *cfnode = (SL::ControlFlowNode *)p_node;
 			if (cfnode->flow_op == SL::FLOW_OP_IF) {
 
-				code += _mktab(p_level) + "if (" + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions) + ")\n";
-				code += _dump_node_code(cfnode->blocks[0], p_level + 1, r_gen_code, p_actions, p_default_actions);
+				code += _mktab(p_level) + "if (" + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + ")\n";
+				code += _dump_node_code(cfnode->blocks[0], p_level + 1, r_gen_code, p_actions, p_default_actions, p_assigning);
 				if (cfnode->blocks.size() == 2) {
 
 					code += _mktab(p_level) + "else\n";
-					code += _dump_node_code(cfnode->blocks[1], p_level + 1, r_gen_code, p_actions, p_default_actions);
+					code += _dump_node_code(cfnode->blocks[1], p_level + 1, r_gen_code, p_actions, p_default_actions, p_assigning);
 				}
 			} else if (cfnode->flow_op == SL::FLOW_OP_WHILE) {
 
-				code += _mktab(p_level) + "while (" + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions) + ")\n";
-				code += _dump_node_code(cfnode->blocks[0], p_level + 1, r_gen_code, p_actions, p_default_actions);
+				code += _mktab(p_level) + "while (" + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + ")\n";
+				code += _dump_node_code(cfnode->blocks[0], p_level + 1, r_gen_code, p_actions, p_default_actions, p_assigning);
 			} else if (cfnode->flow_op == SL::FLOW_OP_FOR) {
 
-				String left = _dump_node_code(cfnode->blocks[0], p_level, r_gen_code, p_actions, p_default_actions);
-				String middle = _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions);
-				String right = _dump_node_code(cfnode->expressions[1], p_level, r_gen_code, p_actions, p_default_actions);
+				String left = _dump_node_code(cfnode->blocks[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
+				String middle = _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
+				String right = _dump_node_code(cfnode->expressions[1], p_level, r_gen_code, p_actions, p_default_actions, p_assigning);
 				code += _mktab(p_level) + "for (" + left + ";" + middle + ";" + right + ")\n";
-				code += _dump_node_code(cfnode->blocks[1], p_level + 1, r_gen_code, p_actions, p_default_actions);
+				code += _dump_node_code(cfnode->blocks[1], p_level + 1, r_gen_code, p_actions, p_default_actions, p_assigning);
 
 			} else if (cfnode->flow_op == SL::FLOW_OP_RETURN) {
 
 				if (cfnode->expressions.size()) {
-					code = "return " + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions) + ";";
+					code = "return " + _dump_node_code(cfnode->expressions[0], p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + ";";
 				} else {
 					code = "return;";
 				}
@@ -658,7 +656,7 @@ String ShaderCompilerGLES3::_dump_node_code(SL::Node *p_node, int p_level, Gener
 		} break;
 		case SL::Node::TYPE_MEMBER: {
 			SL::MemberNode *mnode = (SL::MemberNode *)p_node;
-			code = _dump_node_code(mnode->owner, p_level, r_gen_code, p_actions, p_default_actions) + "." + mnode->name;
+			code = _dump_node_code(mnode->owner, p_level, r_gen_code, p_actions, p_default_actions, p_assigning) + "." + mnode->name;
 
 		} break;
 	}
@@ -694,7 +692,7 @@ Error ShaderCompilerGLES3::compile(VS::ShaderMode p_mode, const String &p_code,
 	used_rmode_defines.clear();
 	used_flag_pointers.clear();
 
-	_dump_node_code(parser.get_shader(), 1, r_gen_code, *p_actions, actions[p_mode]);
+	_dump_node_code(parser.get_shader(), 1, r_gen_code, *p_actions, actions[p_mode], false);
 
 	if (r_gen_code.uniform_total_size) { //uniforms used?
 		int md = sizeof(float) * 4;
diff --git a/drivers/gles3/shader_compiler_gles3.h b/drivers/gles3/shader_compiler_gles3.h
index 44141c09f1..85e8e02b8e 100644
--- a/drivers/gles3/shader_compiler_gles3.h
+++ b/drivers/gles3/shader_compiler_gles3.h
@@ -78,7 +78,7 @@ private:
 	};
 
 	void _dump_function_deps(ShaderLanguage::ShaderNode *p_node, const StringName &p_for_func, const Map<StringName, String> &p_func_code, String &r_to_add, Set<StringName> &added);
-	String _dump_node_code(ShaderLanguage::Node *p_node, int p_level, GeneratedCode &r_gen_code, IdentifierActions &p_actions, const DefaultIdentifierActions &p_default_actions);
+	String _dump_node_code(ShaderLanguage::Node *p_node, int p_level, GeneratedCode &r_gen_code, IdentifierActions &p_actions, const DefaultIdentifierActions &p_default_actions, bool p_assigning);
 
 	StringName current_func_name;
 	StringName vertex_name;