From 92b476bf042eebcec9362a673005b9e3b2e90fdd Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Wed, 15 Jan 2025 18:26:44 +0900
Subject: [PATCH] [qfcc] Make type attribute functions usable in expressions

Unfortunately, this require using different syntax for the two cases:
type.attr works in cases where types are expected, but not in
expressions (lots of shift/reduce and reduce/reduce conflicts). However,
treating type like an Objective-C class works nicely, though
`[type attrib(params)]` looks a little odd. However, this allows using
generic types to provide function calls (eg, converting texture
coordinates).
---
 tools/qfcc/include/attribute.h |  1 +
 tools/qfcc/source/attribute.c  | 17 +++++++++++------
 tools/qfcc/source/dot_expr.c   |  7 +++++--
 tools/qfcc/source/qc-parse.y   | 11 ++++++++++-
 4 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/tools/qfcc/include/attribute.h b/tools/qfcc/include/attribute.h
index a5ffaa2a9..022b8be24 100644
--- a/tools/qfcc/include/attribute.h
+++ b/tools/qfcc/include/attribute.h
@@ -38,6 +38,7 @@ typedef struct attribute_s {
 } attribute_t;
 
 struct expr_s;
+attribute_t *new_attrfunc(const char *name, const struct expr_s *params);
 attribute_t *new_attribute(const char *name, const struct expr_s *params);
 
 #endif//attribute_h
diff --git a/tools/qfcc/source/attribute.c b/tools/qfcc/source/attribute.c
index a22c72d87..247b41a48 100644
--- a/tools/qfcc/source/attribute.c
+++ b/tools/qfcc/source/attribute.c
@@ -40,6 +40,16 @@
 
 ALLOC_STATE (attribute_t, attributes);
 
+attribute_t *
+new_attrfunc (const char *name, const expr_t *params)
+{
+	attribute_t *attr;
+	ALLOC (16384, attribute_t, attributes, attr);
+	attr->name = save_string (name);
+	attr->params = params;
+	return attr;
+}
+
 attribute_t *
 new_attribute(const char *name, const expr_t *params)
 {
@@ -68,10 +78,5 @@ new_attribute(const char *name, const expr_t *params)
 	if (err) {
 		return nullptr;
 	}
-
-	attribute_t *attr;
-	ALLOC (16384, attribute_t, attributes, attr);
-	attr->name = save_string (name);
-	attr->params = params;
-	return attr;
+	return new_attrfunc (name, params);
 }
diff --git a/tools/qfcc/source/dot_expr.c b/tools/qfcc/source/dot_expr.c
index 79defeaf1..65356748d 100644
--- a/tools/qfcc/source/dot_expr.c
+++ b/tools/qfcc/source/dot_expr.c
@@ -351,8 +351,11 @@ print_type_expr (dstring_t *dstr, const expr_t *e, int level, int id,
 		}
 	} else if (e->typ.attrib) {
 		auto attrib = e->typ.attrib;
-		_print_expr (dstr, attrib->params, level + 1, id, nullptr);
-		dasprintf (dstr, "%*se_%p -> e_%p;\n", indent, "", e, attrib->params);
+		if (attrib->params) {
+			_print_expr (dstr, attrib->params, level + 1, id, nullptr);
+			dasprintf (dstr, "%*se_%p -> e_%p;\n", indent, "", e,
+					   attrib->params);
+		}
 		str = attrib->name;
 	} else if (e->typ.sym) {
 	   str = e->typ.sym->name;
diff --git a/tools/qfcc/source/qc-parse.y b/tools/qfcc/source/qc-parse.y
index f48735309..a36e0f6c1 100644
--- a/tools/qfcc/source/qc-parse.y
+++ b/tools/qfcc/source/qc-parse.y
@@ -189,7 +189,7 @@ int yylex (YYSTYPE *yylval, YYLTYPE *yylloc);
 %type	<expr>		initdecl notype_initdecl
 %type	<mut_expr>	initdecls notype_initdecls
 
-%type	<attribute>	attribute_list attribute
+%type	<attribute>	attribute_list attribute attrfunc
 
 %type	<param>		function_params
 %type   <param>		qc_func_params qc_param_list qc_first_param qc_param
@@ -1392,6 +1392,11 @@ attribute
 	| NAME '(' expr_list ')'	{ $$ = new_attribute ($1->name, $3); }
 	;
 
+attrfunc
+	: NAME %prec LOW			{ $$ = new_attrfunc ($1->name, 0); }
+	| NAME '(' expr_list ')'	{ $$ = new_attrfunc ($1->name, $3); }
+	;
+
 tag : NAME ;
 
 algebra_specifier
@@ -2839,6 +2844,10 @@ obj_messageexpr
 			scoped_src_loc ($receiver);
 			$$ = new_message_expr ($receiver, $messageargs);
 		}
+	| '[' TYPE_NAME[spec] attrfunc ']'
+		{
+			$$ = type_attribute ($spec, $attrfunc);
+		}
 	;
 
 receiver