[qfcc] Remove union hack for block expressions

I don't remember why I thought it was a good idea at the time, but I
decided that having the union was a bit iffy and making the list
"official" would be a good idea. In the end, it removed a nice chunk of
code (redundant list manipulations).

tools/qfcc/include/expr.h

@@ -112,15 +112,11 @@ typedef struct ex_list_s {
 	ex_listitem_t **tail;
 } ex_list_t;
 
-typedef union {
+typedef struct {
 	ex_list_t   list;
-	struct {
+	const expr_t *result;		///< the result of this block if non-void
-		ex_listitem_t *head;
+	int         is_call;		///< this block exprssion forms a function call
-		ex_listitem_t **tail;
+	void       *return_addr;	///< who allocated this
-		const expr_t *result;	///< the result of this block if non-void
-		int         is_call;	///< this block exprssion forms a function call
-		void       *return_addr;///< who allocated this
-	};
 } ex_block_t;
 
 typedef struct {

tools/qfcc/source/expr.c

@@ -549,17 +549,11 @@ new_block_expr (const expr_t *old)
 	expr_t     *b = new_expr ();
 
 	b->type = ex_block;
-	b->block.head = 0;
-	b->block.tail = &b->block.head;
 	if (old) {
 		if (old->type != ex_block) {
 			internal_error (old, "not a block expression");
 		}
-		if ((b->block.head = old->block.head)) {
+		b->block = old->block;
-			b->block.tail = old->block.tail;
-		}
-		b->block.result = old->block.result;
-		b->block.is_call = old->block.is_call;
 	}
 	b->block.return_addr = __builtin_return_address (0);
 	return b;
@@ -593,10 +587,9 @@ build_block_expr (expr_t *list, bool set_result)
 	}
 	expr_t     *b = new_block_expr (0);
 
-	b->block.head = list->list.head;
+	b->block.list = list->list;
-	b->block.tail = list->list.tail;
+	if (set_result && b->block.list.tail != &b->block.list.head) {
-	if (set_result && b->block.tail != &b->block.head) {
+		auto last = (ex_listitem_t *) b->block.list.tail;
-		auto last = (ex_listitem_t *) b->block.tail;
 		b->block.result = last->expr;
 	}
 	return b;
@@ -1606,9 +1599,7 @@ append_expr (expr_t *block, const expr_t *e)
 	if (!e || e->type == ex_error)
 		return block;
 
-	auto li = new_listitem (e);
+	list_append (&block->block.list, e);
-	*block->block.tail = li;
-	block->block.tail = &li->next;
 
 	return block;
 }
@@ -1622,13 +1613,7 @@ prepend_expr (expr_t *block, const expr_t *e)
 	if (!e || e->type == ex_error)
 		return block;
 
-	auto li = new_listitem (e);
+	list_prepend (&block->block.list, e);
-	li->next = block->block.head;
-	block->block.head = li;
-
-	if (block->block.tail == &block->block.head) {
-		block->block.tail = &li->next;
-	}
 
 	return block;
 }
@@ -1887,7 +1872,7 @@ has_function_call (const expr_t *e)
 			if (e->block.is_call)
 				return 1;
 		case ex_list:
-			for (auto li = e->block.head; li; li = li->next)
+			for (auto li = e->block.list.head; li; li = li->next)
 				if (has_function_call (li->expr))
 					return 1;
 			return 0;

tools/qfcc/source/expr_bool.c

@@ -308,8 +308,8 @@ convert_bool (const expr_t *e, int block)
 			auto b = new_block_expr (0);
 			append_expr (b, branch_expr (QC_NE, e, 0));
 			append_expr (b, goto_expr (0));
-			e = new_bool_expr (make_list (b->block.head->expr),
+			e = new_bool_expr (make_list (b->block.list.head->expr),
-							   make_list (b->block.head->next->expr), b);
+							   make_list (b->block.list.head->next->expr), b);
 		}
 	}
 	if (block && e->boolean.e->type != ex_block) {

tools/qfcc/source/qc-parse.y

@@ -2160,7 +2160,7 @@ identifier_list
 classdecl
 	: CLASS identifier_list ';'
 		{
-			for (auto li = $2->block.head; li; li = li->next) {
+			for (auto li = $2->block.list.head; li; li = li->next) {
 				auto e = li->expr;
 				get_class (e->symbol, 1);
 				if (!e->symbol->table)

tools/qfcc/source/statements.c

@@ -2274,7 +2274,7 @@ build_bool_block (expr_t *block, expr_t *e)
 			break;
 		case ex_block:
 			if (!e->block.result) {
-				for (auto t = e->block.head; t; t = t->next) {
+				for (auto t = e->block.list.head; t; t = t->next) {
 					build_bool_block (block, (expr_t *) t->expr);
 				}
 				return;