Fix #1888

src/check_expr.cpp

@@ -8643,6 +8643,8 @@ ExprKind check_selector_call_expr(CheckerContext *c, Operand *o, Ast *node, Type
 	Ast *first_arg = x.expr->SelectorExpr.expr;
 	GB_ASSERT(first_arg != nullptr);
 
+	first_arg->state_flags |= StateFlag_SelectorCallExpr;
+
 	Type *pt = base_type(x.type);
 	GB_ASSERT(pt->kind == Type_Proc);
 	Type *first_type = nullptr;
@@ -8668,6 +8670,7 @@ ExprKind check_selector_call_expr(CheckerContext *c, Operand *o, Ast *node, Type
 	y.mode = first_arg->tav.mode;
 	y.type = first_arg->tav.type;
 	y.value = first_arg->tav.value;
+
 	if (check_is_assignable_to(c, &y, first_type)) {
 		// Do nothing, it's valid
 	} else {
@@ -10034,9 +10037,10 @@ gbString write_expr_to_string(gbString str, Ast *node, bool shorthand) {
 		str = write_expr_to_string(str, ce->proc, shorthand);
 		str = gb_string_appendc(str, "(");
 
-		for_array(i, ce->args) {
+		isize idx0 = cast(isize)ce->was_selector;
+		for (isize i = idx0; i < ce->args.count; i++) {
 			Ast *arg = ce->args[i];
-			if (i > 0) {
+			if (i > idx0) {
 				str = gb_string_appendc(str, ", ");
 			}
 			str = write_expr_to_string(str, arg, shorthand);

src/llvm_backend.hpp

@@ -292,6 +292,8 @@ struct lbProcedure {
 	LLVMMetadataRef debug_info;
 
 	lbCopyElisionHint copy_elision_hint;
+
+	PtrMap<Ast *, lbValue> selector_values;
 };
 
 

src/llvm_backend_expr.cpp

@@ -2993,9 +2993,8 @@ lbValue lb_build_unary_and(lbProcedure *p, Ast *expr) {
 	return lb_build_addr_ptr(p, ue->expr);
 }
 
+lbValue lb_build_expr_internal(lbProcedure *p, Ast *expr);
 lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
-	lbModule *m = p->module;
-
 	u16 prev_state_flags = p->state_flags;
 	defer (p->state_flags = prev_state_flags);
 
@@ -3022,6 +3021,32 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 		p->state_flags = out;
 	}
 
+
+	// IMPORTANT NOTE(bill):
+	// Selector Call Expressions (foo->bar(...))
+	// must only evaluate `foo` once as it gets transformed into
+	// `foo.bar(foo, ...)`
+	// And if `foo` is a procedure call or something more complex, storing the value
+	// once is a very good idea
+	// If a stored value is found, it must be removed from the cache
+	if (expr->state_flags & StateFlag_SelectorCallExpr) {
+		lbValue *pp = map_get(&p->selector_values, expr);
+		if (pp != nullptr) {
+			lbValue res = *pp;
+			map_remove(&p->selector_values, expr);
+			return res;
+		}
+	}
+	lbValue res = lb_build_expr_internal(p, expr);
+	if (expr->state_flags & StateFlag_SelectorCallExpr) {
+		map_set(&p->selector_values, expr, res);
+	}
+	return res;
+}
+
+lbValue lb_build_expr_internal(lbProcedure *p, Ast *expr) {
+	lbModule *m = p->module;
+
 	expr = unparen_expr(expr);
 
 	TokenPos expr_pos = ast_token(expr).pos;
@@ -3119,14 +3144,7 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 
 	case_ast_node(se, SelectorCallExpr, expr);
 		GB_ASSERT(se->modified_call);
-		TypeAndValue tav = type_and_value_of_expr(expr);
-		GB_ASSERT(tav.mode != Addressing_Invalid);
-		lbValue res = lb_build_call_expr(p, se->call);
-
-		ast_node(ce, CallExpr, se->call);
-		ce->sce_temp_data = gb_alloc_copy(permanent_allocator(), &res, gb_size_of(res));
-
-		return res;
+		return lb_build_call_expr(p, se->call);
 	case_end;
 
 	case_ast_node(te, TernaryIfExpr, expr);

src/llvm_backend_proc.cpp

@@ -113,6 +113,7 @@ lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool ignore_body)
 	p->branch_blocks.allocator = a;
 	p->context_stack.allocator = a;
 	p->scope_stack.allocator   = a;
+	map_init(&p->selector_values, a);
 
 	if (p->is_foreign) {
 		lb_add_foreign_library_path(p->module, entity->Procedure.foreign_library);
@@ -2832,10 +2833,6 @@ lbValue lb_build_call_expr(lbProcedure *p, Ast *expr) {
 	expr = unparen_expr(expr);
 	ast_node(ce, CallExpr, expr);
 
-	if (ce->sce_temp_data) {
-		return *(lbValue *)ce->sce_temp_data;
-	}
-
 	lbValue res = lb_build_call_expr_internal(p, expr);
 
 	if (ce->optional_ok_one) { // TODO(bill): Minor hack for #optional_ok procedures

src/parser.cpp

@@ -164,6 +164,7 @@ Ast *clone_ast(Ast *node) {
 	case Ast_SelectorCallExpr:
 		n->SelectorCallExpr.expr = clone_ast(n->SelectorCallExpr.expr);
 		n->SelectorCallExpr.call = clone_ast(n->SelectorCallExpr.call);
+		GB_ASSERT(n->SelectorCallExpr.modified_call);
 		break;
 	case Ast_IndexExpr:
 		n->IndexExpr.expr  = clone_ast(n->IndexExpr.expr);

src/parser.hpp

@@ -282,6 +282,8 @@ enum StateFlag : u8 {
 	StateFlag_type_assert     = 1<<2,
 	StateFlag_no_type_assert  = 1<<3,
 
+	StateFlag_SelectorCallExpr = 1<<6,
+
 	StateFlag_BeenHandled = 1<<7,
 };
 
@@ -411,7 +413,7 @@ AST_KIND(_ExprBegin,  "",  bool) \
 		Token        ellipsis; \
 		ProcInlining inlining; \
 		bool         optional_ok_one; \
-		void *sce_temp_data; \
+		bool         was_selector; \
 	}) \
 	AST_KIND(FieldValue,      "field value",              struct { Token eq; Ast *field, *value; }) \
 	AST_KIND(EnumFieldValue,  "enum field value",         struct { \