comptime: fix T.indirections comparison (fix #24630) (#24636)

cmd/tools/vvet/vvet.v

@@ -404,8 +404,8 @@ fn (mut vt Vet) const_decl(stmt ast.ConstDecl) {
 fn (mut vt Vet) vet_empty_str(expr ast.InfixExpr) {
 	if expr.left is ast.SelectorExpr && expr.right is ast.IntegerLiteral {
 		operand := (expr.left as ast.SelectorExpr) // TODO: remove as-casts when multiple conds can be smart-casted.
-		if operand.expr is ast.Ident && operand.expr.info.typ == ast.string_type_idx
+		if operand.expr is ast.Ident && operand.field_name == 'len'
-			&& operand.field_name == 'len' {
+			&& operand.expr.info.typ == ast.string_type_idx {
 			if expr.op != .lt && expr.right.val == '0' {
 				// Case: `var.len > 0`, `var.len == 0`, `var.len != 0`
 				op := if expr.op == .gt { '!=' } else { expr.op.str() }

vlib/v/checker/comptime.v

@@ -846,10 +846,14 @@ fn (mut c Checker) comptime_if_cond(mut cond ast.Expr, pos token.Pos) ComptimeBr
 					}
 				}
 				.eq, .ne {
-					if cond.left is ast.SelectorExpr
+					if mut cond.left is ast.SelectorExpr
 						&& cond.right in [ast.IntegerLiteral, ast.StringLiteral] {
 						// $if field.indirections == 1
 						// $if method.args.len == 1
+						if cond.left.typ == 0 && cond.left.name_type == 0
+							&& (cond.left.expr is ast.Ident && cond.left.expr.name.len == 1) {
+							c.expr(mut cond.left)
+						}
 						return .unknown
 					} else if cond.left is ast.SelectorExpr
 						&& c.comptime.check_comptime_is_field_selector_bool(cond.left) {
@@ -908,6 +912,11 @@ fn (mut c Checker) comptime_if_cond(mut cond ast.Expr, pos token.Pos) ComptimeBr
 					}
 				}
 				.gt, .lt, .ge, .le {
+					if cond.left is ast.SelectorExpr && cond.left.typ == 0
+						&& cond.left.name_type == 0
+						&& (cond.left.expr is ast.Ident && cond.left.expr.name.len == 1) {
+						c.expr(mut cond.left)
+					}
 					if cond.left is ast.SelectorExpr && cond.right is ast.IntegerLiteral
 						&& c.comptime.is_comptime_selector_field_name(cond.left, 'indirections') {
 						return .unknown

vlib/v/gen/c/comptime.v

@@ -612,7 +612,8 @@ fn (mut g Gen) comptime_if_cond(cond ast.Expr, pkg_exist bool) (bool, bool) {
 				.eq, .ne {
 					// TODO: Implement `$if method.args.len == 1`
 					if cond.left is ast.SelectorExpr && (g.comptime.comptime_for_field_var.len > 0
-						|| g.comptime.comptime_for_method != unsafe { nil }) {
+						|| g.comptime.comptime_for_method != unsafe { nil }
+						|| cond.left.name_type != 0) {
 						if cond.right is ast.StringLiteral {
 							if cond.left.expr is ast.Ident && cond.left.field_name == 'name' {
 								if g.comptime.comptime_for_method_var.len > 0
@@ -645,9 +646,14 @@ fn (mut g Gen) comptime_if_cond(cond ast.Expr, pkg_exist bool) (bool, bool) {
 							}
 						} else if cond.right is ast.IntegerLiteral {
 							if g.comptime.is_comptime_selector_field_name(cond.left, 'indirections') {
+								left_muls := if cond.left.name_type != 0 {
+									g.unwrap_generic(cond.left.name_type).nr_muls()
+								} else {
+									g.comptime.comptime_for_field_type.nr_muls()
+								}
 								is_true := match cond.op {
-									.eq { g.comptime.comptime_for_field_type.nr_muls() == cond.right.val.i64() }
+									.eq { left_muls == cond.right.val.i64() }
-									.ne { g.comptime.comptime_for_field_type.nr_muls() != cond.right.val.i64() }
+									.ne { left_muls != cond.right.val.i64() }
 									else { false }
 								}
 								if is_true {
@@ -723,11 +729,17 @@ fn (mut g Gen) comptime_if_cond(cond ast.Expr, pkg_exist bool) (bool, bool) {
 				.gt, .lt, .ge, .le {
 					if cond.left is ast.SelectorExpr && cond.right is ast.IntegerLiteral
 						&& g.comptime.is_comptime_selector_field_name(cond.left, 'indirections') {
+						left := cond.left as ast.SelectorExpr
+						left_muls := if left.name_type != 0 {
+							g.unwrap_generic(left.name_type).nr_muls()
+						} else {
+							g.comptime.comptime_for_field_type.nr_muls()
+						}
 						is_true := match cond.op {
-							.gt { g.comptime.comptime_for_field_type.nr_muls() > cond.right.val.i64() }
+							.gt { left_muls > cond.right.val.i64() }
-							.lt { g.comptime.comptime_for_field_type.nr_muls() < cond.right.val.i64() }
+							.lt { left_muls < cond.right.val.i64() }
-							.ge { g.comptime.comptime_for_field_type.nr_muls() >= cond.right.val.i64() }
+							.ge { left_muls >= cond.right.val.i64() }
-							.le { g.comptime.comptime_for_field_type.nr_muls() <= cond.right.val.i64() }
+							.le { left_muls <= cond.right.val.i64() }
 							else { false }
 						}
 						if is_true {

vlib/v/tests/comptime/comptime_indirections_test.v

@@ -0,0 +1,23 @@
+fn count_muls[T](val T) int {
+	mut nr_muls := 0
+	dump(T.indirections)
+	dump(typeof(val).indirections)
+	$if T.indirections > 0 {
+		nr_muls = (int(typeof(val).idx) >> 16) & 0xff
+	}
+	assert nr_muls == T.indirections
+	$if T.indirections != 0 {
+		nr_muls = (int(typeof(val).idx) >> 16) & 0xff
+	}
+	assert nr_muls == T.indirections
+	return nr_muls
+}
+
+fn test_main() {
+	val := ''
+	pval := &val
+	ppval := &pval
+	assert count_muls(val) == 0
+	assert count_muls(pval) == 1
+	assert count_muls(ppval) == 2
+}

vlib/v/type_resolver/comptime_resolver.v

@@ -177,11 +177,12 @@ pub fn (mut t TypeResolver) get_comptime_selector_type(node ast.ComptimeSelector
 	return default_type
 }
 
-// is_comptime_selector_field_name checks if the SelectorExpr is related to $for variable accessing specific field name provided by `field_name`
+// is_comptime_selector_field_name checks if the SelectorExpr is related to $for variable or generic letter accessing specific field name provided by `field_name`
 @[inline]
 pub fn (t &ResolverInfo) is_comptime_selector_field_name(node ast.SelectorExpr, field_name string) bool {
-	return t.comptime_for_field_var != '' && node.expr is ast.Ident
+	return ((t.comptime_for_field_var != '' && node.expr is ast.Ident
-		&& node.expr.name == t.comptime_for_field_var && node.field_name == field_name
+		&& node.expr.name == t.comptime_for_field_var) || node.name_type != 0)
+		&& node.field_name == field_name
 }
 
 // is_comptime_selector_type checks if the SelectorExpr is related to $for variable accessing .typ field