Initial project import

tools/v/vlib/builtin/autostr.v

@@ -0,0 +1,87 @@
+module builtin
+
+import strings
+
+const autostr_type_stack_max_depth = 64
+
+__global g_autostr_type_stack = [autostr_type_stack_max_depth]int{}
+__global g_autostr_type_stack_len = 0
+
+@[markused]
+fn autostr_type_in_stack(typ int) bool {
+	for i := 0; i < g_autostr_type_stack_len; i++ {
+		if g_autostr_type_stack[i] == typ {
+			return true
+		}
+	}
+	return false
+}
+
+@[markused]
+fn autostr_type_push(typ int) {
+	if g_autostr_type_stack_len >= autostr_type_stack_max_depth {
+		return
+	}
+	g_autostr_type_stack[g_autostr_type_stack_len] = typ
+	g_autostr_type_stack_len++
+}
+
+@[markused]
+fn autostr_type_pop() {
+	if g_autostr_type_stack_len > 0 {
+		g_autostr_type_stack_len--
+	}
+}
+
+// Address-based circular reference detection.
+// Tracks visited struct addresses to detect actual circular references
+// (same instance reached again) without false positives from same-type
+// different instances.
+
+__global g_autostr_addr_stack = [autostr_type_stack_max_depth]voidptr{}
+__global g_autostr_addr_stack_len = 0
+
+@[markused]
+fn autostr_addr_in_stack(addr voidptr) bool {
+	for i := 0; i < g_autostr_addr_stack_len; i++ {
+		if g_autostr_addr_stack[i] == addr {
+			return true
+		}
+	}
+	return false
+}
+
+@[markused]
+fn autostr_addr_push(addr voidptr) {
+	if g_autostr_addr_stack_len >= autostr_type_stack_max_depth {
+		return
+	}
+	g_autostr_addr_stack[g_autostr_addr_stack_len] = addr
+	g_autostr_addr_stack_len++
+}
+
+@[markused]
+fn autostr_addr_pop() {
+	if g_autostr_addr_stack_len > 0 {
+		g_autostr_addr_stack_len--
+	}
+}
+
+@[markused]
+fn autostr_array_circular(len int) string {
+	if len <= 0 {
+		return '[]'
+	}
+	mut sb := strings.new_builder(2 + len * 12)
+	sb.write_string('[')
+	for i in 0 .. len {
+		if i > 0 {
+			sb.write_string(', ')
+		}
+		sb.write_string('<circular>')
+	}
+	sb.write_string(']')
+	res := sb.str()
+	unsafe { sb.free() }
+	return res
+}