rb_sys/
utils.rs

1//! Internal utility functions.
2
3/// Check if the Ruby VM is globally available.
4///
5/// Unfortunately there is no public API for this check, but there's a hidden
6/// `ruby_current_vm_ptr` symbol in libruby 2.5 - 3.2 which we can use to
7/// determine if the VM has been initialized, or shut down.
8///
9/// # Notes
10///
11/// Ruby 2.4 and below don't have a global VM pointer, so we can't check if it's
12/// null. Ruby 2.4 is EOL, and support will be dropped soon anyway.
13//
14/// In Ruby 3.3, the global VM pointer is no longer exported, so there's no
15/// simple way to check the global VM pointer, so instead we check if known
16/// static value is non-zero.
17///
18/// On Ruby < 3.3, we also need to check if the global VM pointer is null to
19/// ensure the VM hasn't stopped, which makes the function name a bit of a
20/// misnomer... but in actuality this function can only guarantee that the
21/// VM is started, not that it's still running.
22#[allow(dead_code)]
23pub(crate) unsafe fn is_ruby_vm_started() -> bool {
24    #[cfg(ruby_engine = "mri")]
25    let ret = {
26        #[cfg(all(ruby_gt_2_4, ruby_lte_3_2))]
27        let ret = !crate::hidden::ruby_current_vm_ptr.is_null();
28
29        #[cfg(any(ruby_lte_2_4, ruby_gt_3_2))]
30        let ret = crate::rb_cBasicObject != 0;
31
32        ret
33    };
34
35    #[cfg(ruby_engine = "truffleruby")]
36    let ret = crate::rb_cBasicObject != 0;
37
38    ret
39}
40
41/// Macro for conditionally asserting type checks in Ruby, only active when RUBY_DEBUG is enabled.
42/// This matches Ruby's behavior of only checking types in debug mode.
43#[macro_export]
44macro_rules! debug_ruby_assert_type {
45    ($obj:expr, $type:expr, $message:expr) => {
46        #[cfg(ruby_ruby_debug = "true")]
47        {
48            #[allow(clippy::macro_metavars_in_unsafe)]
49            unsafe {
50                assert!(
51                    !$crate::SPECIAL_CONST_P($obj) && $crate::RB_BUILTIN_TYPE($obj) == $type,
52                    $message
53                );
54            }
55        }
56        #[cfg(not(ruby_ruby_debug = "true"))]
57        {
58            let _ = ($obj, $type, $message); // Prevent unused variable warnings
59        }
60    };
61}
62
63#[cfg(test)]
64mod tests {
65    use super::*;
66    use rusty_fork::rusty_fork_test;
67    use std::ptr::addr_of_mut;
68
69    rusty_fork_test! {
70        #[test]
71        fn test_is_ruby_vm_started() {
72            assert!(!unsafe { is_ruby_vm_started() });
73
74            // Call ruby_sysinit which handles platform-specific initialization
75            // (rb_w32_sysinit on Windows) and sets up standard file descriptors
76            let mut argc = 0;
77            let mut argv: [*mut std::os::raw::c_char; 0] = [];
78            let mut argv_ptr = argv.as_mut_ptr();
79            unsafe { crate::ruby_sysinit(&mut argc, &mut argv_ptr) };
80
81            // ruby_init_stack must be called before ruby_setup, especially on
82            // Windows where it's required for proper GC stack scanning
83            let mut stack_marker: crate::VALUE = 0;
84            unsafe { crate::ruby_init_stack(addr_of_mut!(stack_marker) as *mut _) };
85
86            match unsafe { crate::ruby_setup() } {
87                0 => {}
88                code => panic!("Failed to setup Ruby (error code: {})", code),
89            };
90
91            assert!(unsafe { is_ruby_vm_started() });
92        }
93    }
94}
rb_sys/utils.rs

rb_sys/
utils.rs
