b22a714840
The JIT that runs makepad apps from source: lexer, front end, type checker, lazy borrow checker (Gandalf; `--check-first` opts in), codegen, session and warm/cold caches keyed by compiler stamp, provided crates bound late, startup images, live patching. User-facing name is `makepad run` (binary `makepad`, MAKEPAD_RUN_* env, ~/.makepad-run); libs/relax stays the internal library name. `makepad check` reports rustc-style diagnostics with rustc error codes and checks a whole workspace (`--workspace`). Runs on macOS, Linux, Windows and Android. makepad-remote: one tool schema for apps and the WM (app/1): grabs, captures, traces, frame profiles and tweaks. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
45 lines
1.8 KiB
Rust
45 lines
1.8 KiB
Rust
// Foreign fn items as values: fn-pointer coercion (return, argument, let), `as` casts to fn
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// pointers / usize / raw pointers, stored in a static and a const, inside a generic fn, and
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// the objc-sys shape (`extern "C" { fn f(); }` taken as `unsafe extern "C" fn()`, transmuted to
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// the real signature, called). The value is the symbol's real address (= dlsym), as in rustc.
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extern "C" {
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fn abs(x: i32) -> i32;
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fn labs(x: i64) -> i64;
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fn dlsym(handle: *mut u8, name: *const u8) -> *mut u8;
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}
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mod objc_like {
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extern "C" {
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pub fn abs();
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}
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}
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type Imp = unsafe extern "C" fn();
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fn imp() -> Imp {
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objc_like::abs
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}
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static ABS_PTR: unsafe extern "C" fn(i32) -> i32 = abs;
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const LABS_PTR: unsafe extern "C" fn(i64) -> i64 = labs;
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fn call_with(f: unsafe extern "C" fn(i32) -> i32, x: i32) -> i32 {
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unsafe { f(x) }
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}
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fn generic_call<F: Fn(i32) -> i32>(f: F, x: i32) -> i32 {
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f(x)
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}
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#[test]
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fn values() {
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// RTLD_DEFAULT: -2 on macOS, 0 on Linux
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let default = if cfg!(target_os = "macos") { -2isize as usize } else { 0 };
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let real = unsafe { dlsym(default as *mut u8, b"abs\0".as_ptr()) } as usize;
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let f: unsafe extern "C" fn(i32) -> i32 = abs;
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println!("let coercion {}", unsafe { f(-3) });
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println!("argument {}", call_with(abs, -4));
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println!("static {} const {}", unsafe { ABS_PTR(-6) }, unsafe { LABS_PTR(-7) });
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let g: extern "C" fn(i32) -> i32 = unsafe { std::mem::transmute(imp()) };
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println!("objc shape {}", g(-5));
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println!("generic {}", generic_call(|x| unsafe { abs(x) }, -8));
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let as_usize = abs as usize;
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let as_ptr = abs as *const u8 as usize;
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let via_fn = f as usize;
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let via_imp = imp() as usize;
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println!("same address: cast {} ptr {} coerced {} imp {} static {}", as_usize == real, as_ptr == real, via_fn == real, via_imp == real, ABS_PTR as usize == real);
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}
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