1 files changed, 100 insertions, 0 deletions
diff --git a/third_party/rust/wgpu-hal/src/auxil/dxgi/exception.rs b/third_party/rust/wgpu-hal/src/auxil/dxgi/exception.rs
new file mode 100644
index 0000000000..fceac7db5f
--- /dev/null
+++ b/third_party/rust/wgpu-hal/src/auxil/dxgi/exception.rs
@@ -0,0 +1,100 @@
+use std::{borrow::Cow, slice};
+
+use parking_lot::{lock_api::RawMutex, Mutex};
+use winapi::{
+    um::{errhandlingapi, winnt},
+    vc::excpt,
+};
+
+// This is a mutex as opposed to an atomic as we need to completely
+// lock everyone out until we have registered or unregistered the
+// exception handler, otherwise really nasty races could happen.
+//
+// By routing all the registration through these functions we can guarentee
+// there is either 1 or 0 exception handlers registered, not multiple.
+static EXCEPTION_HANLDER_COUNT: Mutex<usize> = Mutex::const_new(parking_lot::RawMutex::INIT, 0);
+
+pub fn register_exception_handler() {
+    let mut count_guard = EXCEPTION_HANLDER_COUNT.lock();
+    if *count_guard == 0 {
+        unsafe {
+            errhandlingapi::AddVectoredExceptionHandler(0, Some(output_debug_string_handler))
+        };
+    }
+    *count_guard += 1;
+}
+
+pub fn unregister_exception_handler() {
+    let mut count_guard = EXCEPTION_HANLDER_COUNT.lock();
+    if *count_guard == 1 {
+        unsafe {
+            errhandlingapi::RemoveVectoredExceptionHandler(output_debug_string_handler as *mut _)
+        };
+    }
+    *count_guard -= 1;
+}
+
+const MESSAGE_PREFIXES: &[(&str, log::Level)] = &[
+    ("CORRUPTION", log::Level::Error),
+    ("ERROR", log::Level::Error),
+    ("WARNING", log::Level::Warn),
+    ("INFO", log::Level::Info),
+    ("MESSAGE", log::Level::Debug),
+];
+
+unsafe extern "system" fn output_debug_string_handler(
+    exception_info: *mut winnt::EXCEPTION_POINTERS,
+) -> i32 {
+    // See https://stackoverflow.com/a/41480827
+    let record = unsafe { &*(*exception_info).ExceptionRecord };
+    if record.NumberParameters != 2 {
+        return excpt::EXCEPTION_CONTINUE_SEARCH;
+    }
+    let message = match record.ExceptionCode {
+        winnt::DBG_PRINTEXCEPTION_C => String::from_utf8_lossy(unsafe {
+            slice::from_raw_parts(
+                record.ExceptionInformation[1] as *const u8,
+                record.ExceptionInformation[0],
+            )
+        }),
+        winnt::DBG_PRINTEXCEPTION_WIDE_C => Cow::Owned(String::from_utf16_lossy(unsafe {
+            slice::from_raw_parts(
+                record.ExceptionInformation[1] as *const u16,
+                record.ExceptionInformation[0],
+            )
+        })),
+        _ => return excpt::EXCEPTION_CONTINUE_SEARCH,
+    };
+
+    let message = match message.strip_prefix("D3D12 ") {
+        Some(msg) => msg
+            .trim_end_matches("\n\0")
+            .trim_end_matches("[ STATE_CREATION WARNING #0: UNKNOWN]"),
+        None => return excpt::EXCEPTION_CONTINUE_SEARCH,
+    };
+
+    let (message, level) = match MESSAGE_PREFIXES
+        .iter()
+        .find(|&&(prefix, _)| message.starts_with(prefix))
+    {
+        Some(&(prefix, level)) => (&message[prefix.len() + 2..], level),
+        None => (message, log::Level::Debug),
+    };
+
+    if level == log::Level::Warn && message.contains("#82") {
+        // This is are useless spammy warnings (#820, #821):
+        // "The application did not pass any clear value to resource creation"
+        return excpt::EXCEPTION_CONTINUE_SEARCH;
+    }
+
+    let _ = std::panic::catch_unwind(|| {
+        log::log!(level, "{}", message);
+    });
+
+    if cfg!(debug_assertions) && level == log::Level::Error {
+        // Set canary and continue
+        crate::VALIDATION_CANARY.set();
+    }
+
+    excpt::EXCEPTION_CONTINUE_EXECUTION
+}