Vendor things

third-party/vendor/hassle-rs/src/os.rs

@@ -0,0 +1,121 @@
+// Allow uppercase names to match Windows API:
+#![allow(clippy::upper_case_acronyms)]
+
+#[cfg(windows)]
+mod os_defs {
+    pub use winapi::shared::{
+        ntdef::{HRESULT, LPCSTR, LPCWSTR, LPSTR, LPWSTR, WCHAR},
+        wtypes::BSTR,
+    };
+
+    pub use winapi::um::combaseapi::CoTaskMemFree;
+    pub use winapi::um::oleauto::{SysFreeString, SysStringLen};
+}
+
+#[cfg(not(windows))]
+mod os_defs {
+    pub type CHAR = std::os::raw::c_char;
+    pub type UINT = u32;
+    pub type WCHAR = widestring::WideChar;
+    pub type OLECHAR = WCHAR;
+    pub type LPSTR = *mut CHAR;
+    pub type LPWSTR = *mut WCHAR;
+    pub type LPCSTR = *const CHAR;
+    pub type LPCWSTR = *const WCHAR;
+    pub type BSTR = *mut OLECHAR;
+    pub type LPBSTR = *mut BSTR;
+    pub type HRESULT = i32;
+
+    /// Returns a mutable pointer to the length prefix of the string
+    fn len_ptr(p: BSTR) -> *mut UINT {
+        // The first four bytes before the pointer contain the length prefix:
+        // https://docs.microsoft.com/en-us/previous-versions/windows/desktop/automat/bstr#remarks
+        unsafe { p.cast::<UINT>().offset(-1) }
+    }
+
+    #[allow(non_snake_case)]
+    /// # Safety
+    /// `p` must be a valid pointer to an allocation made with `malloc`, or null.
+    pub unsafe fn CoTaskMemFree(p: *mut libc::c_void) {
+        // https://github.com/microsoft/DirectXShaderCompiler/blob/56e22b30c5e43632f56a1f97865f37108ec35463/include/dxc/Support/WinAdapter.h#L46
+        if !p.is_null() {
+            libc::free(p)
+        }
+    }
+
+    #[allow(non_snake_case)]
+    /// # Safety
+    /// `p` must be a valid pointer to an allocation made with `malloc`, or null.
+    pub unsafe fn SysFreeString(p: BSTR) {
+        // https://github.com/microsoft/DirectXShaderCompiler/blob/56e22b30c5e43632f56a1f97865f37108ec35463/lib/DxcSupport/WinAdapter.cpp#L50-L53
+        if !p.is_null() {
+            libc::free(len_ptr(p).cast::<_>())
+        }
+    }
+
+    #[allow(non_snake_case)]
+    /// Returns the size of `p` in bytes, excluding terminating NULL character
+    ///
+    /// # Safety
+    /// `p` must be a valid pointer to a [`BSTR`] with size-prefix in the `4` leading bytes, or null.
+    ///
+    /// https://docs.microsoft.com/en-us/previous-versions/windows/desktop/automat/bstr#remarks
+    pub unsafe fn SysStringByteLen(p: BSTR) -> UINT {
+        if p.is_null() {
+            0
+        } else {
+            *len_ptr(p)
+        }
+    }
+
+    #[allow(non_snake_case)]
+    /// Returns the size of `p` in characters, excluding terminating NULL character
+    ///
+    /// # Safety
+    /// `p` must be a valid pointer to a [`BSTR`] with size-prefix in the `4` leading bytes, or null.
+    ///
+    /// https://docs.microsoft.com/en-us/previous-versions/windows/desktop/automat/bstr#remarks
+    pub unsafe fn SysStringLen(p: BSTR) -> UINT {
+        SysStringByteLen(p) / std::mem::size_of::<OLECHAR>() as UINT
+    }
+}
+
+pub use os_defs::*;
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(transparent)]
+#[must_use]
+pub struct HRESULT(pub os_defs::HRESULT);
+impl HRESULT {
+    pub fn is_err(&self) -> bool {
+        self.0 < 0
+    }
+}
+
+impl From<i32> for HRESULT {
+    fn from(v: i32) -> Self {
+        Self(v)
+    }
+}
+
+impl std::fmt::Debug for HRESULT {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        <Self as std::fmt::Display>::fmt(self, f)
+    }
+}
+
+impl std::fmt::Display for HRESULT {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!("{:#x}", self))
+    }
+}
+
+impl std::fmt::LowerHex for HRESULT {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let prefix = if f.alternate() { "0x" } else { "" };
+        let bare_hex = format!("{:x}", self.0.abs());
+        // https://stackoverflow.com/a/44712309
+        f.pad_integral(self.0 >= 0, prefix, &bare_hex)
+        // <i32 as std::fmt::LowerHex>::fmt(&self.0, f)
+    }
+}