Ensure that _bindgen_ty_1 names ERR_LIB newtypes

boring-sys/build/main.rs

@@ -810,7 +810,24 @@ fn generate_bindings(config: &Config) {
     }
 
     let bindings = builder.generate().expect("Unable to generate bindings");
+    let mut source_code = Vec::new();
     bindings
-        .write_to_file(config.out_dir.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
+        .write(Box::new(&mut source_code))
+        .expect("Couldn't serialize bindings!");
+    ensure_err_lib_enum_is_named(&mut source_code);
+    fs::write(config.out_dir.join("bindings.rs"), source_code).expect("Couldn't write bindings!");
+}
+
+/// err.h has anonymous `enum { ERR_LIB_NONE = 1 }`, which makes a dodgy `_bindgen_ty_1` name
+fn ensure_err_lib_enum_is_named(source_code: &mut Vec<u8>) {
+    let src = String::from_utf8_lossy(source_code);
+    let enum_type = src
+        .split_once("ERR_LIB_SSL:")
+        .and_then(|(_, def)| Some(def.split_once("=")?.0))
+        .unwrap_or("_bindgen_ty_1");
+
+    source_code.extend_from_slice(
+        format!("\n/// Newtype for [`ERR_LIB_SSL`] constants\npub use {enum_type} as ErrLib;\n")
+            .as_bytes(),
+    );
 }

boring/src/error.rs

@@ -27,6 +27,8 @@ use std::str;
 
 use crate::ffi;
 
+pub use crate::ffi::ErrLib;
+
 /// Collection of [`Error`]s from OpenSSL.
 ///
 /// [`Error`]: struct.Error.html
@@ -194,11 +196,23 @@ impl Error {
         }
     }
 
+    /// Get `{lib}_R_{reason}` reason code for the given library, or `None` if the error is from a different library.
+    ///
+    /// Libraries are identified by [`ERR_LIB_{name}`(ffi::ERR_LIB_SSL) constants.
+    #[inline]
+    #[must_use]
+    #[track_caller]
+    pub fn library_reason(&self, library_code: ErrLib) -> Option<c_int> {
+        debug_assert!(library_code.0 < ffi::ERR_NUM_LIBS.0);
+        (self.library_code() == library_code.0 as c_int).then_some(self.reason_code())
+    }
+
     /// Returns a raw OpenSSL **packed** error code for this error, which **can't be reliably compared to any error constant**.
     ///
-    /// Use [`Error::library_code()`] and [`Error::reason_code()`] instead.
+    /// Use [`Error::library_code()`] and [`Error::library_reason()`] instead.
     /// Packed error codes are different than [SSL error codes](crate::ssl::ErrorCode).
     #[must_use]
+    #[deprecated(note = "use library_reason() to compare error codes")]
     pub fn code(&self) -> c_uint {
         self.code
     }
@@ -223,7 +237,7 @@ impl Error {
 
     /// Returns the raw OpenSSL error constant for the library reporting the error (`ERR_LIB_{name}`).
     ///
-    /// Error [reason codes](Error::reason_code) are not globally unique, but scoped to each library.
+    /// Error [reason codes](Error::library_reason) are not globally unique, but scoped to each library.
     #[must_use]
     pub fn library_code(&self) -> c_int {
         ffi::ERR_GET_LIB(self.code)
@@ -249,6 +263,7 @@ impl Error {
     /// Returns [library-specific](Error::library_code) reason code corresponding to some of the `{lib}_R_{reason}` constants.
     ///
     /// Reason codes are ambiguous, and different libraries reuse the same numeric values for different errors.
+    /// Use [`Error::library_reason`] to compare error codes.
     ///
     /// For `ERR_LIB_SYS` the reason code is `errno`. `ERR_LIB_USER` can use any values.
     /// Other libraries may use [`ERR_R_*`](ffi::ERR_R_FATAL) or their own codes.