openpgp-ffi: New crate.

  - This creates a new crate, 'sequoia-openpgp-ffi', and moves a
    handful of functions from 'sequoia-ffi' to it.

  - The 'sequoia-ffi' crate is a superset of the 'sequoia-openpgp-ffi'
    crate.  This is accomplished by some include! magic.

  - My first attempt involved having 'sequoia-ffi' depend on
    'sequoia-openpgp-ffi', so that the former just re-exports the
    symbols.  However, that turned out to be unreliable, and might be
    not what we want, because it could also duplicate parts of Rust's
    standard library.

  - Fixes #144.

1 files changed, 5 insertions, 113 deletions

diff --git a/ffi/src/error.rs b/ffi/src/error.rs
index 369cbb25..d9fb2c21 100644
--- a/ffi/src/error.rs
+++ b/ffi/src/error.rs
@@ -2,125 +2,17 @@
 
 use failure;
 use std::io;
-use libc::c_char;
 
 extern crate sequoia_openpgp as openpgp;
 use sequoia_core as core;
+pub use openpgp::error::Status;
 
-/// Frees an error.
-#[::ffi_catch_abort] #[no_mangle]
-pub extern "system" fn sq_error_free(error: Option<&mut failure::Error>) {
-    ffi_free!(error)
+trait FromSequoiaError<'a> {
+    fn from_sequoia_error(&'a failure::Error) -> Status;
 }
 
-/// Returns the error message.
-///
-/// The returned value must be freed with `free(3)`.
-#[::ffi_catch_abort] #[no_mangle]
-pub extern "system" fn sq_error_string(error: *const failure::Error)
-                                       -> *mut c_char {
-    let error = ffi_param_ref!(error);
-    ffi_return_string!(&format!("{}", error))
-}
-
-/// Returns the error status code.
-#[::ffi_catch_abort] #[no_mangle]
-pub extern "system" fn sq_error_status(error: *const failure::Error)
-                                       -> Status {
-    let error = ffi_param_ref!(error);
-    error.into()
-}
-
-/// XXX: Reorder and name-space before release.
-#[derive(PartialEq, Debug)]
-#[repr(C)]
-pub enum Status {
-    /// The operation was successful.
-    Success = 0,
-
-    /// An unknown error occurred.
-    UnknownError = -1,
-
-    /// The network policy was violated by the given action.
-    NetworkPolicyViolation = -2,
-
-    /// An IO error occurred.
-    IoError = -3,
-
-    /// A given argument is invalid.
-    InvalidArgument = -15,
-
-    /// The requested operation is invalid.
-    InvalidOperation = -4,
-
-    /// The packet is malformed.
-    MalformedPacket = -5,
-
-    /// Unsupported hash algorithm.
-    UnsupportedHashAlgorithm = -9,
-
-    /// Unsupported public key algorithm.
-    UnsupportedPublicKeyAlgorithm = -18,
-
-    /// Unsupported elliptic curve.
-    UnsupportedEllipticCurve = -21,
-
-    /// Unsupported symmetric algorithm.
-    UnsupportedSymmetricAlgorithm = -10,
-
-    /// Unsupported AEAD algorithm.
-    UnsupportedAEADAlgorithm = -26,
-
-    /// Unsupport signature type.
-    UnsupportedSignatureType = -20,
-
-    /// Invalid password.
-    InvalidPassword = -11,
-
-    /// Invalid session key.
-    InvalidSessionKey = -12,
-
-    /// Missing session key.
-    MissingSessionKey = -27,
-
-    /// Malformed TPK.
-    MalformedTPK = -13,
-
-    // XXX: -14 was UserIDNotFound.
-
-    // XXX: Skipping InvalidArgument = -15.
-
-    /// Malformed MPI.
-    MalformedMPI = -16,
-
-    // XXX: Skipping UnknownPublicKeyAlgorithm = -17.
-    // XXX: Skipping UnsupportedPublicKeyAlgorithm = -18
-
-    /// Bad signature.
-    BadSignature = -19,
-
-    /// Message has been manipulated.
-    ManipulatedMessage = -25,
-
-    // XXX: Skipping UnsupportedSignatureType = -20
-    // XXX: Skipping UnsupportedEllipticCurve = -21
-
-    /// Malformed message.
-    MalformedMessage = -22,
-
-    /// Index out of range.
-    IndexOutOfRange = -23,
-
-    /// TPK not supported.
-    UnsupportedTPK = -24,
-
-    // XXX: Skipping ManipulatedMessage = -25
-    // XXX: Skipping UnsupportedAEADAlgorithm = -26
-    // XXX: Skipping MissingSessionKey = -27
-}
-
-impl<'a> From<&'a failure::Error> for Status {
-    fn from(e: &'a failure::Error) -> Self {
+impl<'a> FromSequoiaError<'a> for Status {
+    fn from_sequoia_error(e: &'a failure::Error) -> Self {
         if let Some(e) = e.downcast_ref::<core::Error>() {
             return match e {
                 &core::Error::NetworkPolicyViolation(_) =>