ffi: Add and use ffi_free!.

10 files changed, 42 insertions, 117 deletions

diff --git a/ffi/src/core.rs b/ffi/src/core.rs
index faa007c4..e31513a5 100644
--- a/ffi/src/core.rs
+++ b/ffi/src/core.rs
@@ -108,10 +108,7 @@ pub extern "system" fn sq_context_new(domain: *const c_char,
 /// Frees a context.
 #[no_mangle]
 pub extern "system" fn sq_context_free(context: *mut Context) {
-    if context.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(context));
-    }
+    ffi_free!(context)
 }
 
 /// Creates a Context that can be configured.
@@ -295,10 +292,7 @@ pub extern "system" fn sq_reader_from_bytes(buf: *const uint8_t,
 /// Frees a reader.
 #[no_mangle]
 pub extern "system" fn sq_reader_free(reader: *mut Box<Read>) {
-    if reader.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(reader));
-    }
+    ffi_free!(reader)
 }
 
 /// Reads up to `len` bytes into `buf`.
@@ -412,10 +406,7 @@ impl Write for WriterAlloc {
 /// Frees a writer.
 #[no_mangle]
 pub extern "system" fn sq_writer_free(writer: *mut Box<Write>) {
-    if writer.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(writer));
-    }
+    ffi_free!(writer)
 }
 
 /// Writes up to `len` bytes of `buf` into `writer`.
diff --git a/ffi/src/error.rs b/ffi/src/error.rs
index 96a64c96..05a1998a 100644
--- a/ffi/src/error.rs
+++ b/ffi/src/error.rs
@@ -11,9 +11,7 @@ use sequoia_core as core;
 /// Frees an error.
 #[no_mangle]
 pub extern "system" fn sq_error_free(error: *mut failure::Error) {
-    if ! error.is_null() {
-        unsafe { drop(Box::from_raw(error)) }
-    }
+    ffi_free!(error)
 }
 
 /// Returns the error message.
diff --git a/ffi/src/lib.rs b/ffi/src/lib.rs
index ebb74a6a..c9410816 100644
--- a/ffi/src/lib.rs
+++ b/ffi/src/lib.rs
@@ -126,6 +126,21 @@ extern crate sequoia_store;
 use std::collections::hash_map::{DefaultHasher, RandomState};
 use std::hash::BuildHasher;
 
+/* Canonical free().  */
+
+/// Transfers ownership from C to Rust, then frees the object.
+///
+/// NOP if called with NULL.
+macro_rules! ffi_free {
+    ($name:ident) => {{
+        if ! $name.is_null() {
+            unsafe {
+                drop(Box::from_raw($name))
+            }
+        }
+    }};
+}
+
 /// Like try! for ffi glue.
 ///
 /// Evaluates the given expression.  On success, evaluate to
diff --git a/ffi/src/net.rs b/ffi/src/net.rs
index 416cedcf..bd98bca1 100644
--- a/ffi/src/net.rs
+++ b/ffi/src/net.rs
@@ -108,12 +108,7 @@ pub extern "system" fn sq_keyserver_sks_pool(ctx: Option<&mut Context>)
 /// Frees a keyserver object.
 #[no_mangle]
 pub extern "system" fn sq_keyserver_free(ks: *mut KeyServer) {
-    if ks.is_null() {
-        return
-    }
-    unsafe {
-        drop(Box::from_raw(ks));
-    }
+    ffi_free!(ks)
 }
 
 /// Retrieves the key with the given `keyid`.
diff --git a/ffi/src/openpgp/fingerprint.rs b/ffi/src/openpgp/fingerprint.rs
index 256156b6..3c2a38ad 100644
--- a/ffi/src/openpgp/fingerprint.rs
+++ b/ffi/src/openpgp/fingerprint.rs
@@ -41,10 +41,7 @@ pub extern "system" fn sq_fingerprint_from_hex(hex: *const c_char)
 /// Frees a sq_fingerprint_t.
 #[no_mangle]
 pub extern "system" fn sq_fingerprint_free(fp: *mut Fingerprint) {
-    if fp.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(fp));
-    }
+    ffi_free!(fp)
 }
 
 /// Clones the Fingerprint.
diff --git a/ffi/src/openpgp/keyid.rs b/ffi/src/openpgp/keyid.rs
index ed4bb11e..5d739609 100644
--- a/ffi/src/openpgp/keyid.rs
+++ b/ffi/src/openpgp/keyid.rs
@@ -36,10 +36,7 @@ pub extern "system" fn sq_keyid_from_hex(id: *const c_char) -> *mut KeyID {
 /// Frees an `KeyID` object.
 #[no_mangle]
 pub extern "system" fn sq_keyid_free(keyid: *mut KeyID) {
-    if keyid.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(keyid));
-    }
+    ffi_free!(keyid)
 }
 
 /// Clones the KeyID.
diff --git a/ffi/src/openpgp/mod.rs b/ffi/src/openpgp/mod.rs
index 05afe9c0..9dc9548c 100644
--- a/ffi/src/openpgp/mod.rs
+++ b/ffi/src/openpgp/mod.rs
@@ -122,10 +122,7 @@ pub extern "system" fn sq_revocation_status_variant(
 pub extern "system" fn sq_revocation_status_free(
     rs: *mut RevocationStatus)
 {
-    if rs.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(rs))
-    };
+    ffi_free!(rs)
 }
 
 /* TSK */
@@ -158,12 +155,7 @@ pub extern "system" fn sq_tsk_new(ctx: Option<&mut Context>,
 /// Frees the TSK.
 #[no_mangle]
 pub extern "system" fn sq_tsk_free(tsk: *mut TSK) {
-    if tsk.is_null() {
-        return
-    }
-    unsafe {
-        drop(Box::from_raw(tsk));
-    }
+    ffi_free!(tsk)
 }
 
 /// Returns a reference to the corresponding TPK.
@@ -202,10 +194,7 @@ pub extern "system" fn sq_tsk_serialize(ctx: Option<&mut Context>,
 /// Frees the Packet.
 #[no_mangle]
 pub extern "system" fn sq_packet_free(p: *mut Packet) {
-    if p.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(p));
-    }
+    ffi_free!(p)
 }
 
 /// Returns the `Packet's` corresponding OpenPGP tag.
@@ -242,10 +231,7 @@ pub extern "system" fn sq_packet_kind(p: Option<&Packet>)
 /// Frees the Signature.
 #[no_mangle]
 pub extern "system" fn sq_signature_free(s: *mut Signature) {
-    if s.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(s));
-    }
+    ffi_free!(s)
 }
 
 /// Converts the signature to a packet.
@@ -721,19 +707,13 @@ pub extern "system" fn sq_packet_parser_from_bytes
 pub extern "system" fn sq_packet_parser_result_free(
     ppr: *mut PacketParserResult)
 {
-    if ppr.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(ppr));
-    }
+    ffi_free!(ppr)
 }
 
 /// Frees the packet parser.
 #[no_mangle]
 pub extern "system" fn sq_packet_parser_free(pp: *mut PacketParser) {
-    if pp.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(pp));
-    }
+    ffi_free!(pp)
 }
 
 /// Frees the packet parser EOF object.
@@ -749,10 +729,7 @@ pub extern "system" fn sq_packet_parser_eof_is_message(
 /// Frees the packet parser EOF object.
 #[no_mangle]
 pub extern "system" fn sq_packet_parser_eof_free(eof: *mut PacketParserEOF) {
-    if eof.is_null() { return }
-    unsafe {
-        drop(Box::from_raw(eof));
-    }
+    ffi_free!(eof)
 }
 
 /// Returns a reference to the packet that is being parsed.
diff --git a/ffi/src/openpgp/packet_pile.rs b/ffi/src/openpgp/packet_pile.rs
index fd87130c..552152db 100644
--- a/ffi/src/openpgp/packet_pile.rs
+++ b/ffi/src/openpgp/packet_pile.rs
@@ -74,12 +74,7 @@ pub extern "system" fn sq_packet_pile_from_bytes(ctx: Option<&mut Context>,
 /// Frees the packet_pile.
 #[no_mangle]
 pub extern "system" fn sq_packet_pile_free(packet_pile: *mut PacketPile) {
-    if packet_pile.is_null() {
-        return
-    }
-    unsafe {
-        drop(Box::from_raw(packet_pile));
-    }
+    ffi_free!(packet_pile)
 }
 
 /// Clones the PacketPile.
diff --git a/ffi/src/openpgp/tpk.rs b/ffi/src/openpgp/tpk.rs
index eaa8ef40..49d6513b 100644
--- a/ffi/src/openpgp/tpk.rs
+++ b/ffi/src/openpgp/tpk.rs
@@ -107,12 +107,7 @@ pub extern "system" fn sq_tpk_from_packet_parser(ctx: Option<&mut Context>,
 /// Frees the TPK.
 #[no_mangle]
 pub extern "system" fn sq_tpk_free(tpk: *mut TPK) {
-    if tpk.is_null() {
-        return
-    }
-    unsafe {
-        drop(Box::from_raw(tpk));
-    }
+    ffi_free!(tpk)
 }
 
 /// Clones the TPK.
@@ -499,10 +494,7 @@ pub extern "system" fn sq_tpk_user_id_binding_iter(tpk: Option<&TPK>)
 pub extern "system" fn sq_user_id_binding_iter_free(
     iter: *mut UserIDBindingIter)
 {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 /// Returns the next `UserIDBinding`.
@@ -542,10 +534,7 @@ pub extern "system" fn sq_tpk_key_iter(tpk: Option<&TPK>)
 pub extern "system" fn sq_tpk_key_iter_free(
     iter: *mut KeyIterWrapper)
 {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 /// Returns the next key.  Returns NULL if there are no more elements.
@@ -626,12 +615,7 @@ pub extern "system" fn sq_tpk_builder_autocrypt() -> *mut TPKBuilder {
 #[no_mangle]
 pub extern "system" fn sq_tpk_builder_free(tpkb: *mut TPKBuilder)
 {
-    if tpkb.is_null() {
-        return
-    }
-    unsafe {
-        drop(Box::from_raw(tpkb));
-    }
+    ffi_free!(tpkb)
 }
 
 /// Sets the encryption and signature algorithms for primary and all
diff --git a/ffi/src/store.rs b/ffi/src/store.rs
index a18239f7..4a248a35 100644
--- a/ffi/src/store.rs
+++ b/ffi/src/store.rs
@@ -97,10 +97,7 @@ pub extern "system" fn sq_store_iter_next(iter: Option<&mut StoreIter>,
 /// Frees a sq_store_iter_t.
 #[no_mangle]
 pub extern "system" fn sq_store_iter_free(iter: *mut StoreIter) {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 /// Lists all keys in the common key pool.
@@ -145,10 +142,7 @@ pub extern "system" fn sq_key_iter_next(iter: Option<&mut KeyIter>,
 /// Frees a sq_key_iter_t.
 #[no_mangle]
 pub extern "system" fn sq_key_iter_free(iter: *mut KeyIter) {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 
@@ -190,10 +184,7 @@ pub extern "system" fn sq_log_iter_next(iter: Option<&mut LogIter>)
 /// Frees a sq_log_iter_t.
 #[no_mangle]
 pub extern "system" fn sq_log_iter_free(iter: *mut LogIter) {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 /// Opens a store.
@@ -224,10 +215,7 @@ pub extern "system" fn sq_store_open(ctx: Option<&mut Context>,
 /// Frees a sq_store_t.
 #[no_mangle]
 pub extern "system" fn sq_store_free(store: *mut Store) {
-    if store.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(store))
-    };
+    ffi_free!(store)
 }
 
 /// Adds a key identified by fingerprint to the store.
@@ -365,10 +353,7 @@ pub extern "system" fn sq_binding_iter_next(iter: Option<&mut BindingIter>,
 /// Frees a sq_binding_iter_t.
 #[no_mangle]
 pub extern "system" fn sq_binding_iter_free(iter: *mut BindingIter) {
-    if iter.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(iter))
-    };
+    ffi_free!(iter)
 }
 
 /// Lists all log entries related to this store.
@@ -385,19 +370,13 @@ pub extern "system" fn sq_store_log(ctx: Option<&mut Context>,
 /// Frees a sq_binding_t.
 #[no_mangle]
 pub extern "system" fn sq_binding_free(binding: *mut Binding) {
-    if binding.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(binding))
-    };
+    ffi_free!(binding)
 }
 
 /// Frees a sq_key_t.
 #[no_mangle]
 pub extern "system" fn sq_key_free(key: *mut Key) {
-    if key.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(key))
-    };
+    ffi_free!(key)
 }
 
 /// Frees a sq_log_t.
@@ -587,10 +566,7 @@ pub extern "system" fn sq_key_log(ctx: Option<&mut Context>,
 /// Frees a sq_stats_t.
 #[no_mangle]
 pub extern "system" fn sq_stats_free(stats: *mut Stats) {
-    if stats.is_null() { return };
-    unsafe {
-        drop(Box::from_raw(stats))
-    };
+    ffi_free!(stats)
 }
 
 /// Counter and timestamps.