add checked_struct

crypto/ffi.c

@@ -0,0 +1,92 @@
+// Copyright 2015 Brian Smith.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+#include "ffi.h"
+
+/* Do not include any *ring* headers here other than ffi.h. *ring* headers must
+ * only be included after the |RING_*_METADATA| macros have been defined near
+ * the end of this file. */
+
+#include <stddef.h>
+
+struct ring_ffi_struct_metadata {
+  // Keep in sync with |ring::ffi|.
+  const char *name;
+  size_t size;
+  size_t alignment;
+
+  /* The array is terminated by an element with a |NULL| name. */
+  const struct struct_member_metadata *members;
+};
+
+struct ring_ffi_struct_member_metadata {
+  // Keep in sync with |ring::ffi|.
+  const char *name;
+  size_t offset;
+};
+
+#if defined(_MSC_VER)
+#define RING_ALIGNOF __alignof
+#else
+#define RING_ALIGNOF _Alignof
+#endif
+
+#define RING_META_META_STRUCT(struct_name) \
+        size_t struct_name##_size(void) { \
+            return sizeof(struct struct_name); \
+        } \
+        \
+        size_t struct_name##_alignment(void) { \
+            return RING_ALIGNOF(struct struct_name); \
+        }
+
+#define RING_META_META_MEMBER(struct_name, member_name) \
+        size_t struct_name##_##member_name##_offset(void) { \
+            return offsetof(struct struct_name, member_name); \
+        }
+
+RING_META_META_STRUCT(ring_ffi_struct_metadata)
+RING_META_META_MEMBER(ring_ffi_struct_metadata, name)
+RING_META_META_MEMBER(ring_ffi_struct_metadata, size)
+RING_META_META_MEMBER(ring_ffi_struct_metadata, alignment)
+RING_META_META_MEMBER(ring_ffi_struct_metadata, members)
+
+RING_META_META_STRUCT(ring_ffi_struct_member_metadata)
+RING_META_META_MEMBER(ring_ffi_struct_member_metadata, name)
+RING_META_META_MEMBER(ring_ffi_struct_member_metadata, offset)
+
+/* These macros are defined in ffi.h to expand to nothing. However, now we need
+ * them to expand into the definitions of the metadata functions. */
+
+#undef RING_BEGIN_STRUCT_METADATA
+#define RING_BEGIN_STRUCT_METADATA(struct_name) \
+        const struct ring_ffi_struct_metadata \
+        *ring_ffi_##struct_name##_metadata(void) { \
+          static const struct ring_ffi_struct_metadata METADATA = { \
+            #struct_name, \
+            sizeof(struct struct_name), \
+            ALIGNOF(struct struct_name), \
+            { \
+
+#undef RING_MEMBER_METADATA
+#define RING_MEMBER_METADATA(struct_name, member_name) \
+              { #member_name, offsetof(struct struct_name, member_name) }
+
+#undef RING_END_STRUCT_METADATA
+#define RING_END_STRUCT_METADATA(struct_name) \
+              { NULL, 0 } \
+            } \
+          }; \
+          return &METADATA; \
+        }

crypto/ffi.h

@@ -0,0 +1,58 @@
+/* Copyright 2015 Brian Smith.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef RING_HEADER_CRYPTO_FFI_H
+#define RING_HEADER_CRYPTO_FFI_H
+
+/* The *ring* FFI consistency interface provides a means for ensuring that
+ * C and Rust definitions of structs match.
+ *
+ * # Example:
+ *
+ * ```C
+ * struct foo_foo {
+ *   // Keep this in sync with |ring::foo::foo| and the metadata below.
+ *   uint64_t bar[12];
+ *   int baz;
+ * };
+ *
+ * RING_BEGIN_STRUCT_METADATA(foo_foo)
+ *   RING_MEMBER_METADATA(foo_foo, bar)
+ *   RING_MEMBER_METADATA(foo_foo, baz)
+ * RING_END_STRUCT_METADATA(foo_foo)
+ * ```
+ *
+ * ```rust
+ *
+ * use libc;
+ *
+ * #[macro_use(checked_struct)]
+ * use ring::ffi;
+ *
+ * checked_struct!{
+ *     struct foo_foo {
+ *         bar: [u64; 12],
+ *         baz: libc::c_int,
+ *     },
+ *     test_foo_foo_struct_consistency,
+ *     ring_ffi_foo_foo_metadata
+ * }
+ * ```
+ */
+
+#define RING_BEGIN_STRUCT_METADATA(struct_name)
+#define RING_MEMBER_METADATA(struct_name, member_name)
+#define RING_END_STRUCT_METADATA(struct_name)
+
+#endif

crypto/libring.Windows.vcxproj

@@ -64,6 +64,7 @@
     <ClCompile Include="ecdh\ecdh.c" />
     <ClCompile Include="ecdsa\ecdsa.c" />
     <ClCompile Include="ecdsa\ecdsa_asn1.c" />
+    <ClCompile Include="ffi.c" />
     <ClCompile Include="mem.c" />
     <ClCompile Include="modes\cbc.c" />
     <ClCompile Include="modes\ctr.c" />
@@ -110,4 +111,4 @@
     </ClCompile>
   </ItemDefinitionGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-</Project>
+</Project>

mk/ring.mk

@@ -68,6 +68,7 @@ RING_SRCS = $(addprefix $(RING_PREFIX), \
   crypto/ecdh/ecdh.c \
   crypto/ecdsa/ecdsa.c \
   crypto/ecdsa/ecdsa_asn1.c \
+  crypto/ffi.c \
   crypto/mem.c \
   crypto/modes/cbc.c \
   crypto/modes/ctr.c \