Merge pull request sfackler#1359 from stbuehler/const-ptr-api-macro

Add and use const_ptr_api macro in openssl-sys
hargoniX · Oct 25, 2020 · f958176 · f958176
2 parents e796b76 + 1dbeb8c
commit f958176
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Showing 10 changed files with 395 additions and 441 deletions.
diff --git a/openssl-sys/src/asn1.rs b/openssl-sys/src/asn1.rs
@@ -61,14 +61,8 @@ extern "C" {
     pub fn ASN1_TIME_set_string_X509(s: *mut ASN1_TIME, str: *const c_char) -> c_int;
 }
 
-cfg_if! {
-    if #[cfg(any(ossl110, libressl280))] {
-        extern "C" {
-            pub fn ASN1_STRING_to_UTF8(out: *mut *mut c_uchar, s: *const ASN1_STRING) -> c_int;
-        }
-    } else {
-        extern "C" {
-            pub fn ASN1_STRING_to_UTF8(out: *mut *mut c_uchar, s: *mut ASN1_STRING) -> c_int;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn ASN1_STRING_to_UTF8(out: *mut *mut c_uchar, s: #[const_ptr_if(any(ossl110, libressl280))] ASN1_STRING) -> c_int;
     }
 }
diff --git a/openssl-sys/src/bio.rs b/openssl-sys/src/bio.rs
@@ -60,17 +60,10 @@ pub unsafe fn BIO_get_mem_data(b: *mut BIO, pp: *mut *mut c_char) -> c_long {
     BIO_ctrl(b, BIO_CTRL_INFO, 0, pp as *mut c_void)
 }
 
-cfg_if! {
-    if #[cfg(any(ossl110, libressl280))] {
-        extern "C" {
-            pub fn BIO_s_file() -> *const BIO_METHOD;
-            pub fn BIO_new(type_: *const BIO_METHOD) -> *mut BIO;
-        }
-    } else {
-        extern "C" {
-            pub fn BIO_s_file() -> *mut BIO_METHOD;
-            pub fn BIO_new(type_: *mut BIO_METHOD) -> *mut BIO;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn BIO_s_file() -> #[const_ptr_if(any(ossl110, libressl280))] BIO_METHOD;
+        pub fn BIO_new(type_: #[const_ptr_if(any(ossl110, libressl280))] BIO_METHOD) -> *mut BIO;
     }
 }
 extern "C" {
@@ -88,26 +81,10 @@ extern "C" {
     pub fn BIO_free_all(b: *mut BIO);
 }
 
-cfg_if! {
-    if #[cfg(any(ossl110, libressl280))] {
-        extern "C" {
-            pub fn BIO_s_mem() -> *const BIO_METHOD;
-        }
-    } else {
-        extern "C" {
-            pub fn BIO_s_mem() -> *mut BIO_METHOD;
-        }
-    }
-}
-cfg_if! {
-    if #[cfg(any(ossl102, libressl280))] {
-        extern "C" {
-            pub fn BIO_new_mem_buf(buf: *const c_void, len: c_int) -> *mut BIO;
-        }
-    } else {
-        extern "C" {
-            pub fn BIO_new_mem_buf(buf: *mut c_void, len: c_int) -> *mut BIO;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn BIO_s_mem() -> #[const_ptr_if(any(ossl110, libressl280))] BIO_METHOD;
+        pub fn BIO_new_mem_buf(buf: #[const_ptr_if(any(ossl102, libressl280))] c_void, len: c_int) -> *mut BIO;
     }
 }
 

diff --git a/openssl-sys/src/evp.rs b/openssl-sys/src/evp.rs
@@ -174,15 +174,9 @@ extern "C" {
         outl: *mut c_int,
     ) -> c_int;
 }
-cfg_if! {
-    if #[cfg(any(ossl111b, libressl280))] {
-        extern "C" {
-            pub fn EVP_PKEY_size(pkey: *const EVP_PKEY) -> c_int;
-        }
-    } else {
-        extern "C" {
-            pub fn EVP_PKEY_size(pkey: *mut EVP_PKEY) -> c_int;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn EVP_PKEY_size(pkey: #[const_ptr_if(any(ossl111b, libressl280))] EVP_PKEY) -> c_int;
     }
 }
 cfg_if! {
@@ -206,23 +200,13 @@ cfg_if! {
         }
     }
 }
-cfg_if! {
-    if #[cfg(any(ossl102, libressl280))] {
-        extern "C" {
-            pub fn EVP_DigestVerifyFinal(
-                ctx: *mut EVP_MD_CTX,
-                sigret: *const c_uchar,
-                siglen: size_t,
-            ) -> c_int;
-        }
-    } else {
-        extern "C" {
-            pub fn EVP_DigestVerifyFinal(
-                ctx: *mut EVP_MD_CTX,
-                sigret: *mut c_uchar,
-                siglen: size_t,
-            ) -> c_int;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn EVP_DigestVerifyFinal(
+            ctx: *mut EVP_MD_CTX,
+            sigret: #[const_ptr_if(any(ossl102, libressl280))] c_uchar,
+            siglen: size_t,
+        ) -> c_int;
     }
 }
 
@@ -317,15 +301,9 @@ extern "C" {
 
     pub fn EVP_PKEY_id(pkey: *const EVP_PKEY) -> c_int;
 }
-cfg_if! {
-    if #[cfg(any(ossl110, libressl280))] {
-        extern "C" {
-            pub fn EVP_PKEY_bits(key: *const EVP_PKEY) -> c_int;
-        }
-    } else {
-        extern "C" {
-            pub fn EVP_PKEY_bits(key: *mut EVP_PKEY) -> c_int;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn EVP_PKEY_bits(key: #[const_ptr_if(any(ossl110, libressl280))] EVP_PKEY) -> c_int;
     }
 }
 extern "C" {
@@ -456,15 +434,9 @@ extern "C" {
     ) -> c_int;
 }
 
-cfg_if! {
-    if #[cfg(any(ossl110, libressl280))] {
-        extern "C" {
-            pub fn EVP_PKCS82PKEY(p8: *const PKCS8_PRIV_KEY_INFO) -> *mut EVP_PKEY;
-        }
-    } else {
-        extern "C" {
-            pub fn EVP_PKCS82PKEY(p8: *mut PKCS8_PRIV_KEY_INFO) -> *mut EVP_PKEY;
-        }
+const_ptr_api! {
+    extern "C" {
+        pub fn EVP_PKCS82PKEY(p8: #[const_ptr_if(any(ossl110, libressl280))] PKCS8_PRIV_KEY_INFO) -> *mut EVP_PKEY;
     }
 }
 

diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
@@ -9,6 +9,7 @@
     unused_imports
 )]
 #![doc(html_root_url = "https://docs.rs/openssl-sys/0.9")]
+#![recursion_limit = "128"] // configure fixed limit across all rust versions
 
 extern crate libc;
 

diff --git a/openssl-sys/src/macros.rs b/openssl-sys/src/macros.rs
@@ -85,3 +85,212 @@ macro_rules! const_fn {
         )*
     }
 }
+
+// openssl changes `*mut` to `*const` in certain parameters in certain versions;
+// in C this is ABI and (mostly) API compatible.
+//
+// We need to handle this explicitly, and this macro helps annotate which
+// parameter got converted in which version.
+//
+// Input is:
+//    extern "C" {
+//        #[attributes...]
+//        pub fn name(args) -> rettype; // `-> rettype` optional
+//        // more functions...
+//    }
+//
+// This macro replaces `#[const_ptr_if(...)]` in types with `*const` or `*mut`
+// (depending on the inner cfg flags)
+//
+// Walks through all argument and return types, but only finds inner types of
+// `*const` and `*mut`; doesn't walk arrays or generics.
+//
+// NOTE: can't abstract `pub` as `$fn_vis:vis`, as ctest macro handling doesn't
+// support it (old syntax crate). But we really only need `pub` anyway.
+//
+// NOTE: ctest seams to simply ignore macros it can't expand (whatever the
+// reason)
+macro_rules! const_ptr_api {
+    // ----------------------------------------------------------------
+    // (partialarg): partial argument, waiting for "final" argument type
+    // MAGIC PART 1: hande conditional const ptr in argument type
+    ( (partialarg)
+        { $(#[$fn_attr:meta])* pub fn $fn_name:ident }
+        $args_packed:tt
+        [ $($part_arg:tt)* ]
+        [ #[const_ptr_if( $($cfg:tt)* )] $($arg_rem:tt)* ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (partialarg) { #[cfg($($cfg)*)]      $(#[$fn_attr])* pub fn $fn_name } $args_packed [ $($part_arg)* *const ] [ $($arg_rem)* ] $ret_packed );
+        const_ptr_api!( (partialarg) { #[cfg(not($($cfg)*))] $(#[$fn_attr])* pub fn $fn_name } $args_packed [ $($part_arg)* *mut   ] [ $($arg_rem)* ] $ret_packed );
+    };
+    // continue partial argument with `*mut` pointer (might need special const handling in inner type)
+    ( (partialarg)
+        $def_packed:tt
+        $args_packed:tt
+        [ $($part_arg:tt)* ]
+        [ *mut $($arg_rem:tt)* ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (partialarg) $def_packed $args_packed [ $($part_arg)* *mut ] [ $($arg_rem)* ] $ret_packed );
+    };
+    // continue partial argument with `*const` pointer (might need special const handling in inner type)
+    ( (partialarg)
+        $def_packed:tt
+        $args_packed:tt
+        [ $($part_arg:tt)* ]
+        [ *const $($arg_rem:tt)* ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (partialarg) $def_packed $args_packed [ $($part_arg)* *const ] [ $($arg_rem)* ] $ret_packed );
+    };
+    // finish partial argument with trailing comma
+    ( (partialarg)
+        $def_packed:tt
+        { $($args_tt:tt)* }
+        [ $($part_arg:tt)* ]
+        [ $arg_ty:ty, $($arg_rem:tt)* ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (parseargs) $def_packed { $($args_tt)* { $($part_arg)* $arg_ty } } [ $($arg_rem)* ] $ret_packed );
+    };
+    // finish final partial argument (no trailing comma)
+    ( (partialarg)
+        $def_packed:tt
+        { $($args_tt:tt)* }
+        [ $($part_arg:tt)* ]
+        [ $arg_ty:ty ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (parseargs) $def_packed { $($args_tt)* { $($part_arg)* $arg_ty } } [ ] $ret_packed );
+    };
+
+    // ----------------------------------------------------------------
+    // (parseargs): parsing arguments
+    // start next argument
+    ( (parseargs)
+        $def_packed:tt
+        $args_packed:tt
+        [ $arg_name:ident : $($arg_rem:tt)* ]
+        $ret_packed:tt
+    ) => {
+        const_ptr_api!( (partialarg) $def_packed $args_packed [ $arg_name: ] [ $($arg_rem)* ] $ret_packed );
+    };
+    // end of arguments, there is a return type; start parsing it
+    ( (parseargs)
+        $def_packed:tt
+        $args_packed:tt
+        [ ]
+        [ -> $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (partialret) $def_packed $args_packed [] [ $($rem)* ] );
+    };
+    // end of arguments, no return type
+    ( (parseargs)
+        $def_packed:tt
+        $args_packed:tt
+        [ ]
+        [ ]
+    ) => {
+        const_ptr_api!( (generate) $def_packed $args_packed { () } );
+    };
+
+    // ----------------------------------------------------------------
+    // (partialret): have partial return type, waiting for final return type
+    // MAGIC PART 2: hande conditional const ptr in return type
+    ( (partialret)
+        { $(#[$fn_attr:meta])* pub fn $fn_name:ident }
+        $args_packed:tt
+        [ $($part_ret:tt)* ]
+        [ #[const_ptr_if( $($cfg:tt)* )] $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (partialret) { #[cfg($($cfg)*)]      $(#[$fn_attr])* pub fn $fn_name } $args_packed [ $($part_ret)* *const ] [ $($rem)* ] );
+        const_ptr_api!( (partialret) { #[cfg(not($($cfg)*))] $(#[$fn_attr])* pub fn $fn_name } $args_packed [ $($part_ret)* *mut   ] [ $($rem)* ] );
+    };
+    // `* mut` part in return type; continue parsing to find inner conditional const ptr
+    ( (partialret)
+        $def_packed:tt
+        $args_packed:tt
+        [ $($part_ret:tt)* ]
+        [ *mut $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (partialret) $def_packed $args_packed [ $($part_ret)* *mut ] [ $($rem)* ] );
+    };
+    // `* const` part in return type; continue parsing to find inner conditional const ptr
+    ( (partialret)
+        $def_packed:tt
+        $args_packed:tt
+        [ $($part_ret:tt)* ]
+        [ *const $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (partialret) $def_packed $args_packed [ $($part_ret)* *const ] [ $($rem)* ] );
+    };
+    // final part of return type
+    ( (partialret)
+        $def_packed:tt
+        $args_packed:tt
+        [ $($part_ret:tt)* ]
+        [ $ret_ty:ty ]
+    ) => {
+        const_ptr_api!( (generate) $def_packed $args_packed { $($part_ret)* $ret_ty } );
+    };
+
+    // ----------------------------------------------------------------
+    // generate
+    ( (generate)
+        { $(#[$fn_attr:meta])* pub fn $fn_name:ident }
+        { $({ $arg_name:ident: $($arg_ty:tt)* })* }
+        { $ret_ty:ty }
+    ) => {
+        extern "C" {
+            $(#[$fn_attr])*
+            pub fn $fn_name( $(
+                $arg_name: $($arg_ty)*
+            ),* ) -> $ret_ty;
+        }
+    };
+
+    // ----------------------------------------------------------------
+    // (fn): gather tokens for return type until ";"
+    // found end; start parsing current function, and parse remaining functions
+    ( (fn)
+        $def_packed:tt
+        $arg_tts_packed:tt
+        $ret_packed:tt
+        [ ; $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (parseargs) $def_packed {} $arg_tts_packed $ret_packed );
+        const_ptr_api!( (extern) [ $($rem)* ] );
+    };
+    // not ";" - all other tokens are part of the return type.
+    // don't expand return type yet; otherwise we'd have to remember in which branch `rem` needs
+    // to be used to parse further functions.
+    ( (fn)
+        $def_packed:tt
+        $arg_tts_packed:tt
+        [ $($ret_tt:tt)* ]
+        [ $tt:tt $($rem:tt)* ]
+    ) => {
+        const_ptr_api!( (fn) $def_packed $arg_tts_packed [ $($ret_tt)* $tt ] [ $($rem)* ] );
+    };
+
+    // ----------------------------------------------------------------
+    // (extern): in extern block, find next function
+    // try to split into functions as fast as possible to reduce recursion depth
+    ( (extern) [
+        $(#[$fn_attr:meta])*
+        pub fn $fn_name:ident( $($arg_rem:tt)* ) $($rem:tt)*
+    ] ) => {
+        const_ptr_api!( (fn)
+            { $(#[$fn_attr])* pub fn $fn_name } [ $($arg_rem)* ] [] [ $($rem)* ]
+        );
+    };
+    // end of extern block
+    ( (extern) [] ) => {};
+
+    // ----------------------------------------------------------------
+    // macro start; find extern block
+    ( extern "C" { $($rem:tt)* } ) => {
+        const_ptr_api!( (extern) [ $($rem)* ] );
+    };
+}