auto merge of #10367 : alexcrichton/rust/system-abi, r=nikomatsakis

This adds an other ABI option which allows a custom selection over the target
architecture and OS. The only current candidate for this change is that kernel32
on win32 uses stdcall, but on win64 it uses the cdecl calling convention.
Otherwise everywhere else this is defined as using the Cdecl calling convention.

cc #10049
Closes #8774

doc/tutorial-ffi.md

@@ -418,15 +418,32 @@ calling foreign functions. Some foreign functions, most notably the Windows API,
 conventions. Rust provides a way to tell the compiler which convention to use:
 
 ~~~~
-#[cfg(target_os = "win32")]
+#[cfg(target_os = "win32", target_arch = "x86")]
 #[link_name = "kernel32"]
 extern "stdcall" {
     fn SetEnvironmentVariableA(n: *u8, v: *u8) -> int;
 }
 ~~~~
 
-This applies to the entire `extern` block, and must be either `"cdecl"` or
-`"stdcall"`. The compiler may eventually support other calling conventions.
+This applies to the entire `extern` block. The list of supported ABI constraints
+are:
+
+* `stdcall`
+* `aapcs`
+* `cdecl`
+* `fastcall`
+* `Rust`
+* `rust-intrinsic`
+* `system`
+* `C`
+
+Most of the abis in this list are self-explanatory, but the `system` abi may
+seem a little odd. This constraint selects whatever the appropriate ABI is for
+interoperating with the target's libraries. For example, on win32 with a x86
+architecture, this means that the abi used would be `stdcall`. On x86_64,
+however, windows uses the `C` calling convention, so `C` would be used. This
+means that in our previous example, we could have used `extern "system" { ... }`
+to define a block for all windows systems, not just x86 ones.
 
 # Interoperability with foreign code
 

src/librustc/back/arm.rs

@@ -10,49 +10,49 @@
 
 use back::target_strs;
 use driver::session::sess_os_to_meta_os;
-use driver::session;
 use metadata::loader::meta_section_name;
+use syntax::abi;
 
-pub fn get_target_strs(target_triple: ~str, target_os: session::Os) -> target_strs::t {
+pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::t {
     return target_strs::t {
         module_asm: ~"",
 
         meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
-          session::OsMacos => {
+          abi::OsMacos => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsWin32 => {
+          abi::OsWin32 => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsLinux => {
+          abi::OsLinux => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsAndroid => {
+          abi::OsAndroid => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsFreebsd => {
+          abi::OsFreebsd => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +

src/librustc/back/link.rs

@@ -32,6 +32,7 @@ use std::run;
 use std::str;
 use std::vec;
 use std::rt::io::fs;
+use syntax::abi;
 use syntax::ast;
 use syntax::ast_map::{path, path_mod, path_name, path_pretty_name};
 use syntax::attr;
@@ -877,13 +878,13 @@ pub fn mangle_internal_name_by_path(ccx: &mut CrateContext, path: path) -> ~str
 }
 
 
-pub fn output_dll_filename(os: session::Os, lm: LinkMeta) -> ~str {
+pub fn output_dll_filename(os: abi::Os, lm: LinkMeta) -> ~str {
     let (dll_prefix, dll_suffix) = match os {
-        session::OsWin32 => (win32::DLL_PREFIX, win32::DLL_SUFFIX),
-        session::OsMacos => (macos::DLL_PREFIX, macos::DLL_SUFFIX),
-        session::OsLinux => (linux::DLL_PREFIX, linux::DLL_SUFFIX),
-        session::OsAndroid => (android::DLL_PREFIX, android::DLL_SUFFIX),
-        session::OsFreebsd => (freebsd::DLL_PREFIX, freebsd::DLL_SUFFIX),
+        abi::OsWin32 => (win32::DLL_PREFIX, win32::DLL_SUFFIX),
+        abi::OsMacos => (macos::DLL_PREFIX, macos::DLL_SUFFIX),
+        abi::OsLinux => (linux::DLL_PREFIX, linux::DLL_SUFFIX),
+        abi::OsAndroid => (android::DLL_PREFIX, android::DLL_SUFFIX),
+        abi::OsFreebsd => (freebsd::DLL_PREFIX, freebsd::DLL_SUFFIX),
     };
     format!("{}{}-{}-{}{}", dll_prefix, lm.name, lm.extras_hash, lm.vers, dll_suffix)
 }
@@ -898,7 +899,7 @@ pub fn get_cc_prog(sess: Session) -> ~str {
     match sess.opts.linker {
         Some(ref linker) => linker.to_str(),
         None => match sess.targ_cfg.os {
-            session::OsAndroid =>
+            abi::OsAndroid =>
                 match &sess.opts.android_cross_path {
                     &Some(ref path) => {
                         format!("{}/bin/arm-linux-androideabi-gcc", *path)
@@ -908,7 +909,7 @@ pub fn get_cc_prog(sess: Session) -> ~str {
                                     (--android-cross-path)")
                     }
                 },
-            session::OsWin32 => ~"g++",
+            abi::OsWin32 => ~"g++",
             _ => ~"cc"
         }
     }
@@ -956,7 +957,7 @@ pub fn link_binary(sess: Session,
     }
 
     // Clean up on Darwin
-    if sess.targ_cfg.os == session::OsMacos {
+    if sess.targ_cfg.os == abi::OsMacos {
         // FIXME (#9639): This needs to handle non-utf8 paths
         run::process_status("dsymutil", [output.as_str().unwrap().to_owned()]);
     }
@@ -985,7 +986,7 @@ pub fn link_args(sess: Session,
     // Converts a library file-stem into a cc -l argument
     fn unlib(config: @session::config, stem: ~str) -> ~str {
         if stem.starts_with("lib") &&
-            config.os != session::OsWin32 {
+            config.os != abi::OsWin32 {
             stem.slice(3, stem.len()).to_owned()
         } else {
             stem
@@ -1029,7 +1030,7 @@ pub fn link_args(sess: Session,
         obj_filename.as_str().unwrap().to_owned()]);
 
     let lib_cmd = match sess.targ_cfg.os {
-        session::OsMacos => ~"-dynamiclib",
+        abi::OsMacos => ~"-dynamiclib",
         _ => ~"-shared"
     };
 
@@ -1080,7 +1081,7 @@ pub fn link_args(sess: Session,
 
         // On mac we need to tell the linker to let this library
         // be rpathed
-        if sess.targ_cfg.os == session::OsMacos {
+        if sess.targ_cfg.os == abi::OsMacos {
             // FIXME (#9639): This needs to handle non-utf8 paths
             args.push("-Wl,-install_name,@rpath/"
                       + output.filename_str().unwrap());
@@ -1089,20 +1090,20 @@ pub fn link_args(sess: Session,
 
     // On linux librt and libdl are an indirect dependencies via rustrt,
     // and binutils 2.22+ won't add them automatically
-    if sess.targ_cfg.os == session::OsLinux {
+    if sess.targ_cfg.os == abi::OsLinux {
         args.push_all([~"-lrt", ~"-ldl"]);
 
         // LLVM implements the `frem` instruction as a call to `fmod`,
         // which lives in libm. Similar to above, on some linuxes we
         // have to be explicit about linking to it. See #2510
         args.push(~"-lm");
     }
-    else if sess.targ_cfg.os == session::OsAndroid {
+    else if sess.targ_cfg.os == abi::OsAndroid {
         args.push_all([~"-ldl", ~"-llog",  ~"-lsupc++", ~"-lgnustl_shared"]);
         args.push(~"-lm");
     }
 
-    if sess.targ_cfg.os == session::OsFreebsd {
+    if sess.targ_cfg.os == abi::OsFreebsd {
         args.push_all([~"-pthread", ~"-lrt",
                        ~"-L/usr/local/lib", ~"-lexecinfo",
                        ~"-L/usr/local/lib/gcc46",

src/librustc/back/mips.rs

@@ -9,50 +9,50 @@
 // except according to those terms.
 
 use back::target_strs;
-use driver::session;
 use driver::session::sess_os_to_meta_os;
 use metadata::loader::meta_section_name;
+use syntax::abi;
 
-pub fn get_target_strs(target_triple: ~str, target_os: session::Os) -> target_strs::t {
+pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::t {
     return target_strs::t {
         module_asm: ~"",
 
         meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
-          session::OsMacos => {
+          abi::OsMacos => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsWin32 => {
+          abi::OsWin32 => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsLinux => {
+          abi::OsLinux => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsAndroid => {
+          abi::OsAndroid => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +
                 "-v64:64:64-v128:64:128" +
                 "-a0:0:64-n32"
           }
 
-          session::OsFreebsd => {
+          abi::OsFreebsd => {
             ~"e-p:32:32:32" +
                 "-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" +
                 "-f32:32:32-f64:64:64" +

src/librustc/back/rpath.rs

@@ -15,17 +15,18 @@ use metadata::filesearch;
 
 use std::hashmap::HashSet;
 use std::{os, vec};
+use syntax::abi;
 
-fn not_win32(os: session::Os) -> bool {
-  os != session::OsWin32
+fn not_win32(os: abi::Os) -> bool {
+  os != abi::OsWin32
 }
 
 pub fn get_rpath_flags(sess: session::Session, out_filename: &Path)
                     -> ~[~str] {
     let os = sess.targ_cfg.os;
 
     // No rpath on windows
-    if os == session::OsWin32 {
+    if os == abi::OsWin32 {
         return ~[];
     }
 
@@ -55,7 +56,7 @@ pub fn rpaths_to_flags(rpaths: &[~str]) -> ~[~str] {
     rpaths.iter().map(|rpath| format!("-Wl,-rpath,{}",*rpath)).collect()
 }
 
-fn get_rpaths(os: session::Os,
+fn get_rpaths(os: abi::Os,
               sysroot: &Path,
               output: &Path,
               libs: &[Path],
@@ -100,13 +101,13 @@ fn get_rpaths(os: session::Os,
     return rpaths;
 }
 
-fn get_rpaths_relative_to_output(os: session::Os,
+fn get_rpaths_relative_to_output(os: abi::Os,
                                  output: &Path,
                                  libs: &[Path]) -> ~[~str] {
     libs.iter().map(|a| get_rpath_relative_to_output(os, output, a)).collect()
 }
 
-pub fn get_rpath_relative_to_output(os: session::Os,
+pub fn get_rpath_relative_to_output(os: abi::Os,
                                     output: &Path,
                                     lib: &Path)
                                  -> ~str {
@@ -116,10 +117,10 @@ pub fn get_rpath_relative_to_output(os: session::Os,
 
     // Mac doesn't appear to support $ORIGIN
     let prefix = match os {
-        session::OsAndroid | session::OsLinux | session::OsFreebsd
+        abi::OsAndroid | abi::OsLinux | abi::OsFreebsd
                           => "$ORIGIN",
-        session::OsMacos => "@loader_path",
-        session::OsWin32 => unreachable!()
+        abi::OsMacos => "@loader_path",
+        abi::OsWin32 => unreachable!()
     };
 
     let mut lib = os::make_absolute(lib);
@@ -169,13 +170,10 @@ pub fn minimize_rpaths(rpaths: &[~str]) -> ~[~str] {
 mod test {
     use std::os;
 
-    // FIXME(#2119): the outer attribute should be #[cfg(unix, test)], then
-    // these redundant #[cfg(test)] blocks can be removed
-    #[cfg(test)]
-    #[cfg(test)]
     use back::rpath::{get_absolute_rpath, get_install_prefix_rpath};
     use back::rpath::{minimize_rpaths, rpaths_to_flags, get_rpath_relative_to_output};
     use driver::session;
+    use syntax::abi;
 
     #[test]
     fn test_rpaths_to_flags() {
@@ -219,7 +217,7 @@ mod test {
     #[cfg(target_os = "linux")]
     #[cfg(target_os = "android")]
     fn test_rpath_relative() {
-      let o = session::OsLinux;
+      let o = abi::OsLinux;
       let res = get_rpath_relative_to_output(o,
             &Path::new("bin/rustc"), &Path::new("lib/libstd.so"));
       assert_eq!(res.as_slice(), "$ORIGIN/../lib");
@@ -228,7 +226,7 @@ mod test {
     #[test]
     #[cfg(target_os = "freebsd")]
     fn test_rpath_relative() {
-        let o = session::OsFreebsd;
+        let o = abi::OsFreebsd;
         let res = get_rpath_relative_to_output(o,
             &Path::new("bin/rustc"), &Path::new("lib/libstd.so"));
         assert_eq!(res.as_slice(), "$ORIGIN/../lib");
@@ -237,7 +235,7 @@ mod test {
     #[test]
     #[cfg(target_os = "macos")]
     fn test_rpath_relative() {
-        let o = session::OsMacos;
+        let o = abi::OsMacos;
         let res = get_rpath_relative_to_output(o,
                                                &Path::new("bin/rustc"),
                                                &Path::new("lib/libstd.so"));