Add AbiSet and integrate it into the AST.

I believe this patch incorporates all expected syntax changes from extern
function reform (#3678). You can now write things like:

    extern "<abi>" fn foo(s: S) -> T { ... }
    extern "<abi>" mod { ... }
    extern "<abi>" fn(S) -> T

The ABI for foreign functions is taken from this syntax (rather than from an
annotation).  We support the full ABI specification I described on the mailing
list.  The correct ABI is chosen based on the target architecture.

Calls by pointer to C functions are not yet supported, and the Rust type of
crust fns is still *u8.

Author: nikomatsakis

src/libcore/cast.rs

@@ -13,7 +13,7 @@
 pub mod rusti {
     #[abi = "rust-intrinsic"]
     #[link_name = "rusti"]
-    pub extern {
+    pub extern "rust-intrinsic" {
         fn forget<T>(+x: T);
         fn reinterpret_cast<T, U>(&&e: T) -> U;
     }

src/libcore/libc.rs

@@ -1617,7 +1617,7 @@ pub mod funcs {
             use libc::types::os::arch::extra::{HANDLE};
 
             #[abi = "stdcall"]
-            pub extern {
+            pub extern "stdcall" {
                 unsafe fn GetEnvironmentVariableW(n: LPCWSTR,
                                                   v: LPWSTR,
                                                   nsize: DWORD)

src/libcore/os.rs

@@ -942,7 +942,7 @@ pub fn errno() -> uint {
 
     #[link_name = "kernel32"]
     #[abi = "stdcall"]
-    extern {
+    extern "stdcall" {
         unsafe fn GetLastError() -> DWORD;
     }
 
@@ -1004,7 +1004,7 @@ pub fn last_os_error() -> ~str {
 
         #[link_name = "kernel32"]
         #[abi = "stdcall"]
-        extern {
+        extern "stdcall" {
             unsafe fn FormatMessageA(flags: DWORD, lpSrc: LPVOID,
                                      msgId: DWORD, langId: DWORD,
                                      buf: LPSTR, nsize: DWORD,
@@ -1118,15 +1118,15 @@ type LPCWSTR = *u16;
 #[cfg(windows)]
 #[link_name="kernel32"]
 #[abi="stdcall"]
-extern {
+extern "stdcall" {
     fn GetCommandLineW() -> LPCWSTR;
     fn LocalFree(ptr: *c_void);
 }
 
 #[cfg(windows)]
 #[link_name="shell32"]
 #[abi="stdcall"]
-extern {
+extern "stdcall" {
     fn CommandLineToArgvW(lpCmdLine: LPCWSTR, pNumArgs: *mut c_int) -> **u16;
 }
 

src/libcore/ptr.rs

@@ -43,7 +43,7 @@ pub mod libc_ {
 
 pub mod rusti {
     #[abi = "rust-intrinsic"]
-    pub extern {
+    pub extern "rust-intrinsic" {
         fn addr_of<T>(&&val: T) -> *T;
     }
 }

src/libcore/rt/thread_local_storage.rs

@@ -73,7 +73,7 @@ pub unsafe fn get(key: Key) -> *mut c_void {
 
 #[cfg(windows)]
 #[abi = "stdcall"]
-extern {
+extern "stdcall" {
        fn TlsAlloc() -> DWORD;
        fn TlsSetValue(dwTlsIndex: DWORD, lpTlsvalue: LPVOID) -> BOOL;
        fn TlsGetValue(dwTlsIndex: DWORD) -> LPVOID;

src/libcore/stackwalk.rs

@@ -94,7 +94,7 @@ pub mod rustrt {
 
 pub mod rusti {
     #[abi = "rust-intrinsic"]
-    pub extern {
+    pub extern "rust-intrinsic" {
         pub fn frame_address(f: &once fn(x: *u8));
     }
 }

src/libcore/sys.rs

@@ -39,7 +39,7 @@ pub struct Closure {
 
 pub mod rusti {
     #[abi = "rust-intrinsic"]
-    pub extern {
+    pub extern "rust-intrinsic" {
         fn get_tydesc<T>() -> *();
         fn size_of<T>() -> uint;
         fn pref_align_of<T>() -> uint;

src/libcore/unstable/intrinsics.rs

@@ -15,7 +15,7 @@ The intrinsics are defined in librustc/middle/trans/foreign.rs.
 */
 
 #[abi = "rust-intrinsic"]
-pub extern {
+pub extern "rust-intrinsic" {
     pub fn atomic_cxchg(dst: &mut int, old: int, src: int) -> int;
     pub fn atomic_cxchg_acq(dst: &mut int, old: int, src: int) -> int;
     pub fn atomic_cxchg_rel(dst: &mut int, old: int, src: int) -> int;

src/librustc/back/link.rs

@@ -97,7 +97,7 @@ pub mod jit {
     pub mod rusti {
         #[nolink]
         #[abi = "rust-intrinsic"]
-        pub extern {
+        pub extern "rust-intrinsic" {
             pub fn morestack_addr() -> *();
         }
     }

src/librustc/driver/driver.rs

@@ -33,6 +33,7 @@ use std::getopts::groups::{optopt, optmulti, optflag, optflagopt, getopts};
 use std::getopts::{opt_present};
 use std::getopts;
 use syntax::ast;
+use syntax::abi;
 use syntax::attr;
 use syntax::codemap;
 use syntax::diagnostic;
@@ -85,10 +86,10 @@ pub fn default_configuration(sess: Session, +argv0: ~str, input: input) ->
     // ARM is bi-endian, however using NDK seems to default
     // to little-endian unless a flag is provided.
     let (end,arch,wordsz) = match sess.targ_cfg.arch {
-      session::arch_x86 => (~"little",~"x86",~"32"),
-      session::arch_x86_64 => (~"little",~"x86_64",~"64"),
-      session::arch_arm => (~"little",~"arm",~"32"),
-      session::arch_mips => (~"little",~"arm",~"32")
+        abi::X86 => (~"little",~"x86",~"32"),
+        abi::X86_64 => (~"little",~"x86_64",~"64"),
+        abi::Arm => (~"little",~"arm",~"32"),
+        abi::Mips => (~"little",~"arm",~"32")
     };
 
     return ~[ // Target bindings.
@@ -308,7 +309,7 @@ pub fn compile_rest(sess: Session, cfg: ast::crate_cfg,
     };
 
     // NOTE: Android hack
-    if sess.targ_cfg.arch == session::arch_arm &&
+    if sess.targ_cfg.arch == abi::Arm &&
             (sess.opts.output_type == link::output_type_object ||
              sess.opts.output_type == link::output_type_exe) {
         let output_type = link::output_type_assembly;
@@ -453,20 +454,20 @@ pub fn get_os(triple: &str) -> Option<session::os> {
         } else { None }
 }
 
-pub fn get_arch(triple: &str) -> Option<session::arch> {
+pub fn get_arch(triple: &str) -> Option<abi::Architecture> {
     if str::contains(triple, ~"i386") ||
         str::contains(triple, ~"i486") ||
                str::contains(triple, ~"i586") ||
                str::contains(triple, ~"i686") ||
                str::contains(triple, ~"i786") {
-            Some(session::arch_x86)
+            Some(abi::X86)
         } else if str::contains(triple, ~"x86_64") {
-            Some(session::arch_x86_64)
+            Some(abi::X86_64)
         } else if str::contains(triple, ~"arm") ||
                       str::contains(triple, ~"xscale") {
-            Some(session::arch_arm)
+            Some(abi::Arm)
         } else if str::contains(triple, ~"mips") {
-            Some(session::arch_mips)
+            Some(abi::Mips)
         } else { None }
 }
 
@@ -483,16 +484,16 @@ pub fn build_target_config(sopts: @session::options,
                           ~"unknown architecture: " + sopts.target_triple)
     };
     let (int_type, uint_type, float_type) = match arch {
-      session::arch_x86 => (ast::ty_i32, ast::ty_u32, ast::ty_f64),
-      session::arch_x86_64 => (ast::ty_i64, ast::ty_u64, ast::ty_f64),
-      session::arch_arm => (ast::ty_i32, ast::ty_u32, ast::ty_f64),
-      session::arch_mips => (ast::ty_i32, ast::ty_u32, ast::ty_f64)
+      abi::X86 => (ast::ty_i32, ast::ty_u32, ast::ty_f64),
+      abi::X86_64 => (ast::ty_i64, ast::ty_u64, ast::ty_f64),
+      abi::Arm => (ast::ty_i32, ast::ty_u32, ast::ty_f64),
+      abi::Mips => (ast::ty_i32, ast::ty_u32, ast::ty_f64)
     };
     let target_strs = match arch {
-      session::arch_x86 => x86::get_target_strs(os),
-      session::arch_x86_64 => x86_64::get_target_strs(os),
-      session::arch_arm => arm::get_target_strs(os),
-      session::arch_mips => mips::get_target_strs(os)
+      abi::X86 => x86::get_target_strs(os),
+      abi::X86_64 => x86_64::get_target_strs(os),
+      abi::Arm => arm::get_target_strs(os),
+      abi::Mips => mips::get_target_strs(os)
     };
     let target_cfg = @session::config {
         os: os,