Create "platform-intrinsic" ABI for SIMD/platform intrinsics.

This is purposely separate to the "rust-intrinsic" ABI, because these
intrinsics are theoretically going to become stable, and should be fine
to be independent of the compiler/language internals since they're
intimately to the platform.

2 files changed, 15 insertions, 4 deletions

diff --git a/src/libsyntax/abi.rs b/src/libsyntax/abi.rs
index 50c86a80b4a..c0fe541ead5 100644
--- a/src/libsyntax/abi.rs
+++ b/src/libsyntax/abi.rs
@@ -47,6 +47,7 @@ pub enum Abi {
     System,
     RustIntrinsic,
     RustCall,
+    PlatformIntrinsic,
 }
 
 #[allow(non_camel_case_types)]
@@ -95,6 +96,7 @@ const AbiDatas: &'static [AbiData] = &[
     AbiData {abi: System, name: "system" },
     AbiData {abi: RustIntrinsic, name: "rust-intrinsic" },
     AbiData {abi: RustCall, name: "rust-call" },
+    AbiData {abi: PlatformIntrinsic, name: "platform-intrinsic" }
 ];
 
 /// Returns the ABI with the given name (if any).
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 9a1c97a4d29..b0167d75bc0 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -184,6 +184,9 @@ const KNOWN_FEATURES: &'static [(&'static str, &'static str, Status)] = &[
 
     // Allows cfg(target_feature = "...").
     ("cfg_target_feature", "1.3.0", Active),
+
+    // allow `extern "platform-intrinsic" { ... }`
+    ("platform_intrinsics", "1.4.0", Active),
 ];
 // (changing above list without updating src/doc/reference.md makes @cmr sad)
 
@@ -694,10 +697,16 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> {
                                        across platforms, it is recommended to \
                                        use `#[link(name = \"foo\")]` instead")
                 }
-                if foreign_module.abi == Abi::RustIntrinsic {
-                    self.gate_feature("intrinsics",
-                                      i.span,
-                                      "intrinsics are subject to change")
+                let maybe_feature = match foreign_module.abi {
+                    Abi::RustIntrinsic => Some(("intrinsics", "intrinsics are subject to change")),
+                    Abi::PlatformIntrinsic => {
+                        Some(("platform_intrinsics",
+                              "platform intrinsics are experimental and possibly buggy"))
+                    }
+                    _ => None
+                };
+                if let Some((feature, msg)) = maybe_feature {
+                    self.gate_feature(feature, i.span, msg)
                 }
             }