Auto merge of #27176 - alexcrichton:fix-stock-llvm, r=brson

This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:

* LLVM changes its IR syntax from time to time, so it's very difficult to
  have these files build across many LLVM versions simultaneously. We'll likely
  want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
  itself, so it makes sense to fold it into a location which can do more
  platform-specific checks for various implementation details (such as MSVC 32
  vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
  end up becoming very useful if we move towards building the standard library
  with Cargo.

In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.

3 files changed, 47 insertions, 39 deletions

diff --git a/src/libstd/rt/unwind/gcc.rs b/src/libstd/rt/unwind/gcc.rs
index 84c6d6864a9..87941e79b2f 100644
--- a/src/libstd/rt/unwind/gcc.rs
+++ b/src/libstd/rt/unwind/gcc.rs
@@ -8,10 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(private_no_mangle_fns)]
+
 use prelude::v1::*;
 
 use any::Any;
-use libc::c_void;
 use rt::libunwind as uw;
 
 struct Exception {
@@ -41,7 +42,7 @@ pub unsafe fn panic(data: Box<Any + Send + 'static>) -> ! {
     }
 }
 
-pub unsafe fn cleanup(ptr: *mut c_void) -> Box<Any + Send + 'static> {
+pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send + 'static> {
     let my_ep = ptr as *mut Exception;
     rtdebug!("caught {}", (*my_ep).uwe.exception_class);
     let cause = (*my_ep).cause.take();
@@ -89,7 +90,7 @@ pub mod eabi {
     use rt::libunwind as uw;
     use libc::c_int;
 
-    extern "C" {
+    extern {
         fn __gcc_personality_v0(version: c_int,
                                 actions: uw::_Unwind_Action,
                                 exception_class: uw::_Unwind_Exception_Class,
@@ -98,9 +99,8 @@ pub mod eabi {
             -> uw::_Unwind_Reason_Code;
     }
 
-    #[lang="eh_personality"]
-    #[no_mangle] // referenced from rust_try.ll
-    #[allow(private_no_mangle_fns)]
+    #[lang = "eh_personality"]
+    #[no_mangle]
     extern fn rust_eh_personality(
         version: c_int,
         actions: uw::_Unwind_Action,
@@ -115,8 +115,9 @@ pub mod eabi {
         }
     }
 
-    #[no_mangle] // referenced from rust_try.ll
-    pub extern "C" fn rust_eh_personality_catch(
+    #[cfg_attr(not(stage0), lang = "eh_personality_catch")]
+    #[no_mangle]
+    pub extern fn rust_eh_personality_catch(
         _version: c_int,
         actions: uw::_Unwind_Action,
         _exception_class: uw::_Unwind_Exception_Class,
@@ -142,7 +143,7 @@ pub mod eabi {
     use rt::libunwind as uw;
     use libc::c_int;
 
-    extern "C" {
+    extern {
         fn __gcc_personality_sj0(version: c_int,
                                 actions: uw::_Unwind_Action,
                                 exception_class: uw::_Unwind_Exception_Class,
@@ -151,9 +152,9 @@ pub mod eabi {
             -> uw::_Unwind_Reason_Code;
     }
 
-    #[lang="eh_personality"]
-    #[no_mangle] // referenced from rust_try.ll
-    pub extern "C" fn rust_eh_personality(
+    #[lang = "eh_personality"]
+    #[no_mangle]
+    pub extern fn rust_eh_personality(
         version: c_int,
         actions: uw::_Unwind_Action,
         exception_class: uw::_Unwind_Exception_Class,
@@ -167,8 +168,9 @@ pub mod eabi {
         }
     }
 
-    #[no_mangle] // referenced from rust_try.ll
-    pub extern "C" fn rust_eh_personality_catch(
+    #[cfg_attr(not(stage0), lang = "eh_personality_catch")]
+    #[no_mangle]
+    pub extern fn rust_eh_personality_catch(
         _version: c_int,
         actions: uw::_Unwind_Action,
         _exception_class: uw::_Unwind_Exception_Class,
@@ -196,17 +198,16 @@ pub mod eabi {
     use rt::libunwind as uw;
     use libc::c_int;
 
-    extern "C" {
+    extern {
         fn __gcc_personality_v0(state: uw::_Unwind_State,
                                 ue_header: *mut uw::_Unwind_Exception,
                                 context: *mut uw::_Unwind_Context)
             -> uw::_Unwind_Reason_Code;
     }
 
-    #[lang="eh_personality"]
-    #[no_mangle] // referenced from rust_try.ll
-    #[allow(private_no_mangle_fns)]
-    extern "C" fn rust_eh_personality(
+    #[lang = "eh_personality"]
+    #[no_mangle]
+    extern fn rust_eh_personality(
         state: uw::_Unwind_State,
         ue_header: *mut uw::_Unwind_Exception,
         context: *mut uw::_Unwind_Context
@@ -217,8 +218,9 @@ pub mod eabi {
         }
     }
 
-    #[no_mangle] // referenced from rust_try.ll
-    pub extern "C" fn rust_eh_personality_catch(
+    #[cfg_attr(not(stage0), lang = "eh_personality_catch")]
+    #[no_mangle]
+    pub extern fn rust_eh_personality_catch(
         state: uw::_Unwind_State,
         _ue_header: *mut uw::_Unwind_Exception,
         _context: *mut uw::_Unwind_Context
@@ -266,7 +268,7 @@ pub mod eabi {
     }
 
     type _Unwind_Personality_Fn =
-        extern "C" fn(
+        extern fn(
             version: c_int,
             actions: uw::_Unwind_Action,
             exception_class: uw::_Unwind_Exception_Class,
@@ -274,7 +276,7 @@ pub mod eabi {
             context: *mut uw::_Unwind_Context
         ) -> uw::_Unwind_Reason_Code;
 
-    extern "C" {
+    extern {
         fn __gcc_personality_seh0(
             exceptionRecord: *mut EXCEPTION_RECORD,
             establisherFrame: *mut c_void,
@@ -291,10 +293,9 @@ pub mod eabi {
         ) -> EXCEPTION_DISPOSITION;
     }
 
-    #[lang="eh_personality"]
-    #[no_mangle] // referenced from rust_try.ll
-    #[allow(private_no_mangle_fns)]
-    extern "C" fn rust_eh_personality(
+    #[lang = "eh_personality"]
+    #[no_mangle]
+    extern fn rust_eh_personality(
         exceptionRecord: *mut EXCEPTION_RECORD,
         establisherFrame: *mut c_void,
         contextRecord: *mut CONTEXT,
@@ -307,15 +308,16 @@ pub mod eabi {
         }
     }
 
-    #[no_mangle] // referenced from rust_try.ll
-    pub extern "C" fn rust_eh_personality_catch(
+    #[cfg_attr(not(stage0), lang = "eh_personality_catch")]
+    #[no_mangle]
+    pub extern fn rust_eh_personality_catch(
         exceptionRecord: *mut EXCEPTION_RECORD,
         establisherFrame: *mut c_void,
         contextRecord: *mut CONTEXT,
         dispatcherContext: *mut DISPATCHER_CONTEXT
     ) -> EXCEPTION_DISPOSITION
     {
-        extern "C" fn inner(
+        extern fn inner(
                 _version: c_int,
                 actions: uw::_Unwind_Action,
                 _exception_class: uw::_Unwind_Exception_Class,
diff --git a/src/libstd/rt/unwind/mod.rs b/src/libstd/rt/unwind/mod.rs
index c403976745a..db2310ba361 100644
--- a/src/libstd/rt/unwind/mod.rs
+++ b/src/libstd/rt/unwind/mod.rs
@@ -69,7 +69,6 @@ use cmp;
 use panicking;
 use fmt;
 use intrinsics;
-use libc::c_void;
 use mem;
 use sync::atomic::{self, Ordering};
 use sys_common::mutex::Mutex;
@@ -127,7 +126,7 @@ extern {}
 ///   run.
 pub unsafe fn try<F: FnOnce()>(f: F) -> Result<(), Box<Any + Send>> {
     let mut f = Some(f);
-    return inner_try(try_fn::<F>, &mut f as *mut _ as *mut c_void);
+    return inner_try(try_fn::<F>, &mut f as *mut _ as *mut u8);
 
     // If an inner function were not used here, then this generic function `try`
     // uses the native symbol `rust_try`, for which the code is statically
@@ -140,11 +139,12 @@ pub unsafe fn try<F: FnOnce()>(f: F) -> Result<(), Box<Any + Send>> {
     // `dllexport`, but it's easier to not have conditional `src/rt/rust_try.ll`
     // files and instead just have this non-generic shim the compiler can take
     // care of exposing correctly.
-    unsafe fn inner_try(f: extern fn(*mut c_void), data: *mut c_void)
+    #[cfg(not(stage0))]
+    unsafe fn inner_try(f: fn(*mut u8), data: *mut u8)
                         -> Result<(), Box<Any + Send>> {
         let prev = PANICKING.with(|s| s.get());
         PANICKING.with(|s| s.set(false));
-        let ep = rust_try(f, data);
+        let ep = intrinsics::try(f, data);
         PANICKING.with(|s| s.set(prev));
         if ep.is_null() {
             Ok(())
@@ -152,8 +152,13 @@ pub unsafe fn try<F: FnOnce()>(f: F) -> Result<(), Box<Any + Send>> {
             Err(imp::cleanup(ep))
         }
     }
+    #[cfg(stage0)]
+    unsafe fn inner_try(f: fn(*mut u8), data: *mut u8)
+                        -> Result<(), Box<Any + Send>> {
+        Ok(f(data))
+    }
 
-    extern fn try_fn<F: FnOnce()>(opt_closure: *mut c_void) {
+    fn try_fn<F: FnOnce()>(opt_closure: *mut u8) {
         let opt_closure = opt_closure as *mut Option<F>;
         unsafe { (*opt_closure).take().unwrap()(); }
     }
@@ -163,8 +168,8 @@ pub unsafe fn try<F: FnOnce()>(f: F) -> Result<(), Box<Any + Send>> {
         // When f(...) returns normally, the return value is null.
         // When f(...) throws, the return value is a pointer to the caught
         // exception object.
-        fn rust_try(f: extern fn(*mut c_void),
-                    data: *mut c_void) -> *mut c_void;
+        fn rust_try(f: extern fn(*mut u8),
+                    data: *mut u8) -> *mut u8;
     }
 }
 
diff --git a/src/libstd/rt/unwind/seh.rs b/src/libstd/rt/unwind/seh.rs
index 632ab4f8e25..ed44f9a8bda 100644
--- a/src/libstd/rt/unwind/seh.rs
+++ b/src/libstd/rt/unwind/seh.rs
@@ -102,7 +102,7 @@ pub unsafe fn panic(data: Box<Any + Send + 'static>) -> ! {
     rtabort!("could not unwind stack");
 }
 
-pub unsafe fn cleanup(ptr: *mut c_void) -> Box<Any + Send + 'static> {
+pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send + 'static> {
     // The `ptr` here actually corresponds to the code of the exception, and our
     // real data is stored in our thread local.
     rtassert!(ptr as DWORD == RUST_PANIC);
@@ -135,8 +135,9 @@ fn rust_eh_personality() {
 // to ensure that it's code is RUST_PANIC, which was set by the call to
 // `RaiseException` above in the `panic` function.
 #[no_mangle]
+#[lang = "msvc_try_filter"]
 pub extern fn __rust_try_filter(eh_ptrs: *mut EXCEPTION_POINTERS,
-                                _rbp: *mut c_void) -> i32 {
+                                _rbp: *mut u8) -> i32 {
     unsafe {
         ((*(*eh_ptrs).ExceptionRecord).ExceptionCode == RUST_PANIC) as i32
     }