rollup merge of #21414: ejjeong/aarch64-linux-android

Initial support for aarch64-linux-android (#18920)
- Add new configuration files
- Modify some options to compile & link succesfully.
  (PIE, disable tls on jemalloc, modify some external function linkage, ..)
- To build, refer to https://github.com/rust-lang/rust/wiki/Doc-building-for-android.
   (tested with platform=21 and toolchain=aarch64-linux-android-4.9)

src/liblibc/lib.rs

@@ -4648,13 +4648,13 @@ pub mod funcs {
             use types::os::arch::c95::c_int;
             use types::os::common::posix01::sighandler_t;
 
-            #[cfg(not(target_os = "android"))]
+            #[cfg(not(all(target_os = "android", target_arch = "arm")))]
             extern {
                 pub fn signal(signum: c_int,
                               handler: sighandler_t) -> sighandler_t;
             }
 
-            #[cfg(target_os = "android")]
+            #[cfg(all(target_os = "android", target_arch = "arm"))]
             extern {
                 #[link_name = "bsd_signal"]
                 pub fn signal(signum: c_int,

src/librustc_back/target/aarch64_linux_android.rs

@@ -0,0 +1,28 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use target::Target;
+
+pub fn target() -> Target {
+    let mut base = super::linux_base::opts();
+    base.pre_link_args.push("-Wl,--allow-multiple-definition".to_string());
+    base.position_independent_executables = true;
+    Target {
+        data_layout: "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-\
+                      f32:32:32-f64:64:64-v64:64:64-v128:128:128-a:0:64-\
+                      n32:64-S128".to_string(),
+        llvm_target: "aarch64-linux-android".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        arch: "aarch64".to_string(),
+        target_os: "android".to_string(),
+        options: base,
+    }
+}

src/librustc_back/target/mod.rs

@@ -65,6 +65,7 @@ mod arm_linux_androideabi;
 mod arm_unknown_linux_gnueabi;
 mod arm_unknown_linux_gnueabihf;
 mod aarch64_apple_ios;
+mod aarch64_linux_android;
 mod aarch64_unknown_linux_gnu;
 mod i686_apple_darwin;
 mod i686_pc_windows_gnu;
@@ -357,6 +358,7 @@ impl Target {
             i386_apple_ios,
             x86_64_apple_ios,
             aarch64_apple_ios,
+            aarch64_linux_android,
             armv7_apple_ios,
             armv7s_apple_ios,
 

src/libstd/sys/unix/backtrace.rs

@@ -418,7 +418,7 @@ mod uw {
                                  trace_argument: *mut libc::c_void)
                     -> _Unwind_Reason_Code;
 
-        #[cfg(all(not(target_os = "android"),
+        #[cfg(all(not(all(target_os = "android", target_arch = "arm")),
                   not(all(target_os = "linux", target_arch = "arm"))))]
         pub fn _Unwind_GetIP(ctx: *mut _Unwind_Context) -> libc::uintptr_t;
 
@@ -431,7 +431,7 @@ mod uw {
     // On android, the function _Unwind_GetIP is a macro, and this is the
     // expansion of the macro. This is all copy/pasted directly from the
     // header file with the definition of _Unwind_GetIP.
-    #[cfg(any(target_os = "android",
+    #[cfg(any(all(target_os = "android", target_arch = "arm"),
               all(target_os = "linux", target_arch = "arm")))]
     pub unsafe fn _Unwind_GetIP(ctx: *mut _Unwind_Context) -> libc::uintptr_t {
         #[repr(C)]