Auto merge of #45041 - est31:master, r=alexcrichton

Remove support for the PNaCl target (le32-unknown-nacl)

This removes support for the `le32-unknown-nacl` target which is currently supported by rustc on tier 3. Despite the "nacl" in the name, the target doesn't output native code (x86, ARM, MIPS), instead it outputs binaries in the PNaCl format.

There are two reasons for the removal:

* Google [has announced](https://blog.chromium.org/2017/05/goodbye-pnacl-hello-webassembly.html) deprecation of the PNaCl format. The suggestion is to migrate to wasm. Happens we already have a wasm backend!
* Our PNaCl LLVM backend is provided by the fastcomp patch set that the LLVM fork used by rustc contains in addition to vanilla LLVM (`src/llvm/lib/Target/JSBackend/NaCl`). Upstream LLVM doesn't have PNaCl support. Removing PNaCl support will enable us to move away from fastcomp (#44006) and have a lighter set of patches on top of upstream LLVM inside our LLVM fork. This will help distribution packagers of Rust.

Fixes #42420

5 files changed, 4 insertions, 29 deletions

diff --git a/src/libstd/sys/unix/env.rs b/src/libstd/sys/unix/env.rs
index 3d9a06bedd5..00cf7eca75d 100644
--- a/src/libstd/sys/unix/env.rs
+++ b/src/libstd/sys/unix/env.rs
@@ -118,27 +118,6 @@ pub mod os {
     pub const EXE_EXTENSION: &'static str = "";
 }
 
-#[cfg(all(target_os = "nacl", not(target_arch = "le32")))]
-pub mod os {
-    pub const FAMILY: &'static str = "unix";
-    pub const OS: &'static str = "nacl";
-    pub const DLL_PREFIX: &'static str = "lib";
-    pub const DLL_SUFFIX: &'static str = ".so";
-    pub const DLL_EXTENSION: &'static str = "so";
-    pub const EXE_SUFFIX: &'static str = ".nexe";
-    pub const EXE_EXTENSION: &'static str = "nexe";
-}
-#[cfg(all(target_os = "nacl", target_arch = "le32"))]
-pub mod os {
-    pub const FAMILY: &'static str = "unix";
-    pub const OS: &'static str = "pnacl";
-    pub const DLL_PREFIX: &'static str = "lib";
-    pub const DLL_SUFFIX: &'static str = ".pso";
-    pub const DLL_EXTENSION: &'static str = "pso";
-    pub const EXE_SUFFIX: &'static str = ".pexe";
-    pub const EXE_EXTENSION: &'static str = "pexe";
-}
-
 #[cfg(target_os = "haiku")]
 pub mod os {
     pub const FAMILY: &'static str = "unix";
diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
index 1b3f1000b77..c2772e2e2cc 100644
--- a/src/libstd/sys/unix/mod.rs
+++ b/src/libstd/sys/unix/mod.rs
@@ -22,7 +22,6 @@ use libc;
 #[cfg(all(not(dox), target_os = "haiku"))]     pub use os::haiku as platform;
 #[cfg(all(not(dox), target_os = "ios"))]       pub use os::ios as platform;
 #[cfg(all(not(dox), target_os = "macos"))]     pub use os::macos as platform;
-#[cfg(all(not(dox), target_os = "nacl"))]      pub use os::nacl as platform;
 #[cfg(all(not(dox), target_os = "netbsd"))]    pub use os::netbsd as platform;
 #[cfg(all(not(dox), target_os = "openbsd"))]   pub use os::openbsd as platform;
 #[cfg(all(not(dox), target_os = "solaris"))]   pub use os::solaris as platform;
@@ -77,11 +76,11 @@ pub fn init() {
         reset_sigpipe();
     }
 
-    #[cfg(not(any(target_os = "nacl", target_os = "emscripten", target_os="fuchsia")))]
+    #[cfg(not(any(target_os = "emscripten", target_os="fuchsia")))]
     unsafe fn reset_sigpipe() {
         assert!(signal(libc::SIGPIPE, libc::SIG_IGN) != libc::SIG_ERR);
     }
-    #[cfg(any(target_os = "nacl", target_os = "emscripten", target_os="fuchsia"))]
+    #[cfg(any(target_os = "emscripten", target_os="fuchsia"))]
     unsafe fn reset_sigpipe() {}
 }
 
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index 5ef98d24710..d8c30534eed 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -483,12 +483,10 @@ pub fn home_dir() -> Option<PathBuf> {
 
     #[cfg(any(target_os = "android",
               target_os = "ios",
-              target_os = "nacl",
               target_os = "emscripten"))]
     unsafe fn fallback() -> Option<OsString> { None }
     #[cfg(not(any(target_os = "android",
                   target_os = "ios",
-                  target_os = "nacl",
                   target_os = "emscripten")))]
     unsafe fn fallback() -> Option<OsString> {
         let amt = match libc::sysconf(libc::_SC_GETPW_R_SIZE_MAX) {
diff --git a/src/libstd/sys/unix/process/process_common.rs b/src/libstd/sys/unix/process/process_common.rs
index 689ccd78524..383434b1cd8 100644
--- a/src/libstd/sys/unix/process/process_common.rs
+++ b/src/libstd/sys/unix/process/process_common.rs
@@ -464,7 +464,6 @@ mod tests {
     // test from being flaky we ignore it on macOS.
     #[test]
     #[cfg_attr(target_os = "macos", ignore)]
-    #[cfg_attr(target_os = "nacl", ignore)] // no signals on NaCl.
     // When run under our current QEMU emulation test suite this test fails,
     // although the reason isn't very clear as to why. For now this test is
     // ignored there.
diff --git a/src/libstd/sys/unix/process/process_unix.rs b/src/libstd/sys/unix/process/process_unix.rs
index 870db820027..743c458d580 100644
--- a/src/libstd/sys/unix/process/process_unix.rs
+++ b/src/libstd/sys/unix/process/process_unix.rs
@@ -184,8 +184,8 @@ impl Command {
             *sys::os::environ() = envp.as_ptr();
         }
 
-        // NaCl has no signal support.
-        #[cfg(not(any(target_os = "nacl", target_os = "emscripten")))]
+        // emscripten has no signal support.
+        #[cfg(not(any(target_os = "emscripten")))]
         {
             use mem;
             // Reset signal handling so the child process starts in a