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

Author: bors

src/librustc_back/target/le32_unknown_nacl.rs

@@ -215,7 +215,6 @@ supported_targets! {
     ("i686-pc-windows-msvc", i686_pc_windows_msvc),
     ("i586-pc-windows-msvc", i586_pc_windows_msvc),
 
-    ("le32-unknown-nacl", le32_unknown_nacl),
     ("asmjs-unknown-emscripten", asmjs_unknown_emscripten),
     ("wasm32-unknown-emscripten", wasm32_unknown_emscripten),
     ("wasm32-experimental-emscripten", wasm32_experimental_emscripten),

src/librustc_back/target/mod.rs

@@ -88,7 +88,7 @@ fn main() {
     let is_crossed = target != host;
 
     let mut optional_components =
-        vec!["x86", "arm", "aarch64", "mips", "powerpc", "pnacl",
+        vec!["x86", "arm", "aarch64", "mips", "powerpc",
              "systemz", "jsbackend", "webassembly", "msp430", "sparc", "nvptx"];
 
     let mut version_cmd = Command::new(&llvm_config);

src/librustc_llvm/build.rs

@@ -346,10 +346,6 @@ pub fn initialize_available_targets() {
                  LLVMInitializePowerPCTargetMC,
                  LLVMInitializePowerPCAsmPrinter,
                  LLVMInitializePowerPCAsmParser);
-    init_target!(llvm_component = "pnacl",
-                 LLVMInitializePNaClTargetInfo,
-                 LLVMInitializePNaClTarget,
-                 LLVMInitializePNaClTargetMC);
     init_target!(llvm_component = "systemz",
                  LLVMInitializeSystemZTargetInfo,
                  LLVMInitializeSystemZTarget,

src/librustc_llvm/lib.rs

@@ -337,7 +337,6 @@ impl<'a> fmt::Display for Html<'a> {
                         "l4re" => "L4Re",
                         "linux" => "Linux",
                         "macos" => "macOS",
-                        "nacl" => "NaCl",
                         "netbsd" => "NetBSD",
                         "openbsd" => "OpenBSD",
                         "redox" => "Redox",
@@ -886,4 +885,4 @@ mod test {
                 only."
         );
     }
-}
+}

src/librustdoc/clean/cfg.rs

@@ -38,7 +38,6 @@ pub mod linux;
 #[cfg(all(not(dox), target_os = "haiku"))]      pub mod haiku;
 #[cfg(all(not(dox), target_os = "ios"))]        pub mod ios;
 #[cfg(all(not(dox), target_os = "macos"))]      pub mod macos;
-#[cfg(all(not(dox), target_os = "nacl"))]       pub mod nacl;
 #[cfg(all(not(dox), target_os = "netbsd"))]     pub mod netbsd;
 #[cfg(all(not(dox), target_os = "openbsd"))]    pub mod openbsd;
 #[cfg(all(not(dox), target_os = "solaris"))]    pub mod solaris;

src/libstd/os/mod.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";