Enable more tests for Emscripten targets

Specifically, enable SIMD intrinsic tests, target-independent asm!
tests, and tests that were ignored due to old fastcomp bugs that have
long since become irrelevant.

Also re-enables asmjs tests that pass -g by reducing the corresponding
Emscripten debug level so that it does not error out with a message
about source maps being unsupported. This required fixing the asmjs
target's `arch` string to be `"asmjs"` rather than `"wasm32"`, and
that in turn required auditing many cfg attributes and fixing them to
include both asmjs and wasm32.

For many tests that could not be re-enabled, also adds an explanatory
comment to make future auditing easier. In particular, tests requiring
threads are left to be re-enabled in future work.

Author: tlively

src/bootstrap/native.rs

@@ -520,10 +520,6 @@ impl Step for TestHelpers {
         builder.info("Building test helpers");
         t!(fs::create_dir_all(&dst));
         let mut cfg = cc::Build::new();
-        // FIXME: Workaround for https://github.com/emscripten-core/emscripten/issues/9013
-        if target.contains("emscripten") {
-            cfg.pic(false);
-        }
 
         // We may have found various cross-compilers a little differently due to our
         // extra configuration, so inform gcc of these compilers. Note, though, that

src/ci/docker/scripts/emscripten.sh

@@ -19,5 +19,5 @@ exit 1
 
 git clone https://github.com/emscripten-core/emsdk.git /emsdk-portable
 cd /emsdk-portable
-hide_output ./emsdk install 1.38.46-upstream
-./emsdk activate 1.38.46-upstream
+hide_output ./emsdk install 1.39.5
+./emsdk activate 1.39.5

src/ci/docker/wasm32/Dockerfile

@@ -33,12 +33,4 @@ ENV EMCC_CFLAGS=-O1
 # Emscripten installation is user-specific
 ENV NO_CHANGE_USER=1
 
-# FIXME: Re-enable these tests once https://github.com/rust-lang/cargo/pull/7476
-# is picked up by CI
-ENV SCRIPT python2.7 ../x.py test --target $TARGETS \
-    --exclude src/libcore \
-    --exclude src/liballoc \
-    --exclude src/libproc_macro \
-    --exclude src/libstd \
-    --exclude src/libterm \
-    --exclude src/libtest
+ENV SCRIPT python2.7 ../x.py test --target $TARGETS

src/liballoc/collections/linked_list/tests.rs

@@ -181,7 +181,7 @@ fn test_insert_prev() {
 }
 
 #[test]
-#[cfg_attr(target_os = "emscripten", ignore)]
+#[cfg_attr(target_os = "emscripten", ignore)] // Emscripten does not support threads
 #[cfg_attr(miri, ignore)] // Miri does not support threads
 fn test_send() {
     let n = list_from(&[1, 2, 3]);

src/liballoc/tests/binary_heap.rs

@@ -345,9 +345,7 @@ fn assert_covariance() {
 // even if the order may not be correct.
 //
 // Destructors must be called exactly once per element.
-// FIXME: re-enable emscripten once it can unwind again
 #[test]
-#[cfg(not(target_os = "emscripten"))]
 fn panic_safe() {
     use rand::{seq::SliceRandom, thread_rng};
     use std::cmp;

src/liballoc/tests/lib.rs

@@ -36,9 +36,6 @@ fn hash<T: Hash>(t: &T) -> u64 {
     s.finish()
 }
 
-// FIXME: Instantiated functions with i128 in the signature is not supported in Emscripten.
-// See https://github.com/kripken/emscripten-fastcomp/issues/169
-#[cfg(not(target_os = "emscripten"))]
 #[test]
 fn test_boxed_hasher() {
     let ordinary_hash = hash(&5u32);

src/liballoc/tests/slice.rs

@@ -1395,7 +1395,6 @@ fn test_box_slice_clone() {
 
 #[test]
 #[allow(unused_must_use)] // here, we care about the side effects of `.clone()`
-#[cfg_attr(target_os = "emscripten", ignore)]
 fn test_box_slice_clone_panics() {
     use std::sync::atomic::{AtomicUsize, Ordering};
     use std::sync::Arc;
@@ -1636,7 +1635,6 @@ macro_rules! test {
 thread_local!(static SILENCE_PANIC: Cell<bool> = Cell::new(false));
 
 #[test]
-#[cfg_attr(target_os = "emscripten", ignore)] // no threads
 fn panic_safe() {
     let prev = panic::take_hook();
     panic::set_hook(Box::new(move |info| {

src/liballoc/tests/vec.rs

@@ -937,9 +937,7 @@ fn drain_filter_complex() {
     }
 }
 
-// FIXME: re-enable emscripten once it can unwind again
 #[test]
-#[cfg(not(target_os = "emscripten"))]
 fn drain_filter_consumed_panic() {
     use std::rc::Rc;
     use std::sync::Mutex;
@@ -989,9 +987,7 @@ fn drain_filter_consumed_panic() {
     }
 }
 
-// FIXME: Re-enable emscripten once it can catch panics
 #[test]
-#[cfg(not(target_os = "emscripten"))]
 fn drain_filter_unconsumed_panic() {
     use std::rc::Rc;
     use std::sync::Mutex;

src/libcore/fmt/num.rs

@@ -258,7 +258,7 @@ macro_rules! impl_Display {
 
 // Include wasm32 in here since it doesn't reflect the native pointer size, and
 // often cares strongly about getting a smaller code size.
-#[cfg(any(target_pointer_width = "64", target_arch = "wasm32"))]
+#[cfg(any(target_pointer_width = "64", target_arch = "wasm32", target_arch = "asmjs"))]
 mod imp {
     use super::*;
     impl_Display!(
@@ -267,7 +267,7 @@ mod imp {
     );
 }
 
-#[cfg(not(any(target_pointer_width = "64", target_arch = "wasm32")))]
+#[cfg(not(any(target_pointer_width = "64", target_arch = "wasm32", target_arch = "asmjs")))]
 mod imp {
     use super::*;
     impl_Display!(i8, u8, i16, u16, i32, u32, isize, usize as u32 via to_u32 named fmt_u32);

src/libcore/ptr/mod.rs

@@ -426,8 +426,8 @@ unsafe fn swap_nonoverlapping_bytes(x: *mut u8, y: *mut u8, len: usize) {
     // Haswell E processors. LLVM is more able to optimize if we give a struct a
     // #[repr(simd)], even if we don't actually use this struct directly.
     //
-    // FIXME repr(simd) broken on emscripten and redox
-    #[cfg_attr(not(any(target_os = "emscripten", target_os = "redox")), repr(simd))]
+    // FIXME repr(simd) broken on redox
+    #[cfg_attr(not(target_os = "redox"), repr(simd))]
     struct Block(u64, u64, u64, u64);
     struct UnalignedBlock(u64, u64, u64, u64);
 

src/libcore/sync/atomic.rs

@@ -2517,15 +2517,7 @@ unsafe fn atomic_umin<T>(dst: *mut T, val: T, order: Ordering) -> T {
 /// [`Relaxed`]: enum.Ordering.html#variant.Relaxed
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
 pub fn fence(order: Ordering) {
-    // On wasm32 it looks like fences aren't implemented in LLVM yet in that
-    // they will cause LLVM to abort. The wasm instruction set doesn't have
-    // fences right now. There's discussion online about the best way for tools
-    // to conventionally implement fences at
-    // https://github.com/WebAssembly/tool-conventions/issues/59. We should
-    // follow that discussion and implement a solution when one comes about!
-    #[cfg(not(target_arch = "wasm32"))]
     unsafe {
         match order {
             Acquire => intrinsics::atomic_fence_acq(),

src/libcore/tests/hash/mod.rs

@@ -127,9 +127,6 @@ fn test_custom_state() {
     assert_eq!(hash(&Custom { hash: 5 }), 5);
 }
 
-// FIXME: Instantiated functions with i128 in the signature is not supported in Emscripten.
-// See https://github.com/kripken/emscripten-fastcomp/issues/169
-#[cfg(not(target_os = "emscripten"))]
 #[test]
 fn test_indirect_hasher() {
     let mut hasher = MyHasher { hash: 0 };

src/libcore/tests/num/dec2flt/mod.rs

@@ -23,7 +23,6 @@ macro_rules! test_literal {
     }};
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn ordinary() {
     test_literal!(1.0);
@@ -40,7 +39,6 @@ fn ordinary() {
     test_literal!(2.2250738585072014e-308);
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn special_code_paths() {
     test_literal!(36893488147419103229.0); // 2^65 - 3, triggers half-to-even with even significand

src/libcore/tests/num/dec2flt/rawfp.rs

@@ -83,7 +83,6 @@ fn rounding_overflow() {
     assert_eq!(rounded.k, adjusted_k + 1);
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn prev_float_monotonic() {
     let mut x = 1.0;
@@ -119,7 +118,6 @@ fn next_float_inf() {
     assert_eq!(next_float(f64::INFINITY), f64::INFINITY);
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn next_prev_identity() {
     for &x in &SOME_FLOATS {
@@ -130,7 +128,6 @@ fn next_prev_identity() {
     }
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn next_float_monotonic() {
     let mut x = 0.49999999999999;

src/libcore/tests/num/flt2dec/random.rs

@@ -1,5 +1,3 @@
-#![cfg(not(target_arch = "wasm32"))]
-
 use std::i16;
 use std::str;
 
@@ -89,9 +87,6 @@ where
     F: FnMut(&Decoded, &mut [u8]) -> Option<(usize, i16)>,
     G: FnMut(&Decoded, &mut [u8]) -> (usize, i16),
 {
-    if cfg!(target_os = "emscripten") {
-        return; // using rng pulls in i128 support, which doesn't work
-    }
     let mut rng = StdRng::from_entropy();
     let f32_range = Uniform::new(0x0000_0001u32, 0x7f80_0000);
     iterate("f32_random_equivalence_test", k, n, f, g, |_| {
@@ -105,9 +100,6 @@ where
     F: FnMut(&Decoded, &mut [u8]) -> Option<(usize, i16)>,
     G: FnMut(&Decoded, &mut [u8]) -> (usize, i16),
 {
-    if cfg!(target_os = "emscripten") {
-        return; // using rng pulls in i128 support, which doesn't work
-    }
     let mut rng = StdRng::from_entropy();
     let f64_range = Uniform::new(0x0000_0000_0000_0001u64, 0x7ff0_0000_0000_0000);
     iterate("f64_random_equivalence_test", k, n, f, g, |_| {

src/libcore/tests/num/flt2dec/strategy/dragon.rs

@@ -13,7 +13,6 @@ fn test_mul_pow10() {
     }
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn shortest_sanity_test() {
     f64_shortest_sanity_test(format_shortest);

src/libcore/tests/num/flt2dec/strategy/grisu.rs

@@ -32,7 +32,6 @@ fn test_max_pow10_no_more_than() {
     }
 }
 
-#[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
 #[test]
 fn shortest_sanity_test() {
     f64_shortest_sanity_test(format_shortest);

src/libcore/tests/slice.rs

@@ -1221,7 +1221,6 @@ fn brute_force_rotate_test_1() {
 }
 
 #[test]
-#[cfg(not(target_arch = "wasm32"))]
 fn sort_unstable() {
     use core::cmp::Ordering::{Equal, Greater, Less};
     use core::slice::heapsort;
@@ -1301,7 +1300,6 @@ fn sort_unstable() {
 }
 
 #[test]
-#[cfg(not(target_arch = "wasm32"))]
 #[cfg_attr(miri, ignore)] // Miri is too slow
 fn partition_at_index() {
     use core::cmp::Ordering::{Equal, Greater, Less};

src/librustc_codegen_ssa/back/linker.rs

@@ -154,9 +154,10 @@ impl<'a> GccLinker<'a> {
         // platforms where currently this is guaranteed to *not* be the case:
         //
         // * On OSX they have their own linker, not binutils'
-        // * For WebAssembly the only functional linker is LLD, which doesn't
+        // * For WebAssembly/JS the only functional linker is LLD, which doesn't
         //   support hint flags
-        !self.sess.target.target.options.is_like_osx && self.sess.target.target.arch != "wasm32"
+        !self.sess.target.target.options.is_like_osx && self.sess.target.target.arch != "wasm32" &&
+            self.sess.target.target.arch != "asmjs"
     }
 
     // Some platforms take hints about whether a library is static or dynamic.
@@ -866,7 +867,9 @@ impl<'a> Linker for EmLinker<'a> {
         self.cmd.arg(match self.sess.opts.debuginfo {
             DebugInfo::None => "-g0",
             DebugInfo::Limited => "-g3",
-            DebugInfo::Full => "-g4",
+            // FIXME: wasm2js errors with -g3 and above because it does not support source maps.
+            // See https://github.com/WebAssembly/binaryen/issues/2410
+            DebugInfo::Full => if self.sess.target.target.arch == "asmjs" { "-g3" } else { "-g4" },
         });
     }
 

src/librustc_codegen_ssa/back/write.rs

@@ -86,8 +86,7 @@ pub struct ModuleConfig {
     pub merge_functions: bool,
     pub inline_threshold: Option<usize>,
     // Instead of creating an object file by doing LLVM codegen, just
-    // make the object file bitcode. Provides easy compatibility with
-    // emscripten's ecc compiler, when used as the linker.
+    // make the object file bitcode.
     pub obj_is_bitcode: bool,
     pub no_integrated_as: bool,
     pub embed_bitcode: bool,

src/librustc_target/spec/asmjs_unknown_emscripten.rs

@@ -8,5 +8,6 @@ pub fn target() -> Result<Target, String> {
         .entry(LinkerFlavor::Em)
         .or_default()
         .extend(vec!["-s".to_string(), "WASM=0".to_string()]);
+    target.arch = "asmjs".to_string();
     Ok(target)
 }

src/libstd/f64.rs

@@ -1054,7 +1054,6 @@ mod tests {
         assert_eq!(Fp::Zero, neg_zero.classify());
     }
 
-    #[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
     #[test]
     fn test_one() {
         let one: f64 = 1.0f64;
@@ -1107,7 +1106,6 @@ mod tests {
         assert!((-109.2f64).is_finite());
     }
 
-    #[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
     #[test]
     fn test_is_normal() {
         let nan: f64 = NAN;
@@ -1125,7 +1123,6 @@ mod tests {
         assert!(!1e-308f64.is_normal());
     }
 
-    #[cfg_attr(all(target_arch = "wasm32", target_os = "emscripten"), ignore)] // issue 42630
     #[test]
     fn test_classify() {
         let nan: f64 = NAN;

src/libstd/io/mod.rs

@@ -2416,7 +2416,7 @@ mod tests {
     use crate::ops::Deref;
 
     #[test]
-    #[cfg_attr(target_os = "emscripten", ignore)]
+    #[cfg_attr(all(target_arch = "wasm32", not(target_os = "emscripten")), ignore)]
     fn read_until() {
         let mut buf = Cursor::new(&b"12"[..]);
         let mut v = Vec::new();

src/libstd/net/tcp.rs

@@ -758,7 +758,7 @@ impl TcpListener {
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
         // On WASM, `TcpStream` is uninhabited (as it's unsupported) and so
         // the `a` variable here is technically unused.
-        #[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
+        #[cfg_attr(any(target_arch = "wasm32", target_arch = "asmjs"), allow(unused_variables))]
         self.0.accept().map(|(a, b)| (TcpStream(a), b))
     }
 

src/libstd/sys/mod.rs

@@ -41,7 +41,7 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "wasi")] {
         mod wasi;
         pub use self::wasi::*;
-    } else if #[cfg(target_arch = "wasm32")] {
+    } else if #[cfg(any(target_arch = "wasm32", target_arch = "asmjs"))] {
         mod wasm;
         pub use self::wasm::*;
     } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
@@ -64,7 +64,8 @@ cfg_if::cfg_if! {
         pub use self::ext as unix_ext;
     } else if #[cfg(any(target_os = "cloudabi",
                         target_os = "hermit",
-                        target_arch = "wasm32",
+                        all(not(target_os = "emscripten"),
+                            target_arch = "wasm32"),
                         all(target_vendor = "fortanix", target_env = "sgx")))] {
         // On CloudABI and wasm right now the module below doesn't compile
         // (missing things in `libc` which is empty) so just omit everything
@@ -88,7 +89,8 @@ cfg_if::cfg_if! {
         #[stable(feature = "rust1", since = "1.0.0")]
         pub use self::ext as windows_ext;
     } else if #[cfg(any(target_os = "cloudabi",
-                        target_arch = "wasm32",
+                        all(not(target_os = "emscripten"),
+                            target_arch = "wasm32"),
                         all(target_vendor = "fortanix", target_env = "sgx")))] {
         // On CloudABI and wasm right now the shim below doesn't compile, so
         // just omit it

src/libstd/sys/unix/env.rs

@@ -108,18 +108,7 @@ pub mod os {
     pub const EXE_EXTENSION: &str = "";
 }
 
-#[cfg(all(target_os = "emscripten", target_arch = "asmjs"))]
-pub mod os {
-    pub const FAMILY: &str = "unix";
-    pub const OS: &str = "emscripten";
-    pub const DLL_PREFIX: &str = "lib";
-    pub const DLL_SUFFIX: &str = ".so";
-    pub const DLL_EXTENSION: &str = "so";
-    pub const EXE_SUFFIX: &str = ".js";
-    pub const EXE_EXTENSION: &str = "js";
-}
-
-#[cfg(all(target_os = "emscripten", target_arch = "wasm32"))]
+#[cfg(target_os = "emscripten")]
 pub mod os {
     pub const FAMILY: &str = "unix";
     pub const OS: &str = "emscripten";

src/libstd/sys_common/mod.rs

@@ -57,6 +57,7 @@ pub mod mutex;
           target_os = "cloudabi",
           target_os = "hermit",
           target_arch = "wasm32",
+          target_arch = "asmjs",
           all(target_vendor = "fortanix", target_env = "sgx")))]
 pub mod os_str_bytes;
 pub mod poison;