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);