Upgrade Emscripten targets to use upstream LLVM backend

config.toml.example

@@ -377,6 +377,7 @@
 # but you can also optionally enable the "emscripten" backend for asm.js or
 # make this an empty array (but that probably won't get too far in the
 # bootstrap)
+# FIXME: remove the obsolete emscripten backend option.
 #codegen-backends = ["llvm"]
 
 # This is the name of the directory in which codegen backends will get installed

src/bootstrap/builder.rs

@@ -980,6 +980,7 @@ impl<'a> Builder<'a> {
                 Some("-Wl,-rpath,@loader_path/../lib")
             } else if !target.contains("windows") &&
                       !target.contains("wasm32") &&
+                      !target.contains("emscripten") &&
                       !target.contains("fuchsia") {
                 Some("-Wl,-rpath,$ORIGIN/../lib")
             } else {

src/bootstrap/test.rs

@@ -1047,10 +1047,11 @@ impl Step for Compiletest {
         // Also provide `rust_test_helpers` for the host.
         builder.ensure(native::TestHelpers { target: compiler.host });
 
-        // wasm32 can't build the test helpers
-        if !target.contains("wasm32") {
+        // As well as the target, except for plain wasm32, which can't build it
+        if !target.contains("wasm32") || target.contains("emscripten") {
             builder.ensure(native::TestHelpers { target });
         }
+
         builder.ensure(RemoteCopyLibs { compiler, target });
 
         let mut cmd = builder.tool_cmd(Tool::Compiletest);

src/ci/azure-pipelines/auto.yml

@@ -124,14 +124,14 @@ jobs:
         IMAGE: dist-x86_64-netbsd
         DEPLOY: 1
 
-      asmjs:
-        IMAGE: asmjs
       i686-gnu:
         IMAGE: i686-gnu
       i686-gnu-nopt:
         IMAGE: i686-gnu-nopt
       test-various:
         IMAGE: test-various
+      wasm32:
+        IMAGE: wasm32
       x86_64-gnu:
         IMAGE: x86_64-gnu
       x86_64-gnu-full-bootstrap:

src/ci/docker/disabled/asmjs/Dockerfile

@@ -0,0 +1,41 @@
+FROM ubuntu:16.04
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  g++ \
+  make \
+  file \
+  curl \
+  ca-certificates \
+  python \
+  git \
+  cmake \
+  sudo \
+  gdb \
+  xz-utils \
+  bzip2
+
+COPY scripts/emscripten.sh /scripts/
+RUN bash /scripts/emscripten.sh
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+ENV PATH=$PATH:/emsdk-portable
+ENV PATH=$PATH:/emsdk-portable/upstream/emscripten/
+ENV PATH=$PATH:/emsdk-portable/node/12.9.1_64bit/bin/
+ENV BINARYEN_ROOT=/emsdk-portable/upstream/
+
+ENV TARGETS=asmjs-unknown-emscripten
+
+# Use -O1 optimizations in the link step to reduce time spent optimizing JS.
+ENV EMCC_CFLAGS=-O1
+
+# Emscripten installation is user-specific
+ENV NO_CHANGE_USER=1
+
+ENV SCRIPT python2.7 ../x.py test --target $TARGETS
+
+# This is almost identical to the wasm32-unknown-emscripten target, so
+# running with assertions again is not useful
+ENV NO_DEBUG_ASSERTIONS=1
+ENV NO_LLVM_ASSERTIONS=1

src/ci/docker/scripts/emscripten.sh

@@ -17,22 +17,7 @@ exit 1
   set -x
 }
 
-cd /
-curl -fL https://mozilla-games.s3.amazonaws.com/emscripten/releases/emsdk-portable.tar.gz | \
-    tar -xz
-
+git clone https://github.com/emscripten-core/emsdk.git /emsdk-portable
 cd /emsdk-portable
-./emsdk update
-hide_output ./emsdk install sdk-1.38.15-64bit
-./emsdk activate sdk-1.38.15-64bit
-
-# Compile and cache libc
-source ./emsdk_env.sh
-echo "main(){}" > a.c
-HOME=/emsdk-portable/ emcc a.c
-HOME=/emsdk-portable/ emcc -s BINARYEN=1 a.c
-rm -f a.*
-
-# Make emsdk usable by any user
-cp /root/.emscripten /emsdk-portable
-chmod a+rxw -R /emsdk-portable
+hide_output ./emsdk install 1.38.46-upstream
+./emsdk activate 1.38.46-upstream

src/ci/docker/wasm32/Dockerfile

@@ -0,0 +1,44 @@
+FROM ubuntu:16.04
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  g++ \
+  make \
+  file \
+  curl \
+  ca-certificates \
+  python \
+  git \
+  cmake \
+  sudo \
+  gdb \
+  xz-utils \
+  bzip2
+
+COPY scripts/emscripten.sh /scripts/
+RUN bash /scripts/emscripten.sh
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+ENV PATH=$PATH:/emsdk-portable
+ENV PATH=$PATH:/emsdk-portable/upstream/emscripten/
+ENV PATH=$PATH:/emsdk-portable/node/12.9.1_64bit/bin/
+ENV BINARYEN_ROOT=/emsdk-portable/upstream/
+
+ENV TARGETS=wasm32-unknown-emscripten
+
+# Use -O1 optimizations in the link step to reduce time spent optimizing.
+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

src/liballoc/tests/binary_heap.rs

@@ -1,10 +1,5 @@
-use std::cmp;
 use std::collections::BinaryHeap;
 use std::collections::binary_heap::{Drain, PeekMut};
-use std::panic::{self, AssertUnwindSafe};
-use std::sync::atomic::{AtomicUsize, Ordering};
-
-use rand::{thread_rng, seq::SliceRandom};
 
 #[test]
 fn test_iterator() {
@@ -281,9 +276,15 @@ 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(miri))] // Miri does not support catching panics
+#[cfg(not(any(miri, target_os = "emscripten")))] // Miri does not support catching panics
 fn panic_safe() {
+    use std::cmp;
+    use std::panic::{self, AssertUnwindSafe};
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    use rand::{thread_rng, seq::SliceRandom};
+
     static DROP_COUNTER: AtomicUsize = AtomicUsize::new(0);
 
     #[derive(Eq, PartialEq, Ord, Clone, Debug)]

src/liballoc/tests/str.rs

@@ -483,7 +483,7 @@ mod slice_index {
     }
 
     #[test]
-    #[cfg(not(target_arch = "asmjs"))] // hits an OOM
+    #[cfg(not(target_os = "emscripten"))] // hits an OOM
     #[cfg(not(miri))] // Miri is too slow
     fn simple_big() {
         fn a_million_letter_x() -> String {

src/liballoc/tests/vec.rs

@@ -944,8 +944,10 @@ fn drain_filter_complex() {
     }
 }
 
+// Miri does not support catching panics
+// FIXME: re-enable emscripten once it can unwind again
 #[test]
-#[cfg(not(miri))] // Miri does not support catching panics
+#[cfg(not(any(miri, target_os = "emscripten")))]
 fn drain_filter_consumed_panic() {
     use std::rc::Rc;
     use std::sync::Mutex;
@@ -995,8 +997,9 @@ fn drain_filter_consumed_panic() {
     }
 }
 
+// FIXME: Re-enable emscripten once it can catch panics
 #[test]
-#[cfg(not(miri))] // Miri does not support catching panics
+#[cfg(not(any(miri, target_os = "emscripten")))] // Miri does not support catching panics
 fn drain_filter_unconsumed_panic() {
     use std::rc::Rc;
     use std::sync::Mutex;