Auto merge of rust-lang#137457 - JayAndJef:issue-132802-fix, r=<try>

fix for issue 132802: x86 code in `wasm32-unknown-unknown` binaries

This is a direct fix for issue [132802](rust-lang#132802).
Followed the outline as follows:
> * give a hard error in bootstrap when using gcc to compile for wasm
> * change our CI to use clang instead of gcc
> * add a test that compiling a sample program for wasm32-unknown doesn't give any linker warnings

The `test-various` ci job was also changed.

try-job: test-various
try-job: dist-various-1
try-job: dist-various-2
try-job: x86_64-msvc-1

Author: bors

src/bootstrap/src/core/sanity.rs

@@ -311,6 +311,17 @@ than building it.
             .entry(*target)
             .or_insert_with(|| Target::from_triple(&target.triple));
 
+        // compiler-rt c fallbacks for wasm cannot be built with gcc
+        if target.contains("wasm")
+            && (build.config.optimized_compiler_builtins(*target)
+                || build.config.rust_std_features.contains("compiler-builtins-c"))
+        {
+            let is_clang = build.cc_tool(*target).is_like_clang();
+            if !is_clang {
+                panic!("only clang supports building c code for wasm targets");
+            }
+        }
+
         if (target.contains("-none-") || target.contains("nvptx"))
             && build.no_std(*target) == Some(false)
         {

src/ci/docker/host-x86_64/dist-various-1/Dockerfile

@@ -58,6 +58,12 @@ RUN ./install-riscv32-none-elf.sh
 COPY host-x86_64/dist-various-1/install-llvm-mingw.sh /build
 RUN ./install-llvm-mingw.sh
 
+COPY host-x86_64/dist-various-1/install-emscripten.sh /build
+RUN ./install-emscripten.sh
+
+# Add Emscripten to PATH
+ENV PATH="/build/emsdk:/build/emsdk/upstream/emscripten:/build/emsdk/node/current/bin:${PATH}"
+
 # Suppress some warnings in the openwrt toolchains we downloaded
 ENV STAGING_DIR=/tmp
 

src/ci/docker/host-x86_64/dist-various-1/install-emscripten.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -ex
+
+apt-get update
+apt-get install -y --no-install-recommends \
+  nodejs \
+  default-jre
+
+git clone https://github.com/emscripten-core/emsdk.git
+cd emsdk
+./emsdk install latest
+./emsdk activate latest

src/ci/docker/host-x86_64/dist-various-2/Dockerfile

@@ -65,6 +65,10 @@ ENV \
     CXX_i686_unknown_uefi=clang++-11 \
     CC_x86_64_unknown_uefi=clang-11 \
     CXX_x86_64_unknown_uefi=clang++-11 \
+    CC_wasm32_unknown_unknown=clang-11 \
+    CXX_wasm32_unknown_unknown=clang++-11 \
+    CC_wasm32v1_none=clang-11 \
+    CXX_wasm32v1_none=clang++-11 \
     CC=gcc-9 \
     CXX=g++-9
 

src/ci/docker/host-x86_64/test-various/Dockerfile

@@ -4,6 +4,7 @@ ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update && apt-get install -y --no-install-recommends \
   clang-11 \
   llvm-11 \
+  gcc-multilib \
   g++ \
   make \
   ninja-build \
@@ -59,8 +60,8 @@ RUN curl -L https://github.com/bytecodealliance/wasmtime/releases/download/v19.0
   tar -xJ
 ENV PATH "$PATH:/wasmtime-v19.0.0-x86_64-linux"
 
-ENV WASM_TARGETS=wasm32-wasip1
-ENV WASM_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $WASM_TARGETS \
+ENV WASM_WASIP_TARGET=wasm32-wasip1 
+ENV WASM_WASIP_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $WASM_WASIP_TARGET \
   tests/run-make \
   tests/ui \
   tests/mir-opt \
@@ -90,4 +91,4 @@ ENV UEFI_TARGETS=aarch64-unknown-uefi,i686-unknown-uefi,x86_64-unknown-uefi \
 ENV UEFI_SCRIPT python3 /checkout/x.py --stage 2 build --host='' --target $UEFI_TARGETS && \
   python3 -u /uefi_qemu_test/run.py
 
-ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT
+ENV SCRIPT $WASM_WASIP_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT