Disable unwinding for emscripten again

Author: Jules-Bertholet

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -12,7 +12,7 @@ use rustc_middle::bug;
 use rustc_session::config::PrintRequest;
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;
-use rustc_target::spec::{MergeFunctions, PanicStrategy};
+use rustc_target::spec::MergeFunctions;
 use smallvec::{smallvec, SmallVec};
 use std::ffi::{CStr, CString};
 use tracing::debug;
@@ -109,10 +109,6 @@ unsafe fn configure_llvm(sess: &Session) {
             }
         }
 
-        if sess.target.os == "emscripten" && sess.panic_strategy() == PanicStrategy::Unwind {
-            add("-enable-emscripten-cxx-exceptions", false);
-        }
-
         // HACK(eddyb) LLVM inserts `llvm.assume` calls to preserve align attributes
         // during inlining. Unfortunately these may block other optimizations.
         add("-preserve-alignment-assumptions-during-inlining=false", false);

compiler/rustc_target/src/spec/wasm32_unknown_emscripten.rs

@@ -1,5 +1,5 @@
 use super::{cvs, wasm_base};
-use super::{LinkArgs, LinkerFlavor, PanicStrategy, Target, TargetOptions};
+use super::{LinkArgs, LinkerFlavor, Target, TargetOptions};
 
 pub fn target() -> Target {
     let mut options = wasm_base::options();
@@ -22,6 +22,8 @@ pub fn target() -> Target {
             "-s".into(),
             "ASSERTIONS=1".into(),
             "-s".into(),
+            "DISABLE_EXCEPTION_CATCHING=1".into(),
+            "-s".into(),
             "ABORTING_MALLOC=0".into(),
             "-Wl,--fatal-warnings".into(),
         ],
@@ -35,7 +37,6 @@ pub fn target() -> Target {
         exe_suffix: ".js".into(),
         linker: None,
         is_like_emscripten: true,
-        panic_strategy: PanicStrategy::Unwind,
         post_link_args,
         families: cvs!["unix", "wasm"],
         ..options

library/panic_abort/src/lib.rs

@@ -116,7 +116,7 @@ pub unsafe fn __rust_start_panic(_payload: *mut &mut dyn BoxMeUp) -> u32 {
 pub mod personalities {
     #[rustc_std_internal_symbol]
     #[cfg(not(any(
-        all(target_family = "wasm", not(target_os = "emscripten")),
+        all(target_family = "wasm"),
         all(target_os = "windows", target_env = "gnu", target_arch = "x86_64",),
     )))]
     pub extern "C" fn rust_eh_personality() {}

library/test/src/lib.rs

@@ -457,10 +457,8 @@ pub fn run_test(
 ) -> Option<thread::JoinHandle<()>> {
     let TestDescAndFn { desc, testfn } = test;
 
-    // Emscripten can catch panics but other wasm targets cannot
-    let ignore_because_no_process_support = desc.should_panic != ShouldPanic::No
-        && cfg!(target_family = "wasm")
-        && !cfg!(target_os = "emscripten");
+    let ignore_because_no_process_support =
+        desc.should_panic != ShouldPanic::No && cfg!(target_family = "wasm");
 
     if force_ignore || desc.ignore || ignore_because_no_process_support {
         let message = CompletedTest::new(id, desc, TrIgnored, None, Vec::new());