Disable unwinding for emscripten again

compiler/rustc_codegen_llvm/src/context.rs

@@ -99,7 +99,6 @@ pub struct CodegenCx<'ll, 'tcx> {
     pub dbg_cx: Option<debuginfo::CodegenUnitDebugContext<'ll, 'tcx>>,
 
     eh_personality: Cell<Option<&'ll Value>>,
-    eh_catch_typeinfo: Cell<Option<&'ll Value>>,
     pub rust_try_fn: Cell<Option<(&'ll Type, &'ll Value)>>,
 
     intrinsics: RefCell<FxHashMap<&'static str, (&'ll Type, &'ll Value)>>,
@@ -439,7 +438,6 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
             coverage_cx,
             dbg_cx,
             eh_personality: Cell::new(None),
-            eh_catch_typeinfo: Cell::new(None),
             rust_try_fn: Cell::new(None),
             intrinsics: Default::default(),
             local_gen_sym_counter: Cell::new(0),
@@ -889,25 +887,6 @@ impl<'ll> CodegenCx<'ll, '_> {
         }
         None
     }
-
-    pub(crate) fn eh_catch_typeinfo(&self) -> &'ll Value {
-        if let Some(eh_catch_typeinfo) = self.eh_catch_typeinfo.get() {
-            return eh_catch_typeinfo;
-        }
-        let tcx = self.tcx;
-        assert!(self.sess().target.is_like_emscripten);
-        let eh_catch_typeinfo = match tcx.lang_items().eh_catch_typeinfo() {
-            Some(def_id) => self.get_static(def_id),
-            _ => {
-                let ty = self
-                    .type_struct(&[self.type_ptr_to(self.type_isize()), self.type_i8p()], false);
-                self.declare_global("rust_eh_catch_typeinfo", ty)
-            }
-        };
-        let eh_catch_typeinfo = self.const_bitcast(eh_catch_typeinfo, self.type_i8p());
-        self.eh_catch_typeinfo.set(Some(eh_catch_typeinfo));
-        eh_catch_typeinfo
-    }
 }
 
 impl CodegenCx<'_, '_> {

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -431,8 +431,6 @@ fn try_intrinsic<'ll>(
         bx.store(bx.const_i32(0), dest, ret_align);
     } else if wants_msvc_seh(bx.sess()) {
         codegen_msvc_try(bx, try_func, data, catch_func, dest);
-    } else if bx.sess().target.is_like_emscripten {
-        codegen_emcc_try(bx, try_func, data, catch_func, dest);
     } else {
         codegen_gnu_try(bx, try_func, data, catch_func, dest);
     }
@@ -656,91 +654,6 @@ fn codegen_gnu_try<'ll>(
     bx.store(ret, dest, i32_align);
 }
 
-// Variant of codegen_gnu_try used for emscripten where Rust panics are
-// implemented using C++ exceptions. Here we use exceptions of a specific type
-// (`struct rust_panic`) to represent Rust panics.
-fn codegen_emcc_try<'ll>(
-    bx: &mut Builder<'_, 'll, '_>,
-    try_func: &'ll Value,
-    data: &'ll Value,
-    catch_func: &'ll Value,
-    dest: &'ll Value,
-) {
-    let (llty, llfn) = get_rust_try_fn(bx, &mut |mut bx| {
-        // Codegens the shims described above:
-        //
-        //   bx:
-        //      invoke %try_func(%data) normal %normal unwind %catch
-        //
-        //   normal:
-        //      ret 0
-        //
-        //   catch:
-        //      (%ptr, %selector) = landingpad
-        //      %rust_typeid = @llvm.eh.typeid.for(@_ZTI10rust_panic)
-        //      %is_rust_panic = %selector == %rust_typeid
-        //      %catch_data = alloca { i8*, i8 }
-        //      %catch_data[0] = %ptr
-        //      %catch_data[1] = %is_rust_panic
-        //      call %catch_func(%data, %catch_data)
-        //      ret 1
-        let then = bx.append_sibling_block("then");
-        let catch = bx.append_sibling_block("catch");
-
-        let try_func = llvm::get_param(bx.llfn(), 0);
-        let data = llvm::get_param(bx.llfn(), 1);
-        let catch_func = llvm::get_param(bx.llfn(), 2);
-        let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void());
-        bx.invoke(try_func_ty, try_func, &[data], then, catch, None);
-
-        bx.switch_to_block(then);
-        bx.ret(bx.const_i32(0));
-
-        // Type indicator for the exception being thrown.
-        //
-        // The first value in this tuple is a pointer to the exception object
-        // being thrown.  The second value is a "selector" indicating which of
-        // the landing pad clauses the exception's type had been matched to.
-        bx.switch_to_block(catch);
-        let tydesc = bx.eh_catch_typeinfo();
-        let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false);
-        let vals = bx.landing_pad(lpad_ty, bx.eh_personality(), 2);
-        bx.add_clause(vals, tydesc);
-        bx.add_clause(vals, bx.const_null(bx.type_i8p()));
-        let ptr = bx.extract_value(vals, 0);
-        let selector = bx.extract_value(vals, 1);
-
-        // Check if the typeid we got is the one for a Rust panic.
-        let rust_typeid = bx.call_intrinsic("llvm.eh.typeid.for", &[tydesc]);
-        let is_rust_panic = bx.icmp(IntPredicate::IntEQ, selector, rust_typeid);
-        let is_rust_panic = bx.zext(is_rust_panic, bx.type_bool());
-
-        // We need to pass two values to catch_func (ptr and is_rust_panic), so
-        // create an alloca and pass a pointer to that.
-        let ptr_align = bx.tcx().data_layout.pointer_align.abi;
-        let i8_align = bx.tcx().data_layout.i8_align.abi;
-        let catch_data_type = bx.type_struct(&[bx.type_i8p(), bx.type_bool()], false);
-        let catch_data = bx.alloca(catch_data_type, ptr_align);
-        let catch_data_0 =
-            bx.inbounds_gep(catch_data_type, catch_data, &[bx.const_usize(0), bx.const_usize(0)]);
-        bx.store(ptr, catch_data_0, ptr_align);
-        let catch_data_1 =
-            bx.inbounds_gep(catch_data_type, catch_data, &[bx.const_usize(0), bx.const_usize(1)]);
-        bx.store(is_rust_panic, catch_data_1, i8_align);
-        let catch_data = bx.bitcast(catch_data, bx.type_i8p());
-
-        let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void());
-        bx.call(catch_ty, catch_func, &[data, catch_data], None);
-        bx.ret(bx.const_i32(1));
-    });
-
-    // Note that no invoke is used here because by definition this function
-    // can't panic (that's what it's catching).
-    let ret = bx.call(llty, llfn, &[try_func, data, catch_func], None);
-    let i32_align = bx.tcx().data_layout.i32_align.abi;
-    bx.store(ret, dest, i32_align);
-}
-
 // Helper function to give a Block to a closure to codegen a shim function.
 // This is currently primarily used for the `try` intrinsic functions above.
 fn gen_fn<'ll, 'tcx>(

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_codegen_ssa/src/back/link.rs

@@ -21,7 +21,7 @@ use rustc_span::symbol::Symbol;
 use rustc_span::DebuggerVisualizerFile;
 use rustc_target::spec::crt_objects::{CrtObjects, CrtObjectsFallback};
 use rustc_target::spec::{LinkOutputKind, LinkerFlavor, LldFlavor, SplitDebuginfo};
-use rustc_target::spec::{PanicStrategy, RelocModel, RelroLevel, SanitizerSet, Target};
+use rustc_target::spec::{RelocModel, RelroLevel, SanitizerSet, Target};
 
 use super::archive::{find_library, ArchiveBuilder};
 use super::command::Command;
@@ -2047,15 +2047,6 @@ fn add_order_independent_options(
         cmd.no_crt_objects();
     }
 
-    if sess.target.is_like_emscripten {
-        cmd.arg("-s");
-        cmd.arg(if sess.panic_strategy() == PanicStrategy::Abort {
-            "DISABLE_EXCEPTION_CATCHING=1"
-        } else {
-            "DISABLE_EXCEPTION_CATCHING=0"
-        });
-    }
-
     if flavor == LinkerFlavor::PtxLinker {
         // Provide the linker with fallback to internal `target-cpu`.
         cmd.arg("--fallback-arch");

compiler/rustc_hir/src/lang_items.rs

@@ -270,7 +270,6 @@ language_item_table! {
     Start,                   sym::start,               start_fn,                   Target::Fn,             GenericRequirement::Exact(1);
 
     EhPersonality,           sym::eh_personality,      eh_personality,             Target::Fn,             GenericRequirement::None;
-    EhCatchTypeinfo,         sym::eh_catch_typeinfo,   eh_catch_typeinfo,          Target::Static,         GenericRequirement::None;
 
     OwnedBox,                sym::owned_box,           owned_box,                  Target::Struct,         GenericRequirement::Minimum(1);
 

compiler/rustc_hir/src/weak_lang_items.rs

@@ -42,6 +42,5 @@ impl LanguageItems {
 weak_lang_items! {
     panic_impl,         PanicImpl,          rust_begin_unwind;
     eh_personality,     EhPersonality,      rust_eh_personality;
-    eh_catch_typeinfo,  EhCatchTypeinfo,    rust_eh_catch_typeinfo;
     oom,                Oom,                rust_oom;
 }

compiler/rustc_middle/src/middle/lang_items.rs

@@ -53,9 +53,7 @@ pub fn required(tcx: TyCtxt<'_>, lang_item: LangItem) -> bool {
     // symbols. Other panic runtimes ensure that the relevant symbols are
     // available to link things together, but they're never exercised.
     match tcx.sess.panic_strategy() {
-        PanicStrategy::Abort => {
-            lang_item != LangItem::EhPersonality && lang_item != LangItem::EhCatchTypeinfo
-        }
+        PanicStrategy::Abort => lang_item != LangItem::EhPersonality,
         PanicStrategy::Unwind => true,
     }
 }

compiler/rustc_passes/src/weak_lang_items.rs

@@ -17,9 +17,6 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>, items: &mut lang_items::LanguageItem
     if items.eh_personality().is_none() {
         items.missing.push(LangItem::EhPersonality);
     }
-    if tcx.sess.target.is_like_emscripten && items.eh_catch_typeinfo().is_none() {
-        items.missing.push(LangItem::EhCatchTypeinfo);
-    }
 
     let crate_items = tcx.hir_crate_items(());
     for id in crate_items.foreign_items() {

compiler/rustc_span/src/symbol.rs

@@ -619,7 +619,6 @@ symbols! {
         e,
         edition_macro_pats,
         edition_panic,
-        eh_catch_typeinfo,
         eh_personality,
         emit_enum,
         emit_enum_variant,
@@ -1164,7 +1163,6 @@ symbols! {
         rust_2024_preview,
         rust_begin_unwind,
         rust_cold_cc,
-        rust_eh_catch_typeinfo,
         rust_eh_personality,
         rust_eh_register_frames,
         rust_eh_unregister_frames,

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();
@@ -16,7 +16,7 @@ pub fn target() -> Target {
     let mut post_link_args = LinkArgs::new();
     post_link_args.insert(
         LinkerFlavor::Em,
-        vec!["-sABORTING_MALLOC=0".into(), "-Wl,--fatal-warnings".into()],
+        vec!["-s".into(), "ABORTING_MALLOC=0".into(), "-Wl,--fatal-warnings".into()],
     );
 
     let opts = TargetOptions {
@@ -27,7 +27,6 @@ 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/alloc/src/collections/binary_heap/tests.rs

@@ -290,6 +290,7 @@ fn test_drain_sorted() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_drain_sorted_leak() {
     static DROPS: AtomicU32 = AtomicU32::new(0);
 
@@ -411,9 +412,8 @@ fn test_retain() {
 // even if the order might 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"))]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn panic_safe() {
     use rand::{seq::SliceRandom, thread_rng};
     use std::cmp;

library/alloc/src/collections/btree/map/tests.rs

@@ -1122,6 +1122,7 @@ mod test_drain_filter {
     }
 
     #[test]
+    #[cfg_attr(not(panic = "unwind"), should_panic)]
     fn drop_panic_leak() {
         let a = CrashTestDummy::new(0);
         let b = CrashTestDummy::new(1);
@@ -1142,6 +1143,7 @@ mod test_drain_filter {
     }
 
     #[test]
+    #[cfg_attr(not(panic = "unwind"), should_panic)]
     fn pred_panic_leak() {
         let a = CrashTestDummy::new(0);
         let b = CrashTestDummy::new(1);
@@ -1168,6 +1170,7 @@ mod test_drain_filter {
 
     // Same as above, but attempt to use the iterator again after the panic in the predicate
     #[test]
+    #[cfg_attr(not(panic = "unwind"), should_panic)]
     fn pred_panic_reuse() {
         let a = CrashTestDummy::new(0);
         let b = CrashTestDummy::new(1);
@@ -1416,6 +1419,7 @@ fn test_clear() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_clear_drop_panic_leak() {
     let a = CrashTestDummy::new(0);
     let b = CrashTestDummy::new(1);
@@ -1507,11 +1511,13 @@ fn test_clone_panic_leak(size: usize) {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_clone_panic_leak_height_0() {
     test_clone_panic_leak(3)
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_clone_panic_leak_height_1() {
     test_clone_panic_leak(MIN_INSERTS_HEIGHT_1)
 }
@@ -2066,6 +2072,7 @@ create_append_test!(test_append_239, 239);
 create_append_test!(test_append_1700, 1700);
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_append_drop_leak() {
     let a = CrashTestDummy::new(0);
     let b = CrashTestDummy::new(1);
@@ -2207,6 +2214,7 @@ fn test_split_off_large_random_sorted() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_into_iter_drop_leak_height_0() {
     let a = CrashTestDummy::new(0);
     let b = CrashTestDummy::new(1);
@@ -2230,6 +2238,7 @@ fn test_into_iter_drop_leak_height_0() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_into_iter_drop_leak_height_1() {
     let size = MIN_INSERTS_HEIGHT_1;
     for panic_point in vec![0, 1, size - 2, size - 1] {

library/alloc/src/collections/btree/set/tests.rs

@@ -377,6 +377,7 @@ fn test_drain_filter() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_drain_filter_drop_panic_leak() {
     let a = CrashTestDummy::new(0);
     let b = CrashTestDummy::new(1);
@@ -397,6 +398,7 @@ fn test_drain_filter_drop_panic_leak() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_drain_filter_pred_panic_leak() {
     let a = CrashTestDummy::new(0);
     let b = CrashTestDummy::new(1);

library/alloc/src/collections/linked_list/tests.rs

@@ -983,6 +983,7 @@ fn drain_filter_complex() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn drain_filter_drop_panic_leak() {
     static mut DROPS: i32 = 0;
 
@@ -1017,6 +1018,7 @@ fn drain_filter_drop_panic_leak() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn drain_filter_pred_panic_leak() {
     static mut DROPS: i32 = 0;
 
@@ -1123,6 +1125,7 @@ fn test_drop_clear() {
 }
 
 #[test]
+#[cfg_attr(not(panic = "unwind"), should_panic)]
 fn test_drop_panic() {
     static mut DROPS: i32 = 0;