Invoke panic handler instead of trap for assert_* intrinsics

Author: bjorn3

src/base.rs

@@ -274,47 +274,26 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
                 fx.bcx.switch_to_block(failure);
                 fx.bcx.ins().nop();
 
-                let location = fx
-                    .get_caller_location(bb_data.terminator().source_info.span)
-                    .load_scalar(fx);
-
-                let args;
-                let lang_item = match msg {
+                match msg {
                     AssertKind::BoundsCheck { ref len, ref index } => {
                         let len = trans_operand(fx, len).load_scalar(fx);
                         let index = trans_operand(fx, index).load_scalar(fx);
-                        args = [index, len, location];
-                        rustc_hir::LangItem::PanicBoundsCheck
+                        let location = fx
+                            .get_caller_location(bb_data.terminator().source_info.span)
+                            .load_scalar(fx);
+
+                        codegen_panic_inner(
+                            fx,
+                            rustc_hir::LangItem::PanicBoundsCheck,
+                            &[index, len, location],
+                            bb_data.terminator().source_info.span,
+                        );
                     }
                     _ => {
                         let msg_str = msg.description();
-                        let msg_ptr = fx.anonymous_str("assert", msg_str);
-                        let msg_len = fx
-                            .bcx
-                            .ins()
-                            .iconst(fx.pointer_type, i64::try_from(msg_str.len()).unwrap());
-                        args = [msg_ptr, msg_len, location];
-                        rustc_hir::LangItem::Panic
+                        codegen_panic(fx, msg_str, bb_data.terminator().source_info.span);
                     }
-                };
-
-                let def_id = fx.tcx.lang_items().require(lang_item).unwrap_or_else(|s| {
-                    fx.tcx
-                        .sess
-                        .span_fatal(bb_data.terminator().source_info.span, &s)
-                });
-
-                let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
-                let symbol_name = fx.tcx.symbol_name(instance).name;
-
-                fx.lib_call(
-                    &*symbol_name,
-                    vec![fx.pointer_type, fx.pointer_type, fx.pointer_type],
-                    vec![],
-                    &args,
-                );
-
-                crate::trap::trap_unreachable(fx, "panic lang item returned");
+                }
             }
 
             TerminatorKind::SwitchInt {
@@ -997,3 +976,45 @@ pub(crate) fn trans_operand<'tcx>(
         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
     }
 }
+
+pub(crate) fn codegen_panic<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
+    msg_str: &str,
+    span: Span,
+) {
+    let location = fx.get_caller_location(span).load_scalar(fx);
+
+    let msg_ptr = fx.anonymous_str("assert", msg_str);
+    let msg_len = fx
+        .bcx
+        .ins()
+        .iconst(fx.pointer_type, i64::try_from(msg_str.len()).unwrap());
+    let args = [msg_ptr, msg_len, location];
+
+    codegen_panic_inner(fx, rustc_hir::LangItem::Panic, &args, span);
+}
+
+pub(crate) fn codegen_panic_inner<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
+    lang_item: rustc_hir::LangItem,
+    args: &[Value],
+    span: Span,
+) {
+    let def_id = fx
+        .tcx
+        .lang_items()
+        .require(lang_item)
+        .unwrap_or_else(|s| fx.tcx.sess.span_fatal(span, &s));
+
+    let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
+    let symbol_name = fx.tcx.symbol_name(instance).name;
+
+    fx.lib_call(
+        &*symbol_name,
+        vec![fx.pointer_type, fx.pointer_type, fx.pointer_type],
+        vec![],
+        args,
+    );
+
+    crate::trap::trap_unreachable(fx, "panic lang item returned");
+}

src/intrinsics/mod.rs

@@ -413,13 +413,13 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
             // Insert non returning intrinsics here
             match intrinsic {
                 "abort" => {
-                    trap_panic(fx, "Called intrinsic::abort.");
+                    trap_abort(fx, "Called intrinsic::abort.");
                 }
                 "unreachable" => {
                     trap_unreachable(fx, "[corruption] Called intrinsic::unreachable.");
                 }
                 "transmute" => {
-                    trap_unreachable(fx, "[corruption] Transmuting to uninhabited type.");
+                    crate::base::codegen_panic(fx, "Transmuting to uninhabited type.", span);
                 }
                 _ => unimplemented!("unsupported instrinsic {}", intrinsic),
             }
@@ -819,17 +819,29 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
         assert_inhabited | assert_zero_valid | assert_uninit_valid, <T> () {
             let layout = fx.layout_of(T);
             if layout.abi.is_uninhabited() {
-                crate::trap::trap_panic(fx, &format!("attempted to instantiate uninhabited type `{}`", T));
+                crate::base::codegen_panic(
+                    fx,
+                    &format!("attempted to instantiate uninhabited type `{}`", T),
+                    span,
+                );
                 return;
             }
 
             if intrinsic == "assert_zero_valid" && !layout.might_permit_raw_init(fx, /*zero:*/ true).unwrap() {
-                crate::trap::trap_panic(fx, &format!("attempted to zero-initialize type `{}`, which is invalid", T));
+                crate::base::codegen_panic(
+                    fx,
+                    &format!("attempted to zero-initialize type `{}`, which is invalid", T),
+                    span,
+                );
                 return;
             }
 
             if intrinsic == "assert_uninit_valid" && !layout.might_permit_raw_init(fx, /*zero:*/ false).unwrap() {
-                crate::trap::trap_panic(fx, &format!("attempted to leave type `{}` uninitialized, which is invalid", T));
+                crate::base::codegen_panic(
+                    fx,
+                    &format!("attempted to leave type `{}` uninitialized, which is invalid", T),
+                    span,
+                );
                 return;
             }
         };

src/trap.rs

@@ -28,15 +28,13 @@ fn codegen_print(fx: &mut FunctionCx<'_, '_, impl cranelift_module::Backend>, ms
     fx.bcx.ins().call(puts, &[msg_ptr]);
 }
 
-/// Use this when `rustc_codegen_llvm` would insert a call to the panic handler.
-///
-/// Trap code: user0
-pub(crate) fn trap_panic(
+/// Trap code: user1
+pub(crate) fn trap_abort(
     fx: &mut FunctionCx<'_, '_, impl cranelift_module::Backend>,
     msg: impl AsRef<str>,
 ) {
     codegen_print(fx, msg.as_ref());
-    fx.bcx.ins().trap(TrapCode::User(0));
+    fx.bcx.ins().trap(TrapCode::User(1));
 }
 
 /// Use this for example when a function call should never return. This will fill the current block,