Auto merge of rust-lang#3851 - rust-lang:rustup-2024-08-29, r=RalfJung

Automatic Rustup

Author: bors

rust-version

@@ -1 +1 @@
-d9a2cc4daee38c63b2f69710ed61d40acc32b709
+acb4e8b6251f1d8da36f08e7a70fa23fc581839e

src/machine.rs

@@ -946,16 +946,48 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         ecx.machine.validation == ValidationMode::Deep
     }
 
-    #[inline(always)]
-    fn enforce_abi(_ecx: &MiriInterpCx<'tcx>) -> bool {
-        true
-    }
-
     #[inline(always)]
     fn ignore_optional_overflow_checks(ecx: &MiriInterpCx<'tcx>) -> bool {
         !ecx.tcx.sess.overflow_checks()
     }
 
+    fn check_fn_target_features(
+        ecx: &MiriInterpCx<'tcx>,
+        instance: ty::Instance<'tcx>,
+    ) -> InterpResult<'tcx> {
+        let attrs = ecx.tcx.codegen_fn_attrs(instance.def_id());
+        if attrs
+            .target_features
+            .iter()
+            .any(|feature| !ecx.tcx.sess.target_features.contains(&feature.name))
+        {
+            let unavailable = attrs
+                .target_features
+                .iter()
+                .filter(|&feature| {
+                    !feature.implied && !ecx.tcx.sess.target_features.contains(&feature.name)
+                })
+                .fold(String::new(), |mut s, feature| {
+                    if !s.is_empty() {
+                        s.push_str(", ");
+                    }
+                    s.push_str(feature.name.as_str());
+                    s
+                });
+            let msg = format!(
+                "calling a function that requires unavailable target features: {unavailable}"
+            );
+            // On WASM, this is not UB, but instead gets rejected during validation of the module
+            // (see #84988).
+            if ecx.tcx.sess.target.is_like_wasm {
+                throw_machine_stop!(TerminationInfo::Abort(msg));
+            } else {
+                throw_ub_format!("{msg}");
+            }
+        }
+        Ok(())
+    }
+
     #[inline(always)]
     fn find_mir_or_eval_fn(
         ecx: &mut MiriInterpCx<'tcx>,
@@ -1060,6 +1092,10 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         ecx.generate_nan(inputs)
     }
 
+    fn ub_checks(ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool> {
+        Ok(ecx.tcx.sess.ub_checks())
+    }
+
     fn thread_local_static_pointer(
         ecx: &mut MiriInterpCx<'tcx>,
         def_id: DefId,

tests/fail/function_calls/target_feature_wasm.rs

@@ -0,0 +1,13 @@
+//@only-target-wasm: tests WASM-specific behavior
+//@compile-flags: -C target-feature=-simd128
+
+fn main() {
+    // Calling functions with `#[target_feature]` is not unsound on WASM, see #84988.
+    // But if the compiler actually uses the target feature, it will lead to an error when the module is loaded.
+    // We emulate this with an "unsupported" error.
+    assert!(!cfg!(target_feature = "simd128"));
+    simd128_fn(); //~ERROR: unavailable target features
+}
+
+#[target_feature(enable = "simd128")]
+fn simd128_fn() {}

tests/fail/function_calls/target_feature_wasm.stderr

@@ -0,0 +1,13 @@
+error: abnormal termination: calling a function that requires unavailable target features: simd128
+  --> $DIR/target_feature_wasm.rs:LL:CC
+   |
+LL |     simd128_fn();
+   |     ^^^^^^^^^^^^ calling a function that requires unavailable target features: simd128
+   |
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/target_feature_wasm.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/fail/intrinsics/intrinsic_target_feature.rs

@@ -7,7 +7,7 @@
 //@ignore-target-avr
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
-//@ignore-target-wasm32
+//@ignore-target-wasm
 // Explicitly disable SSE4.1 because it is enabled by default on macOS
 //@compile-flags: -C target-feature=-sse4.1
 

tests/pass/function_calls/target_feature_wasm.rs

@@ -6,7 +6,7 @@
 //@ignore-target-avr
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
-//@ignore-target-wasm32
+//@ignore-target-wasm
 //@compile-flags: -C target-feature=+sha,+sse2,+ssse3,+sse4.1
 
 #[cfg(target_arch = "x86")]

tests/pass/shims/x86/intrinsics-sha.rs

@@ -6,7 +6,7 @@
 //@ignore-target-avr
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
-//@ignore-target-wasm32
+//@ignore-target-wasm
 //@compile-flags: -C target-feature=+adx
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]

tests/pass/shims/x86/intrinsics-x86-adx.rs

@@ -6,7 +6,7 @@
 //@ignore-target-avr
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
-//@ignore-target-wasm32
+//@ignore-target-wasm
 //@compile-flags: -C target-feature=+aes,+vaes,+avx512f
 
 #![feature(avx512_target_feature, stdarch_x86_avx512)]

tests/pass/shims/x86/intrinsics-x86-aes-vaes.rs

@@ -6,7 +6,7 @@
 //@ignore-target-avr
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
-//@ignore-target-wasm32
+//@ignore-target-wasm
 //@compile-flags: -C target-feature=+avx
 
 #[cfg(target_arch = "x86")]