diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs index e9b66b54c58..ff03df79ab1 100644 --- a/compiler/rustc_codegen_llvm/src/abi.rs +++ b/compiler/rustc_codegen_llvm/src/abi.rs @@ -37,7 +37,7 @@ impl ArgAttributeExt for ArgAttribute { where F: FnMut(llvm::Attribute), { - for_each_kind!(self, f, NoAlias, NoCapture, NonNull, ReadOnly, InReg) + for_each_kind!(self, f, NoAlias, NoCapture, NonNull, ReadOnly, InReg, NoUndef) } } @@ -69,7 +69,9 @@ impl ArgAttributesExt for ArgAttributes { } else { llvm::LLVMRustAddDereferenceableOrNullAttr(llfn, idx.as_uint(), deref); } + // dereferenceable implies nonnull noundef; dereferenceable_or_null implies noundef regular -= ArgAttribute::NonNull; + regular -= ArgAttribute::NoUndef; } if let Some(align) = self.pointee_align { llvm::LLVMRustAddAlignmentAttr(llfn, idx.as_uint(), align.bytes() as u32); @@ -109,7 +111,9 @@ impl ArgAttributesExt for ArgAttributes { deref, ); } + // dereferenceable implies nonnull noundef; dereferenceable_or_null implies noundef regular -= ArgAttribute::NonNull; + regular -= ArgAttribute::NoUndef; } if let Some(align) = self.pointee_align { llvm::LLVMRustAddAlignmentCallSiteAttr( diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 367c86a1dc9..4f62c685568 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -189,6 +189,7 @@ pub enum Attribute { StackProtectReq = 30, StackProtectStrong = 31, StackProtect = 32, + NoUndef = 33, } /// LLVMIntPredicate diff --git a/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h b/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h index e2ce7da0e84..9e0a9b354e1 100644 --- a/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h +++ b/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h @@ -82,6 +82,7 @@ enum LLVMRustAttribute { StackProtectReq = 30, StackProtectStrong = 31, StackProtect = 32, + NoUndef = 33, }; typedef struct OpaqueRustString *RustStringRef; diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index d871290744f..fb9c5e6a527 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp @@ -224,6 +224,8 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) { return Attribute::StackProtectStrong; case StackProtect: return Attribute::StackProtect; + case NoUndef: + return Attribute::NoUndef; } report_fatal_error("bad AttributeKind"); } diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs index ad817e185a3..d2d22fbf31c 100644 --- a/compiler/rustc_middle/src/ty/layout.rs +++ b/compiler/rustc_middle/src/ty/layout.rs @@ -3048,9 +3048,10 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> { layout: TyAndLayout<'tcx>, offset: Size, is_return: bool| { - // Booleans are always an i1 that needs to be zero-extended. + // Booleans are always a noundef i1 that needs to be zero-extended. if scalar.is_bool() { attrs.ext(ArgExtension::Zext); + attrs.set(ArgAttribute::NoUndef); return; } @@ -3075,6 +3076,11 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> { _ => pointee.size, }; + // `Box`, `&T`, and `&mut T` cannot be undef. + // Note that this only applies to the value of the pointer itself; + // this attribute doesn't make it UB for the pointed-to data to be undef. + attrs.set(ArgAttribute::NoUndef); + // `Box` pointer parameters never alias because ownership is transferred // `&mut` pointer parameters never alias other parameters, // or mutable global data diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs index 735b7e76e38..b605f21d051 100644 --- a/compiler/rustc_target/src/abi/call/mod.rs +++ b/compiler/rustc_target/src/abi/call/mod.rs @@ -73,6 +73,7 @@ mod attr_impl { // or not to actually emit the attribute. It can also be controlled // with the `-Zmutable-noalias` debugging option. const NoAliasMutRef = 1 << 6; + const NoUndef = 1 << 7; } } } @@ -494,7 +495,11 @@ impl<'a, Ty> ArgAbi<'a, Ty> { // For non-immediate arguments the callee gets its own copy of // the value on the stack, so there are no aliases. It's also // program-invisible so can't possibly capture - attrs.set(ArgAttribute::NoAlias).set(ArgAttribute::NoCapture).set(ArgAttribute::NonNull); + attrs + .set(ArgAttribute::NoAlias) + .set(ArgAttribute::NoCapture) + .set(ArgAttribute::NonNull) + .set(ArgAttribute::NoUndef); attrs.pointee_size = layout.size; // FIXME(eddyb) We should be doing this, but at least on // i686-pc-windows-msvc, it results in wrong stack offsets. diff --git a/src/test/codegen/function-arguments.rs b/src/test/codegen/function-arguments.rs index 3e10e227e55..998f3890900 100644 --- a/src/test/codegen/function-arguments.rs +++ b/src/test/codegen/function-arguments.rs @@ -11,7 +11,7 @@ pub struct UnsafeInner { _field: std::cell::UnsafeCell, } -// CHECK: zeroext i1 @boolean(i1 zeroext %x) +// CHECK: noundef zeroext i1 @boolean(i1 noundef zeroext %x) #[no_mangle] pub fn boolean(x: bool) -> bool { x @@ -64,9 +64,14 @@ pub fn indirect_struct(_: S) { pub fn borrowed_struct(_: &S) { } +// CHECK: @raw_struct(%S* %_1) +#[no_mangle] +pub fn raw_struct(_: *const S) { +} + // `Box` can get deallocated during execution of the function, so it should // not get `dereferenceable`. -// CHECK: noalias nonnull align 4 i32* @_box(i32* noalias nonnull align 4 %x) +// CHECK: noalias noundef nonnull align 4 i32* @_box(i32* noalias noundef nonnull align 4 %x) #[no_mangle] pub fn _box(x: Box) -> Box { x @@ -86,48 +91,58 @@ pub fn struct_return() -> S { pub fn helper(_: usize) { } -// CHECK: @slice([0 x i8]* noalias nonnull readonly align 1 %_1.0, [[USIZE]] %_1.1) +// CHECK: @slice([0 x i8]* noalias noundef nonnull readonly align 1 %_1.0, [[USIZE]] %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn slice(_: &[u8]) { } -// CHECK: @mutable_slice([0 x i8]* noalias nonnull align 1 %_1.0, [[USIZE]] %_1.1) +// CHECK: @mutable_slice([0 x i8]* noalias noundef nonnull align 1 %_1.0, [[USIZE]] %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn mutable_slice(_: &mut [u8]) { } -// CHECK: @unsafe_slice([0 x i16]* nonnull align 2 %_1.0, [[USIZE]] %_1.1) +// CHECK: @unsafe_slice([0 x i16]* noundef nonnull align 2 %_1.0, [[USIZE]] %_1.1) // unsafe interior means this isn't actually readonly and there may be aliases ... #[no_mangle] pub fn unsafe_slice(_: &[UnsafeInner]) { } -// CHECK: @str([0 x i8]* noalias nonnull readonly align 1 %_1.0, [[USIZE]] %_1.1) +// CHECK: @raw_slice([0 x i8]* %_1.0, [[USIZE]] %_1.1) +#[no_mangle] +pub fn raw_slice(_: *const [u8]) { +} + +// CHECK: @str([0 x i8]* noalias noundef nonnull readonly align 1 %_1.0, [[USIZE]] %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn str(_: &[u8]) { } -// CHECK: @trait_borrow({}* nonnull align 1 %_1.0, [3 x [[USIZE]]]* noalias readonly align {{.*}} dereferenceable({{.*}}) %_1.1) +// CHECK: @trait_borrow({}* noundef nonnull align 1 %_1.0, [3 x [[USIZE]]]* noalias readonly align {{.*}} dereferenceable({{.*}}) %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn trait_borrow(_: &Drop) { } -// CHECK: @trait_box({}* noalias nonnull align 1{{( %0)?}}, [3 x [[USIZE]]]* noalias readonly align {{.*}} dereferenceable({{.*}}){{( %1)?}}) +// CHECK: @trait_raw({}* %_1.0, [3 x [[USIZE]]]* noalias readonly align {{.*}} dereferenceable({{.*}}) %_1.1) +#[no_mangle] +pub fn trait_raw(_: *const Drop) { +} + +// CHECK: @trait_box({}* noalias noundef nonnull align 1{{( %0)?}}, [3 x [[USIZE]]]* noalias readonly align {{.*}} dereferenceable({{.*}}){{( %1)?}}) #[no_mangle] pub fn trait_box(_: Box) { } -// CHECK: { i8*, i8* } @trait_option(i8* noalias align 1 %x.0, i8* %x.1) +// CHECK: { i8*, i8* } @trait_option(i8* noalias noundef align 1 %x.0, i8* %x.1) #[no_mangle] pub fn trait_option(x: Option>) -> Option> { x } -// CHECK: { [0 x i16]*, [[USIZE]] } @return_slice([0 x i16]* noalias nonnull readonly align 2 %x.0, [[USIZE]] %x.1) +// CHECK: { [0 x i16]*, [[USIZE]] } @return_slice([0 x i16]* noalias noundef nonnull readonly align 2 %x.0, [[USIZE]] %x.1) #[no_mangle] pub fn return_slice(x: &[u16]) -> &[u16] { x @@ -139,7 +154,7 @@ pub fn enum_id_1(x: Option>) -> Option> { x } -// CHECK: { i8, i8 } @enum_id_2(i1 zeroext %x.0, i8 %x.1) +// CHECK: { i8, i8 } @enum_id_2(i1 noundef zeroext %x.0, i8 %x.1) #[no_mangle] pub fn enum_id_2(x: Option) -> Option { x diff --git a/src/test/codegen/scalar-pair-bool.rs b/src/test/codegen/scalar-pair-bool.rs index 473272158d0..264f28fdb5f 100644 --- a/src/test/codegen/scalar-pair-bool.rs +++ b/src/test/codegen/scalar-pair-bool.rs @@ -2,25 +2,25 @@ #![crate_type = "lib"] -// CHECK: define{{.*}}{ i8, i8 } @pair_bool_bool(i1 zeroext %pair.0, i1 zeroext %pair.1) +// CHECK: define{{.*}}{ i8, i8 } @pair_bool_bool(i1 noundef zeroext %pair.0, i1 noundef zeroext %pair.1) #[no_mangle] pub fn pair_bool_bool(pair: (bool, bool)) -> (bool, bool) { pair } -// CHECK: define{{.*}}{ i8, i32 } @pair_bool_i32(i1 zeroext %pair.0, i32 %pair.1) +// CHECK: define{{.*}}{ i8, i32 } @pair_bool_i32(i1 noundef zeroext %pair.0, i32 %pair.1) #[no_mangle] pub fn pair_bool_i32(pair: (bool, i32)) -> (bool, i32) { pair } -// CHECK: define{{.*}}{ i32, i8 } @pair_i32_bool(i32 %pair.0, i1 zeroext %pair.1) +// CHECK: define{{.*}}{ i32, i8 } @pair_i32_bool(i32 %pair.0, i1 noundef zeroext %pair.1) #[no_mangle] pub fn pair_i32_bool(pair: (i32, bool)) -> (i32, bool) { pair } -// CHECK: define{{.*}}{ i8, i8 } @pair_and_or(i1 zeroext %_1.0, i1 zeroext %_1.1) +// CHECK: define{{.*}}{ i8, i8 } @pair_and_or(i1 noundef zeroext %_1.0, i1 noundef zeroext %_1.1) #[no_mangle] pub fn pair_and_or((a, b): (bool, bool)) -> (bool, bool) { // Make sure it can operate directly on the unpacked args @@ -30,7 +30,7 @@ pub fn pair_and_or((a, b): (bool, bool)) -> (bool, bool) { (a && b, a || b) } -// CHECK: define{{.*}}void @pair_branches(i1 zeroext %_1.0, i1 zeroext %_1.1) +// CHECK: define{{.*}}void @pair_branches(i1 noundef zeroext %_1.0, i1 noundef zeroext %_1.1) #[no_mangle] pub fn pair_branches((a, b): (bool, bool)) { // Make sure it can branch directly on the unpacked bool args diff --git a/src/test/codegen/transmute-scalar.rs b/src/test/codegen/transmute-scalar.rs index e9584929f3a..a5aeb80de85 100644 --- a/src/test/codegen/transmute-scalar.rs +++ b/src/test/codegen/transmute-scalar.rs @@ -15,7 +15,7 @@ pub fn f32_to_bits(x: f32) -> u32 { unsafe { std::mem::transmute(x) } } -// CHECK-LABEL: define{{.*}}i8 @bool_to_byte(i1 zeroext %b) +// CHECK-LABEL: define{{.*}}i8 @bool_to_byte(i1 noundef zeroext %b) // CHECK: %1 = zext i1 %b to i8 // CHECK-NEXT: store i8 %1, i8* %0 // CHECK-NEXT: %2 = load i8, i8* %0 @@ -25,7 +25,7 @@ pub fn bool_to_byte(b: bool) -> u8 { unsafe { std::mem::transmute(b) } } -// CHECK-LABEL: define{{.*}}zeroext i1 @byte_to_bool(i8 %byte) +// CHECK-LABEL: define{{.*}}noundef zeroext i1 @byte_to_bool(i8 %byte) // CHECK: %1 = trunc i8 %byte to i1 // CHECK-NEXT: %2 = zext i1 %1 to i8 // CHECK-NEXT: store i8 %2, i8* %0 diff --git a/src/test/codegen/union-abi.rs b/src/test/codegen/union-abi.rs index f282fd23705..bb87d263bdf 100644 --- a/src/test/codegen/union-abi.rs +++ b/src/test/codegen/union-abi.rs @@ -75,7 +75,7 @@ pub union CUnionU128x2{a:(u128, u128)} pub fn test_CUnionU128x2(_: CUnionU128x2) { loop {} } pub union UnionBool { b:bool } -// CHECK: define zeroext i1 @test_UnionBool(i8 %b) +// CHECK: define noundef zeroext i1 @test_UnionBool(i8 %b) #[no_mangle] pub fn test_UnionBool(b: UnionBool) -> bool { unsafe { b.b } } // CHECK: %0 = trunc i8 %b to i1