diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs index 043123fcab2cb..399f8b6e76287 100644 --- a/compiler/rustc_codegen_llvm/src/abi.rs +++ b/compiler/rustc_codegen_llvm/src/abi.rs @@ -42,12 +42,13 @@ trait ArgAttributesExt { const ABI_AFFECTING_ATTRIBUTES: [(ArgAttribute, llvm::AttributeKind); 1] = [(ArgAttribute::InReg, llvm::AttributeKind::InReg)]; -const OPTIMIZATION_ATTRIBUTES: [(ArgAttribute, llvm::AttributeKind); 5] = [ +const OPTIMIZATION_ATTRIBUTES: [(ArgAttribute, llvm::AttributeKind); 6] = [ (ArgAttribute::NoAlias, llvm::AttributeKind::NoAlias), (ArgAttribute::NoCapture, llvm::AttributeKind::NoCapture), (ArgAttribute::NonNull, llvm::AttributeKind::NonNull), (ArgAttribute::ReadOnly, llvm::AttributeKind::ReadOnly), (ArgAttribute::NoUndef, llvm::AttributeKind::NoUndef), + (ArgAttribute::CapturesReadOnly, llvm::AttributeKind::CapturesReadOnly), ]; fn get_attrs<'ll>(this: &ArgAttributes, cx: &CodegenCx<'ll, '_>) -> SmallVec<[&'ll Attribute; 8]> { @@ -83,6 +84,10 @@ fn get_attrs<'ll>(this: &ArgAttributes, cx: &CodegenCx<'ll, '_>) -> SmallVec<[&' } for (attr, llattr) in OPTIMIZATION_ATTRIBUTES { if regular.contains(attr) { + // captures(address, read_provenance) is only available since LLVM 21. + if attr == ArgAttribute::CapturesReadOnly && llvm_util::get_version() < (21, 0, 0) { + continue; + } attrs.push(llattr.create_attr(cx.llcx)); } } diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 55d26a97e2d60..2461f70a86e35 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -251,6 +251,7 @@ pub(crate) enum AttributeKind { Writable = 42, DeadOnUnwind = 43, DeadOnReturn = 44, + CapturesReadOnly = 45, } /// LLVMIntPredicate diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index e4fe1fc2e429f..e699e4b9c13f8 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp @@ -278,6 +278,7 @@ enum class LLVMRustAttributeKind { Writable = 42, DeadOnUnwind = 43, DeadOnReturn = 44, + CapturesReadOnly = 45, }; static Attribute::AttrKind fromRust(LLVMRustAttributeKind Kind) { @@ -376,6 +377,8 @@ static Attribute::AttrKind fromRust(LLVMRustAttributeKind Kind) { #else report_fatal_error("DeadOnReturn attribute requires LLVM 21 or later"); #endif + case LLVMRustAttributeKind::CapturesReadOnly: + report_fatal_error("Should be handled separately"); } report_fatal_error("bad LLVMRustAttributeKind"); } @@ -430,6 +433,11 @@ LLVMRustCreateAttrNoValue(LLVMContextRef C, LLVMRustAttributeKind RustAttr) { if (RustAttr == LLVMRustAttributeKind::NoCapture) { return wrap(Attribute::getWithCaptureInfo(*unwrap(C), CaptureInfo::none())); } + if (RustAttr == LLVMRustAttributeKind::CapturesReadOnly) { + return wrap(Attribute::getWithCaptureInfo( + *unwrap(C), CaptureInfo(CaptureComponents::Address | + CaptureComponents::ReadProvenance))); + } #endif return wrap(Attribute::get(*unwrap(C), fromRust(RustAttr))); } diff --git a/compiler/rustc_target/src/callconv/mod.rs b/compiler/rustc_target/src/callconv/mod.rs index 63e56744aec96..5f2a6f7ba38a1 100644 --- a/compiler/rustc_target/src/callconv/mod.rs +++ b/compiler/rustc_target/src/callconv/mod.rs @@ -119,6 +119,7 @@ mod attr_impl { const ReadOnly = 1 << 4; const InReg = 1 << 5; const NoUndef = 1 << 6; + const CapturesReadOnly = 1 << 7; } } rustc_data_structures::external_bitflags_debug! { ArgAttribute } diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs index 89d1dd8cf231b..e4ed084b073b6 100644 --- a/compiler/rustc_ty_utils/src/abi.rs +++ b/compiler/rustc_ty_utils/src/abi.rs @@ -356,6 +356,7 @@ fn arg_attrs_for_rust_scalar<'tcx>( if matches!(kind, PointerKind::SharedRef { frozen: true }) && !is_return { attrs.set(ArgAttribute::ReadOnly); + attrs.set(ArgAttribute::CapturesReadOnly); } } } diff --git a/tests/codegen-llvm/function-arguments.rs b/tests/codegen-llvm/function-arguments.rs index a3fafbe6f821c..db5086828628b 100644 --- a/tests/codegen-llvm/function-arguments.rs +++ b/tests/codegen-llvm/function-arguments.rs @@ -80,7 +80,7 @@ pub fn option_nonzero_int(x: Option>) -> Option> { x } -// CHECK: @readonly_borrow(ptr noalias noundef readonly align 4 dereferenceable(4) %_1) +// CHECK: @readonly_borrow(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable(4) %_1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn readonly_borrow(_: &i32) {} @@ -91,12 +91,12 @@ pub fn readonly_borrow_ret() -> &'static i32 { loop {} } -// CHECK: @static_borrow(ptr noalias noundef readonly align 4 dereferenceable(4) %_1) +// CHECK: @static_borrow(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable(4) %_1) // static borrow may be captured #[no_mangle] pub fn static_borrow(_: &'static i32) {} -// CHECK: @named_borrow(ptr noalias noundef readonly align 4 dereferenceable(4) %_1) +// CHECK: @named_borrow(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable(4) %_1) // borrow with named lifetime may be captured #[no_mangle] pub fn named_borrow<'r>(_: &'r i32) {} @@ -129,7 +129,7 @@ pub fn mutable_borrow_ret() -> &'static mut i32 { // . pub fn mutable_notunpin_borrow(_: &mut NotUnpin) {} -// CHECK: @notunpin_borrow(ptr noalias noundef readonly align 4 dereferenceable(4) %_1) +// CHECK: @notunpin_borrow(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable(4) %_1) // But `&NotUnpin` behaves perfectly normal. #[no_mangle] pub fn notunpin_borrow(_: &NotUnpin) {} @@ -138,12 +138,12 @@ pub fn notunpin_borrow(_: &NotUnpin) {} #[no_mangle] pub fn indirect_struct(_: S) {} -// CHECK: @borrowed_struct(ptr noalias noundef readonly align 4 dereferenceable(32) %_1) +// CHECK: @borrowed_struct(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable(32) %_1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn borrowed_struct(_: &S) {} -// CHECK: @option_borrow(ptr noalias noundef readonly align 4 dereferenceable_or_null(4) %_x) +// CHECK: @option_borrow(ptr noalias noundef readonly align 4{{( captures\(address, read_provenance\))?}} dereferenceable_or_null(4) %_x) #[no_mangle] pub fn option_borrow(_x: Option<&i32>) {} @@ -185,7 +185,7 @@ pub fn _box(x: Box) -> Box { // With a custom allocator, it should *not* have `noalias`. (See // for why.) The second argument is the allocator, // which is a reference here that still carries `noalias` as usual. -// CHECK: @_box_custom(ptr noundef nonnull align 4 %x.0, ptr noalias noundef nonnull readonly align 1 %x.1) +// CHECK: @_box_custom(ptr noundef nonnull align 4 %x.0, ptr noalias noundef nonnull readonly align 1{{( captures\(address, read_provenance\))?}} %x.1) #[no_mangle] pub fn _box_custom(x: Box) { drop(x) @@ -208,7 +208,7 @@ pub fn struct_return() -> S { #[no_mangle] pub fn helper(_: usize) {} -// CHECK: @slice(ptr noalias noundef nonnull readonly align 1 %_1.0, [[USIZE]] noundef %_1.1) +// CHECK: @slice(ptr noalias noundef nonnull readonly align 1{{( captures\(address, read_provenance\))?}} %_1.0, [[USIZE]] noundef %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn slice(_: &[u8]) {} @@ -227,7 +227,7 @@ pub fn unsafe_slice(_: &[UnsafeInner]) {} #[no_mangle] pub fn raw_slice(_: *const [u8]) {} -// CHECK: @str(ptr noalias noundef nonnull readonly align 1 %_1.0, [[USIZE]] noundef %_1.1) +// CHECK: @str(ptr noalias noundef nonnull readonly align 1{{( captures\(address, read_provenance\))?}} %_1.0, [[USIZE]] noundef %_1.1) // FIXME #25759 This should also have `nocapture` #[no_mangle] pub fn str(_: &[u8]) {} @@ -259,7 +259,7 @@ pub fn trait_option(x: Option>) -> Option &[u16] { x diff --git a/tests/codegen-llvm/range-attribute.rs b/tests/codegen-llvm/range-attribute.rs index b81ff9ab3e2b5..865d36d474745 100644 --- a/tests/codegen-llvm/range-attribute.rs +++ b/tests/codegen-llvm/range-attribute.rs @@ -67,7 +67,7 @@ pub fn enum2_value(x: Enum2) -> Enum2 { x } -// CHECK: noundef [[USIZE]] @takes_slice(ptr noalias noundef nonnull readonly align 4 %x.0, [[USIZE]] noundef %x.1) +// CHECK: noundef [[USIZE]] @takes_slice(ptr {{.*}} %x.0, [[USIZE]] noundef %x.1) #[no_mangle] pub fn takes_slice(x: &[i32]) -> usize { x.len() diff --git a/tests/codegen-llvm/read-only-capture-opt.rs b/tests/codegen-llvm/read-only-capture-opt.rs new file mode 100644 index 0000000000000..ab4a638cdd0e9 --- /dev/null +++ b/tests/codegen-llvm/read-only-capture-opt.rs @@ -0,0 +1,18 @@ +//@ compile-flags: -O -Z mir-opt-level=0 +//@ min-llvm-version: 21 + +#![crate_type = "lib"] + +unsafe extern "C" { + safe fn do_something(p: &i32); +} + +#[unsafe(no_mangle)] +pub fn test() -> i32 { + // CHECK-LABEL: @test( + // CHECK: ret i32 0 + let i = 0; + do_something(&i); + do_something(&i); + i +} diff --git a/tests/ui/abi/debug.generic.stderr b/tests/ui/abi/debug.generic.stderr index 3b29efc810251..8375de3e81769 100644 --- a/tests/ui/abi/debug.generic.stderr +++ b/tests/ui/abi/debug.generic.stderr @@ -939,7 +939,7 @@ error: fn_abi_of(assoc_test) = FnAbi { }, mode: Direct( ArgAttributes { - regular: NoAlias | NonNull | ReadOnly | NoUndef, + regular: NoAlias | NonNull | ReadOnly | NoUndef | CapturesReadOnly, arg_ext: None, pointee_size: Size(2 bytes), pointee_align: Some( diff --git a/tests/ui/abi/debug.riscv64.stderr b/tests/ui/abi/debug.riscv64.stderr index 2417396de2f5a..bddf0aea3d746 100644 --- a/tests/ui/abi/debug.riscv64.stderr +++ b/tests/ui/abi/debug.riscv64.stderr @@ -939,7 +939,7 @@ error: fn_abi_of(assoc_test) = FnAbi { }, mode: Direct( ArgAttributes { - regular: NoAlias | NonNull | ReadOnly | NoUndef, + regular: NoAlias | NonNull | ReadOnly | NoUndef | CapturesReadOnly, arg_ext: None, pointee_size: Size(2 bytes), pointee_align: Some( diff --git a/tests/ui/codegen/equal-pointers-unequal/as-cast/segfault.rs b/tests/ui/codegen/equal-pointers-unequal/as-cast/segfault.rs index 70cbb9a52f706..c69565a81f20e 100644 --- a/tests/ui/codegen/equal-pointers-unequal/as-cast/segfault.rs +++ b/tests/ui/codegen/equal-pointers-unequal/as-cast/segfault.rs @@ -55,6 +55,7 @@ fn main() { // The `Box` has been deallocated by now, so this is a dangling reference! let r: &u8 = &*r; println!("{:p}", r); + println!("{}", i); // The following might segfault. Or it might not. // Depends on the platform semantics diff --git a/tests/ui/codegen/equal-pointers-unequal/exposed-provenance/segfault.rs b/tests/ui/codegen/equal-pointers-unequal/exposed-provenance/segfault.rs index ad1d7b56c8cb7..b74f85290a762 100644 --- a/tests/ui/codegen/equal-pointers-unequal/exposed-provenance/segfault.rs +++ b/tests/ui/codegen/equal-pointers-unequal/exposed-provenance/segfault.rs @@ -58,6 +58,7 @@ fn main() { // The `Box` has been deallocated by now, so this is a dangling reference! let r: &u8 = &*r; println!("{:p}", r); + println!("{}", i); // The following might segfault. Or it might not. // Depends on the platform semantics diff --git a/tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs b/tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs index 637f0042adaef..18d5bd3335530 100644 --- a/tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs +++ b/tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs @@ -58,6 +58,7 @@ fn main() { // The `Box` has been deallocated by now, so this is a dangling reference! let r: &u8 = &*r; println!("{:p}", r); + println!("{}", i); // The following might segfault. Or it might not. // Depends on the platform semantics