diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/attributes.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/attributes.rs | 162 |
1 files changed, 132 insertions, 30 deletions
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 32bfa5094c3..6d00464e0a0 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -12,8 +12,9 @@ use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType, StackProtec use smallvec::SmallVec; use crate::attributes; +use crate::errors::{MissingFeatures, SanitizerMemtagRequiresMte, TargetFeatureDisableOrEnable}; use crate::llvm::AttributePlace::Function; -use crate::llvm::{self, Attribute, AttributeKind, AttributePlace}; +use crate::llvm::{self, AllocKindFlags, Attribute, AttributeKind, AttributePlace, MemoryEffects}; use crate::llvm_util; pub use rustc_attr::{InlineAttr, InstructionSetAttr, OptimizeAttr}; @@ -35,6 +36,10 @@ pub fn apply_to_callsite(callsite: &Value, idx: AttributePlace, attrs: &[&Attrib /// Get LLVM attribute for the provided inline heuristic. #[inline] fn inline_attr<'ll>(cx: &CodegenCx<'ll, '_>, inline: InlineAttr) -> Option<&'ll Attribute> { + if !cx.tcx.sess.opts.unstable_opts.inline_llvm { + // disable LLVM inlining + return Some(AttributeKind::NoInline.create_attr(cx.llcx)); + } match inline { InlineAttr::Hint => Some(AttributeKind::InlineHint.create_attr(cx.llcx)), InlineAttr::Always => Some(AttributeKind::AlwaysInline.create_attr(cx.llcx)), @@ -57,7 +62,7 @@ pub fn sanitize_attrs<'ll>( ) -> SmallVec<[&'ll Attribute; 4]> { let mut attrs = SmallVec::new(); let enabled = cx.tcx.sess.opts.unstable_opts.sanitizer - no_sanitize; - if enabled.contains(SanitizerSet::ADDRESS) { + if enabled.contains(SanitizerSet::ADDRESS) || enabled.contains(SanitizerSet::KERNELADDRESS) { attrs.push(llvm::AttributeKind::SanitizeAddress.create_attr(cx.llcx)); } if enabled.contains(SanitizerSet::MEMORY) { @@ -69,17 +74,23 @@ pub fn sanitize_attrs<'ll>( if enabled.contains(SanitizerSet::HWADDRESS) { attrs.push(llvm::AttributeKind::SanitizeHWAddress.create_attr(cx.llcx)); } + if enabled.contains(SanitizerSet::SHADOWCALLSTACK) { + attrs.push(llvm::AttributeKind::ShadowCallStack.create_attr(cx.llcx)); + } if enabled.contains(SanitizerSet::MEMTAG) { // Check to make sure the mte target feature is actually enabled. let features = cx.tcx.global_backend_features(()); let mte_feature = features.iter().map(|s| &s[..]).rfind(|n| ["+mte", "-mte"].contains(&&n[..])); if let None | Some("-mte") = mte_feature { - cx.tcx.sess.err("`-Zsanitizer=memtag` requires `-Ctarget-feature=+mte`"); + cx.tcx.sess.emit_err(SanitizerMemtagRequiresMte); } attrs.push(llvm::AttributeKind::SanitizeMemTag.create_attr(cx.llcx)); } + if enabled.contains(SanitizerSet::SAFESTACK) { + attrs.push(llvm::AttributeKind::SanitizeSafeStack.create_attr(cx.llcx)); + } attrs } @@ -94,10 +105,10 @@ pub fn uwtable_attr(llcx: &llvm::Context) -> &Attribute { pub fn frame_pointer_type_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { let mut fp = cx.sess().target.frame_pointer; + let opts = &cx.sess().opts; // "mcount" function relies on stack pointer. // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>. - if cx.sess().instrument_mcount() || matches!(cx.sess().opts.cg.force_frame_pointers, Some(true)) - { + if opts.unstable_opts.instrument_mcount || matches!(opts.cg.force_frame_pointers, Some(true)) { fp = FramePointer::Always; } let attr_value = match fp { @@ -110,8 +121,9 @@ pub fn frame_pointer_type_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attr /// Tell LLVM what instrument function to insert. #[inline] -fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { - if cx.sess().instrument_mcount() { +fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> SmallVec<[&'ll Attribute; 4]> { + let mut attrs = SmallVec::new(); + if cx.sess().opts.unstable_opts.instrument_mcount { // Similar to `clang -pg` behavior. Handled by the // `post-inline-ee-instrument` LLVM pass. @@ -119,14 +131,49 @@ fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribu // See test/CodeGen/mcount.c in clang. let mcount_name = cx.sess().target.mcount.as_ref(); - Some(llvm::CreateAttrStringValue( + attrs.push(llvm::CreateAttrStringValue( cx.llcx, "instrument-function-entry-inlined", &mcount_name, - )) - } else { - None + )); + } + if let Some(options) = &cx.sess().opts.unstable_opts.instrument_xray { + // XRay instrumentation is similar to __cyg_profile_func_{enter,exit}. + // Function prologue and epilogue are instrumented with NOP sleds, + // a runtime library later replaces them with detours into tracing code. + if options.always { + attrs.push(llvm::CreateAttrStringValue(cx.llcx, "function-instrument", "xray-always")); + } + if options.never { + attrs.push(llvm::CreateAttrStringValue(cx.llcx, "function-instrument", "xray-never")); + } + if options.ignore_loops { + attrs.push(llvm::CreateAttrString(cx.llcx, "xray-ignore-loops")); + } + // LLVM will not choose the default for us, but rather requires specific + // threshold in absence of "xray-always". Use the same default as Clang. + let threshold = options.instruction_threshold.unwrap_or(200); + attrs.push(llvm::CreateAttrStringValue( + cx.llcx, + "xray-instruction-threshold", + &threshold.to_string(), + )); + if options.skip_entry { + attrs.push(llvm::CreateAttrString(cx.llcx, "xray-skip-entry")); + } + if options.skip_exit { + attrs.push(llvm::CreateAttrString(cx.llcx, "xray-skip-exit")); + } + } + attrs +} + +fn nojumptables_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { + if !cx.sess().opts.unstable_opts.no_jump_tables { + return None; } + + Some(llvm::CreateAttrStringValue(cx.llcx, "no-jump-tables", "true")) } fn probestack_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { @@ -224,6 +271,10 @@ pub(crate) fn default_optimisation_attrs<'ll>( attrs } +fn create_alloc_family_attr(llcx: &llvm::Context) -> &llvm::Attribute { + llvm::CreateAttrStringValue(llcx, "alloc-family", "__rust_alloc") +} + /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`) /// attributes. pub fn from_fn_attrs<'ll, 'tcx>( @@ -246,13 +297,12 @@ pub fn from_fn_attrs<'ll, 'tcx>( OptimizeAttr::Speed => {} } - let inline = if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { - InlineAttr::Never - } else if codegen_fn_attrs.inline == InlineAttr::None && instance.def.requires_inline(cx.tcx) { - InlineAttr::Hint - } else { - codegen_fn_attrs.inline - }; + let inline = + if codegen_fn_attrs.inline == InlineAttr::None && instance.def.requires_inline(cx.tcx) { + InlineAttr::Hint + } else { + codegen_fn_attrs.inline + }; to_add.extend(inline_attr(cx, inline)); // The `uwtable` attribute according to LLVM is: @@ -282,6 +332,7 @@ pub fn from_fn_attrs<'ll, 'tcx>( // FIXME: none of these three functions interact with source level attributes. to_add.extend(frame_pointer_type_attr(cx)); to_add.extend(instrument_function_attr(cx)); + to_add.extend(nojumptables_attr(cx)); to_add.extend(probestack_attr(cx)); to_add.extend(stackprotector_attr(cx)); @@ -292,19 +343,68 @@ pub fn from_fn_attrs<'ll, 'tcx>( to_add.push(AttributeKind::ReturnsTwice.create_attr(cx.llcx)); } if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::FFI_PURE) { - to_add.push(AttributeKind::ReadOnly.create_attr(cx.llcx)); + to_add.push(MemoryEffects::ReadOnly.create_attr(cx.llcx)); } if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::FFI_CONST) { - to_add.push(AttributeKind::ReadNone.create_attr(cx.llcx)); + to_add.push(MemoryEffects::None.create_attr(cx.llcx)); } if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { to_add.push(AttributeKind::Naked.create_attr(cx.llcx)); + // HACK(jubilee): "indirect branch tracking" works by attaching prologues to functions. + // And it is a module-level attribute, so the alternative is pulling naked functions into new LLVM modules. + // Otherwise LLVM's "naked" functions come with endbr prefixes per https://github.com/rust-lang/rust/issues/98768 + to_add.push(AttributeKind::NoCfCheck.create_attr(cx.llcx)); + // Need this for AArch64. + to_add.push(llvm::CreateAttrStringValue(cx.llcx, "branch-target-enforcement", "false")); } - if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) { + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) + || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR_ZEROED) + { + if llvm_util::get_version() >= (15, 0, 0) { + to_add.push(create_alloc_family_attr(cx.llcx)); + // apply to argument place instead of function + let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx); + attributes::apply_to_llfn(llfn, AttributePlace::Argument(1), &[alloc_align]); + to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 0)); + let mut flags = AllocKindFlags::Alloc | AllocKindFlags::Aligned; + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) { + flags |= AllocKindFlags::Uninitialized; + } else { + flags |= AllocKindFlags::Zeroed; + } + to_add.push(llvm::CreateAllocKindAttr(cx.llcx, flags)); + } // apply to return place instead of function (unlike all other attributes applied in this function) let no_alias = AttributeKind::NoAlias.create_attr(cx.llcx); attributes::apply_to_llfn(llfn, AttributePlace::ReturnValue, &[no_alias]); } + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::REALLOCATOR) { + if llvm_util::get_version() >= (15, 0, 0) { + to_add.push(create_alloc_family_attr(cx.llcx)); + to_add.push(llvm::CreateAllocKindAttr( + cx.llcx, + AllocKindFlags::Realloc | AllocKindFlags::Aligned, + )); + // applies to argument place instead of function place + let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx); + attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]); + // apply to argument place instead of function + let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx); + attributes::apply_to_llfn(llfn, AttributePlace::Argument(2), &[alloc_align]); + to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 3)); + } + let no_alias = AttributeKind::NoAlias.create_attr(cx.llcx); + attributes::apply_to_llfn(llfn, AttributePlace::ReturnValue, &[no_alias]); + } + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::DEALLOCATOR) { + if llvm_util::get_version() >= (15, 0, 0) { + to_add.push(create_alloc_family_attr(cx.llcx)); + to_add.push(llvm::CreateAllocKindAttr(cx.llcx, AllocKindFlags::Free)); + // applies to argument place instead of function place + let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx); + attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]); + } + } if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY) { to_add.push(llvm::CreateAttrString(cx.llcx, "cmse_nonsecure_entry")); } @@ -330,15 +430,17 @@ pub fn from_fn_attrs<'ll, 'tcx>( ) { let span = cx .tcx - .get_attr(instance.def_id(), sym::target_feature) + .get_attrs(instance.def_id(), sym::target_feature) + .next() .map_or_else(|| cx.tcx.def_span(instance.def_id()), |a| a.span); - let msg = format!( - "the target features {} must all be either enabled or disabled together", - f.join(", ") - ); - let mut err = cx.tcx.sess.struct_span_err(span, &msg); - err.help("add the missing features in a `target_feature` attribute"); - err.emit(); + cx.tcx + .sess + .create_err(TargetFeatureDisableOrEnable { + features: f, + span: Some(span), + missing_features: Some(MissingFeatures), + }) + .emit(); return; } @@ -370,7 +472,7 @@ pub fn from_fn_attrs<'ll, 'tcx>( // the WebAssembly specification, which has this feature. This won't be // needed when LLVM enables this `multivalue` feature by default. if !cx.tcx.is_closure(instance.def_id()) { - let abi = cx.tcx.fn_sig(instance.def_id()).abi(); + let abi = cx.tcx.fn_sig(instance.def_id()).skip_binder().abi(); if abi == Abi::Wasm { function_features.push("+multivalue".to_string()); } |