diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
33 files changed, 1143 insertions, 526 deletions
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 5552a241060..95e0481b035 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -1,6 +1,6 @@ //! Set and unset common attributes on LLVM values. -use rustc_attr::{InlineAttr, InstructionSetAttr, OptimizeAttr}; +use rustc_attr_parsing::{InlineAttr, InstructionSetAttr, OptimizeAttr}; use rustc_codegen_ssa::traits::*; use rustc_hir::def_id::DefId; use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, PatchableFunctionEntry}; @@ -37,7 +37,9 @@ fn inline_attr<'ll>(cx: &CodegenCx<'ll, '_>, inline: InlineAttr) -> Option<&'ll } match inline { InlineAttr::Hint => Some(AttributeKind::InlineHint.create_attr(cx.llcx)), - InlineAttr::Always => Some(AttributeKind::AlwaysInline.create_attr(cx.llcx)), + InlineAttr::Always | InlineAttr::Force { .. } => { + Some(AttributeKind::AlwaysInline.create_attr(cx.llcx)) + } InlineAttr::Never => { if cx.sess().target.arch != "amdgpu" { Some(AttributeKind::NoInline.create_attr(cx.llcx)) @@ -472,7 +474,11 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>( let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx); attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]); } - if let Some(align) = codegen_fn_attrs.alignment { + // function alignment can be set globally with the `-Zmin-function-alignment=<n>` flag; + // the alignment from a `#[repr(align(<n>))]` is used if it specifies a higher alignment. + if let Some(align) = + Ord::max(cx.tcx.sess.opts.unstable_opts.min_function_alignment, codegen_fn_attrs.alignment) + { llvm::set_alignment(llfn, align); } if let Some(backchain) = backchain_attr(cx) { diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs index f6d2ec24da6..78c759bbe8c 100644 --- a/compiler/rustc_codegen_llvm/src/back/lto.rs +++ b/compiler/rustc_codegen_llvm/src/back/lto.rs @@ -1,7 +1,6 @@ use std::collections::BTreeMap; use std::ffi::{CStr, CString}; use std::fs::File; -use std::mem::ManuallyDrop; use std::path::Path; use std::sync::Arc; use std::{io, iter, slice}; @@ -9,7 +8,7 @@ use std::{io, iter, slice}; use object::read::archive::ArchiveFile; use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule, ThinShared}; use rustc_codegen_ssa::back::symbol_export; -use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput, TargetMachineFactoryConfig}; +use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput}; use rustc_codegen_ssa::traits::*; use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file}; use rustc_data_structures::fx::FxHashMap; @@ -604,7 +603,14 @@ pub(crate) fn run_pass_manager( debug!("running the pass manager"); let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO }; let opt_level = config.opt_level.unwrap_or(config::OptLevel::No); - unsafe { write::llvm_optimize(cgcx, dcx, module, config, opt_level, opt_stage) }?; + + // If this rustc version was build with enzyme/autodiff enabled, and if users applied the + // `#[autodiff]` macro at least once, then we will later call llvm_optimize a second time. + let first_run = true; + debug!("running llvm pm opt pipeline"); + unsafe { + write::llvm_optimize(cgcx, dcx, module, config, opt_level, opt_stage, first_run)?; + } debug!("lto done"); Ok(()) } @@ -699,18 +705,15 @@ pub(crate) unsafe fn optimize_thin_module( let dcx = dcx.handle(); let module_name = &thin_module.shared.module_names[thin_module.idx]; - let tm_factory_config = TargetMachineFactoryConfig::new(cgcx, module_name.to_str().unwrap()); - let tm = (cgcx.tm_factory)(tm_factory_config).map_err(|e| write::llvm_err(dcx, e))?; // Right now the implementation we've got only works over serialized // modules, so we create a fresh new LLVM context and parse the module // into that context. One day, however, we may do this for upstream // crates but for locally codegened modules we may be able to reuse // that LLVM Context and Module. - let llcx = unsafe { llvm::LLVMRustContextCreate(cgcx.fewer_names) }; - let llmod_raw = parse_module(llcx, module_name, thin_module.data(), dcx)? as *const _; + let module_llvm = ModuleLlvm::parse(cgcx, module_name, thin_module.data(), dcx)?; let mut module = ModuleCodegen { - module_llvm: ModuleLlvm { llmod_raw, llcx, tm: ManuallyDrop::new(tm) }, + module_llvm, name: thin_module.name().to_string(), kind: ModuleKind::Regular, }; @@ -730,11 +733,7 @@ pub(crate) unsafe fn optimize_thin_module( { let _timer = cgcx.prof.generic_activity_with_arg("LLVM_thin_lto_rename", thin_module.name()); - if unsafe { - !llvm::LLVMRustPrepareThinLTORename(thin_module.shared.data.0, llmod, target) - } { - return Err(write::llvm_err(dcx, LlvmError::PrepareThinLtoModule)); - } + unsafe { llvm::LLVMRustPrepareThinLTORename(thin_module.shared.data.0, llmod, target) }; save_temp_bitcode(cgcx, &module, "thin-lto-after-rename"); } diff --git a/compiler/rustc_codegen_llvm/src/back/owned_target_machine.rs b/compiler/rustc_codegen_llvm/src/back/owned_target_machine.rs index 44c30d22a9e..4cbd49aa44d 100644 --- a/compiler/rustc_codegen_llvm/src/back/owned_target_machine.rs +++ b/compiler/rustc_codegen_llvm/src/back/owned_target_machine.rs @@ -25,7 +25,7 @@ impl OwnedTargetMachine { model: llvm::CodeModel, reloc: llvm::RelocModel, level: llvm::CodeGenOptLevel, - use_soft_fp: bool, + float_abi: llvm::FloatAbi, function_sections: bool, data_sections: bool, unique_section_names: bool, @@ -57,7 +57,7 @@ impl OwnedTargetMachine { model, reloc, level, - use_soft_fp, + float_abi, function_sections, data_sections, unique_section_names, diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 66ca4e2b473..509b24dd703 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -25,10 +25,9 @@ use rustc_session::Session; use rustc_session::config::{ self, Lto, OutputType, Passes, RemapPathScopeComponents, SplitDwarfKind, SwitchWithOptPath, }; -use rustc_span::symbol::sym; -use rustc_span::{BytePos, InnerSpan, Pos, SpanData, SyntaxContext}; -use rustc_target::spec::{CodeModel, RelocModel, SanitizerSet, SplitDebuginfo, TlsModel}; -use tracing::debug; +use rustc_span::{BytePos, InnerSpan, Pos, SpanData, SyntaxContext, sym}; +use rustc_target::spec::{CodeModel, FloatAbi, RelocModel, SanitizerSet, SplitDebuginfo, TlsModel}; +use tracing::{debug, trace}; use crate::back::lto::ThinBuffer; use crate::back::owned_target_machine::OwnedTargetMachine; @@ -182,6 +181,14 @@ pub(crate) fn to_llvm_code_model(code_model: Option<CodeModel>) -> llvm::CodeMod } } +fn to_llvm_float_abi(float_abi: Option<FloatAbi>) -> llvm::FloatAbi { + match float_abi { + None => llvm::FloatAbi::Default, + Some(FloatAbi::Soft) => llvm::FloatAbi::Soft, + Some(FloatAbi::Hard) => llvm::FloatAbi::Hard, + } +} + pub(crate) fn target_machine_factory( sess: &Session, optlvl: config::OptLevel, @@ -190,12 +197,12 @@ pub(crate) fn target_machine_factory( let reloc_model = to_llvm_relocation_model(sess.relocation_model()); let (opt_level, _) = to_llvm_opt_settings(optlvl); - let use_softfp = if sess.target.arch == "arm" && sess.target.abi == "eabihf" { - sess.opts.cg.soft_float + let float_abi = if sess.target.arch == "arm" && sess.opts.cg.soft_float { + llvm::FloatAbi::Soft } else { // `validate_commandline_args_with_session_available` has already warned about this being // ignored. Let's make sure LLVM doesn't suddenly start using this flag on more targets. - false + to_llvm_float_abi(sess.target.llvm_floatabi) }; let ffunction_sections = @@ -291,7 +298,7 @@ pub(crate) fn target_machine_factory( code_model, reloc_model, opt_level, - use_softfp, + float_abi, ffunction_sections, fdata_sections, funique_section_names, @@ -530,9 +537,35 @@ pub(crate) unsafe fn llvm_optimize( config: &ModuleConfig, opt_level: config::OptLevel, opt_stage: llvm::OptStage, + skip_size_increasing_opts: bool, ) -> Result<(), FatalError> { - let unroll_loops = - opt_level != config::OptLevel::Size && opt_level != config::OptLevel::SizeMin; + // Enzyme: + // The whole point of compiler based AD is to differentiate optimized IR instead of unoptimized + // source code. However, benchmarks show that optimizations increasing the code size + // tend to reduce AD performance. Therefore deactivate them before AD, then differentiate the code + // and finally re-optimize the module, now with all optimizations available. + // FIXME(ZuseZ4): In a future update we could figure out how to only optimize individual functions getting + // differentiated. + + let unroll_loops; + let vectorize_slp; + let vectorize_loop; + + // When we build rustc with enzyme/autodiff support, we want to postpone size-increasing + // optimizations until after differentiation. FIXME(ZuseZ4): Before shipping on nightly, + // we should make this more granular, or at least check that the user has at least one autodiff + // call in their code, to justify altering the compilation pipeline. + if skip_size_increasing_opts && cfg!(llvm_enzyme) { + unroll_loops = false; + vectorize_slp = false; + vectorize_loop = false; + } else { + unroll_loops = + opt_level != config::OptLevel::Size && opt_level != config::OptLevel::SizeMin; + vectorize_slp = config.vectorize_slp; + vectorize_loop = config.vectorize_loop; + } + trace!(?unroll_loops, ?vectorize_slp, ?vectorize_loop); let using_thin_buffers = opt_stage == llvm::OptStage::PreLinkThinLTO || config.bitcode_needed(); let pgo_gen_path = get_pgo_gen_path(config); let pgo_use_path = get_pgo_use_path(config); @@ -596,8 +629,8 @@ pub(crate) unsafe fn llvm_optimize( using_thin_buffers, config.merge_functions, unroll_loops, - config.vectorize_slp, - config.vectorize_loop, + vectorize_slp, + vectorize_loop, config.no_builtins, config.emit_lifetime_markers, sanitizer_options.as_ref(), @@ -641,6 +674,8 @@ pub(crate) unsafe fn optimize( unsafe { llvm::LLVMWriteBitcodeToFile(llmod, out.as_ptr()) }; } + // FIXME(ZuseZ4): support SanitizeHWAddress and prevent illegal/unsupported opts + if let Some(opt_level) = config.opt_level { let opt_stage = match cgcx.lto { Lto::Fat => llvm::OptStage::PreLinkFatLTO, @@ -648,7 +683,20 @@ pub(crate) unsafe fn optimize( _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO, _ => llvm::OptStage::PreLinkNoLTO, }; - return unsafe { llvm_optimize(cgcx, dcx, module, config, opt_level, opt_stage) }; + + // If we know that we will later run AD, then we disable vectorization and loop unrolling + let skip_size_increasing_opts = cfg!(llvm_enzyme); + return unsafe { + llvm_optimize( + cgcx, + dcx, + module, + config, + opt_level, + opt_stage, + skip_size_increasing_opts, + ) + }; } Ok(()) } diff --git a/compiler/rustc_codegen_llvm/src/base.rs b/compiler/rustc_codegen_llvm/src/base.rs index f62310bd948..d05faf5577b 100644 --- a/compiler/rustc_codegen_llvm/src/base.rs +++ b/compiler/rustc_codegen_llvm/src/base.rs @@ -23,7 +23,7 @@ use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs; use rustc_middle::mir::mono::{Linkage, Visibility}; use rustc_middle::ty::TyCtxt; use rustc_session::config::DebugInfo; -use rustc_span::symbol::Symbol; +use rustc_span::Symbol; use rustc_target::spec::SanitizerSet; use super::ModuleLlvm; diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs index b5bb7630ca6..5a34b52e6ef 100644 --- a/compiler/rustc_codegen_llvm/src/builder.rs +++ b/compiler/rustc_codegen_llvm/src/builder.rs @@ -2,6 +2,8 @@ use std::borrow::Cow; use std::ops::Deref; use std::{iter, ptr}; +pub(crate) mod autodiff; + use libc::{c_char, c_uint}; use rustc_abi as abi; use rustc_abi::{Align, Size, WrappingRange}; @@ -608,14 +610,6 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { } fn range_metadata(&mut self, load: &'ll Value, range: WrappingRange) { - if self.sess().target.arch == "amdgpu" { - // amdgpu/LLVM does something weird and thinks an i64 value is - // split into a v2i32, halving the bitwidth LLVM expects, - // tripping an assertion. So, for now, just disable this - // optimization. - return; - } - if self.cx.sess().opts.optimize == OptLevel::No { // Don't emit metadata we're not going to use return; diff --git a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs new file mode 100644 index 00000000000..38f7eaa090f --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs @@ -0,0 +1,344 @@ +use std::ptr; + +use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, AutoDiffItem, DiffActivity, DiffMode}; +use rustc_codegen_ssa::ModuleCodegen; +use rustc_codegen_ssa::back::write::ModuleConfig; +use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, BuilderMethods}; +use rustc_errors::FatalError; +use rustc_middle::ty::TyCtxt; +use rustc_session::config::Lto; +use tracing::{debug, trace}; + +use crate::back::write::{llvm_err, llvm_optimize}; +use crate::builder::Builder; +use crate::declare::declare_raw_fn; +use crate::errors::LlvmError; +use crate::llvm::AttributePlace::Function; +use crate::llvm::{Metadata, True}; +use crate::value::Value; +use crate::{CodegenContext, LlvmCodegenBackend, ModuleLlvm, attributes, context, llvm}; + +fn get_params(fnc: &Value) -> Vec<&Value> { + unsafe { + let param_num = llvm::LLVMCountParams(fnc) as usize; + let mut fnc_args: Vec<&Value> = vec![]; + fnc_args.reserve(param_num); + llvm::LLVMGetParams(fnc, fnc_args.as_mut_ptr()); + fnc_args.set_len(param_num); + fnc_args + } +} + +/// When differentiating `fn_to_diff`, take a `outer_fn` and generate another +/// function with expected naming and calling conventions[^1] which will be +/// discovered by the enzyme LLVM pass and its body populated with the differentiated +/// `fn_to_diff`. `outer_fn` is then modified to have a call to the generated +/// function and handle the differences between the Rust calling convention and +/// Enzyme. +/// [^1]: <https://enzyme.mit.edu/getting_started/CallingConvention/> +// FIXME(ZuseZ4): `outer_fn` should include upstream safety checks to +// cover some assumptions of enzyme/autodiff, which could lead to UB otherwise. +fn generate_enzyme_call<'ll, 'tcx>( + cx: &context::CodegenCx<'ll, 'tcx>, + fn_to_diff: &'ll Value, + outer_fn: &'ll Value, + attrs: AutoDiffAttrs, +) { + let inputs = attrs.input_activity; + let output = attrs.ret_activity; + + // We have to pick the name depending on whether we want forward or reverse mode autodiff. + // FIXME(ZuseZ4): The new pass based approach should not need the {Forward/Reverse}First method anymore, since + // it will handle higher-order derivatives correctly automatically (in theory). Currently + // higher-order derivatives fail, so we should debug that before adjusting this code. + let mut ad_name: String = match attrs.mode { + DiffMode::Forward => "__enzyme_fwddiff", + DiffMode::Reverse => "__enzyme_autodiff", + DiffMode::ForwardFirst => "__enzyme_fwddiff", + DiffMode::ReverseFirst => "__enzyme_autodiff", + _ => panic!("logic bug in autodiff, unrecognized mode"), + } + .to_string(); + + // add outer_fn name to ad_name to make it unique, in case users apply autodiff to multiple + // functions. Unwrap will only panic, if LLVM gave us an invalid string. + let name = llvm::get_value_name(outer_fn); + let outer_fn_name = std::ffi::CStr::from_bytes_with_nul(name).unwrap().to_str().unwrap(); + ad_name.push_str(outer_fn_name.to_string().as_str()); + + // Let us assume the user wrote the following function square: + // + // ```llvm + // define double @square(double %x) { + // entry: + // %0 = fmul double %x, %x + // ret double %0 + // } + // ``` + // + // The user now applies autodiff to the function square, in which case fn_to_diff will be `square`. + // Our macro generates the following placeholder code (slightly simplified): + // + // ```llvm + // define double @dsquare(double %x) { + // ; placeholder code + // return 0.0; + // } + // ``` + // + // so our `outer_fn` will be `dsquare`. The unsafe code section below now removes the placeholder + // code and inserts an autodiff call. We also add a declaration for the __enzyme_autodiff call. + // Again, the arguments to all functions are slightly simplified. + // ```llvm + // declare double @__enzyme_autodiff_square(...) + // + // define double @dsquare(double %x) { + // entry: + // %0 = tail call double (...) @__enzyme_autodiff_square(double (double)* nonnull @square, double %x) + // ret double %0 + // } + // ``` + unsafe { + // On LLVM-IR, we can luckily declare __enzyme_ functions without specifying the input + // arguments. We do however need to declare them with their correct return type. + // We already figured the correct return type out in our frontend, when generating the outer_fn, + // so we can now just go ahead and use that. FIXME(ZuseZ4): This doesn't handle sret yet. + let fn_ty = llvm::LLVMGlobalGetValueType(outer_fn); + let ret_ty = llvm::LLVMGetReturnType(fn_ty); + + // LLVM can figure out the input types on it's own, so we take a shortcut here. + let enzyme_ty = llvm::LLVMFunctionType(ret_ty, ptr::null(), 0, True); + + //FIXME(ZuseZ4): the CC/Addr/Vis values are best effort guesses, we should look at tests and + // think a bit more about what should go here. + let cc = llvm::LLVMGetFunctionCallConv(outer_fn); + let ad_fn = declare_raw_fn( + cx, + &ad_name, + llvm::CallConv::try_from(cc).expect("invalid callconv"), + llvm::UnnamedAddr::No, + llvm::Visibility::Default, + enzyme_ty, + ); + + // Otherwise LLVM might inline our temporary code before the enzyme pass has a chance to + // do it's work. + let attr = llvm::AttributeKind::NoInline.create_attr(cx.llcx); + attributes::apply_to_llfn(ad_fn, Function, &[attr]); + + // first, remove all calls from fnc + let entry = llvm::LLVMGetFirstBasicBlock(outer_fn); + let br = llvm::LLVMRustGetTerminator(entry); + llvm::LLVMRustEraseInstFromParent(br); + + let last_inst = llvm::LLVMRustGetLastInstruction(entry).unwrap(); + let mut builder = Builder::build(cx, entry); + + let num_args = llvm::LLVMCountParams(&fn_to_diff); + let mut args = Vec::with_capacity(num_args as usize + 1); + args.push(fn_to_diff); + + let enzyme_const = cx.create_metadata("enzyme_const".to_string()).unwrap(); + let enzyme_out = cx.create_metadata("enzyme_out".to_string()).unwrap(); + let enzyme_dup = cx.create_metadata("enzyme_dup".to_string()).unwrap(); + let enzyme_dupnoneed = cx.create_metadata("enzyme_dupnoneed".to_string()).unwrap(); + let enzyme_primal_ret = cx.create_metadata("enzyme_primal_return".to_string()).unwrap(); + + match output { + DiffActivity::Dual => { + args.push(cx.get_metadata_value(enzyme_primal_ret)); + } + DiffActivity::Active => { + args.push(cx.get_metadata_value(enzyme_primal_ret)); + } + _ => {} + } + + trace!("matching autodiff arguments"); + // We now handle the issue that Rust level arguments not always match the llvm-ir level + // arguments. A slice, `&[f32]`, for example, is represented as a pointer and a length on + // llvm-ir level. The number of activities matches the number of Rust level arguments, so we + // need to match those. + // FIXME(ZuseZ4): This logic is a bit more complicated than it should be, can we simplify it + // using iterators and peek()? + let mut outer_pos: usize = 0; + let mut activity_pos = 0; + let outer_args: Vec<&llvm::Value> = get_params(outer_fn); + while activity_pos < inputs.len() { + let activity = inputs[activity_pos as usize]; + // Duplicated arguments received a shadow argument, into which enzyme will write the + // gradient. + let (activity, duplicated): (&Metadata, bool) = match activity { + DiffActivity::None => panic!("not a valid input activity"), + DiffActivity::Const => (enzyme_const, false), + DiffActivity::Active => (enzyme_out, false), + DiffActivity::ActiveOnly => (enzyme_out, false), + DiffActivity::Dual => (enzyme_dup, true), + DiffActivity::DualOnly => (enzyme_dupnoneed, true), + DiffActivity::Duplicated => (enzyme_dup, true), + DiffActivity::DuplicatedOnly => (enzyme_dupnoneed, true), + DiffActivity::FakeActivitySize => (enzyme_const, false), + }; + let outer_arg = outer_args[outer_pos]; + args.push(cx.get_metadata_value(activity)); + args.push(outer_arg); + if duplicated { + // We know that duplicated args by construction have a following argument, + // so this can not be out of bounds. + let next_outer_arg = outer_args[outer_pos + 1]; + let next_outer_ty = cx.val_ty(next_outer_arg); + // FIXME(ZuseZ4): We should add support for Vec here too, but it's less urgent since + // vectors behind references (&Vec<T>) are already supported. Users can not pass a + // Vec by value for reverse mode, so this would only help forward mode autodiff. + let slice = { + if activity_pos + 1 >= inputs.len() { + // If there is no arg following our ptr, it also can't be a slice, + // since that would lead to a ptr, int pair. + false + } else { + let next_activity = inputs[activity_pos + 1]; + // We analyze the MIR types and add this dummy activity if we visit a slice. + next_activity == DiffActivity::FakeActivitySize + } + }; + if slice { + // A duplicated slice will have the following two outer_fn arguments: + // (..., ptr1, int1, ptr2, int2, ...). We add the following llvm-ir to our __enzyme call: + // (..., metadata! enzyme_dup, ptr, ptr, int1, ...). + // FIXME(ZuseZ4): We will upstream a safety check later which asserts that + // int2 >= int1, which means the shadow vector is large enough to store the gradient. + assert!(llvm::LLVMRustGetTypeKind(next_outer_ty) == llvm::TypeKind::Integer); + let next_outer_arg2 = outer_args[outer_pos + 2]; + let next_outer_ty2 = cx.val_ty(next_outer_arg2); + assert!(llvm::LLVMRustGetTypeKind(next_outer_ty2) == llvm::TypeKind::Pointer); + let next_outer_arg3 = outer_args[outer_pos + 3]; + let next_outer_ty3 = cx.val_ty(next_outer_arg3); + assert!(llvm::LLVMRustGetTypeKind(next_outer_ty3) == llvm::TypeKind::Integer); + args.push(next_outer_arg2); + args.push(cx.get_metadata_value(enzyme_const)); + args.push(next_outer_arg); + outer_pos += 4; + activity_pos += 2; + } else { + // A duplicated pointer will have the following two outer_fn arguments: + // (..., ptr, ptr, ...). We add the following llvm-ir to our __enzyme call: + // (..., metadata! enzyme_dup, ptr, ptr, ...). + assert!(llvm::LLVMRustGetTypeKind(next_outer_ty) == llvm::TypeKind::Pointer); + args.push(next_outer_arg); + outer_pos += 2; + activity_pos += 1; + } + } else { + // We do not differentiate with resprect to this argument. + // We already added the metadata and argument above, so just increase the counters. + outer_pos += 1; + activity_pos += 1; + } + } + + let call = builder.call(enzyme_ty, None, None, ad_fn, &args, None, None); + + // This part is a bit iffy. LLVM requires that a call to an inlineable function has some + // metadata attachted to it, but we just created this code oota. Given that the + // differentiated function already has partly confusing metadata, and given that this + // affects nothing but the auttodiff IR, we take a shortcut and just steal metadata from the + // dummy code which we inserted at a higher level. + // FIXME(ZuseZ4): Work with Enzyme core devs to clarify what debug metadata issues we have, + // and how to best improve it for enzyme core and rust-enzyme. + let md_ty = cx.get_md_kind_id("dbg"); + if llvm::LLVMRustHasMetadata(last_inst, md_ty) { + let md = llvm::LLVMRustDIGetInstMetadata(last_inst) + .expect("failed to get instruction metadata"); + let md_todiff = cx.get_metadata_value(md); + llvm::LLVMSetMetadata(call, md_ty, md_todiff); + } else { + // We don't panic, since depending on whether we are in debug or release mode, we might + // have no debug info to copy, which would then be ok. + trace!("no dbg info"); + } + // Now that we copied the metadata, get rid of dummy code. + llvm::LLVMRustEraseInstBefore(entry, last_inst); + llvm::LLVMRustEraseInstFromParent(last_inst); + + if cx.val_ty(outer_fn) != cx.type_void() { + builder.ret(call); + } else { + builder.ret_void(); + } + + // Let's crash in case that we messed something up above and generated invalid IR. + llvm::LLVMRustVerifyFunction( + outer_fn, + llvm::LLVMRustVerifierFailureAction::LLVMAbortProcessAction, + ); + } +} + +pub(crate) fn differentiate<'ll, 'tcx>( + module: &'ll ModuleCodegen<ModuleLlvm>, + cgcx: &CodegenContext<LlvmCodegenBackend>, + tcx: TyCtxt<'tcx>, + diff_items: Vec<AutoDiffItem>, + config: &ModuleConfig, +) -> Result<(), FatalError> { + for item in &diff_items { + trace!("{}", item); + } + + let diag_handler = cgcx.create_dcx(); + let (_, cgus) = tcx.collect_and_partition_mono_items(()); + let cx = context::CodegenCx::new(tcx, &cgus.first().unwrap(), &module.module_llvm); + + // Before dumping the module, we want all the TypeTrees to become part of the module. + for item in diff_items.iter() { + let name = item.source.clone(); + let fn_def: Option<&llvm::Value> = cx.get_function(&name); + let Some(fn_def) = fn_def else { + return Err(llvm_err(diag_handler.handle(), LlvmError::PrepareAutoDiff { + src: item.source.clone(), + target: item.target.clone(), + error: "could not find source function".to_owned(), + })); + }; + debug!(?item.target); + let fn_target: Option<&llvm::Value> = cx.get_function(&item.target); + let Some(fn_target) = fn_target else { + return Err(llvm_err(diag_handler.handle(), LlvmError::PrepareAutoDiff { + src: item.source.clone(), + target: item.target.clone(), + error: "could not find target function".to_owned(), + })); + }; + + generate_enzyme_call(&cx, fn_def, fn_target, item.attrs.clone()); + } + + // FIXME(ZuseZ4): support SanitizeHWAddress and prevent illegal/unsupported opts + + if let Some(opt_level) = config.opt_level { + let opt_stage = match cgcx.lto { + Lto::Fat => llvm::OptStage::PreLinkFatLTO, + Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO, + _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO, + _ => llvm::OptStage::PreLinkNoLTO, + }; + // This is our second opt call, so now we run all opts, + // to make sure we get the best performance. + let skip_size_increasing_opts = false; + trace!("running Module Optimization after differentiation"); + unsafe { + llvm_optimize( + cgcx, + diag_handler.handle(), + module, + config, + opt_level, + opt_stage, + skip_size_increasing_opts, + )? + }; + } + trace!("done with differentiate()"); + + Ok(()) +} diff --git a/compiler/rustc_codegen_llvm/src/callee.rs b/compiler/rustc_codegen_llvm/src/callee.rs index ec77f32caf4..aa9a0f34f55 100644 --- a/compiler/rustc_codegen_llvm/src/callee.rs +++ b/compiler/rustc_codegen_llvm/src/callee.rs @@ -106,7 +106,7 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t // This is a monomorphization of a generic function. if !(cx.tcx.sess.opts.share_generics() || tcx.codegen_fn_attrs(instance_def_id).inline - == rustc_attr::InlineAttr::Never) + == rustc_attr_parsing::InlineAttr::Never) { // When not sharing generics, all instances are in the same // crate and have hidden visibility. diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs index c602d99ff9d..d8fbe51b975 100644 --- a/compiler/rustc_codegen_llvm/src/context.rs +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -1,6 +1,6 @@ use std::borrow::Borrow; use std::cell::{Cell, RefCell}; -use std::ffi::{CStr, c_uint}; +use std::ffi::{CStr, c_char, c_uint}; use std::str; use rustc_abi::{HasDataLayout, TargetDataLayout, VariantIdx}; @@ -600,6 +600,31 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> { llvm::set_section(g, c"llvm.metadata"); } } + + pub(crate) fn get_metadata_value(&self, metadata: &'ll Metadata) -> &'ll Value { + unsafe { llvm::LLVMMetadataAsValue(self.llcx, metadata) } + } + + pub(crate) fn get_function(&self, name: &str) -> Option<&'ll Value> { + let name = SmallCStr::new(name); + unsafe { llvm::LLVMGetNamedFunction(self.llmod, name.as_ptr()) } + } + + pub(crate) fn get_md_kind_id(&self, name: &str) -> u32 { + unsafe { + llvm::LLVMGetMDKindIDInContext( + self.llcx, + name.as_ptr() as *const c_char, + name.len() as c_uint, + ) + } + } + + pub(crate) fn create_metadata(&self, name: String) -> Option<&'ll Metadata> { + Some(unsafe { + llvm::LLVMMDStringInContext2(self.llcx, name.as_ptr() as *const c_char, name.len()) + }) + } } impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> { diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs index 1f133141c18..b617f4d37f5 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs @@ -1,6 +1,4 @@ -use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId, SourceRegion}; - -use crate::coverageinfo::mapgen::LocalFileId; +use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId}; /// Must match the layout of `LLVMRustCounterKind`. #[derive(Copy, Clone, Debug)] @@ -126,30 +124,16 @@ pub(crate) struct CoverageSpan { /// Local index into the function's local-to-global file ID table. /// The value at that index is itself an index into the coverage filename /// table in the CGU's `__llvm_covmap` section. - file_id: u32, + pub(crate) file_id: u32, /// 1-based starting line of the source code span. - start_line: u32, + pub(crate) start_line: u32, /// 1-based starting column of the source code span. - start_col: u32, + pub(crate) start_col: u32, /// 1-based ending line of the source code span. - end_line: u32, + pub(crate) end_line: u32, /// 1-based ending column of the source code span. High bit must be unset. - end_col: u32, -} - -impl CoverageSpan { - pub(crate) fn from_source_region( - local_file_id: LocalFileId, - code_region: &SourceRegion, - ) -> Self { - let file_id = local_file_id.as_u32(); - let &SourceRegion { start_line, start_col, end_line, end_col } = code_region; - // Internally, LLVM uses the high bit of `end_col` to distinguish between - // code regions and gap regions, so it can't be used by the column number. - assert!(end_col & (1u32 << 31) == 0, "high bit of `end_col` must be unset: {end_col:#X}"); - Self { file_id, start_line, start_col, end_line, end_col } - } + pub(crate) end_col: u32, } /// Holds tables of the various region types in one struct. @@ -184,7 +168,7 @@ impl Regions { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct CodeRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) counter: Counter, } @@ -192,7 +176,7 @@ pub(crate) struct CodeRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct BranchRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) true_counter: Counter, pub(crate) false_counter: Counter, } @@ -201,7 +185,7 @@ pub(crate) struct BranchRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct MCDCBranchRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) true_counter: Counter, pub(crate) false_counter: Counter, pub(crate) mcdc_branch_params: mcdc::BranchParameters, @@ -211,6 +195,6 @@ pub(crate) struct MCDCBranchRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct MCDCDecisionRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) mcdc_decision_params: mcdc::DecisionParameters, } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs index 086cf1f44a0..2cd7fa3225a 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs @@ -40,11 +40,10 @@ pub(crate) fn create_pgo_func_name_var<'ll>( } } -pub(crate) fn write_filenames_to_buffer<'a>( - filenames: impl IntoIterator<Item = &'a str>, -) -> Vec<u8> { +pub(crate) fn write_filenames_to_buffer(filenames: &[impl AsRef<str>]) -> Vec<u8> { let (pointers, lengths) = filenames .into_iter() + .map(AsRef::as_ref) .map(|s: &str| (s.as_c_char_ptr(), s.len())) .unzip::<_, _, Vec<_>, Vec<_>>(); diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs deleted file mode 100644 index c5d1ebdfe7c..00000000000 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs +++ /dev/null @@ -1,84 +0,0 @@ -use rustc_data_structures::captures::Captures; -use rustc_middle::mir::coverage::{ - CovTerm, CoverageIdsInfo, Expression, FunctionCoverageInfo, Mapping, MappingKind, Op, - SourceRegion, -}; - -use crate::coverageinfo::ffi::{Counter, CounterExpression, ExprKind}; - -pub(crate) struct FunctionCoverage<'tcx> { - pub(crate) function_coverage_info: &'tcx FunctionCoverageInfo, - /// If `None`, the corresponding function is unused. - ids_info: Option<&'tcx CoverageIdsInfo>, -} - -impl<'tcx> FunctionCoverage<'tcx> { - pub(crate) fn new_used( - function_coverage_info: &'tcx FunctionCoverageInfo, - ids_info: &'tcx CoverageIdsInfo, - ) -> Self { - Self { function_coverage_info, ids_info: Some(ids_info) } - } - - pub(crate) fn new_unused(function_coverage_info: &'tcx FunctionCoverageInfo) -> Self { - Self { function_coverage_info, ids_info: None } - } - - /// Returns true for a used (called) function, and false for an unused function. - pub(crate) fn is_used(&self) -> bool { - self.ids_info.is_some() - } - - /// Return the source hash, generated from the HIR node structure, and used to indicate whether - /// or not the source code structure changed between different compilations. - pub(crate) fn source_hash(&self) -> u64 { - if self.is_used() { self.function_coverage_info.function_source_hash } else { 0 } - } - - /// Convert this function's coverage expression data into a form that can be - /// passed through FFI to LLVM. - pub(crate) fn counter_expressions( - &self, - ) -> impl Iterator<Item = CounterExpression> + ExactSizeIterator + Captures<'_> { - // We know that LLVM will optimize out any unused expressions before - // producing the final coverage map, so there's no need to do the same - // thing on the Rust side unless we're confident we can do much better. - // (See `CounterExpressionsMinimizer` in `CoverageMappingWriter.cpp`.) - - self.function_coverage_info.expressions.iter().map(move |&Expression { lhs, op, rhs }| { - CounterExpression { - lhs: self.counter_for_term(lhs), - kind: match op { - Op::Add => ExprKind::Add, - Op::Subtract => ExprKind::Subtract, - }, - rhs: self.counter_for_term(rhs), - } - }) - } - - /// Converts this function's coverage mappings into an intermediate form - /// that will be used by `mapgen` when preparing for FFI. - pub(crate) fn counter_regions( - &self, - ) -> impl Iterator<Item = (MappingKind, &SourceRegion)> + ExactSizeIterator { - self.function_coverage_info.mappings.iter().map(move |mapping| { - let Mapping { kind, source_region } = mapping; - let kind = - kind.map_terms(|term| if self.is_zero_term(term) { CovTerm::Zero } else { term }); - (kind, source_region) - }) - } - - fn counter_for_term(&self, term: CovTerm) -> Counter { - if self.is_zero_term(term) { Counter::ZERO } else { Counter::from_term(term) } - } - - fn is_zero_term(&self, term: CovTerm) -> bool { - match self.ids_info { - Some(ids_info) => ids_info.is_zero_term(term), - // This function is unused, so all coverage counters/expressions are zero. - None => true, - } - } -} diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index 4f2af732527..b3ad2a0e409 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,28 +1,28 @@ -use std::iter; +use std::sync::Arc; -use itertools::Itertools as _; +use itertools::Itertools; use rustc_abi::Align; use rustc_codegen_ssa::traits::{ BaseTypeCodegenMethods, ConstCodegenMethods, StaticCodegenMethods, }; -use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet}; +use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_index::IndexVec; +use rustc_middle::mir; use rustc_middle::ty::{self, TyCtxt}; -use rustc_middle::{bug, mir}; use rustc_session::RemapFileNameExt; use rustc_session::config::RemapPathScopeComponents; use rustc_span::def_id::DefIdSet; -use rustc_span::{Span, Symbol}; +use rustc_span::{SourceFile, StableSourceFileId}; use tracing::debug; use crate::common::CodegenCx; use crate::coverageinfo::llvm_cov; -use crate::coverageinfo::map_data::FunctionCoverage; use crate::coverageinfo::mapgen::covfun::prepare_covfun_record; use crate::llvm; mod covfun; +mod spans; /// Generates and exports the coverage map, which is embedded in special /// linker sections in the final binary. @@ -49,46 +49,40 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { debug!("Generating coverage map for CodegenUnit: `{}`", cx.codegen_unit.name()); - // In order to show that unused functions have coverage counts of zero (0), LLVM requires the - // functions exist. Generate synthetic functions with a (required) single counter, and add the - // MIR `Coverage` code regions to the `function_coverage_map`, before calling - // `ctx.take_function_coverage_map()`. - if cx.codegen_unit.is_code_coverage_dead_code_cgu() { - add_unused_functions(cx); - } - // FIXME(#132395): Can this be none even when coverage is enabled? - let function_coverage_map = match cx.coverage_cx { - Some(ref cx) => cx.take_function_coverage_map(), + let instances_used = match cx.coverage_cx { + Some(ref cx) => cx.instances_used.borrow(), None => return, }; - if function_coverage_map.is_empty() { - // This CGU has no functions with coverage instrumentation. - return; - } - - let all_file_names = function_coverage_map - .iter() - .map(|(_, fn_cov)| fn_cov.function_coverage_info.body_span) - .map(|span| span_file_name(tcx, span)); - let global_file_table = GlobalFileTable::new(all_file_names); - - // Encode all filenames referenced by coverage mappings in this CGU. - let filenames_buffer = global_file_table.make_filenames_buffer(tcx); - // The `llvm-cov` tool uses this hash to associate each covfun record with - // its corresponding filenames table, since the final binary will typically - // contain multiple covmap records from different compilation units. - let filenames_hash = llvm_cov::hash_bytes(&filenames_buffer); - let mut unused_function_names = Vec::new(); + // The order of entries in this global file table needs to be deterministic, + // and ideally should also be independent of the details of stable-hashing, + // because coverage tests snapshots (`.cov-map`) can observe the order and + // would need to be re-blessed if it changes. As long as those requirements + // are satisfied, the order can be arbitrary. + let mut global_file_table = GlobalFileTable::new(); - let covfun_records = function_coverage_map - .into_iter() - .filter_map(|(instance, function_coverage)| { - prepare_covfun_record(tcx, &global_file_table, instance, &function_coverage) - }) + let mut covfun_records = instances_used + .iter() + .copied() + // Sort by symbol name, so that the global file table is built in an + // order that doesn't depend on the stable-hash-based order in which + // instances were visited during codegen. + .sorted_by_cached_key(|&instance| tcx.symbol_name(instance).name) + .filter_map(|instance| prepare_covfun_record(tcx, &mut global_file_table, instance, true)) .collect::<Vec<_>>(); + // In a single designated CGU, also prepare covfun records for functions + // in this crate that were instrumented for coverage, but are unused. + if cx.codegen_unit.is_code_coverage_dead_code_cgu() { + let mut unused_instances = gather_unused_function_instances(cx); + // Sort the unused instances by symbol name, for the same reason as the used ones. + unused_instances.sort_by_cached_key(|&instance| tcx.symbol_name(instance).name); + covfun_records.extend(unused_instances.into_iter().filter_map(|instance| { + prepare_covfun_record(tcx, &mut global_file_table, instance, false) + })); + } + // If there are no covfun records for this CGU, don't generate a covmap record. // Emitting a covmap record without any covfun records causes `llvm-cov` to // fail when generating coverage reports, and if there are no covfun records @@ -98,6 +92,15 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { return; } + // Encode all filenames referenced by coverage mappings in this CGU. + let filenames_buffer = global_file_table.make_filenames_buffer(tcx); + // The `llvm-cov` tool uses this hash to associate each covfun record with + // its corresponding filenames table, since the final binary will typically + // contain multiple covmap records from different compilation units. + let filenames_hash = llvm_cov::hash_bytes(&filenames_buffer); + + let mut unused_function_names = vec![]; + for covfun in &covfun_records { unused_function_names.extend(covfun.mangled_function_name_if_unused()); @@ -129,54 +132,51 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { generate_covmap_record(cx, covmap_version, &filenames_buffer); } -/// Maps "global" (per-CGU) file ID numbers to their underlying filenames. +/// Maps "global" (per-CGU) file ID numbers to their underlying source files. struct GlobalFileTable { - /// This "raw" table doesn't include the working dir, so a filename's + /// This "raw" table doesn't include the working dir, so a file's /// global ID is its index in this set **plus one**. - raw_file_table: FxIndexSet<Symbol>, + raw_file_table: FxIndexMap<StableSourceFileId, Arc<SourceFile>>, } impl GlobalFileTable { - fn new(all_file_names: impl IntoIterator<Item = Symbol>) -> Self { - // Collect all of the filenames into a set. Filenames usually come in - // contiguous runs, so we can dedup adjacent ones to save work. - let mut raw_file_table = all_file_names.into_iter().dedup().collect::<FxIndexSet<Symbol>>(); - - // Sort the file table by its actual string values, not the arbitrary - // ordering of its symbols. - raw_file_table.sort_unstable_by(|a, b| a.as_str().cmp(b.as_str())); - - Self { raw_file_table } + fn new() -> Self { + Self { raw_file_table: FxIndexMap::default() } } - fn global_file_id_for_file_name(&self, file_name: Symbol) -> GlobalFileId { - let raw_id = self.raw_file_table.get_index_of(&file_name).unwrap_or_else(|| { - bug!("file name not found in prepared global file table: {file_name}"); - }); + fn global_file_id_for_file(&mut self, file: &Arc<SourceFile>) -> GlobalFileId { + // Ensure the given file has a table entry, and get its index. + let entry = self.raw_file_table.entry(file.stable_id); + let raw_id = entry.index(); + entry.or_insert_with(|| Arc::clone(file)); + // The raw file table doesn't include an entry for the working dir // (which has ID 0), so add 1 to get the correct ID. GlobalFileId::from_usize(raw_id + 1) } fn make_filenames_buffer(&self, tcx: TyCtxt<'_>) -> Vec<u8> { + let mut table = Vec::with_capacity(self.raw_file_table.len() + 1); + // LLVM Coverage Mapping Format version 6 (zero-based encoded as 5) // requires setting the first filename to the compilation directory. // Since rustc generates coverage maps with relative paths, the // compilation directory can be combined with the relative paths // to get absolute paths, if needed. - use rustc_session::RemapFileNameExt; - use rustc_session::config::RemapPathScopeComponents; - let working_dir: &str = &tcx - .sess - .opts - .working_dir - .for_scope(tcx.sess, RemapPathScopeComponents::MACRO) - .to_string_lossy(); - - // Insert the working dir at index 0, before the other filenames. - let filenames = - iter::once(working_dir).chain(self.raw_file_table.iter().map(Symbol::as_str)); - llvm_cov::write_filenames_to_buffer(filenames) + table.push( + tcx.sess + .opts + .working_dir + .for_scope(tcx.sess, RemapPathScopeComponents::MACRO) + .to_string_lossy(), + ); + + // Add the regular entries after the base directory. + table.extend(self.raw_file_table.values().map(|file| { + file.name.for_scope(tcx.sess, RemapPathScopeComponents::MACRO).to_string_lossy() + })); + + llvm_cov::write_filenames_to_buffer(&table) } } @@ -189,7 +189,7 @@ rustc_index::newtype_index! { /// An index into a function's list of global file IDs. That underlying list /// of local-to-global mappings will be embedded in the function's record in /// the `__llvm_covfun` linker section. - pub(crate) struct LocalFileId {} + struct LocalFileId {} } /// Holds a mapping from "local" (per-function) file IDs to "global" (per-CGU) @@ -215,13 +215,6 @@ impl VirtualFileMapping { } } -fn span_file_name(tcx: TyCtxt<'_>, span: Span) -> Symbol { - let source_file = tcx.sess.source_map().lookup_source_file(span.lo()); - let name = - source_file.name.for_scope(tcx.sess, RemapPathScopeComponents::MACRO).to_string_lossy(); - Symbol::intern(&name) -} - /// Generates the contents of the covmap record for this CGU, which mostly /// consists of a header and a list of filenames. The record is then stored /// as a global variable in the `__llvm_covmap` section. @@ -264,39 +257,35 @@ fn generate_covmap_record<'ll>(cx: &CodegenCx<'ll, '_>, version: u32, filenames_ /// coverage map (in a single designated CGU) so that we still emit coverage mappings for them. /// We also end up adding their symbol names to a special global array that LLVM will include in /// its embedded coverage data. -fn add_unused_functions(cx: &CodegenCx<'_, '_>) { +fn gather_unused_function_instances<'tcx>(cx: &CodegenCx<'_, 'tcx>) -> Vec<ty::Instance<'tcx>> { assert!(cx.codegen_unit.is_code_coverage_dead_code_cgu()); let tcx = cx.tcx; let usage = prepare_usage_sets(tcx); let is_unused_fn = |def_id: LocalDefId| -> bool { - let def_id = def_id.to_def_id(); - - // To be eligible for "unused function" mappings, a definition must: - // - Be function-like + // Usage sets expect `DefId`, so convert from `LocalDefId`. + let d: DefId = LocalDefId::to_def_id(def_id); + // To be potentially eligible for "unused function" mappings, a definition must: + // - Be eligible for coverage instrumentation // - Not participate directly in codegen (or have lost all its coverage statements) // - Not have any coverage statements inlined into codegenned functions - tcx.def_kind(def_id).is_fn_like() - && (!usage.all_mono_items.contains(&def_id) - || usage.missing_own_coverage.contains(&def_id)) - && !usage.used_via_inlining.contains(&def_id) + tcx.is_eligible_for_coverage(def_id) + && (!usage.all_mono_items.contains(&d) || usage.missing_own_coverage.contains(&d)) + && !usage.used_via_inlining.contains(&d) }; - // Scan for unused functions that were instrumented for coverage. - for def_id in tcx.mir_keys(()).iter().copied().filter(|&def_id| is_unused_fn(def_id)) { - // Get the coverage info from MIR, skipping functions that were never instrumented. - let body = tcx.optimized_mir(def_id); - let Some(function_coverage_info) = body.function_coverage_info.as_deref() else { continue }; - - // FIXME(79651): Consider trying to filter out dummy instantiations of - // unused generic functions from library crates, because they can produce - // "unused instantiation" in coverage reports even when they are actually - // used by some downstream crate in the same binary. + // FIXME(#79651): Consider trying to filter out dummy instantiations of + // unused generic functions from library crates, because they can produce + // "unused instantiation" in coverage reports even when they are actually + // used by some downstream crate in the same binary. - debug!("generating unused fn: {def_id:?}"); - add_unused_function_coverage(cx, def_id, function_coverage_info); - } + tcx.mir_keys(()) + .iter() + .copied() + .filter(|&def_id| is_unused_fn(def_id)) + .map(|def_id| make_dummy_instance(tcx, def_id)) + .collect::<Vec<_>>() } struct UsageSets<'tcx> { @@ -361,16 +350,11 @@ fn prepare_usage_sets<'tcx>(tcx: TyCtxt<'tcx>) -> UsageSets<'tcx> { UsageSets { all_mono_items, used_via_inlining, missing_own_coverage } } -fn add_unused_function_coverage<'tcx>( - cx: &CodegenCx<'_, 'tcx>, - def_id: LocalDefId, - function_coverage_info: &'tcx mir::coverage::FunctionCoverageInfo, -) { - let tcx = cx.tcx; - let def_id = def_id.to_def_id(); +fn make_dummy_instance<'tcx>(tcx: TyCtxt<'tcx>, local_def_id: LocalDefId) -> ty::Instance<'tcx> { + let def_id = local_def_id.to_def_id(); // Make a dummy instance that fills in all generics with placeholders. - let instance = ty::Instance::new( + ty::Instance::new( def_id, ty::GenericArgs::for_item(tcx, def_id, |param, _| { if let ty::GenericParamDefKind::Lifetime = param.kind { @@ -379,9 +363,5 @@ fn add_unused_function_coverage<'tcx>( tcx.mk_param_from_def(param) } }), - ); - - // An unused function's mappings will all be rewritten to map to zero. - let function_coverage = FunctionCoverage::new_unused(function_coverage_info); - cx.coverage_cx().function_coverage_map.borrow_mut().insert(instance, function_coverage); + ) } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs index 33e7a0f2f20..5428d776f41 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs @@ -10,15 +10,16 @@ use rustc_abi::Align; use rustc_codegen_ssa::traits::{ BaseTypeCodegenMethods, ConstCodegenMethods, StaticCodegenMethods, }; -use rustc_middle::bug; -use rustc_middle::mir::coverage::MappingKind; +use rustc_middle::mir::coverage::{ + CovTerm, CoverageIdsInfo, Expression, FunctionCoverageInfo, Mapping, MappingKind, Op, +}; use rustc_middle::ty::{Instance, TyCtxt}; +use rustc_span::Span; use rustc_target::spec::HasTargetSpec; use tracing::debug; use crate::common::CodegenCx; -use crate::coverageinfo::map_data::FunctionCoverage; -use crate::coverageinfo::mapgen::{GlobalFileTable, VirtualFileMapping, span_file_name}; +use crate::coverageinfo::mapgen::{GlobalFileTable, VirtualFileMapping, spans}; use crate::coverageinfo::{ffi, llvm_cov}; use crate::llvm; @@ -45,77 +46,129 @@ impl<'tcx> CovfunRecord<'tcx> { pub(crate) fn prepare_covfun_record<'tcx>( tcx: TyCtxt<'tcx>, - global_file_table: &GlobalFileTable, + global_file_table: &mut GlobalFileTable, instance: Instance<'tcx>, - function_coverage: &FunctionCoverage<'tcx>, + is_used: bool, ) -> Option<CovfunRecord<'tcx>> { + let fn_cov_info = tcx.instance_mir(instance.def).function_coverage_info.as_deref()?; + let ids_info = tcx.coverage_ids_info(instance.def); + + let expressions = prepare_expressions(fn_cov_info, ids_info, is_used); + let mut covfun = CovfunRecord { mangled_function_name: tcx.symbol_name(instance).name, - source_hash: function_coverage.source_hash(), - is_used: function_coverage.is_used(), + source_hash: if is_used { fn_cov_info.function_source_hash } else { 0 }, + is_used, virtual_file_mapping: VirtualFileMapping::default(), - expressions: function_coverage.counter_expressions().collect::<Vec<_>>(), + expressions, regions: ffi::Regions::default(), }; - fill_region_tables(tcx, global_file_table, function_coverage, &mut covfun); + fill_region_tables(tcx, global_file_table, fn_cov_info, ids_info, &mut covfun); if covfun.regions.has_no_regions() { - if covfun.is_used { - bug!("a used function should have had coverage mapping data but did not: {covfun:?}"); - } else { - debug!(?covfun, "unused function had no coverage mapping data"); - return None; - } + debug!(?covfun, "function has no mappings to embed; skipping"); + return None; } Some(covfun) } +/// Convert the function's coverage-counter expressions into a form suitable for FFI. +fn prepare_expressions( + fn_cov_info: &FunctionCoverageInfo, + ids_info: &CoverageIdsInfo, + is_used: bool, +) -> Vec<ffi::CounterExpression> { + // If any counters or expressions were removed by MIR opts, replace their + // terms with zero. + let counter_for_term = |term| { + if !is_used || ids_info.is_zero_term(term) { + ffi::Counter::ZERO + } else { + ffi::Counter::from_term(term) + } + }; + + // We know that LLVM will optimize out any unused expressions before + // producing the final coverage map, so there's no need to do the same + // thing on the Rust side unless we're confident we can do much better. + // (See `CounterExpressionsMinimizer` in `CoverageMappingWriter.cpp`.) + fn_cov_info + .expressions + .iter() + .map(move |&Expression { lhs, op, rhs }| ffi::CounterExpression { + lhs: counter_for_term(lhs), + kind: match op { + Op::Add => ffi::ExprKind::Add, + Op::Subtract => ffi::ExprKind::Subtract, + }, + rhs: counter_for_term(rhs), + }) + .collect::<Vec<_>>() +} + /// Populates the mapping region tables in the current function's covfun record. fn fill_region_tables<'tcx>( tcx: TyCtxt<'tcx>, - global_file_table: &GlobalFileTable, - function_coverage: &FunctionCoverage<'tcx>, + global_file_table: &mut GlobalFileTable, + fn_cov_info: &'tcx FunctionCoverageInfo, + ids_info: &'tcx CoverageIdsInfo, covfun: &mut CovfunRecord<'tcx>, ) { - let counter_regions = function_coverage.counter_regions(); - if counter_regions.is_empty() { - return; - } - // Currently a function's mappings must all be in the same file as its body span. - let file_name = span_file_name(tcx, function_coverage.function_coverage_info.body_span); + let source_map = tcx.sess.source_map(); + let source_file = source_map.lookup_source_file(fn_cov_info.body_span.lo()); - // Look up the global file ID for that filename. - let global_file_id = global_file_table.global_file_id_for_file_name(file_name); + // Look up the global file ID for that file. + let global_file_id = global_file_table.global_file_id_for_file(&source_file); // Associate that global file ID with a local file ID for this function. let local_file_id = covfun.virtual_file_mapping.local_id_for_global(global_file_id); - debug!(" file id: {local_file_id:?} => {global_file_id:?} = '{file_name:?}'"); let ffi::Regions { code_regions, branch_regions, mcdc_branch_regions, mcdc_decision_regions } = &mut covfun.regions; + let make_cov_span = |span: Span| { + spans::make_coverage_span(local_file_id, source_map, fn_cov_info, &source_file, span) + }; + let discard_all = tcx.sess.coverage_discard_all_spans_in_codegen(); + // For each counter/region pair in this function+file, convert it to a // form suitable for FFI. - for (mapping_kind, region) in counter_regions { - debug!("Adding counter {mapping_kind:?} to map for {region:?}"); - let span = ffi::CoverageSpan::from_source_region(local_file_id, region); - match mapping_kind { + let is_zero_term = |term| !covfun.is_used || ids_info.is_zero_term(term); + for &Mapping { ref kind, span } in &fn_cov_info.mappings { + // If the mapping refers to counters/expressions that were removed by + // MIR opts, replace those occurrences with zero. + let kind = kind.map_terms(|term| if is_zero_term(term) { CovTerm::Zero } else { term }); + + // Convert the `Span` into coordinates that we can pass to LLVM, or + // discard the span if conversion fails. In rare, cases _all_ of a + // function's spans are discarded, and the rest of coverage codegen + // needs to handle that gracefully to avoid a repeat of #133606. + // We don't have a good test case for triggering that organically, so + // instead we set `-Zcoverage-options=discard-all-spans-in-codegen` + // to force it to occur. + let Some(cov_span) = make_cov_span(span) else { continue }; + if discard_all { + continue; + } + + match kind { MappingKind::Code(term) => { - code_regions.push(ffi::CodeRegion { span, counter: ffi::Counter::from_term(term) }); + code_regions + .push(ffi::CodeRegion { cov_span, counter: ffi::Counter::from_term(term) }); } MappingKind::Branch { true_term, false_term } => { branch_regions.push(ffi::BranchRegion { - span, + cov_span, true_counter: ffi::Counter::from_term(true_term), false_counter: ffi::Counter::from_term(false_term), }); } MappingKind::MCDCBranch { true_term, false_term, mcdc_params } => { mcdc_branch_regions.push(ffi::MCDCBranchRegion { - span, + cov_span, true_counter: ffi::Counter::from_term(true_term), false_counter: ffi::Counter::from_term(false_term), mcdc_branch_params: ffi::mcdc::BranchParameters::from(mcdc_params), @@ -123,7 +176,7 @@ fn fill_region_tables<'tcx>( } MappingKind::MCDCDecision(mcdc_decision_params) => { mcdc_decision_regions.push(ffi::MCDCDecisionRegion { - span, + cov_span, mcdc_decision_params: ffi::mcdc::DecisionParameters::from(mcdc_decision_params), }); } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs new file mode 100644 index 00000000000..6d1d91340c2 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs @@ -0,0 +1,126 @@ +use rustc_middle::mir::coverage::FunctionCoverageInfo; +use rustc_span::source_map::SourceMap; +use rustc_span::{BytePos, Pos, SourceFile, Span}; +use tracing::debug; + +use crate::coverageinfo::ffi; +use crate::coverageinfo::mapgen::LocalFileId; + +/// Converts the span into its start line and column, and end line and column. +/// +/// Line numbers and column numbers are 1-based. Unlike most column numbers emitted by +/// the compiler, these column numbers are denoted in **bytes**, because that's what +/// LLVM's `llvm-cov` tool expects to see in coverage maps. +/// +/// Returns `None` if the conversion failed for some reason. This shouldn't happen, +/// but it's hard to rule out entirely (especially in the presence of complex macros +/// or other expansions), and if it does happen then skipping a span or function is +/// better than an ICE or `llvm-cov` failure that the user might have no way to avoid. +pub(crate) fn make_coverage_span( + file_id: LocalFileId, + source_map: &SourceMap, + fn_cov_info: &FunctionCoverageInfo, + file: &SourceFile, + span: Span, +) -> Option<ffi::CoverageSpan> { + let span = ensure_non_empty_span(source_map, fn_cov_info, span)?; + + let lo = span.lo(); + let hi = span.hi(); + + // Column numbers need to be in bytes, so we can't use the more convenient + // `SourceMap` methods for looking up file coordinates. + let line_and_byte_column = |pos: BytePos| -> Option<(usize, usize)> { + let rpos = file.relative_position(pos); + let line_index = file.lookup_line(rpos)?; + let line_start = file.lines()[line_index]; + // Line numbers and column numbers are 1-based, so add 1 to each. + Some((line_index + 1, (rpos - line_start).to_usize() + 1)) + }; + + let (mut start_line, start_col) = line_and_byte_column(lo)?; + let (mut end_line, end_col) = line_and_byte_column(hi)?; + + // Apply an offset so that code in doctests has correct line numbers. + // FIXME(#79417): Currently we have no way to offset doctest _columns_. + start_line = source_map.doctest_offset_line(&file.name, start_line); + end_line = source_map.doctest_offset_line(&file.name, end_line); + + check_coverage_span(ffi::CoverageSpan { + file_id: file_id.as_u32(), + start_line: start_line as u32, + start_col: start_col as u32, + end_line: end_line as u32, + end_col: end_col as u32, + }) +} + +fn ensure_non_empty_span( + source_map: &SourceMap, + fn_cov_info: &FunctionCoverageInfo, + span: Span, +) -> Option<Span> { + if !span.is_empty() { + return Some(span); + } + + let lo = span.lo(); + let hi = span.hi(); + + // The span is empty, so try to expand it to cover an adjacent '{' or '}', + // but only within the bounds of the body span. + let try_next = hi < fn_cov_info.body_span.hi(); + let try_prev = fn_cov_info.body_span.lo() < lo; + if !(try_next || try_prev) { + return None; + } + + source_map + .span_to_source(span, |src, start, end| try { + // Adjusting span endpoints by `BytePos(1)` is normally a bug, + // but in this case we have specifically checked that the character + // we're skipping over is one of two specific ASCII characters, so + // adjusting by exactly 1 byte is correct. + if try_next && src.as_bytes()[end] == b'{' { + Some(span.with_hi(hi + BytePos(1))) + } else if try_prev && src.as_bytes()[start - 1] == b'}' { + Some(span.with_lo(lo - BytePos(1))) + } else { + None + } + }) + .ok()? +} + +/// If `llvm-cov` sees a source region that is improperly ordered (end < start), +/// it will immediately exit with a fatal error. To prevent that from happening, +/// discard regions that are improperly ordered, or might be interpreted in a +/// way that makes them improperly ordered. +fn check_coverage_span(cov_span: ffi::CoverageSpan) -> Option<ffi::CoverageSpan> { + let ffi::CoverageSpan { file_id: _, start_line, start_col, end_line, end_col } = cov_span; + + // Line/column coordinates are supposed to be 1-based. If we ever emit + // coordinates of 0, `llvm-cov` might misinterpret them. + let all_nonzero = [start_line, start_col, end_line, end_col].into_iter().all(|x| x != 0); + // Coverage mappings use the high bit of `end_col` to indicate that a + // region is actually a "gap" region, so make sure it's unset. + let end_col_has_high_bit_unset = (end_col & (1 << 31)) == 0; + // If a region is improperly ordered (end < start), `llvm-cov` will exit + // with a fatal error, which is inconvenient for users and hard to debug. + let is_ordered = (start_line, start_col) <= (end_line, end_col); + + if all_nonzero && end_col_has_high_bit_unset && is_ordered { + Some(cov_span) + } else { + debug!( + ?cov_span, + ?all_nonzero, + ?end_col_has_high_bit_unset, + ?is_ordered, + "Skipping source region that would be misinterpreted or rejected by LLVM" + ); + // If this happens in a debug build, ICE to make it easier to notice. + debug_assert!(false, "Improper source region: {cov_span:?}"); + None + } +} diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs index 82b6677e203..7311cd9d230 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs @@ -5,7 +5,7 @@ use rustc_abi::Size; use rustc_codegen_ssa::traits::{ BuilderMethods, ConstCodegenMethods, CoverageInfoBuilderMethods, MiscCodegenMethods, }; -use rustc_data_structures::fx::{FxHashMap, FxIndexMap}; +use rustc_data_structures::fx::{FxHashMap, FxIndexSet}; use rustc_middle::mir::coverage::CoverageKind; use rustc_middle::ty::Instance; use rustc_middle::ty::layout::HasTyCtxt; @@ -13,18 +13,16 @@ use tracing::{debug, instrument}; use crate::builder::Builder; use crate::common::CodegenCx; -use crate::coverageinfo::map_data::FunctionCoverage; use crate::llvm; pub(crate) mod ffi; mod llvm_cov; -pub(crate) mod map_data; mod mapgen; /// Extra per-CGU context/state needed for coverage instrumentation. pub(crate) struct CguCoverageContext<'ll, 'tcx> { /// Coverage data for each instrumented function identified by DefId. - pub(crate) function_coverage_map: RefCell<FxIndexMap<Instance<'tcx>, FunctionCoverage<'tcx>>>, + pub(crate) instances_used: RefCell<FxIndexSet<Instance<'tcx>>>, pub(crate) pgo_func_name_var_map: RefCell<FxHashMap<Instance<'tcx>, &'ll llvm::Value>>, pub(crate) mcdc_condition_bitmap_map: RefCell<FxHashMap<Instance<'tcx>, Vec<&'ll llvm::Value>>>, @@ -34,17 +32,13 @@ pub(crate) struct CguCoverageContext<'ll, 'tcx> { impl<'ll, 'tcx> CguCoverageContext<'ll, 'tcx> { pub(crate) fn new() -> Self { Self { - function_coverage_map: Default::default(), + instances_used: RefCell::<FxIndexSet<_>>::default(), pgo_func_name_var_map: Default::default(), mcdc_condition_bitmap_map: Default::default(), covfun_section_name: Default::default(), } } - fn take_function_coverage_map(&self) -> FxIndexMap<Instance<'tcx>, FunctionCoverage<'tcx>> { - self.function_coverage_map.replace(FxIndexMap::default()) - } - /// LLVM use a temp value to record evaluated mcdc test vector of each decision, which is /// called condition bitmap. In order to handle nested decisions, several condition bitmaps can /// be allocated for a function body. These values are named `mcdc.addr.{i}` and are a 32-bit @@ -157,12 +151,7 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> { // Mark the instance as used in this CGU, for coverage purposes. // This includes functions that were not partitioned into this CGU, // but were MIR-inlined into one of this CGU's functions. - coverage_cx.function_coverage_map.borrow_mut().entry(instance).or_insert_with(|| { - FunctionCoverage::new_used( - function_coverage_info, - bx.tcx.coverage_ids_info(instance.def), - ) - }); + coverage_cx.instances_used.borrow_mut().insert(instance); match *kind { CoverageKind::SpanMarker | CoverageKind::BlockMarker { .. } => unreachable!( diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs b/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs index 07bd0f4d1c1..e545ce386ed 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs @@ -4,7 +4,7 @@ use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext}; use rustc_codegen_ssa::traits::*; use rustc_data_structures::fx::FxHashMap; use rustc_index::Idx; -use rustc_index::bit_set::BitSet; +use rustc_index::bit_set::DenseBitSet; use rustc_middle::mir::{Body, SourceScope}; use rustc_middle::ty::layout::{FnAbiOf, HasTypingEnv}; use rustc_middle::ty::{self, Instance}; @@ -27,7 +27,7 @@ pub(crate) fn compute_mir_scopes<'ll, 'tcx>( ) { // Find all scopes with variables defined in them. let variables = if cx.sess().opts.debuginfo == DebugInfo::Full { - let mut vars = BitSet::new_empty(mir.source_scopes.len()); + let mut vars = DenseBitSet::new_empty(mir.source_scopes.len()); // FIXME(eddyb) take into account that arguments always have debuginfo, // irrespective of their name (assuming full debuginfo is enabled). // NOTE(eddyb) actually, on second thought, those are always in the @@ -40,7 +40,7 @@ pub(crate) fn compute_mir_scopes<'ll, 'tcx>( // Nothing to emit, of course. None }; - let mut instantiated = BitSet::new_empty(mir.source_scopes.len()); + let mut instantiated = DenseBitSet::new_empty(mir.source_scopes.len()); let mut discriminators = FxHashMap::default(); // Instantiate all scopes. for idx in 0..mir.source_scopes.len() { @@ -63,9 +63,9 @@ fn make_mir_scope<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'tcx>, mir: &Body<'tcx>, - variables: &Option<BitSet<SourceScope>>, + variables: &Option<DenseBitSet<SourceScope>>, debug_context: &mut FunctionDebugContext<'tcx, &'ll DIScope, &'ll DILocation>, - instantiated: &mut BitSet<SourceScope>, + instantiated: &mut DenseBitSet<SourceScope>, discriminators: &mut FxHashMap<BytePos, u32>, scope: SourceScope, ) { diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/dwarf_const.rs b/compiler/rustc_codegen_llvm/src/debuginfo/dwarf_const.rs new file mode 100644 index 00000000000..40842915222 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/debuginfo/dwarf_const.rs @@ -0,0 +1,37 @@ +//! Definitions of various DWARF-related constants. + +use libc::c_uint; + +/// Helper macro to let us redeclare gimli's constants as our own constants +/// with a different type, with less risk of copy-paste errors. +macro_rules! declare_constant { + ( + $name:ident : $type:ty + ) => { + #[allow(non_upper_case_globals)] + pub(crate) const $name: $type = ::gimli::constants::$name.0 as $type; + + // Assert that as-cast probably hasn't changed the value. + const _: () = assert!($name as i128 == ::gimli::constants::$name.0 as i128); + }; +} + +declare_constant!(DW_TAG_const_type: c_uint); + +// DWARF languages. +declare_constant!(DW_LANG_Rust: c_uint); + +// DWARF attribute type encodings. +declare_constant!(DW_ATE_boolean: c_uint); +declare_constant!(DW_ATE_float: c_uint); +declare_constant!(DW_ATE_signed: c_uint); +declare_constant!(DW_ATE_unsigned: c_uint); +declare_constant!(DW_ATE_UTF: c_uint); + +// DWARF expression operators. +declare_constant!(DW_OP_deref: u64); +declare_constant!(DW_OP_plus_uconst: u64); +/// Defined by LLVM in `llvm/include/llvm/BinaryFormat/Dwarf.h`. +/// Double-checked by a static assertion in `RustWrapper.cpp`. +#[allow(non_upper_case_globals)] +pub(crate) const DW_OP_LLVM_fragment: u64 = 0x1000; diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs index aef8642f199..2c9f1cda13a 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs @@ -7,7 +7,7 @@ use rustc_hir::def_id::LOCAL_CRATE; use rustc_middle::bug; use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerType; use rustc_session::config::{CrateType, DebugInfo}; -use rustc_span::symbol::sym; +use rustc_span::sym; use crate::builder::Builder; use crate::common::CodegenCx; diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs index 59275254022..88e43e1c678 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs @@ -16,13 +16,13 @@ use rustc_middle::ty::{ self, AdtKind, CoroutineArgsExt, Instance, PolyExistentialTraitRef, Ty, TyCtxt, Visibility, }; use rustc_session::config::{self, DebugInfo, Lto}; -use rustc_span::symbol::Symbol; -use rustc_span::{DUMMY_SP, FileName, FileNameDisplayPreference, SourceFile, hygiene}; +use rustc_span::{DUMMY_SP, FileName, FileNameDisplayPreference, SourceFile, Symbol, hygiene}; use rustc_symbol_mangling::typeid_for_trait_ref; use rustc_target::spec::DebuginfoKind; use smallvec::smallvec; use tracing::{debug, instrument}; +pub(crate) use self::type_map::TypeMap; use self::type_map::{DINodeCreationResult, Stub, UniqueTypeId}; use super::CodegenUnitDebugContext; use super::namespace::mangled_name_of_instance; @@ -31,6 +31,7 @@ use super::utils::{ DIB, create_DIArray, debug_context, get_namespace_for_item, is_node_local_to_unit, }; use crate::common::{AsCCharPtr, CodegenCx}; +use crate::debuginfo::dwarf_const; use crate::debuginfo::metadata::type_map::build_type_with_children; use crate::debuginfo::utils::{WidePtrKind, wide_pointer_kind}; use crate::llvm::debuginfo::{ @@ -60,20 +61,6 @@ impl fmt::Debug for llvm::Metadata { } } -// From DWARF 5. -// See http://www.dwarfstd.org/ShowIssue.php?issue=140129.1. -const DW_LANG_RUST: c_uint = 0x1c; -#[allow(non_upper_case_globals)] -const DW_ATE_boolean: c_uint = 0x02; -#[allow(non_upper_case_globals)] -const DW_ATE_float: c_uint = 0x04; -#[allow(non_upper_case_globals)] -const DW_ATE_signed: c_uint = 0x05; -#[allow(non_upper_case_globals)] -const DW_ATE_unsigned: c_uint = 0x07; -#[allow(non_upper_case_globals)] -const DW_ATE_UTF: c_uint = 0x10; - pub(super) const UNKNOWN_LINE_NUMBER: c_uint = 0; pub(super) const UNKNOWN_COLUMN_NUMBER: c_uint = 0; @@ -88,8 +75,6 @@ type SmallVec<T> = smallvec::SmallVec<[T; 16]>; mod enums; mod type_map; -pub(crate) use type_map::TypeMap; - /// Returns from the enclosing function if the type debuginfo node with the given /// unique ID can be found in the type map. macro_rules! return_if_di_node_created_in_meantime { @@ -520,7 +505,7 @@ fn recursion_marker_type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>) -> &'ll D name.as_c_char_ptr(), name.len(), cx.tcx.data_layout.pointer_size.bits(), - DW_ATE_unsigned, + dwarf_const::DW_ATE_unsigned, ) } }) @@ -779,6 +764,8 @@ fn build_basic_type_di_node<'ll, 'tcx>( // .natvis visualizers (and perhaps other existing native debuggers?) let cpp_like_debuginfo = cpp_like_debuginfo(cx.tcx); + use dwarf_const::{DW_ATE_UTF, DW_ATE_boolean, DW_ATE_float, DW_ATE_signed, DW_ATE_unsigned}; + let (name, encoding) = match t.kind() { ty::Never => ("!", DW_ATE_unsigned), ty::Tuple(elements) if elements.is_empty() => { @@ -959,7 +946,7 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>( let unit_metadata = llvm::LLVMRustDIBuilderCreateCompileUnit( debug_context.builder, - DW_LANG_RUST, + dwarf_const::DW_LANG_Rust, compile_unit_file, producer.as_c_char_ptr(), producer.len(), diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs index d374767f187..a72e205c9b2 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs @@ -12,6 +12,7 @@ use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty}; use smallvec::smallvec; use crate::common::{AsCCharPtr, CodegenCx}; +use crate::debuginfo::dwarf_const::DW_TAG_const_type; use crate::debuginfo::metadata::enums::DiscrResult; use crate::debuginfo::metadata::type_map::{self, Stub, UniqueTypeId}; use crate::debuginfo::metadata::{ @@ -212,21 +213,17 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>( ), |cx, enum_type_di_node| { match enum_type_and_layout.variants { - Variants::Single { index: variant_index } => { - if enum_adt_def.variants().is_empty() { - // Uninhabited enums have Variants::Single. We don't generate - // any members for them. - return smallvec![]; - } - - build_single_variant_union_fields( - cx, - enum_adt_def, - enum_type_and_layout, - enum_type_di_node, - variant_index, - ) + Variants::Empty => { + // We don't generate any members for uninhabited types. + return smallvec![]; } + Variants::Single { index: variant_index } => build_single_variant_union_fields( + cx, + enum_adt_def, + enum_type_and_layout, + enum_type_di_node, + variant_index, + ), Variants::Multiple { tag_encoding: TagEncoding::Direct, ref variants, @@ -303,6 +300,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>( ) } Variants::Single { .. } + | Variants::Empty | Variants::Multiple { tag_encoding: TagEncoding::Niche { .. }, .. } => { bug!( "Encountered coroutine with non-direct-tag layout: {:?}", @@ -569,22 +567,39 @@ fn build_variant_struct_wrapper_type_di_node<'ll, 'tcx>( None, )); - let build_assoc_const = - |name: &str, type_di_node: &'ll DIType, value: u64, align: Align| unsafe { - llvm::LLVMRustDIBuilderCreateStaticMemberType( - DIB(cx), - wrapper_struct_type_di_node, - name.as_c_char_ptr(), - name.len(), - unknown_file_metadata(cx), - UNKNOWN_LINE_NUMBER, - type_di_node, - DIFlags::FlagZero, - Some(cx.const_u64(value)), - align.bits() as u32, - ) + let build_assoc_const = |name: &str, + type_di_node_: &'ll DIType, + value: u64, + align: Align| unsafe { + // FIXME: Currently we force all DISCR_* values to be u64's as LLDB seems to have + // problems inspecting other value types. Since DISCR_* is typically only going to be + // directly inspected via the debugger visualizer - which compares it to the `tag` value + // (whose type is not modified at all) it shouldn't cause any real problems. + let (t_di, align) = if name == ASSOC_CONST_DISCR_NAME { + (type_di_node_, align.bits() as u32) + } else { + let ty_u64 = Ty::new_uint(cx.tcx, ty::UintTy::U64); + (type_di_node(cx, ty_u64), Align::EIGHT.bits() as u32) }; + // must wrap type in a `const` modifier for LLDB to be able to inspect the value of the member + let field_type = + llvm::LLVMRustDIBuilderCreateQualifiedType(DIB(cx), DW_TAG_const_type, t_di); + + llvm::LLVMRustDIBuilderCreateStaticMemberType( + DIB(cx), + wrapper_struct_type_di_node, + name.as_c_char_ptr(), + name.len(), + unknown_file_metadata(cx), + UNKNOWN_LINE_NUMBER, + field_type, + DIFlags::FlagZero, + Some(cx.const_u64(value)), + align, + ) + }; + // We also always have an associated constant for the discriminant value // of the variant. fields.push(build_assoc_const( diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs index 65ab22ad89e..9f6a5cc89e0 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs @@ -392,7 +392,7 @@ fn compute_discriminant_value<'ll, 'tcx>( variant_index: VariantIdx, ) -> DiscrResult { match enum_type_and_layout.layout.variants() { - &Variants::Single { .. } => DiscrResult::NoDiscriminant, + &Variants::Single { .. } | &Variants::Empty => DiscrResult::NoDiscriminant, &Variants::Multiple { tag_encoding: TagEncoding::Direct, .. } => DiscrResult::Value( enum_type_and_layout.ty.discriminant_for_variant(cx.tcx, variant_index).unwrap().val, ), diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs index 241bf167a81..11824398f24 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs @@ -358,8 +358,8 @@ fn build_discr_member_di_node<'ll, 'tcx>( let containing_scope = enum_or_coroutine_type_di_node; match enum_or_coroutine_type_and_layout.layout.variants() { - // A single-variant enum has no discriminant. - &Variants::Single { .. } => None, + // A single-variant or no-variant enum has no discriminant. + &Variants::Single { .. } | &Variants::Empty => None, &Variants::Multiple { tag_field, .. } => { let tag_base_type = tag_base_type(cx.tcx, enum_or_coroutine_type_and_layout); diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs index a8fdfbed592..755f4816acf 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs @@ -19,9 +19,8 @@ use rustc_middle::ty::layout::{HasTypingEnv, LayoutOf}; use rustc_middle::ty::{self, GenericArgsRef, Instance, Ty, TypeVisitableExt}; use rustc_session::Session; use rustc_session::config::{self, DebugInfo}; -use rustc_span::symbol::Symbol; use rustc_span::{ - BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, + BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, Symbol, }; use smallvec::SmallVec; use tracing::debug; @@ -40,6 +39,7 @@ use crate::llvm::debuginfo::{ use crate::value::Value; mod create_scope_map; +mod dwarf_const; mod gdb; pub(crate) mod metadata; mod namespace; @@ -48,6 +48,10 @@ mod utils; use self::create_scope_map::compute_mir_scopes; pub(crate) use self::metadata::build_global_var_di_node; +// FIXME(Zalathar): These `DW_TAG_*` constants are fake values that were +// removed from LLVM in 2015, and are only used by our own `RustWrapper.cpp` +// to decide which C++ API to call. Instead, we should just have two separate +// FFI functions and choose the correct one on the Rust side. #[allow(non_upper_case_globals)] const DW_TAG_auto_variable: c_uint = 0x100; #[allow(non_upper_case_globals)] @@ -153,29 +157,26 @@ impl<'ll> DebugInfoBuilderMethods for Builder<'_, 'll, '_> { indirect_offsets: &[Size], fragment: Option<Range<Size>>, ) { + use dwarf_const::{DW_OP_LLVM_fragment, DW_OP_deref, DW_OP_plus_uconst}; + // Convert the direct and indirect offsets and fragment byte range to address ops. - // FIXME(eddyb) use `const`s instead of getting the values via FFI, - // the values should match the ones in the DWARF standard anyway. - let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() }; - let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() }; - let op_llvm_fragment = || unsafe { llvm::LLVMRustDIBuilderCreateOpLLVMFragment() }; let mut addr_ops = SmallVec::<[u64; 8]>::new(); if direct_offset.bytes() > 0 { - addr_ops.push(op_plus_uconst()); + addr_ops.push(DW_OP_plus_uconst); addr_ops.push(direct_offset.bytes() as u64); } for &offset in indirect_offsets { - addr_ops.push(op_deref()); + addr_ops.push(DW_OP_deref); if offset.bytes() > 0 { - addr_ops.push(op_plus_uconst()); + addr_ops.push(DW_OP_plus_uconst); addr_ops.push(offset.bytes() as u64); } } if let Some(fragment) = fragment { // `DW_OP_LLVM_fragment` takes as arguments the fragment's // offset and size, both of them in bits. - addr_ops.push(op_llvm_fragment()); + addr_ops.push(DW_OP_LLVM_fragment); addr_ops.push(fragment.start.bits() as u64); addr_ops.push((fragment.end - fragment.start).bits() as u64); } diff --git a/compiler/rustc_codegen_llvm/src/declare.rs b/compiler/rustc_codegen_llvm/src/declare.rs index d338c848754..3ec386f6b07 100644 --- a/compiler/rustc_codegen_llvm/src/declare.rs +++ b/compiler/rustc_codegen_llvm/src/declare.rs @@ -32,7 +32,7 @@ use crate::{attributes, llvm}; /// /// If there’s a value with the same name already declared, the function will /// update the declaration and return existing Value instead. -fn declare_raw_fn<'ll>( +pub(crate) fn declare_raw_fn<'ll>( cx: &CodegenCx<'ll, '_>, name: &str, callconv: llvm::CallConv, diff --git a/compiler/rustc_codegen_llvm/src/errors.rs b/compiler/rustc_codegen_llvm/src/errors.rs index 3cdb5b971d9..f4c9491f758 100644 --- a/compiler/rustc_codegen_llvm/src/errors.rs +++ b/compiler/rustc_codegen_llvm/src/errors.rs @@ -37,6 +37,7 @@ pub(crate) struct UnstableCTargetFeature<'a> { #[note(codegen_llvm_forbidden_ctarget_feature_issue)] pub(crate) struct ForbiddenCTargetFeature<'a> { pub feature: &'a str, + pub enabled: &'a str, pub reason: &'a str, } @@ -90,6 +91,11 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for ParseTargetMachineConfig<'_> { } #[derive(Diagnostic)] +#[diag(codegen_llvm_autodiff_without_lto)] +#[note] +pub(crate) struct AutoDiffWithoutLTO; + +#[derive(Diagnostic)] #[diag(codegen_llvm_lto_disallowed)] pub(crate) struct LtoDisallowed; @@ -131,6 +137,8 @@ pub enum LlvmError<'a> { PrepareThinLtoModule, #[diag(codegen_llvm_parse_bitcode)] ParseBitcode, + #[diag(codegen_llvm_prepare_autodiff)] + PrepareAutoDiff { src: String, target: String, error: String }, } pub(crate) struct WithLlvmError<'a>(pub LlvmError<'a>, pub String); @@ -152,6 +160,7 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for WithLlvmError<'_> { } PrepareThinLtoModule => fluent::codegen_llvm_prepare_thin_lto_module_with_llvm_err, ParseBitcode => fluent::codegen_llvm_parse_bitcode_with_llvm_err, + PrepareAutoDiff { .. } => fluent::codegen_llvm_prepare_autodiff_with_llvm_err, }; self.0 .into_diag(dcx, level) @@ -206,12 +215,6 @@ pub(crate) struct MismatchedDataLayout<'a> { } #[derive(Diagnostic)] -#[diag(codegen_llvm_invalid_target_feature_prefix)] -pub(crate) struct InvalidTargetFeaturePrefix<'a> { - pub feature: &'a str, -} - -#[derive(Diagnostic)] #[diag(codegen_llvm_fixed_x18_invalid_arch)] pub(crate) struct FixedX18InvalidArch<'a> { pub arch: &'a str, diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs index c38c5d4c644..cabcfc9b42b 100644 --- a/compiler/rustc_codegen_llvm/src/intrinsic.rs +++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs @@ -340,6 +340,37 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { self.const_i32(cache_type), ]) } + sym::carrying_mul_add => { + let (size, signed) = fn_args.type_at(0).int_size_and_signed(self.tcx); + + let wide_llty = self.type_ix(size.bits() * 2); + let args = args.as_array().unwrap(); + let [a, b, c, d] = args.map(|a| self.intcast(a.immediate(), wide_llty, signed)); + + let wide = if signed { + let prod = self.unchecked_smul(a, b); + let acc = self.unchecked_sadd(prod, c); + self.unchecked_sadd(acc, d) + } else { + let prod = self.unchecked_umul(a, b); + let acc = self.unchecked_uadd(prod, c); + self.unchecked_uadd(acc, d) + }; + + let narrow_llty = self.type_ix(size.bits()); + let low = self.trunc(wide, narrow_llty); + let bits_const = self.const_uint(wide_llty, size.bits()); + // No need for ashr when signed; LLVM changes it to lshr anyway. + let high = self.lshr(wide, bits_const); + // FIXME: could be `trunc nuw`, even for signed. + let high = self.trunc(high, narrow_llty); + + let pair_llty = self.type_struct(&[narrow_llty, narrow_llty], false); + let pair = self.const_poison(pair_llty); + let pair = self.insert_value(pair, low, 0); + let pair = self.insert_value(pair, high, 1); + pair + } sym::ctlz | sym::ctlz_nonzero | sym::cttz diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs index af8562db054..06afe8bb3ad 100644 --- a/compiler/rustc_codegen_llvm/src/lib.rs +++ b/compiler/rustc_codegen_llvm/src/lib.rs @@ -17,6 +17,8 @@ #![feature(iter_intersperse)] #![feature(let_chains)] #![feature(rustdoc_internals)] +#![feature(slice_as_array)] +#![feature(try_blocks)] #![warn(unreachable_pub)] // tidy-alphabetical-end @@ -26,9 +28,10 @@ use std::mem::ManuallyDrop; use back::owned_target_machine::OwnedTargetMachine; use back::write::{create_informational_target_machine, create_target_machine}; -use errors::ParseTargetMachineConfig; +use errors::{AutoDiffWithoutLTO, ParseTargetMachineConfig}; pub use llvm_util::target_features_cfg; use rustc_ast::expand::allocator::AllocatorKind; +use rustc_ast::expand::autodiff_attrs::AutoDiffItem; use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule}; use rustc_codegen_ssa::back::write::{ CodegenContext, FatLtoInput, ModuleConfig, TargetMachineFactoryConfig, TargetMachineFactoryFn, @@ -42,8 +45,8 @@ use rustc_middle::dep_graph::{WorkProduct, WorkProductId}; use rustc_middle::ty::TyCtxt; use rustc_middle::util::Providers; use rustc_session::Session; -use rustc_session::config::{OptLevel, OutputFilenames, PrintKind, PrintRequest}; -use rustc_span::symbol::Symbol; +use rustc_session::config::{Lto, OptLevel, OutputFilenames, PrintKind, PrintRequest}; +use rustc_span::Symbol; mod back { pub(crate) mod archive; @@ -231,6 +234,20 @@ impl WriteBackendMethods for LlvmCodegenBackend { fn serialize_module(module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer) { (module.name, back::lto::ModuleBuffer::new(module.module_llvm.llmod())) } + /// Generate autodiff rules + fn autodiff( + cgcx: &CodegenContext<Self>, + tcx: TyCtxt<'_>, + module: &ModuleCodegen<Self::Module>, + diff_fncs: Vec<AutoDiffItem>, + config: &ModuleConfig, + ) -> Result<(), FatalError> { + if cgcx.lto != Lto::Fat { + let dcx = cgcx.create_dcx(); + return Err(dcx.handle().emit_almost_fatal(AutoDiffWithoutLTO)); + } + builder::autodiff::differentiate(module, cgcx, tcx, diff_fncs, config) + } } unsafe impl Send for LlvmCodegenBackend {} // Llvm is on a per-thread basis diff --git a/compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs new file mode 100644 index 00000000000..729d6f62e24 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs @@ -0,0 +1,29 @@ +#![allow(non_camel_case_types)] + +use libc::{c_char, c_uint}; + +use super::ffi::{BasicBlock, Metadata, Module, Type, Value}; +use crate::llvm::Bool; +extern "C" { + // Enzyme + pub fn LLVMRustHasMetadata(I: &Value, KindID: c_uint) -> bool; + pub fn LLVMRustEraseInstBefore(BB: &BasicBlock, I: &Value); + pub fn LLVMRustGetLastInstruction<'a>(BB: &BasicBlock) -> Option<&'a Value>; + pub fn LLVMRustDIGetInstMetadata(I: &Value) -> Option<&Metadata>; + pub fn LLVMRustEraseInstFromParent(V: &Value); + pub fn LLVMRustGetTerminator<'a>(B: &BasicBlock) -> &'a Value; + pub fn LLVMRustVerifyFunction(V: &Value, action: LLVMRustVerifierFailureAction) -> Bool; + + pub fn LLVMGetFunctionCallConv(F: &Value) -> c_uint; + pub fn LLVMGetReturnType(T: &Type) -> &Type; + pub fn LLVMGetParams(Fnc: &Value, parms: *mut &Value); + pub fn LLVMGetNamedFunction(M: &Module, Name: *const c_char) -> Option<&Value>; +} + +#[repr(C)] +#[derive(Copy, Clone, PartialEq)] +pub enum LLVMRustVerifierFailureAction { + LLVMAbortProcessAction = 0, + LLVMPrintMessageAction = 1, + LLVMReturnStatusAction = 2, +} diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index d62632d1431..cb4a8c9a5f2 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -56,25 +56,6 @@ pub enum LLVMRustResult { Failure, } -// Rust version of the C struct with the same name in rustc_llvm/llvm-wrapper/RustWrapper.cpp. -#[repr(C)] -pub struct LLVMRustCOFFShortExport { - pub name: *const c_char, - pub ordinal_present: bool, - /// value of `ordinal` only important when `ordinal_present` is true - pub ordinal: u16, -} - -impl LLVMRustCOFFShortExport { - pub fn new(name: *const c_char, ordinal: Option<u16>) -> LLVMRustCOFFShortExport { - LLVMRustCOFFShortExport { - name, - ordinal_present: ordinal.is_some(), - ordinal: ordinal.unwrap_or(0), - } - } -} - /// Translation of LLVM's MachineTypes enum, defined in llvm\include\llvm\BinaryFormat\COFF.h. /// /// We include only architectures supported on Windows. @@ -118,7 +99,7 @@ pub enum ModuleFlagMergeBehavior { /// LLVM CallingConv::ID. Should we wrap this? /// /// See <https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/IR/CallingConv.h> -#[derive(Copy, Clone, PartialEq, Debug)] +#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)] #[repr(C)] pub enum CallConv { CCallConv = 0, @@ -545,7 +526,7 @@ pub struct SanitizerOptions { pub sanitize_kernel_address_recover: bool, } -/// LLVMRelocMode +/// LLVMRustRelocModel #[derive(Copy, Clone, PartialEq)] #[repr(C)] pub enum RelocModel { @@ -557,6 +538,15 @@ pub enum RelocModel { ROPI_RWPI, } +/// LLVMRustFloatABI +#[derive(Copy, Clone, PartialEq)] +#[repr(C)] +pub enum FloatAbi { + Default, + Soft, + Hard, +} + /// LLVMRustCodeModel #[derive(Copy, Clone)] #[repr(C)] @@ -2018,6 +2008,12 @@ unsafe extern "C" { AlignInBits: u32, ) -> &'a DIDerivedType; + pub fn LLVMRustDIBuilderCreateQualifiedType<'a>( + Builder: &DIBuilder<'a>, + Tag: c_uint, + Type: &'a DIType, + ) -> &'a DIDerivedType; + pub fn LLVMRustDIBuilderCreateLexicalBlock<'a>( Builder: &DIBuilder<'a>, Scope: &'a DIScope, @@ -2181,9 +2177,6 @@ unsafe extern "C" { Location: &'a DILocation, BD: c_uint, ) -> Option<&'a DILocation>; - pub fn LLVMRustDIBuilderCreateOpDeref() -> u64; - pub fn LLVMRustDIBuilderCreateOpPlusUconst() -> u64; - pub fn LLVMRustDIBuilderCreateOpLLVMFragment() -> u64; pub fn LLVMRustWriteTypeToString(Type: &Type, s: &RustString); pub fn LLVMRustWriteValueToString(value_ref: &Value, s: &RustString); @@ -2211,7 +2204,7 @@ unsafe extern "C" { Model: CodeModel, Reloc: RelocModel, Level: CodeGenOptLevel, - UseSoftFP: bool, + FloatABIType: FloatAbi, FunctionSections: bool, DataSections: bool, UniqueSectionNames: bool, @@ -2347,15 +2340,6 @@ unsafe extern "C" { ) -> &'a mut RustArchiveMember<'a>; pub fn LLVMRustArchiveMemberFree<'a>(Member: &'a mut RustArchiveMember<'a>); - pub fn LLVMRustWriteImportLibrary( - ImportName: *const c_char, - Path: *const c_char, - Exports: *const LLVMRustCOFFShortExport, - NumExports: usize, - Machine: u16, - MinGW: bool, - ) -> LLVMRustResult; - pub fn LLVMRustSetDataLayoutFromTargetMachine<'a>(M: &'a Module, TM: &'a TargetMachine); pub fn LLVMRustPositionBuilderAtStart<'a>(B: &Builder<'a>, BB: &'a BasicBlock); @@ -2390,7 +2374,7 @@ unsafe extern "C" { Data: &ThinLTOData, Module: &Module, Target: &TargetMachine, - ) -> bool; + ); pub fn LLVMRustPrepareThinLTOResolveWeak(Data: &ThinLTOData, Module: &Module) -> bool; pub fn LLVMRustPrepareThinLTOInternalize(Data: &ThinLTOData, Module: &Module) -> bool; pub fn LLVMRustPrepareThinLTOImport( diff --git a/compiler/rustc_codegen_llvm/src/llvm/mod.rs b/compiler/rustc_codegen_llvm/src/llvm/mod.rs index 909afe35a17..2592a7df95c 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/mod.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/mod.rs @@ -22,8 +22,11 @@ use crate::common::AsCCharPtr; pub mod archive_ro; pub mod diagnostic; +pub mod enzyme_ffi; mod ffi; +pub use self::enzyme_ffi::*; + impl LLVMRustResult { pub fn into_result(self) -> Result<(), ()> { match self { diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 194438af88c..c3d7c217861 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -15,14 +15,14 @@ use rustc_fs_util::path_to_c_string; use rustc_middle::bug; use rustc_session::Session; use rustc_session::config::{PrintKind, PrintRequest}; -use rustc_span::symbol::Symbol; +use rustc_span::Symbol; use rustc_target::spec::{MergeFunctions, PanicStrategy, SmallDataThresholdSupport}; use rustc_target::target_features::{RUSTC_SPECIAL_FEATURES, RUSTC_SPECIFIC_FEATURES}; use crate::back::write::create_informational_target_machine; use crate::errors::{ - FixedX18InvalidArch, ForbiddenCTargetFeature, InvalidTargetFeaturePrefix, PossibleFeature, - UnknownCTargetFeature, UnknownCTargetFeaturePrefix, UnstableCTargetFeature, + FixedX18InvalidArch, ForbiddenCTargetFeature, PossibleFeature, UnknownCTargetFeature, + UnknownCTargetFeaturePrefix, UnstableCTargetFeature, }; use crate::llvm; @@ -109,7 +109,10 @@ unsafe fn configure_llvm(sess: &Session) { add("-wasm-enable-eh", false); } - if sess.target.os == "emscripten" && sess.panic_strategy() == PanicStrategy::Unwind { + if sess.target.os == "emscripten" + && !sess.opts.unstable_opts.emscripten_wasm_eh + && sess.panic_strategy() == PanicStrategy::Unwind + { add("-enable-emscripten-cxx-exceptions", false); } @@ -348,7 +351,16 @@ pub fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<Symbol> { if enabled { // Also add all transitively implied features. - features.extend(sess.target.implied_target_features(std::iter::once(feature))); + + // We don't care about the order in `features` since the only thing we use it for is the + // `features.contains` below. + #[allow(rustc::potential_query_instability)] + features.extend( + sess.target + .implied_target_features(std::iter::once(feature.as_str())) + .iter() + .map(|s| Symbol::intern(s)), + ); } else { // Remove transitively reverse-implied features. @@ -356,7 +368,11 @@ pub fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<Symbol> // `features.contains` below. #[allow(rustc::potential_query_instability)] features.retain(|f| { - if sess.target.implied_target_features(std::iter::once(*f)).contains(&feature) { + if sess + .target + .implied_target_features(std::iter::once(f.as_str())) + .contains(&feature.as_str()) + { // If `f` if implies `feature`, then `!feature` implies `!f`, so we have to // remove `f`. (This is the standard logical contraposition principle.) false @@ -638,7 +654,7 @@ pub(crate) fn global_llvm_features( sess.target .features .split(',') - .filter(|v| !v.is_empty() && backend_feature_name(sess, v).is_some()) + .filter(|v| !v.is_empty()) // Drop +v8plus feature introduced in LLVM 20. .filter(|v| *v != "+v8plus" || get_version() >= (20, 0, 0)) .map(String::from), @@ -651,89 +667,136 @@ pub(crate) fn global_llvm_features( // -Ctarget-features if !only_base_features { let known_features = sess.target.rust_target_features(); + // Will only be filled when `diagnostics` is set! let mut featsmap = FxHashMap::default(); - // insert implied features + // Ensure that all ABI-required features are enabled, and the ABI-forbidden ones + // are disabled. + let abi_feature_constraints = sess.target.abi_required_features(); + let abi_incompatible_set = + FxHashSet::from_iter(abi_feature_constraints.incompatible.iter().copied()); + + // Compute implied features let mut all_rust_features = vec![]; for feature in sess.opts.cg.target_feature.split(',') { - match feature.strip_prefix('+') { - Some(feature) => all_rust_features.extend( - UnordSet::from( - sess.target - .implied_target_features(std::iter::once(Symbol::intern(feature))), - ) - .to_sorted_stable_ord() - .iter() - .map(|s| format!("+{}", s.as_str())), - ), - _ => all_rust_features.push(feature.to_string()), + if let Some(feature) = feature.strip_prefix('+') { + all_rust_features.extend( + UnordSet::from(sess.target.implied_target_features(std::iter::once(feature))) + .to_sorted_stable_ord() + .iter() + .map(|&&s| (true, s)), + ) + } else if let Some(feature) = feature.strip_prefix('-') { + // FIXME: Why do we not remove implied features on "-" here? + // We do the equivalent above in `target_features_cfg`. + // See <https://github.com/rust-lang/rust/issues/134792>. + all_rust_features.push((false, feature)); + } else if !feature.is_empty() { + if diagnostics { + sess.dcx().emit_warn(UnknownCTargetFeaturePrefix { feature }); + } } } + // Remove features that are meant for rustc, not LLVM. + all_rust_features.retain(|(_, feature)| { + // Retain if it is not a rustc feature + !RUSTC_SPECIFIC_FEATURES.contains(feature) + }); - let feats = all_rust_features - .iter() - .filter_map(|s| { - let enable_disable = match s.chars().next() { - None => return None, - Some(c @ ('+' | '-')) => c, - Some(_) => { - if diagnostics { - sess.dcx().emit_warn(UnknownCTargetFeaturePrefix { feature: s }); - } - return None; - } - }; - - // Get the backend feature name, if any. - // This excludes rustc-specific features, which do not get passed to LLVM. - let feature = backend_feature_name(sess, s)?; - // Warn against use of LLVM specific feature names and unstable features on the CLI. - if diagnostics { - let feature_state = known_features.iter().find(|&&(v, _, _)| v == feature); - match feature_state { - None => { - let rust_feature = - known_features.iter().find_map(|&(rust_feature, _, _)| { - let llvm_features = to_llvm_features(sess, rust_feature)?; - if llvm_features.contains(feature) - && !llvm_features.contains(rust_feature) - { - Some(rust_feature) - } else { - None - } - }); - let unknown_feature = if let Some(rust_feature) = rust_feature { - UnknownCTargetFeature { - feature, - rust_feature: PossibleFeature::Some { rust_feature }, - } - } else { - UnknownCTargetFeature { - feature, - rust_feature: PossibleFeature::None, + // Check feature validity. + if diagnostics { + for &(enable, feature) in &all_rust_features { + let feature_state = known_features.iter().find(|&&(v, _, _)| v == feature); + match feature_state { + None => { + let rust_feature = + known_features.iter().find_map(|&(rust_feature, _, _)| { + let llvm_features = to_llvm_features(sess, rust_feature)?; + if llvm_features.contains(feature) + && !llvm_features.contains(rust_feature) + { + Some(rust_feature) + } else { + None } - }; - sess.dcx().emit_warn(unknown_feature); - } - Some((_, stability, _)) => { - if let Err(reason) = - stability.toggle_allowed(&sess.target, enable_disable == '+') - { - sess.dcx().emit_warn(ForbiddenCTargetFeature { feature, reason }); - } else if stability.requires_nightly().is_some() { - // An unstable feature. Warn about using it. It makes little sense - // to hard-error here since we just warn about fully unknown - // features above. - sess.dcx().emit_warn(UnstableCTargetFeature { feature }); + }); + let unknown_feature = if let Some(rust_feature) = rust_feature { + UnknownCTargetFeature { + feature, + rust_feature: PossibleFeature::Some { rust_feature }, } + } else { + UnknownCTargetFeature { feature, rust_feature: PossibleFeature::None } + }; + sess.dcx().emit_warn(unknown_feature); + } + Some((_, stability, _)) => { + if let Err(reason) = stability.toggle_allowed() { + sess.dcx().emit_warn(ForbiddenCTargetFeature { + feature, + enabled: if enable { "enabled" } else { "disabled" }, + reason, + }); + } else if stability.requires_nightly().is_some() { + // An unstable feature. Warn about using it. It makes little sense + // to hard-error here since we just warn about fully unknown + // features above. + sess.dcx().emit_warn(UnstableCTargetFeature { feature }); } } + } - // FIXME(nagisa): figure out how to not allocate a full hashset here. - featsmap.insert(feature, enable_disable == '+'); + // Ensure that the features we enable/disable are compatible with the ABI. + if enable { + if abi_incompatible_set.contains(feature) { + sess.dcx().emit_warn(ForbiddenCTargetFeature { + feature, + enabled: "enabled", + reason: "this feature is incompatible with the target ABI", + }); + } + } else { + // FIXME: we have to request implied features here since + // negative features do not handle implied features above. + for &required in abi_feature_constraints.required.iter() { + let implied = + sess.target.implied_target_features(std::iter::once(required)); + if implied.contains(feature) { + sess.dcx().emit_warn(ForbiddenCTargetFeature { + feature, + enabled: "disabled", + reason: "this feature is required by the target ABI", + }); + } + } } + // FIXME(nagisa): figure out how to not allocate a full hashset here. + featsmap.insert(feature, enable); + } + } + + // To be sure the ABI-relevant features are all in the right state, we explicitly + // (un)set them here. This means if the target spec sets those features wrong, + // we will silently correct them rather than silently producing wrong code. + // (The target sanity check tries to catch this, but we can't know which features are + // enabled in LLVM by default so we can't be fully sure about that check.) + // We add these at the beginning of the list so that `-Ctarget-features` can + // still override it... that's unsound, but more compatible with past behavior. + all_rust_features.splice( + 0..0, + abi_feature_constraints + .required + .iter() + .map(|&f| (true, f)) + .chain(abi_feature_constraints.incompatible.iter().map(|&f| (false, f))), + ); + + // Translate this into LLVM features. + let feats = all_rust_features + .iter() + .filter_map(|&(enable, feature)| { + let enable_disable = if enable { '+' } else { '-' }; // We run through `to_llvm_features` when // passing requests down to LLVM. This means that all in-language // features also work on the command line instead of having two @@ -746,9 +809,9 @@ pub(crate) fn global_llvm_features( enable_disable, llvm_feature.llvm_feature_name )) .chain(llvm_feature.dependency.into_iter().filter_map( - move |feat| match (enable_disable, feat) { - ('-' | '+', TargetFeatureFoldStrength::Both(f)) - | ('+', TargetFeatureFoldStrength::EnableOnly(f)) => { + move |feat| match (enable, feat) { + (_, TargetFeatureFoldStrength::Both(f)) + | (true, TargetFeatureFoldStrength::EnableOnly(f)) => { Some(format!("{enable_disable}{f}")) } _ => None, @@ -780,22 +843,6 @@ pub(crate) fn global_llvm_features( features } -/// Returns a feature name for the given `+feature` or `-feature` string. -/// -/// Only allows features that are backend specific (i.e. not [`RUSTC_SPECIFIC_FEATURES`].) -fn backend_feature_name<'a>(sess: &Session, s: &'a str) -> Option<&'a str> { - // features must start with a `+` or `-`. - let feature = s - .strip_prefix(&['+', '-'][..]) - .unwrap_or_else(|| sess.dcx().emit_fatal(InvalidTargetFeaturePrefix { feature: s })); - // Rustc-specific feature requests like `+crt-static` or `-crt-static` - // are not passed down to LLVM. - if s.is_empty() || RUSTC_SPECIFIC_FEATURES.contains(&feature) { - return None; - } - Some(feature) -} - pub(crate) fn tune_cpu(sess: &Session) -> Option<&str> { let name = sess.opts.unstable_opts.tune_cpu.as_ref()?; Some(handle_native(name)) diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs index 2b05e24a7ba..b0b6da869da 100644 --- a/compiler/rustc_codegen_llvm/src/type_of.rs +++ b/compiler/rustc_codegen_llvm/src/type_of.rs @@ -38,7 +38,7 @@ fn uncached_llvm_type<'a, 'tcx>( if let (&ty::Adt(def, _), &Variants::Single { index }) = (layout.ty.kind(), &layout.variants) { - if def.is_enum() && !def.variants().is_empty() { + if def.is_enum() { write!(&mut name, "::{}", def.variant(index).name).unwrap(); } } |