| use std::borrow::{Borrow, Cow}; |
| use std::cell::{Cell, RefCell}; |
| use std::ffi::{CStr, c_char, c_uint}; |
| use std::marker::PhantomData; |
| use std::ops::{Deref, DerefMut}; |
| use std::str; |
| |
| use rustc_abi::{HasDataLayout, Size, TargetDataLayout, VariantIdx}; |
| use rustc_codegen_ssa::back::versioned_llvm_target; |
| use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh}; |
| use rustc_codegen_ssa::common::TypeKind; |
| use rustc_codegen_ssa::errors as ssa_errors; |
| use rustc_codegen_ssa::traits::*; |
| use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN}; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::small_c_str::SmallCStr; |
| use rustc_hir::def_id::DefId; |
| use rustc_middle::middle::codegen_fn_attrs::PatchableFunctionEntry; |
| use rustc_middle::mir::mono::CodegenUnit; |
| use rustc_middle::ty::layout::{ |
| FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasTypingEnv, LayoutError, LayoutOfHelpers, |
| }; |
| use rustc_middle::ty::{self, Instance, Ty, TyCtxt}; |
| use rustc_middle::{bug, span_bug}; |
| use rustc_session::Session; |
| use rustc_session::config::{ |
| BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, FunctionReturn, PAuthKey, PacRet, |
| }; |
| use rustc_span::source_map::Spanned; |
| use rustc_span::{DUMMY_SP, Span}; |
| use rustc_symbol_mangling::mangle_internal_symbol; |
| use rustc_target::spec::{HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel}; |
| use smallvec::SmallVec; |
| |
| use crate::back::write::to_llvm_code_model; |
| use crate::callee::get_fn; |
| use crate::debuginfo::metadata::apply_vcall_visibility_metadata; |
| use crate::llvm::Metadata; |
| use crate::type_::Type; |
| use crate::value::Value; |
| use crate::{attributes, common, coverageinfo, debuginfo, llvm, llvm_util}; |
| |
| /// `TyCtxt` (and related cache datastructures) can't be move between threads. |
| /// However, there are various cx related functions which we want to be available to the builder and |
| /// other compiler pieces. Here we define a small subset which has enough information and can be |
| /// moved around more freely. |
| pub(crate) struct SCx<'ll> { |
| pub llmod: &'ll llvm::Module, |
| pub llcx: &'ll llvm::Context, |
| pub isize_ty: &'ll Type, |
| } |
| |
| impl<'ll> Borrow<SCx<'ll>> for FullCx<'ll, '_> { |
| fn borrow(&self) -> &SCx<'ll> { |
| &self.scx |
| } |
| } |
| |
| impl<'ll, 'tcx> Deref for FullCx<'ll, 'tcx> { |
| type Target = SimpleCx<'ll>; |
| |
| #[inline] |
| fn deref(&self) -> &Self::Target { |
| &self.scx |
| } |
| } |
| |
| pub(crate) struct GenericCx<'ll, T: Borrow<SCx<'ll>>>(T, PhantomData<SCx<'ll>>); |
| |
| impl<'ll, T: Borrow<SCx<'ll>>> Deref for GenericCx<'ll, T> { |
| type Target = T; |
| |
| #[inline] |
| fn deref(&self) -> &Self::Target { |
| &self.0 |
| } |
| } |
| |
| impl<'ll, T: Borrow<SCx<'ll>>> DerefMut for GenericCx<'ll, T> { |
| #[inline] |
| fn deref_mut(&mut self) -> &mut Self::Target { |
| &mut self.0 |
| } |
| } |
| |
| pub(crate) type SimpleCx<'ll> = GenericCx<'ll, SCx<'ll>>; |
| |
| /// There is one `CodegenCx` per codegen unit. Each one has its own LLVM |
| /// `llvm::Context` so that several codegen units may be processed in parallel. |
| /// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`. |
| pub(crate) type CodegenCx<'ll, 'tcx> = GenericCx<'ll, FullCx<'ll, 'tcx>>; |
| |
| pub(crate) struct FullCx<'ll, 'tcx> { |
| pub tcx: TyCtxt<'tcx>, |
| pub scx: SimpleCx<'ll>, |
| pub use_dll_storage_attrs: bool, |
| pub tls_model: llvm::ThreadLocalMode, |
| |
| pub codegen_unit: &'tcx CodegenUnit<'tcx>, |
| |
| /// Cache instances of monomorphic and polymorphic items |
| pub instances: RefCell<FxHashMap<Instance<'tcx>, &'ll Value>>, |
| /// Cache generated vtables |
| pub vtables: RefCell<FxHashMap<(Ty<'tcx>, Option<ty::ExistentialTraitRef<'tcx>>), &'ll Value>>, |
| /// Cache of constant strings, |
| pub const_str_cache: RefCell<FxHashMap<String, &'ll Value>>, |
| |
| /// Cache of emitted const globals (value -> global) |
| pub const_globals: RefCell<FxHashMap<&'ll Value, &'ll Value>>, |
| |
| /// List of globals for static variables which need to be passed to the |
| /// LLVM function ReplaceAllUsesWith (RAUW) when codegen is complete. |
| /// (We have to make sure we don't invalidate any Values referring |
| /// to constants.) |
| pub statics_to_rauw: RefCell<Vec<(&'ll Value, &'ll Value)>>, |
| |
| /// Statics that will be placed in the llvm.used variable |
| /// See <https://llvm.org/docs/LangRef.html#the-llvm-used-global-variable> for details |
| pub used_statics: Vec<&'ll Value>, |
| |
| /// Statics that will be placed in the llvm.compiler.used variable |
| /// See <https://llvm.org/docs/LangRef.html#the-llvm-compiler-used-global-variable> for details |
| pub compiler_used_statics: Vec<&'ll Value>, |
| |
| /// Mapping of non-scalar types to llvm types. |
| pub type_lowering: RefCell<FxHashMap<(Ty<'tcx>, Option<VariantIdx>), &'ll Type>>, |
| |
| /// Mapping of scalar types to llvm types. |
| pub scalar_lltypes: RefCell<FxHashMap<Ty<'tcx>, &'ll Type>>, |
| |
| /// Extra per-CGU codegen state needed when coverage instrumentation is enabled. |
| pub coverage_cx: Option<coverageinfo::CguCoverageContext<'ll, 'tcx>>, |
| pub dbg_cx: Option<debuginfo::CodegenUnitDebugContext<'ll, 'tcx>>, |
| |
| eh_personality: Cell<Option<&'ll Value>>, |
| eh_catch_typeinfo: Cell<Option<&'ll Value>>, |
| pub rust_try_fn: Cell<Option<(&'ll Type, &'ll Value)>>, |
| |
| intrinsics: |
| RefCell<FxHashMap<(Cow<'static, str>, SmallVec<[&'ll Type; 2]>), (&'ll Type, &'ll Value)>>, |
| |
| /// A counter that is used for generating local symbol names |
| local_gen_sym_counter: Cell<usize>, |
| |
| /// `codegen_static` will sometimes create a second global variable with a |
| /// different type and clear the symbol name of the original global. |
| /// `global_asm!` needs to be able to find this new global so that it can |
| /// compute the correct mangled symbol name to insert into the asm. |
| pub renamed_statics: RefCell<FxHashMap<DefId, &'ll Value>>, |
| } |
| |
| fn to_llvm_tls_model(tls_model: TlsModel) -> llvm::ThreadLocalMode { |
| match tls_model { |
| TlsModel::GeneralDynamic => llvm::ThreadLocalMode::GeneralDynamic, |
| TlsModel::LocalDynamic => llvm::ThreadLocalMode::LocalDynamic, |
| TlsModel::InitialExec => llvm::ThreadLocalMode::InitialExec, |
| TlsModel::LocalExec => llvm::ThreadLocalMode::LocalExec, |
| TlsModel::Emulated => llvm::ThreadLocalMode::GeneralDynamic, |
| } |
| } |
| |
| pub(crate) unsafe fn create_module<'ll>( |
| tcx: TyCtxt<'_>, |
| llcx: &'ll llvm::Context, |
| mod_name: &str, |
| ) -> &'ll llvm::Module { |
| let sess = tcx.sess; |
| let mod_name = SmallCStr::new(mod_name); |
| let llmod = unsafe { llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx) }; |
| |
| let cx = SimpleCx::new(llmod, llcx, tcx.data_layout.pointer_size()); |
| |
| let mut target_data_layout = sess.target.data_layout.to_string(); |
| let llvm_version = llvm_util::get_version(); |
| |
| if llvm_version < (20, 0, 0) { |
| if sess.target.arch == "aarch64" || sess.target.arch.starts_with("arm64") { |
| // LLVM 20 defines three additional address spaces for alternate |
| // pointer kinds used in Windows. |
| // See https://github.com/llvm/llvm-project/pull/111879 |
| target_data_layout = |
| target_data_layout.replace("-p270:32:32-p271:32:32-p272:64:64", ""); |
| } |
| if sess.target.arch.starts_with("sparc") { |
| // LLVM 20 updates the sparc layout to correctly align 128 bit integers to 128 bit. |
| // See https://github.com/llvm/llvm-project/pull/106951 |
| target_data_layout = target_data_layout.replace("-i128:128", ""); |
| } |
| if sess.target.arch.starts_with("mips64") { |
| // LLVM 20 updates the mips64 layout to correctly align 128 bit integers to 128 bit. |
| // See https://github.com/llvm/llvm-project/pull/112084 |
| target_data_layout = target_data_layout.replace("-i128:128", ""); |
| } |
| if sess.target.arch.starts_with("powerpc64") { |
| // LLVM 20 updates the powerpc64 layout to correctly align 128 bit integers to 128 bit. |
| // See https://github.com/llvm/llvm-project/pull/118004 |
| target_data_layout = target_data_layout.replace("-i128:128", ""); |
| } |
| if sess.target.arch.starts_with("wasm32") || sess.target.arch.starts_with("wasm64") { |
| // LLVM 20 updates the wasm(32|64) layout to correctly align 128 bit integers to 128 bit. |
| // See https://github.com/llvm/llvm-project/pull/119204 |
| target_data_layout = target_data_layout.replace("-i128:128", ""); |
| } |
| } |
| if llvm_version < (21, 0, 0) { |
| if sess.target.arch == "nvptx64" { |
| // LLVM 21 updated the default layout on nvptx: https://github.com/llvm/llvm-project/pull/124961 |
| target_data_layout = target_data_layout.replace("e-p6:32:32-i64", "e-i64"); |
| } |
| if sess.target.arch == "amdgpu" { |
| // LLVM 21 adds the address width for address space 8. |
| // See https://github.com/llvm/llvm-project/pull/139419 |
| target_data_layout = target_data_layout.replace("p8:128:128:128:48", "p8:128:128") |
| } |
| } |
| |
| // Ensure the data-layout values hardcoded remain the defaults. |
| { |
| let tm = crate::back::write::create_informational_target_machine(sess, false); |
| unsafe { |
| llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, tm.raw()); |
| } |
| |
| let llvm_data_layout = unsafe { llvm::LLVMGetDataLayoutStr(llmod) }; |
| let llvm_data_layout = |
| str::from_utf8(unsafe { CStr::from_ptr(llvm_data_layout) }.to_bytes()) |
| .expect("got a non-UTF8 data-layout from LLVM"); |
| |
| if target_data_layout != llvm_data_layout { |
| tcx.dcx().emit_err(crate::errors::MismatchedDataLayout { |
| rustc_target: sess.opts.target_triple.to_string().as_str(), |
| rustc_layout: target_data_layout.as_str(), |
| llvm_target: sess.target.llvm_target.borrow(), |
| llvm_layout: llvm_data_layout, |
| }); |
| } |
| } |
| |
| let data_layout = SmallCStr::new(&target_data_layout); |
| unsafe { |
| llvm::LLVMSetDataLayout(llmod, data_layout.as_ptr()); |
| } |
| |
| let llvm_target = SmallCStr::new(&versioned_llvm_target(sess)); |
| unsafe { |
| llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr()); |
| } |
| |
| let reloc_model = sess.relocation_model(); |
| if matches!(reloc_model, RelocModel::Pic | RelocModel::Pie) { |
| unsafe { |
| llvm::LLVMRustSetModulePICLevel(llmod); |
| } |
| // PIE is potentially more effective than PIC, but can only be used in executables. |
| // If all our outputs are executables, then we can relax PIC to PIE. |
| if reloc_model == RelocModel::Pie |
| || tcx.crate_types().iter().all(|ty| *ty == CrateType::Executable) |
| { |
| unsafe { |
| llvm::LLVMRustSetModulePIELevel(llmod); |
| } |
| } |
| } |
| |
| // Linking object files with different code models is undefined behavior |
| // because the compiler would have to generate additional code (to span |
| // longer jumps) if a larger code model is used with a smaller one. |
| // |
| // See https://reviews.llvm.org/D52322 and https://reviews.llvm.org/D52323. |
| unsafe { |
| llvm::LLVMRustSetModuleCodeModel(llmod, to_llvm_code_model(sess.code_model())); |
| } |
| |
| // If skipping the PLT is enabled, we need to add some module metadata |
| // to ensure intrinsic calls don't use it. |
| if !sess.needs_plt() { |
| llvm::add_module_flag_u32(llmod, llvm::ModuleFlagMergeBehavior::Warning, "RtLibUseGOT", 1); |
| } |
| |
| // Enable canonical jump tables if CFI is enabled. (See https://reviews.llvm.org/D65629.) |
| if sess.is_sanitizer_cfi_canonical_jump_tables_enabled() && sess.is_sanitizer_cfi_enabled() { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "CFI Canonical Jump Tables", |
| 1, |
| ); |
| } |
| |
| // If we're normalizing integers with CFI, ensure LLVM generated functions do the same. |
| // See https://github.com/llvm/llvm-project/pull/104826 |
| if sess.is_sanitizer_cfi_normalize_integers_enabled() { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "cfi-normalize-integers", |
| 1, |
| ); |
| } |
| |
| // Enable LTO unit splitting if specified or if CFI is enabled. (See |
| // https://reviews.llvm.org/D53891.) |
| if sess.is_split_lto_unit_enabled() || sess.is_sanitizer_cfi_enabled() { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "EnableSplitLTOUnit", |
| 1, |
| ); |
| } |
| |
| // Add "kcfi" module flag if KCFI is enabled. (See https://reviews.llvm.org/D119296.) |
| if sess.is_sanitizer_kcfi_enabled() { |
| llvm::add_module_flag_u32(llmod, llvm::ModuleFlagMergeBehavior::Override, "kcfi", 1); |
| |
| // Add "kcfi-offset" module flag with -Z patchable-function-entry (See |
| // https://reviews.llvm.org/D141172). |
| let pfe = |
| PatchableFunctionEntry::from_config(sess.opts.unstable_opts.patchable_function_entry); |
| if pfe.prefix() > 0 { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "kcfi-offset", |
| pfe.prefix().into(), |
| ); |
| } |
| |
| // Add "kcfi-arity" module flag if KCFI arity indicator is enabled. (See |
| // https://github.com/llvm/llvm-project/pull/117121.) |
| if sess.is_sanitizer_kcfi_arity_enabled() { |
| // KCFI arity indicator requires LLVM 21.0.0 or later. |
| if llvm_version < (21, 0, 0) { |
| tcx.dcx().emit_err(crate::errors::SanitizerKcfiArityRequiresLLVM2100); |
| } |
| |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "kcfi-arity", |
| 1, |
| ); |
| } |
| } |
| |
| // Control Flow Guard is currently only supported by MSVC and LLVM on Windows. |
| if sess.target.is_like_msvc |
| || (sess.target.options.os == "windows" |
| && sess.target.options.env == "gnu" |
| && sess.target.options.abi == "llvm") |
| { |
| match sess.opts.cg.control_flow_guard { |
| CFGuard::Disabled => {} |
| CFGuard::NoChecks => { |
| // Set `cfguard=1` module flag to emit metadata only. |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Warning, |
| "cfguard", |
| 1, |
| ); |
| } |
| CFGuard::Checks => { |
| // Set `cfguard=2` module flag to emit metadata and checks. |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Warning, |
| "cfguard", |
| 2, |
| ); |
| } |
| } |
| } |
| |
| if let Some(BranchProtection { bti, pac_ret }) = sess.opts.unstable_opts.branch_protection { |
| if sess.target.arch == "aarch64" { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Min, |
| "branch-target-enforcement", |
| bti.into(), |
| ); |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Min, |
| "sign-return-address", |
| pac_ret.is_some().into(), |
| ); |
| let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, pc: false, key: PAuthKey::A }); |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Min, |
| "branch-protection-pauth-lr", |
| pac_opts.pc.into(), |
| ); |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Min, |
| "sign-return-address-all", |
| pac_opts.leaf.into(), |
| ); |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Min, |
| "sign-return-address-with-bkey", |
| u32::from(pac_opts.key == PAuthKey::B), |
| ); |
| } else { |
| bug!( |
| "branch-protection used on non-AArch64 target; \ |
| this should be checked in rustc_session." |
| ); |
| } |
| } |
| |
| // Pass on the control-flow protection flags to LLVM (equivalent to `-fcf-protection` in Clang). |
| if let CFProtection::Branch | CFProtection::Full = sess.opts.unstable_opts.cf_protection { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "cf-protection-branch", |
| 1, |
| ); |
| } |
| if let CFProtection::Return | CFProtection::Full = sess.opts.unstable_opts.cf_protection { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "cf-protection-return", |
| 1, |
| ); |
| } |
| |
| if sess.opts.unstable_opts.virtual_function_elimination { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Error, |
| "Virtual Function Elim", |
| 1, |
| ); |
| } |
| |
| // Set module flag to enable Windows EHCont Guard (/guard:ehcont). |
| if sess.opts.unstable_opts.ehcont_guard { |
| llvm::add_module_flag_u32(llmod, llvm::ModuleFlagMergeBehavior::Warning, "ehcontguard", 1); |
| } |
| |
| match sess.opts.unstable_opts.function_return { |
| FunctionReturn::Keep => {} |
| FunctionReturn::ThunkExtern => { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Override, |
| "function_return_thunk_extern", |
| 1, |
| ); |
| } |
| } |
| |
| match (sess.opts.unstable_opts.small_data_threshold, sess.target.small_data_threshold_support()) |
| { |
| // Set up the small-data optimization limit for architectures that use |
| // an LLVM module flag to control this. |
| (Some(threshold), SmallDataThresholdSupport::LlvmModuleFlag(flag)) => { |
| llvm::add_module_flag_u32( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Error, |
| &flag, |
| threshold as u32, |
| ); |
| } |
| _ => (), |
| }; |
| |
| // Insert `llvm.ident` metadata. |
| // |
| // On the wasm targets it will get hooked up to the "producer" sections |
| // `processed-by` information. |
| #[allow(clippy::option_env_unwrap)] |
| let rustc_producer = |
| format!("rustc version {}", option_env!("CFG_VERSION").expect("CFG_VERSION")); |
| |
| let name_metadata = cx.create_metadata(rustc_producer.as_bytes()); |
| |
| unsafe { |
| llvm::LLVMAddNamedMetadataOperand( |
| llmod, |
| c"llvm.ident".as_ptr(), |
| &cx.get_metadata_value(llvm::LLVMMDNodeInContext2(llcx, &name_metadata, 1)), |
| ); |
| } |
| |
| // Emit RISC-V specific target-abi metadata |
| // to workaround lld as the LTO plugin not |
| // correctly setting target-abi for the LTO object |
| // FIXME: https://github.com/llvm/llvm-project/issues/50591 |
| // If llvm_abiname is empty, emit nothing. |
| let llvm_abiname = &sess.target.options.llvm_abiname; |
| if matches!(sess.target.arch.as_ref(), "riscv32" | "riscv64") && !llvm_abiname.is_empty() { |
| llvm::add_module_flag_str( |
| llmod, |
| llvm::ModuleFlagMergeBehavior::Error, |
| "target-abi", |
| llvm_abiname, |
| ); |
| } |
| |
| // Add module flags specified via -Z llvm_module_flag |
| for (key, value, merge_behavior) in &sess.opts.unstable_opts.llvm_module_flag { |
| let merge_behavior = match merge_behavior.as_str() { |
| "error" => llvm::ModuleFlagMergeBehavior::Error, |
| "warning" => llvm::ModuleFlagMergeBehavior::Warning, |
| "require" => llvm::ModuleFlagMergeBehavior::Require, |
| "override" => llvm::ModuleFlagMergeBehavior::Override, |
| "append" => llvm::ModuleFlagMergeBehavior::Append, |
| "appendunique" => llvm::ModuleFlagMergeBehavior::AppendUnique, |
| "max" => llvm::ModuleFlagMergeBehavior::Max, |
| "min" => llvm::ModuleFlagMergeBehavior::Min, |
| // We already checked this during option parsing |
| _ => unreachable!(), |
| }; |
| llvm::add_module_flag_u32(llmod, merge_behavior, key, *value); |
| } |
| |
| llmod |
| } |
| |
| impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> { |
| pub(crate) fn new( |
| tcx: TyCtxt<'tcx>, |
| codegen_unit: &'tcx CodegenUnit<'tcx>, |
| llvm_module: &'ll crate::ModuleLlvm, |
| ) -> Self { |
| // An interesting part of Windows which MSVC forces our hand on (and |
| // apparently MinGW didn't) is the usage of `dllimport` and `dllexport` |
| // attributes in LLVM IR as well as native dependencies (in C these |
| // correspond to `__declspec(dllimport)`). |
| // |
| // LD (BFD) in MinGW mode can often correctly guess `dllexport` but |
| // relying on that can result in issues like #50176. |
| // LLD won't support that and expects symbols with proper attributes. |
| // Because of that we make MinGW target emit dllexport just like MSVC. |
| // When it comes to dllimport we use it for constants but for functions |
| // rely on the linker to do the right thing. Opposed to dllexport this |
| // task is easy for them (both LD and LLD) and allows us to easily use |
| // symbols from static libraries in shared libraries. |
| // |
| // Whenever a dynamic library is built on Windows it must have its public |
| // interface specified by functions tagged with `dllexport` or otherwise |
| // they're not available to be linked against. This poses a few problems |
| // for the compiler, some of which are somewhat fundamental, but we use |
| // the `use_dll_storage_attrs` variable below to attach the `dllexport` |
| // attribute to all LLVM functions that are exported e.g., they're |
| // already tagged with external linkage). This is suboptimal for a few |
| // reasons: |
| // |
| // * If an object file will never be included in a dynamic library, |
| // there's no need to attach the dllexport attribute. Most object |
| // files in Rust are not destined to become part of a dll as binaries |
| // are statically linked by default. |
| // * If the compiler is emitting both an rlib and a dylib, the same |
| // source object file is currently used but with MSVC this may be less |
| // feasible. The compiler may be able to get around this, but it may |
| // involve some invasive changes to deal with this. |
| // |
| // The flip side of this situation is that whenever you link to a dll and |
| // you import a function from it, the import should be tagged with |
| // `dllimport`. At this time, however, the compiler does not emit |
| // `dllimport` for any declarations other than constants (where it is |
| // required), which is again suboptimal for even more reasons! |
| // |
| // * Calling a function imported from another dll without using |
| // `dllimport` causes the linker/compiler to have extra overhead (one |
| // `jmp` instruction on x86) when calling the function. |
| // * The same object file may be used in different circumstances, so a |
| // function may be imported from a dll if the object is linked into a |
| // dll, but it may be just linked against if linked into an rlib. |
| // * The compiler has no knowledge about whether native functions should |
| // be tagged dllimport or not. |
| // |
| // For now the compiler takes the perf hit (I do not have any numbers to |
| // this effect) by marking very little as `dllimport` and praying the |
| // linker will take care of everything. Fixing this problem will likely |
| // require adding a few attributes to Rust itself (feature gated at the |
| // start) and then strongly recommending static linkage on Windows! |
| let use_dll_storage_attrs = tcx.sess.target.is_like_windows; |
| |
| let tls_model = to_llvm_tls_model(tcx.sess.tls_model()); |
| |
| let (llcx, llmod) = (&*llvm_module.llcx, llvm_module.llmod()); |
| |
| let coverage_cx = |
| tcx.sess.instrument_coverage().then(coverageinfo::CguCoverageContext::new); |
| |
| let dbg_cx = if tcx.sess.opts.debuginfo != DebugInfo::None { |
| let dctx = debuginfo::CodegenUnitDebugContext::new(llmod); |
| debuginfo::metadata::build_compile_unit_di_node( |
| tcx, |
| codegen_unit.name().as_str(), |
| &dctx, |
| ); |
| Some(dctx) |
| } else { |
| None |
| }; |
| |
| GenericCx( |
| FullCx { |
| tcx, |
| scx: SimpleCx::new(llmod, llcx, tcx.data_layout.pointer_size()), |
| use_dll_storage_attrs, |
| tls_model, |
| codegen_unit, |
| instances: Default::default(), |
| vtables: Default::default(), |
| const_str_cache: Default::default(), |
| const_globals: Default::default(), |
| statics_to_rauw: RefCell::new(Vec::new()), |
| used_statics: Vec::new(), |
| compiler_used_statics: Vec::new(), |
| type_lowering: Default::default(), |
| scalar_lltypes: Default::default(), |
| coverage_cx, |
| dbg_cx, |
| eh_personality: Cell::new(None), |
| eh_catch_typeinfo: Cell::new(None), |
| rust_try_fn: Cell::new(None), |
| intrinsics: Default::default(), |
| local_gen_sym_counter: Cell::new(0), |
| renamed_statics: Default::default(), |
| }, |
| PhantomData, |
| ) |
| } |
| |
| pub(crate) fn statics_to_rauw(&self) -> &RefCell<Vec<(&'ll Value, &'ll Value)>> { |
| &self.statics_to_rauw |
| } |
| |
| /// Extra state that is only available when coverage instrumentation is enabled. |
| #[inline] |
| #[track_caller] |
| pub(crate) fn coverage_cx(&self) -> &coverageinfo::CguCoverageContext<'ll, 'tcx> { |
| self.coverage_cx.as_ref().expect("only called when coverage instrumentation is enabled") |
| } |
| |
| pub(crate) fn create_used_variable_impl(&self, name: &'static CStr, values: &[&'ll Value]) { |
| let array = self.const_array(self.type_ptr(), values); |
| |
| let g = llvm::add_global(self.llmod, self.val_ty(array), name); |
| llvm::set_initializer(g, array); |
| llvm::set_linkage(g, llvm::Linkage::AppendingLinkage); |
| llvm::set_section(g, c"llvm.metadata"); |
| } |
| } |
| impl<'ll> SimpleCx<'ll> { |
| pub(crate) fn get_return_type(&self, ty: &'ll Type) -> &'ll Type { |
| assert_eq!(self.type_kind(ty), TypeKind::Function); |
| unsafe { llvm::LLVMGetReturnType(ty) } |
| } |
| pub(crate) fn get_type_of_global(&self, val: &'ll Value) -> &'ll Type { |
| unsafe { llvm::LLVMGlobalGetValueType(val) } |
| } |
| pub(crate) fn val_ty(&self, v: &'ll Value) -> &'ll Type { |
| common::val_ty(v) |
| } |
| } |
| impl<'ll> SimpleCx<'ll> { |
| pub(crate) fn new( |
| llmod: &'ll llvm::Module, |
| llcx: &'ll llvm::Context, |
| pointer_size: Size, |
| ) -> Self { |
| let isize_ty = llvm::Type::ix_llcx(llcx, pointer_size.bits()); |
| Self(SCx { llmod, llcx, isize_ty }, PhantomData) |
| } |
| } |
| |
| impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> { |
| pub(crate) fn get_metadata_value(&self, metadata: &'ll Metadata) -> &'ll Value { |
| llvm::LLVMMetadataAsValue(self.llcx(), metadata) |
| } |
| |
| pub(crate) fn get_const_int(&self, ty: &'ll Type, val: u64) -> &'ll Value { |
| unsafe { llvm::LLVMConstInt(ty, val, llvm::False) } |
| } |
| |
| pub(crate) fn get_const_i64(&self, n: u64) -> &'ll Value { |
| self.get_const_int(self.type_i64(), n) |
| } |
| |
| pub(crate) fn get_const_i32(&self, n: u64) -> &'ll Value { |
| self.get_const_int(self.type_i32(), n) |
| } |
| |
| pub(crate) fn get_const_i16(&self, n: u64) -> &'ll Value { |
| self.get_const_int(self.type_i16(), n) |
| } |
| |
| pub(crate) fn get_const_i8(&self, n: u64) -> &'ll Value { |
| self.get_const_int(self.type_i8(), n) |
| } |
| |
| pub(crate) fn get_function(&self, name: &str) -> Option<&'ll Value> { |
| let name = SmallCStr::new(name); |
| unsafe { llvm::LLVMGetNamedFunction((**self).borrow().llmod, name.as_ptr()) } |
| } |
| |
| pub(crate) fn get_md_kind_id(&self, name: &str) -> llvm::MetadataKindId { |
| unsafe { |
| llvm::LLVMGetMDKindIDInContext( |
| self.llcx(), |
| name.as_ptr() as *const c_char, |
| name.len() as c_uint, |
| ) |
| } |
| } |
| |
| pub(crate) fn create_metadata(&self, name: &[u8]) -> &'ll Metadata { |
| unsafe { |
| llvm::LLVMMDStringInContext2(self.llcx(), name.as_ptr() as *const c_char, name.len()) |
| } |
| } |
| |
| pub(crate) fn get_functions(&self) -> Vec<&'ll Value> { |
| let mut functions = vec![]; |
| let mut func = unsafe { llvm::LLVMGetFirstFunction(self.llmod()) }; |
| while let Some(f) = func { |
| functions.push(f); |
| func = unsafe { llvm::LLVMGetNextFunction(f) } |
| } |
| functions |
| } |
| } |
| |
| impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> { |
| fn vtables( |
| &self, |
| ) -> &RefCell<FxHashMap<(Ty<'tcx>, Option<ty::ExistentialTraitRef<'tcx>>), &'ll Value>> { |
| &self.vtables |
| } |
| |
| fn apply_vcall_visibility_metadata( |
| &self, |
| ty: Ty<'tcx>, |
| poly_trait_ref: Option<ty::ExistentialTraitRef<'tcx>>, |
| vtable: &'ll Value, |
| ) { |
| apply_vcall_visibility_metadata(self, ty, poly_trait_ref, vtable); |
| } |
| |
| fn get_fn(&self, instance: Instance<'tcx>) -> &'ll Value { |
| get_fn(self, instance) |
| } |
| |
| fn get_fn_addr(&self, instance: Instance<'tcx>) -> &'ll Value { |
| get_fn(self, instance) |
| } |
| |
| fn eh_personality(&self) -> &'ll Value { |
| // The exception handling personality function. |
| // |
| // If our compilation unit has the `eh_personality` lang item somewhere |
| // within it, then we just need to codegen that. Otherwise, we're |
| // building an rlib which will depend on some upstream implementation of |
| // this function, so we just codegen a generic reference to it. We don't |
| // specify any of the types for the function, we just make it a symbol |
| // that LLVM can later use. |
| // |
| // Note that MSVC is a little special here in that we don't use the |
| // `eh_personality` lang item at all. Currently LLVM has support for |
| // both Dwarf and SEH unwind mechanisms for MSVC targets and uses the |
| // *name of the personality function* to decide what kind of unwind side |
| // tables/landing pads to emit. It looks like Dwarf is used by default, |
| // injecting a dependency on the `_Unwind_Resume` symbol for resuming |
| // an "exception", but for MSVC we want to force SEH. This means that we |
| // can't actually have the personality function be our standard |
| // `rust_eh_personality` function, but rather we wired it up to the |
| // CRT's custom personality function, which forces LLVM to consider |
| // landing pads as "landing pads for SEH". |
| if let Some(llpersonality) = self.eh_personality.get() { |
| return llpersonality; |
| } |
| |
| let name = if wants_msvc_seh(self.sess()) { |
| Some("__CxxFrameHandler3") |
| } else if wants_wasm_eh(self.sess()) { |
| // LLVM specifically tests for the name of the personality function |
| // There is no need for this function to exist anywhere, it will |
| // not be called. However, its name has to be "__gxx_wasm_personality_v0" |
| // for native wasm exceptions. |
| Some("__gxx_wasm_personality_v0") |
| } else { |
| None |
| }; |
| |
| let tcx = self.tcx; |
| let llfn = match tcx.lang_items().eh_personality() { |
| Some(def_id) if name.is_none() => self.get_fn_addr(ty::Instance::expect_resolve( |
| tcx, |
| self.typing_env(), |
| def_id, |
| ty::List::empty(), |
| DUMMY_SP, |
| )), |
| _ => { |
| let name = name.unwrap_or("rust_eh_personality"); |
| if let Some(llfn) = self.get_declared_value(name) { |
| llfn |
| } else { |
| let fty = self.type_variadic_func(&[], self.type_i32()); |
| let llfn = self.declare_cfn(name, llvm::UnnamedAddr::Global, fty); |
| let target_cpu = attributes::target_cpu_attr(self); |
| attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[target_cpu]); |
| llfn |
| } |
| } |
| }; |
| self.eh_personality.set(Some(llfn)); |
| llfn |
| } |
| |
| fn sess(&self) -> &Session { |
| self.tcx.sess |
| } |
| |
| fn set_frame_pointer_type(&self, llfn: &'ll Value) { |
| if let Some(attr) = attributes::frame_pointer_type_attr(self) { |
| attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[attr]); |
| } |
| } |
| |
| fn apply_target_cpu_attr(&self, llfn: &'ll Value) { |
| let mut attrs = SmallVec::<[_; 2]>::new(); |
| attrs.push(attributes::target_cpu_attr(self)); |
| attrs.extend(attributes::tune_cpu_attr(self)); |
| attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs); |
| } |
| |
| fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> { |
| let entry_name = self.sess().target.entry_name.as_ref(); |
| if self.get_declared_value(entry_name).is_none() { |
| Some(self.declare_entry_fn( |
| entry_name, |
| llvm::CallConv::from_conv( |
| self.sess().target.entry_abi, |
| self.sess().target.arch.borrow(), |
| ), |
| llvm::UnnamedAddr::Global, |
| fn_type, |
| )) |
| } else { |
| // If the symbol already exists, it is an error: for example, the user wrote |
| // #[no_mangle] extern "C" fn main(..) {..} |
| None |
| } |
| } |
| } |
| |
| impl<'ll> CodegenCx<'ll, '_> { |
| pub(crate) fn get_intrinsic( |
| &self, |
| base_name: Cow<'static, str>, |
| type_params: &[&'ll Type], |
| ) -> (&'ll Type, &'ll Value) { |
| *self |
| .intrinsics |
| .borrow_mut() |
| .entry((base_name, SmallVec::from_slice(type_params))) |
| .or_insert_with_key(|(base_name, type_params)| { |
| self.declare_intrinsic(base_name, type_params) |
| }) |
| } |
| |
| fn declare_intrinsic( |
| &self, |
| base_name: &str, |
| type_params: &[&'ll Type], |
| ) -> (&'ll Type, &'ll Value) { |
| // This isn't an "LLVM intrinsic", but LLVM's optimization passes |
| // recognize it like one (including turning it into `bcmp` sometimes) |
| // and we use it to implement intrinsics like `raw_eq` and `compare_bytes` |
| if base_name == "memcmp" { |
| let fn_ty = self |
| .type_func(&[self.type_ptr(), self.type_ptr(), self.type_isize()], self.type_int()); |
| let f = self.declare_cfn("memcmp", llvm::UnnamedAddr::No, fn_ty); |
| |
| return (fn_ty, f); |
| } |
| |
| let intrinsic = llvm::Intrinsic::lookup(base_name.as_bytes()) |
| .unwrap_or_else(|| bug!("Unknown intrinsic: `{base_name}`")); |
| let f = intrinsic.get_declaration(self.llmod, &type_params); |
| |
| (self.get_type_of_global(f), f) |
| } |
| |
| pub(crate) fn eh_catch_typeinfo(&self) -> &'ll Value { |
| if let Some(eh_catch_typeinfo) = self.eh_catch_typeinfo.get() { |
| return eh_catch_typeinfo; |
| } |
| let tcx = self.tcx; |
| assert!(self.sess().target.os == "emscripten"); |
| let eh_catch_typeinfo = match tcx.lang_items().eh_catch_typeinfo() { |
| Some(def_id) => self.get_static(def_id), |
| _ => { |
| let ty = self.type_struct(&[self.type_ptr(), self.type_ptr()], false); |
| self.declare_global(&mangle_internal_symbol(self.tcx, "rust_eh_catch_typeinfo"), ty) |
| } |
| }; |
| self.eh_catch_typeinfo.set(Some(eh_catch_typeinfo)); |
| eh_catch_typeinfo |
| } |
| } |
| |
| impl CodegenCx<'_, '_> { |
| /// Generates a new symbol name with the given prefix. This symbol name must |
| /// only be used for definitions with `internal` or `private` linkage. |
| pub(crate) fn generate_local_symbol_name(&self, prefix: &str) -> String { |
| let idx = self.local_gen_sym_counter.get(); |
| self.local_gen_sym_counter.set(idx + 1); |
| // Include a '.' character, so there can be no accidental conflicts with |
| // user defined names |
| let mut name = String::with_capacity(prefix.len() + 6); |
| name.push_str(prefix); |
| name.push('.'); |
| name.push_str(&(idx as u64).to_base(ALPHANUMERIC_ONLY)); |
| name |
| } |
| } |
| |
| impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> { |
| /// A wrapper for [`llvm::LLVMSetMetadata`], but it takes `Metadata` as a parameter instead of `Value`. |
| pub(crate) fn set_metadata<'a>( |
| &self, |
| val: &'a Value, |
| kind_id: impl Into<llvm::MetadataKindId>, |
| md: &'ll Metadata, |
| ) { |
| let node = self.get_metadata_value(md); |
| llvm::LLVMSetMetadata(val, kind_id.into(), node); |
| } |
| } |
| |
| impl HasDataLayout for CodegenCx<'_, '_> { |
| #[inline] |
| fn data_layout(&self) -> &TargetDataLayout { |
| &self.tcx.data_layout |
| } |
| } |
| |
| impl HasTargetSpec for CodegenCx<'_, '_> { |
| #[inline] |
| fn target_spec(&self) -> &Target { |
| &self.tcx.sess.target |
| } |
| } |
| |
| impl<'tcx> ty::layout::HasTyCtxt<'tcx> for CodegenCx<'_, 'tcx> { |
| #[inline] |
| fn tcx(&self) -> TyCtxt<'tcx> { |
| self.tcx |
| } |
| } |
| |
| impl<'tcx, 'll> HasTypingEnv<'tcx> for CodegenCx<'ll, 'tcx> { |
| fn typing_env(&self) -> ty::TypingEnv<'tcx> { |
| ty::TypingEnv::fully_monomorphized() |
| } |
| } |
| |
| impl<'tcx> LayoutOfHelpers<'tcx> for CodegenCx<'_, 'tcx> { |
| #[inline] |
| fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! { |
| if let LayoutError::SizeOverflow(_) | LayoutError::ReferencesError(_) = err { |
| self.tcx.dcx().emit_fatal(Spanned { span, node: err.into_diagnostic() }) |
| } else { |
| self.tcx.dcx().emit_fatal(ssa_errors::FailedToGetLayout { span, ty, err }) |
| } |
| } |
| } |
| |
| impl<'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'_, 'tcx> { |
| #[inline] |
| fn handle_fn_abi_err( |
| &self, |
| err: FnAbiError<'tcx>, |
| span: Span, |
| fn_abi_request: FnAbiRequest<'tcx>, |
| ) -> ! { |
| match err { |
| FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::Cycle(_)) => { |
| self.tcx.dcx().emit_fatal(Spanned { span, node: err }); |
| } |
| _ => match fn_abi_request { |
| FnAbiRequest::OfFnPtr { sig, extra_args } => { |
| span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}",); |
| } |
| FnAbiRequest::OfInstance { instance, extra_args } => { |
| span_bug!( |
| span, |
| "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}", |
| ); |
| } |
| }, |
| } |
| } |
| } |
