diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/context.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/context.rs | 1018 |
1 files changed, 1018 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs new file mode 100644 index 00000000000..e1e0a442845 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -0,0 +1,1018 @@ +use crate::attributes; +use crate::back::write::to_llvm_code_model; +use crate::callee::get_fn; +use crate::coverageinfo; +use crate::debuginfo; +use crate::llvm; +use crate::llvm_util; +use crate::type_::Type; +use crate::value::Value; + +use cstr::cstr; +use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh}; +use rustc_codegen_ssa::traits::*; +use rustc_data_structures::base_n; +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::small_c_str::SmallCStr; +use rustc_hir::def_id::DefId; +use rustc_middle::mir::mono::CodegenUnit; +use rustc_middle::ty::layout::{ + FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, LayoutError, LayoutOfHelpers, + TyAndLayout, +}; +use rustc_middle::ty::{self, Instance, Ty, TyCtxt}; +use rustc_middle::{bug, span_bug}; +use rustc_session::config::{BranchProtection, CFGuard, CFProtection}; +use rustc_session::config::{CrateType, DebugInfo, PAuthKey, PacRet}; +use rustc_session::Session; +use rustc_span::source_map::Span; +use rustc_span::source_map::Spanned; +use rustc_target::abi::{ + call::FnAbi, HasDataLayout, PointeeInfo, Size, TargetDataLayout, VariantIdx, +}; +use rustc_target::spec::{HasTargetSpec, RelocModel, Target, TlsModel}; +use smallvec::SmallVec; + +use std::cell::{Cell, RefCell}; +use std::ffi::CStr; +use std::str; + +/// There is one `CodegenCx` per compilation unit. Each one has its own LLVM +/// `llvm::Context` so that several compilation units may be optimized in parallel. +/// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`. +pub struct CodegenCx<'ll, 'tcx> { + pub tcx: TyCtxt<'tcx>, + pub check_overflow: bool, + pub use_dll_storage_attrs: bool, + pub tls_model: llvm::ThreadLocalMode, + + pub llmod: &'ll llvm::Module, + pub llcx: &'ll llvm::Context, + 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::PolyExistentialTraitRef<'tcx>>), &'ll Value>>, + /// Cache of constant strings, + pub const_str_cache: RefCell<FxHashMap<String, &'ll Value>>, + + /// Reverse-direction for const ptrs cast from globals. + /// + /// Key is a Value holding a `*T`, + /// Val is a Value holding a `*[T]`. + /// + /// Needed because LLVM loses pointer->pointee association + /// when we ptrcast, and we have to ptrcast during codegen + /// of a `[T]` const because we form a slice, a `(*T,usize)` pair, not + /// a pointer to an LLVM array type. Similar for trait objects. + pub const_unsized: RefCell<FxHashMap<&'ll Value, &'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: RefCell<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: RefCell<Vec<&'ll Value>>, + + /// Mapping of non-scalar types to llvm types and field remapping if needed. + pub type_lowering: RefCell<FxHashMap<(Ty<'tcx>, Option<VariantIdx>), TypeLowering<'ll>>>, + + /// Mapping of scalar types to llvm types. + pub scalar_lltypes: RefCell<FxHashMap<Ty<'tcx>, &'ll Type>>, + + pub pointee_infos: RefCell<FxHashMap<(Ty<'tcx>, Size), Option<PointeeInfo>>>, + pub isize_ty: &'ll Type, + + pub coverage_cx: Option<coverageinfo::CrateCoverageContext<'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<&'static str, (&'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>>, +} + +pub struct TypeLowering<'ll> { + /// Associated LLVM type + pub lltype: &'ll Type, + + /// If padding is used the slice maps fields from source order + /// to llvm order. + pub field_remapping: Option<SmallVec<[u32; 4]>>, +} + +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, + } +} + +pub 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 = llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx); + + let mut target_data_layout = sess.target.data_layout.to_string(); + let llvm_version = llvm_util::get_version(); + if llvm_version < (16, 0, 0) { + if sess.target.arch == "s390x" { + // LLVM 16 data layout changed to always set 64-bit vector alignment, + // which is conditional in earlier LLVM versions. + // https://reviews.llvm.org/D131158 for the discussion. + target_data_layout = target_data_layout.replace("-v128:64", ""); + } else if sess.target.arch == "riscv64" { + // LLVM 16 introduced this change so as to produce more efficient code. + // See https://reviews.llvm.org/D116735 for the discussion. + target_data_layout = target_data_layout.replace("-n32:64-", "-n64-"); + } + } + + // Ensure the data-layout values hardcoded remain the defaults. + if sess.target.is_builtin { + let tm = crate::back::write::create_informational_target_machine(tcx.sess); + llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, tm); + llvm::LLVMRustDisposeTargetMachine(tm); + + let llvm_data_layout = llvm::LLVMGetDataLayoutStr(llmod); + let llvm_data_layout = str::from_utf8(CStr::from_ptr(llvm_data_layout).to_bytes()) + .expect("got a non-UTF8 data-layout from LLVM"); + + // Unfortunately LLVM target specs change over time, and right now we + // don't have proper support to work with any more than one + // `data_layout` than the one that is in the rust-lang/rust repo. If + // this compiler is configured against a custom LLVM, we may have a + // differing data layout, even though we should update our own to use + // that one. + // + // As an interim hack, if CFG_LLVM_ROOT is not an empty string then we + // disable this check entirely as we may be configured with something + // that has a different target layout. + // + // Unsure if this will actually cause breakage when rustc is configured + // as such. + // + // FIXME(#34960) + let cfg_llvm_root = option_env!("CFG_LLVM_ROOT").unwrap_or(""); + let custom_llvm_used = !cfg_llvm_root.trim().is_empty(); + + if !custom_llvm_used && target_data_layout != llvm_data_layout { + bug!( + "data-layout for target `{rustc_target}`, `{rustc_layout}`, \ + differs from LLVM target's `{llvm_target}` default layout, `{llvm_layout}`", + rustc_target = sess.opts.target_triple, + rustc_layout = target_data_layout, + llvm_target = sess.target.llvm_target, + llvm_layout = llvm_data_layout + ); + } + } + + let data_layout = SmallCStr::new(&target_data_layout); + llvm::LLVMSetDataLayout(llmod, data_layout.as_ptr()); + + let llvm_target = SmallCStr::new(&sess.target.llvm_target); + llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr()); + + let reloc_model = sess.relocation_model(); + if matches!(reloc_model, RelocModel::Pic | RelocModel::Pie) { + 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 + || sess.crate_types().iter().all(|ty| *ty == CrateType::Executable) + { + 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. + 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() { + let avoid_plt = "RtLibUseGOT\0".as_ptr().cast(); + llvm::LLVMRustAddModuleFlag(llmod, llvm::LLVMModFlagBehavior::Warning, avoid_plt, 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() { + let canonical_jump_tables = "CFI Canonical Jump Tables\0".as_ptr().cast(); + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Override, + canonical_jump_tables, + 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() { + let enable_split_lto_unit = "EnableSplitLTOUnit\0".as_ptr().cast(); + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Override, + enable_split_lto_unit, + 1, + ); + } + + // Add "kcfi" module flag if KCFI is enabled. (See https://reviews.llvm.org/D119296.) + if sess.is_sanitizer_kcfi_enabled() { + let kcfi = "kcfi\0".as_ptr().cast(); + llvm::LLVMRustAddModuleFlag(llmod, llvm::LLVMModFlagBehavior::Override, kcfi, 1); + } + + // Control Flow Guard is currently only supported by the MSVC linker on Windows. + if sess.target.is_like_msvc { + match sess.opts.cg.control_flow_guard { + CFGuard::Disabled => {} + CFGuard::NoChecks => { + // Set `cfguard=1` module flag to emit metadata only. + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Warning, + "cfguard\0".as_ptr() as *const _, + 1, + ) + } + CFGuard::Checks => { + // Set `cfguard=2` module flag to emit metadata and checks. + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Warning, + "cfguard\0".as_ptr() as *const _, + 2, + ) + } + } + } + + if let Some(BranchProtection { bti, pac_ret }) = sess.opts.unstable_opts.branch_protection { + let behavior = if llvm_version >= (15, 0, 0) { + llvm::LLVMModFlagBehavior::Min + } else { + llvm::LLVMModFlagBehavior::Error + }; + + if sess.target.arch == "aarch64" { + llvm::LLVMRustAddModuleFlag( + llmod, + behavior, + "branch-target-enforcement\0".as_ptr().cast(), + bti.into(), + ); + llvm::LLVMRustAddModuleFlag( + llmod, + behavior, + "sign-return-address\0".as_ptr().cast(), + pac_ret.is_some().into(), + ); + let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A }); + llvm::LLVMRustAddModuleFlag( + llmod, + behavior, + "sign-return-address-all\0".as_ptr().cast(), + pac_opts.leaf.into(), + ); + llvm::LLVMRustAddModuleFlag( + llmod, + behavior, + "sign-return-address-with-bkey\0".as_ptr().cast(), + 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::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Override, + "cf-protection-branch\0".as_ptr().cast(), + 1, + ) + } + if let CFProtection::Return | CFProtection::Full = sess.opts.unstable_opts.cf_protection { + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Override, + "cf-protection-return\0".as_ptr().cast(), + 1, + ) + } + + if sess.opts.unstable_opts.virtual_function_elimination { + llvm::LLVMRustAddModuleFlag( + llmod, + llvm::LLVMModFlagBehavior::Error, + "Virtual Function Elim\0".as_ptr().cast(), + 1, + ); + } + + 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 check_overflow = tcx.sess.overflow_checks(); + + 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::CrateCoverageContext::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 + }; + + let isize_ty = Type::ix_llcx(llcx, tcx.data_layout.pointer_size.bits()); + + CodegenCx { + tcx, + check_overflow, + use_dll_storage_attrs, + tls_model, + llmod, + llcx, + codegen_unit, + instances: Default::default(), + vtables: Default::default(), + const_str_cache: Default::default(), + const_unsized: Default::default(), + const_globals: Default::default(), + statics_to_rauw: RefCell::new(Vec::new()), + used_statics: RefCell::new(Vec::new()), + compiler_used_statics: RefCell::new(Vec::new()), + type_lowering: Default::default(), + scalar_lltypes: Default::default(), + pointee_infos: Default::default(), + isize_ty, + 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(), + } + } + + pub(crate) fn statics_to_rauw(&self) -> &RefCell<Vec<(&'ll Value, &'ll Value)>> { + &self.statics_to_rauw + } + + #[inline] + pub fn coverage_context(&self) -> Option<&coverageinfo::CrateCoverageContext<'ll, 'tcx>> { + self.coverage_cx.as_ref() + } + + pub(crate) fn create_used_variable_impl(&self, name: &'static CStr, values: &[&'ll Value]) { + let section = cstr!("llvm.metadata"); + let array = self.const_array(self.type_ptr_to(self.type_i8()), values); + + unsafe { + let g = llvm::LLVMAddGlobal(self.llmod, self.val_ty(array), name.as_ptr()); + llvm::LLVMSetInitializer(g, array); + llvm::LLVMRustSetLinkage(g, llvm::Linkage::AppendingLinkage); + llvm::LLVMSetSection(g, section.as_ptr()); + } + } +} + +impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> { + fn vtables( + &self, + ) -> &RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), &'ll Value>> + { + &self.vtables + } + + 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::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, ty::List::empty()) + .unwrap() + .unwrap(), + ), + _ => { + 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 check_overflow(&self) -> bool { + self.check_overflow + } + + fn codegen_unit(&self) -> &'tcx CodegenUnit<'tcx> { + self.codegen_unit + } + + 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, + self.sess().target.entry_abi.into(), + 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(..) {..} + // instead of #[start] + None + } + } +} + +impl<'ll> CodegenCx<'ll, '_> { + pub(crate) fn get_intrinsic(&self, key: &str) -> (&'ll Type, &'ll Value) { + if let Some(v) = self.intrinsics.borrow().get(key).cloned() { + return v; + } + + self.declare_intrinsic(key).unwrap_or_else(|| bug!("unknown intrinsic '{}'", key)) + } + + fn insert_intrinsic( + &self, + name: &'static str, + args: Option<&[&'ll llvm::Type]>, + ret: &'ll llvm::Type, + ) -> (&'ll llvm::Type, &'ll llvm::Value) { + let fn_ty = if let Some(args) = args { + self.type_func(args, ret) + } else { + self.type_variadic_func(&[], ret) + }; + let f = self.declare_cfn(name, llvm::UnnamedAddr::No, fn_ty); + self.intrinsics.borrow_mut().insert(name, (fn_ty, f)); + (fn_ty, f) + } + + fn declare_intrinsic(&self, key: &str) -> Option<(&'ll Type, &'ll Value)> { + macro_rules! ifn { + ($name:expr, fn() -> $ret:expr) => ( + if key == $name { + return Some(self.insert_intrinsic($name, Some(&[]), $ret)); + } + ); + ($name:expr, fn(...) -> $ret:expr) => ( + if key == $name { + return Some(self.insert_intrinsic($name, None, $ret)); + } + ); + ($name:expr, fn($($arg:expr),*) -> $ret:expr) => ( + if key == $name { + return Some(self.insert_intrinsic($name, Some(&[$($arg),*]), $ret)); + } + ); + } + macro_rules! mk_struct { + ($($field_ty:expr),*) => (self.type_struct( &[$($field_ty),*], false)) + } + + let i8p = self.type_i8p(); + let void = self.type_void(); + let i1 = self.type_i1(); + let t_i8 = self.type_i8(); + let t_i16 = self.type_i16(); + let t_i32 = self.type_i32(); + let t_i64 = self.type_i64(); + let t_i128 = self.type_i128(); + let t_isize = self.type_isize(); + let t_f32 = self.type_f32(); + let t_f64 = self.type_f64(); + let t_metadata = self.type_metadata(); + let t_token = self.type_token(); + + ifn!("llvm.wasm.get.exception", fn(t_token) -> i8p); + ifn!("llvm.wasm.get.ehselector", fn(t_token) -> t_i32); + + ifn!("llvm.wasm.trunc.unsigned.i32.f32", fn(t_f32) -> t_i32); + ifn!("llvm.wasm.trunc.unsigned.i32.f64", fn(t_f64) -> t_i32); + ifn!("llvm.wasm.trunc.unsigned.i64.f32", fn(t_f32) -> t_i64); + ifn!("llvm.wasm.trunc.unsigned.i64.f64", fn(t_f64) -> t_i64); + ifn!("llvm.wasm.trunc.signed.i32.f32", fn(t_f32) -> t_i32); + ifn!("llvm.wasm.trunc.signed.i32.f64", fn(t_f64) -> t_i32); + ifn!("llvm.wasm.trunc.signed.i64.f32", fn(t_f32) -> t_i64); + ifn!("llvm.wasm.trunc.signed.i64.f64", fn(t_f64) -> t_i64); + + ifn!("llvm.fptosi.sat.i8.f32", fn(t_f32) -> t_i8); + ifn!("llvm.fptosi.sat.i16.f32", fn(t_f32) -> t_i16); + ifn!("llvm.fptosi.sat.i32.f32", fn(t_f32) -> t_i32); + ifn!("llvm.fptosi.sat.i64.f32", fn(t_f32) -> t_i64); + ifn!("llvm.fptosi.sat.i128.f32", fn(t_f32) -> t_i128); + ifn!("llvm.fptosi.sat.i8.f64", fn(t_f64) -> t_i8); + ifn!("llvm.fptosi.sat.i16.f64", fn(t_f64) -> t_i16); + ifn!("llvm.fptosi.sat.i32.f64", fn(t_f64) -> t_i32); + ifn!("llvm.fptosi.sat.i64.f64", fn(t_f64) -> t_i64); + ifn!("llvm.fptosi.sat.i128.f64", fn(t_f64) -> t_i128); + + ifn!("llvm.fptoui.sat.i8.f32", fn(t_f32) -> t_i8); + ifn!("llvm.fptoui.sat.i16.f32", fn(t_f32) -> t_i16); + ifn!("llvm.fptoui.sat.i32.f32", fn(t_f32) -> t_i32); + ifn!("llvm.fptoui.sat.i64.f32", fn(t_f32) -> t_i64); + ifn!("llvm.fptoui.sat.i128.f32", fn(t_f32) -> t_i128); + ifn!("llvm.fptoui.sat.i8.f64", fn(t_f64) -> t_i8); + ifn!("llvm.fptoui.sat.i16.f64", fn(t_f64) -> t_i16); + ifn!("llvm.fptoui.sat.i32.f64", fn(t_f64) -> t_i32); + ifn!("llvm.fptoui.sat.i64.f64", fn(t_f64) -> t_i64); + ifn!("llvm.fptoui.sat.i128.f64", fn(t_f64) -> t_i128); + + ifn!("llvm.trap", fn() -> void); + ifn!("llvm.debugtrap", fn() -> void); + ifn!("llvm.frameaddress", fn(t_i32) -> i8p); + + ifn!("llvm.powi.f32", fn(t_f32, t_i32) -> t_f32); + ifn!("llvm.powi.f64", fn(t_f64, t_i32) -> t_f64); + + ifn!("llvm.pow.f32", fn(t_f32, t_f32) -> t_f32); + ifn!("llvm.pow.f64", fn(t_f64, t_f64) -> t_f64); + + ifn!("llvm.sqrt.f32", fn(t_f32) -> t_f32); + ifn!("llvm.sqrt.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.sin.f32", fn(t_f32) -> t_f32); + ifn!("llvm.sin.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.cos.f32", fn(t_f32) -> t_f32); + ifn!("llvm.cos.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.exp.f32", fn(t_f32) -> t_f32); + ifn!("llvm.exp.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.exp2.f32", fn(t_f32) -> t_f32); + ifn!("llvm.exp2.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.log.f32", fn(t_f32) -> t_f32); + ifn!("llvm.log.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.log10.f32", fn(t_f32) -> t_f32); + ifn!("llvm.log10.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.log2.f32", fn(t_f32) -> t_f32); + ifn!("llvm.log2.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.fma.f32", fn(t_f32, t_f32, t_f32) -> t_f32); + ifn!("llvm.fma.f64", fn(t_f64, t_f64, t_f64) -> t_f64); + + ifn!("llvm.fabs.f32", fn(t_f32) -> t_f32); + ifn!("llvm.fabs.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.minnum.f32", fn(t_f32, t_f32) -> t_f32); + ifn!("llvm.minnum.f64", fn(t_f64, t_f64) -> t_f64); + ifn!("llvm.maxnum.f32", fn(t_f32, t_f32) -> t_f32); + ifn!("llvm.maxnum.f64", fn(t_f64, t_f64) -> t_f64); + + ifn!("llvm.floor.f32", fn(t_f32) -> t_f32); + ifn!("llvm.floor.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.ceil.f32", fn(t_f32) -> t_f32); + ifn!("llvm.ceil.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.trunc.f32", fn(t_f32) -> t_f32); + ifn!("llvm.trunc.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.copysign.f32", fn(t_f32, t_f32) -> t_f32); + ifn!("llvm.copysign.f64", fn(t_f64, t_f64) -> t_f64); + + ifn!("llvm.round.f32", fn(t_f32) -> t_f32); + ifn!("llvm.round.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.roundeven.f32", fn(t_f32) -> t_f32); + ifn!("llvm.roundeven.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.rint.f32", fn(t_f32) -> t_f32); + ifn!("llvm.rint.f64", fn(t_f64) -> t_f64); + ifn!("llvm.nearbyint.f32", fn(t_f32) -> t_f32); + ifn!("llvm.nearbyint.f64", fn(t_f64) -> t_f64); + + ifn!("llvm.ctpop.i8", fn(t_i8) -> t_i8); + ifn!("llvm.ctpop.i16", fn(t_i16) -> t_i16); + ifn!("llvm.ctpop.i32", fn(t_i32) -> t_i32); + ifn!("llvm.ctpop.i64", fn(t_i64) -> t_i64); + ifn!("llvm.ctpop.i128", fn(t_i128) -> t_i128); + + ifn!("llvm.ctlz.i8", fn(t_i8, i1) -> t_i8); + ifn!("llvm.ctlz.i16", fn(t_i16, i1) -> t_i16); + ifn!("llvm.ctlz.i32", fn(t_i32, i1) -> t_i32); + ifn!("llvm.ctlz.i64", fn(t_i64, i1) -> t_i64); + ifn!("llvm.ctlz.i128", fn(t_i128, i1) -> t_i128); + + ifn!("llvm.cttz.i8", fn(t_i8, i1) -> t_i8); + ifn!("llvm.cttz.i16", fn(t_i16, i1) -> t_i16); + ifn!("llvm.cttz.i32", fn(t_i32, i1) -> t_i32); + ifn!("llvm.cttz.i64", fn(t_i64, i1) -> t_i64); + ifn!("llvm.cttz.i128", fn(t_i128, i1) -> t_i128); + + ifn!("llvm.bswap.i16", fn(t_i16) -> t_i16); + ifn!("llvm.bswap.i32", fn(t_i32) -> t_i32); + ifn!("llvm.bswap.i64", fn(t_i64) -> t_i64); + ifn!("llvm.bswap.i128", fn(t_i128) -> t_i128); + + ifn!("llvm.bitreverse.i8", fn(t_i8) -> t_i8); + ifn!("llvm.bitreverse.i16", fn(t_i16) -> t_i16); + ifn!("llvm.bitreverse.i32", fn(t_i32) -> t_i32); + ifn!("llvm.bitreverse.i64", fn(t_i64) -> t_i64); + ifn!("llvm.bitreverse.i128", fn(t_i128) -> t_i128); + + ifn!("llvm.fshl.i8", fn(t_i8, t_i8, t_i8) -> t_i8); + ifn!("llvm.fshl.i16", fn(t_i16, t_i16, t_i16) -> t_i16); + ifn!("llvm.fshl.i32", fn(t_i32, t_i32, t_i32) -> t_i32); + ifn!("llvm.fshl.i64", fn(t_i64, t_i64, t_i64) -> t_i64); + ifn!("llvm.fshl.i128", fn(t_i128, t_i128, t_i128) -> t_i128); + + ifn!("llvm.fshr.i8", fn(t_i8, t_i8, t_i8) -> t_i8); + ifn!("llvm.fshr.i16", fn(t_i16, t_i16, t_i16) -> t_i16); + ifn!("llvm.fshr.i32", fn(t_i32, t_i32, t_i32) -> t_i32); + ifn!("llvm.fshr.i64", fn(t_i64, t_i64, t_i64) -> t_i64); + ifn!("llvm.fshr.i128", fn(t_i128, t_i128, t_i128) -> t_i128); + + ifn!("llvm.sadd.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.sadd.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.sadd.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.sadd.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.sadd.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.uadd.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.uadd.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.uadd.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.uadd.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.uadd.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.ssub.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.ssub.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.ssub.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.ssub.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.ssub.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.usub.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.usub.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.usub.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.usub.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.usub.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.smul.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.smul.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.smul.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.smul.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.smul.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.umul.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1}); + ifn!("llvm.umul.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1}); + ifn!("llvm.umul.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1}); + ifn!("llvm.umul.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1}); + ifn!("llvm.umul.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1}); + + ifn!("llvm.sadd.sat.i8", fn(t_i8, t_i8) -> t_i8); + ifn!("llvm.sadd.sat.i16", fn(t_i16, t_i16) -> t_i16); + ifn!("llvm.sadd.sat.i32", fn(t_i32, t_i32) -> t_i32); + ifn!("llvm.sadd.sat.i64", fn(t_i64, t_i64) -> t_i64); + ifn!("llvm.sadd.sat.i128", fn(t_i128, t_i128) -> t_i128); + + ifn!("llvm.uadd.sat.i8", fn(t_i8, t_i8) -> t_i8); + ifn!("llvm.uadd.sat.i16", fn(t_i16, t_i16) -> t_i16); + ifn!("llvm.uadd.sat.i32", fn(t_i32, t_i32) -> t_i32); + ifn!("llvm.uadd.sat.i64", fn(t_i64, t_i64) -> t_i64); + ifn!("llvm.uadd.sat.i128", fn(t_i128, t_i128) -> t_i128); + + ifn!("llvm.ssub.sat.i8", fn(t_i8, t_i8) -> t_i8); + ifn!("llvm.ssub.sat.i16", fn(t_i16, t_i16) -> t_i16); + ifn!("llvm.ssub.sat.i32", fn(t_i32, t_i32) -> t_i32); + ifn!("llvm.ssub.sat.i64", fn(t_i64, t_i64) -> t_i64); + ifn!("llvm.ssub.sat.i128", fn(t_i128, t_i128) -> t_i128); + + ifn!("llvm.usub.sat.i8", fn(t_i8, t_i8) -> t_i8); + ifn!("llvm.usub.sat.i16", fn(t_i16, t_i16) -> t_i16); + ifn!("llvm.usub.sat.i32", fn(t_i32, t_i32) -> t_i32); + ifn!("llvm.usub.sat.i64", fn(t_i64, t_i64) -> t_i64); + ifn!("llvm.usub.sat.i128", fn(t_i128, t_i128) -> t_i128); + + ifn!("llvm.lifetime.start.p0i8", fn(t_i64, i8p) -> void); + ifn!("llvm.lifetime.end.p0i8", fn(t_i64, i8p) -> void); + + ifn!("llvm.expect.i1", fn(i1, i1) -> i1); + ifn!("llvm.eh.typeid.for", fn(i8p) -> t_i32); + ifn!("llvm.localescape", fn(...) -> void); + ifn!("llvm.localrecover", fn(i8p, i8p, t_i32) -> i8p); + ifn!("llvm.x86.seh.recoverfp", fn(i8p, i8p) -> i8p); + + ifn!("llvm.assume", fn(i1) -> void); + ifn!("llvm.prefetch", fn(i8p, t_i32, t_i32, t_i32) -> void); + + // This isn't an "LLVM intrinsic", but LLVM's optimization passes + // recognize it like one and we assume it exists in `core::slice::cmp` + match self.sess().target.arch.as_ref() { + "avr" | "msp430" => ifn!("memcmp", fn(i8p, i8p, t_isize) -> t_i16), + _ => ifn!("memcmp", fn(i8p, i8p, t_isize) -> t_i32), + } + + // variadic intrinsics + ifn!("llvm.va_start", fn(i8p) -> void); + ifn!("llvm.va_end", fn(i8p) -> void); + ifn!("llvm.va_copy", fn(i8p, i8p) -> void); + + if self.sess().instrument_coverage() { + ifn!("llvm.instrprof.increment", fn(i8p, t_i64, t_i32, t_i32) -> void); + } + + ifn!("llvm.type.test", fn(i8p, t_metadata) -> i1); + ifn!("llvm.type.checked.load", fn(i8p, t_i32, t_metadata) -> mk_struct! {i8p, i1}); + + if self.sess().opts.debuginfo != DebugInfo::None { + ifn!("llvm.dbg.declare", fn(t_metadata, t_metadata) -> void); + ifn!("llvm.dbg.value", fn(t_metadata, t_i64, t_metadata) -> void); + } + + ifn!("llvm.ptrmask", fn(i8p, t_isize) -> i8p); + + None + } + + 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_to(self.type_isize()), self.type_i8p()], false); + self.declare_global("rust_eh_catch_typeinfo", ty) + } + }; + let eh_catch_typeinfo = self.const_bitcast(eh_catch_typeinfo, self.type_i8p()); + 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 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('.'); + base_n::push_str(idx as u128, base_n::ALPHANUMERIC_ONLY, &mut name); + name + } +} + +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> HasParamEnv<'tcx> for CodegenCx<'ll, 'tcx> { + fn param_env(&self) -> ty::ParamEnv<'tcx> { + ty::ParamEnv::reveal_all() + } +} + +impl<'tcx> LayoutOfHelpers<'tcx> for CodegenCx<'_, 'tcx> { + type LayoutOfResult = TyAndLayout<'tcx>; + + #[inline] + fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! { + if let LayoutError::SizeOverflow(_) = err { + self.sess().emit_fatal(Spanned { span, node: err.into_diagnostic() }) + } else { + span_bug!(span, "failed to get layout for `{ty}`: {err:?}") + } + } +} + +impl<'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'_, 'tcx> { + type FnAbiOfResult = &'tcx FnAbi<'tcx, Ty<'tcx>>; + + #[inline] + fn handle_fn_abi_err( + &self, + err: FnAbiError<'tcx>, + span: Span, + fn_abi_request: FnAbiRequest<'tcx>, + ) -> ! { + if let FnAbiError::Layout(LayoutError::SizeOverflow(_)) = err { + self.sess().emit_fatal(Spanned { span, node: err }) + } else { + 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:?}", + ); + } + } + } + } +} |