diff options
Diffstat (limited to 'compiler/rustc_codegen_gcc/src/context.rs')
| -rw-r--r-- | compiler/rustc_codegen_gcc/src/context.rs | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs new file mode 100644 index 00000000000..7677ade7314 --- /dev/null +++ b/compiler/rustc_codegen_gcc/src/context.rs @@ -0,0 +1,475 @@ +use std::cell::{Cell, RefCell}; + +use gccjit::{ + Block, + Context, + CType, + Function, + FunctionType, + LValue, + RValue, + Struct, + Type, +}; +use rustc_codegen_ssa::base::wants_msvc_seh; +use rustc_codegen_ssa::traits::{ + BackendTypes, + MiscMethods, +}; +use rustc_data_structures::base_n; +use rustc_data_structures::fx::{FxHashMap, FxHashSet}; +use rustc_middle::span_bug; +use rustc_middle::mir::mono::CodegenUnit; +use rustc_middle::ty::{self, Instance, ParamEnv, PolyExistentialTraitRef, Ty, TyCtxt}; +use rustc_middle::ty::layout::{FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError, TyAndLayout, LayoutOfHelpers}; +use rustc_session::Session; +use rustc_span::{Span, Symbol}; +use rustc_target::abi::{call::FnAbi, HasDataLayout, PointeeInfo, Size, TargetDataLayout, VariantIdx}; +use rustc_target::spec::{HasTargetSpec, Target, TlsModel}; + +use crate::callee::get_fn; +use crate::declare::mangle_name; + +#[derive(Clone)] +pub struct FuncSig<'gcc> { + pub params: Vec<Type<'gcc>>, + pub return_type: Type<'gcc>, +} + +pub struct CodegenCx<'gcc, 'tcx> { + pub check_overflow: bool, + pub codegen_unit: &'tcx CodegenUnit<'tcx>, + pub context: &'gcc Context<'gcc>, + + // TODO(antoyo): First set it to a dummy block to avoid using Option? + pub current_block: RefCell<Option<Block<'gcc>>>, + pub current_func: RefCell<Option<Function<'gcc>>>, + pub normal_function_addresses: RefCell<FxHashSet<RValue<'gcc>>>, + + pub functions: RefCell<FxHashMap<String, Function<'gcc>>>, + + pub tls_model: gccjit::TlsModel, + + pub bool_type: Type<'gcc>, + pub i8_type: Type<'gcc>, + pub i16_type: Type<'gcc>, + pub i32_type: Type<'gcc>, + pub i64_type: Type<'gcc>, + pub i128_type: Type<'gcc>, + pub isize_type: Type<'gcc>, + + pub u8_type: Type<'gcc>, + pub u16_type: Type<'gcc>, + pub u32_type: Type<'gcc>, + pub u64_type: Type<'gcc>, + pub u128_type: Type<'gcc>, + pub usize_type: Type<'gcc>, + + pub int_type: Type<'gcc>, + pub uint_type: Type<'gcc>, + pub long_type: Type<'gcc>, + pub ulong_type: Type<'gcc>, + pub ulonglong_type: Type<'gcc>, + pub sizet_type: Type<'gcc>, + + pub float_type: Type<'gcc>, + pub double_type: Type<'gcc>, + + pub linkage: Cell<FunctionType>, + pub scalar_types: RefCell<FxHashMap<Ty<'tcx>, Type<'gcc>>>, + pub types: RefCell<FxHashMap<(Ty<'tcx>, Option<VariantIdx>), Type<'gcc>>>, + pub tcx: TyCtxt<'tcx>, + + pub struct_types: RefCell<FxHashMap<Vec<Type<'gcc>>, Type<'gcc>>>, + + pub types_with_fields_to_set: RefCell<FxHashMap<Type<'gcc>, (Struct<'gcc>, TyAndLayout<'tcx>)>>, + + /// Cache instances of monomorphic and polymorphic items + pub instances: RefCell<FxHashMap<Instance<'tcx>, LValue<'gcc>>>, + /// Cache function instances of monomorphic and polymorphic items + pub function_instances: RefCell<FxHashMap<Instance<'tcx>, RValue<'gcc>>>, + /// Cache generated vtables + pub vtables: RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), RValue<'gcc>>>, + + /// Cache of emitted const globals (value -> global) + pub const_globals: RefCell<FxHashMap<RValue<'gcc>, RValue<'gcc>>>, + + /// Cache of constant strings, + pub const_cstr_cache: RefCell<FxHashMap<Symbol, LValue<'gcc>>>, + + /// Cache of globals. + pub globals: RefCell<FxHashMap<String, RValue<'gcc>>>, + + /// A counter that is used for generating local symbol names + local_gen_sym_counter: Cell<usize>, + pub global_gen_sym_counter: Cell<usize>, + + eh_personality: Cell<Option<RValue<'gcc>>>, + + pub pointee_infos: RefCell<FxHashMap<(Ty<'tcx>, Size), Option<PointeeInfo>>>, + + /// NOTE: a hack is used because the rustc API is not suitable to libgccjit and as such, + /// `const_undef()` returns struct as pointer so that they can later be assigned a value. + /// As such, this set remembers which of these pointers were returned by this function so that + /// they can be deferenced later. + /// FIXME(antoyo): fix the rustc API to avoid having this hack. + pub structs_as_pointer: RefCell<FxHashSet<RValue<'gcc>>>, +} + +impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> { + pub fn new(context: &'gcc Context<'gcc>, codegen_unit: &'tcx CodegenUnit<'tcx>, tcx: TyCtxt<'tcx>) -> Self { + let check_overflow = tcx.sess.overflow_checks(); + // TODO(antoyo): fix this mess. libgccjit seems to return random type when using new_int_type(). + let isize_type = context.new_c_type(CType::LongLong); + let usize_type = context.new_c_type(CType::ULongLong); + let bool_type = context.new_type::<bool>(); + let i8_type = context.new_type::<i8>(); + let i16_type = context.new_type::<i16>(); + let i32_type = context.new_type::<i32>(); + let i64_type = context.new_c_type(CType::LongLong); + let i128_type = context.new_c_type(CType::Int128t).get_aligned(8); // TODO(antoyo): should the alignment be hard-coded? + let u8_type = context.new_type::<u8>(); + let u16_type = context.new_type::<u16>(); + let u32_type = context.new_type::<u32>(); + let u64_type = context.new_c_type(CType::ULongLong); + let u128_type = context.new_c_type(CType::UInt128t).get_aligned(8); // TODO(antoyo): should the alignment be hard-coded? + + let tls_model = to_gcc_tls_mode(tcx.sess.tls_model()); + + let float_type = context.new_type::<f32>(); + let double_type = context.new_type::<f64>(); + + let int_type = context.new_c_type(CType::Int); + let uint_type = context.new_c_type(CType::UInt); + let long_type = context.new_c_type(CType::Long); + let ulong_type = context.new_c_type(CType::ULong); + let ulonglong_type = context.new_c_type(CType::ULongLong); + let sizet_type = context.new_c_type(CType::SizeT); + + assert_eq!(isize_type, i64_type); + assert_eq!(usize_type, u64_type); + + let mut functions = FxHashMap::default(); + let builtins = [ + "__builtin_unreachable", "abort", "__builtin_expect", "__builtin_add_overflow", "__builtin_mul_overflow", + "__builtin_saddll_overflow", /*"__builtin_sadd_overflow",*/ "__builtin_smulll_overflow", /*"__builtin_smul_overflow",*/ + "__builtin_ssubll_overflow", /*"__builtin_ssub_overflow",*/ "__builtin_sub_overflow", "__builtin_uaddll_overflow", + "__builtin_uadd_overflow", "__builtin_umulll_overflow", "__builtin_umul_overflow", "__builtin_usubll_overflow", + "__builtin_usub_overflow", "sqrtf", "sqrt", "__builtin_powif", "__builtin_powi", "sinf", "sin", "cosf", "cos", + "powf", "pow", "expf", "exp", "exp2f", "exp2", "logf", "log", "log10f", "log10", "log2f", "log2", "fmaf", + "fma", "fabsf", "fabs", "fminf", "fmin", "fmaxf", "fmax", "copysignf", "copysign", "floorf", "floor", "ceilf", + "ceil", "truncf", "trunc", "rintf", "rint", "nearbyintf", "nearbyint", "roundf", "round", + "__builtin_expect_with_probability", + ]; + + for builtin in builtins.iter() { + functions.insert(builtin.to_string(), context.get_builtin_function(builtin)); + } + + Self { + check_overflow, + codegen_unit, + context, + current_block: RefCell::new(None), + current_func: RefCell::new(None), + normal_function_addresses: Default::default(), + functions: RefCell::new(functions), + + tls_model, + + bool_type, + i8_type, + i16_type, + i32_type, + i64_type, + i128_type, + isize_type, + usize_type, + u8_type, + u16_type, + u32_type, + u64_type, + u128_type, + int_type, + uint_type, + long_type, + ulong_type, + ulonglong_type, + sizet_type, + + float_type, + double_type, + + linkage: Cell::new(FunctionType::Internal), + instances: Default::default(), + function_instances: Default::default(), + vtables: Default::default(), + const_globals: Default::default(), + const_cstr_cache: Default::default(), + globals: Default::default(), + scalar_types: Default::default(), + types: Default::default(), + tcx, + struct_types: Default::default(), + types_with_fields_to_set: Default::default(), + local_gen_sym_counter: Cell::new(0), + global_gen_sym_counter: Cell::new(0), + eh_personality: Cell::new(None), + pointee_infos: Default::default(), + structs_as_pointer: Default::default(), + } + } + + pub fn rvalue_as_function(&self, value: RValue<'gcc>) -> Function<'gcc> { + let function: Function<'gcc> = unsafe { std::mem::transmute(value) }; + debug_assert!(self.functions.borrow().values().find(|value| **value == function).is_some(), + "{:?} ({:?}) is not a function", value, value.get_type()); + function + } + + pub fn sess(&self) -> &Session { + &self.tcx.sess + } +} + +impl<'gcc, 'tcx> BackendTypes for CodegenCx<'gcc, 'tcx> { + type Value = RValue<'gcc>; + type Function = RValue<'gcc>; + + type BasicBlock = Block<'gcc>; + type Type = Type<'gcc>; + type Funclet = (); // TODO(antoyo) + + type DIScope = (); // TODO(antoyo) + type DILocation = (); // TODO(antoyo) + type DIVariable = (); // TODO(antoyo) +} + +impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> { + fn vtables(&self) -> &RefCell<FxHashMap<(Ty<'tcx>, Option<PolyExistentialTraitRef<'tcx>>), RValue<'gcc>>> { + &self.vtables + } + + fn get_fn(&self, instance: Instance<'tcx>) -> RValue<'gcc> { + let func = get_fn(self, instance); + *self.current_func.borrow_mut() = Some(self.rvalue_as_function(func)); + func + } + + fn get_fn_addr(&self, instance: Instance<'tcx>) -> RValue<'gcc> { + let func = get_fn(self, instance); + let func = self.rvalue_as_function(func); + let ptr = func.get_address(None); + + // TODO(antoyo): don't do this twice: i.e. in declare_fn and here. + // FIXME(antoyo): the rustc API seems to call get_fn_addr() when not needed (e.g. for FFI). + + self.normal_function_addresses.borrow_mut().insert(ptr); + + ptr + } + + fn eh_personality(&self) -> RValue<'gcc> { + // 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 tcx = self.tcx; + let llfn = match tcx.lang_items().eh_personality() { + Some(def_id) if !wants_msvc_seh(self.sess()) => self.get_fn_addr( + ty::Instance::resolve( + tcx, + ty::ParamEnv::reveal_all(), + def_id, + tcx.intern_substs(&[]), + ) + .unwrap().unwrap(), + ), + _ => { + let _name = if wants_msvc_seh(self.sess()) { + "__CxxFrameHandler3" + } else { + "rust_eh_personality" + }; + //let func = self.declare_func(name, self.type_i32(), &[], true); + // FIXME(antoyo): this hack should not be needed. That will probably be removed when + // unwinding support is added. + self.context.new_rvalue_from_int(self.int_type, 0) + } + }; + // TODO(antoyo): apply target cpu attributes. + 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 used_statics(&self) -> &RefCell<Vec<RValue<'gcc>>> { + unimplemented!(); + } + + fn set_frame_pointer_type(&self, _llfn: RValue<'gcc>) { + // TODO(antoyo) + } + + fn apply_target_cpu_attr(&self, _llfn: RValue<'gcc>) { + // TODO(antoyo) + } + + fn create_used_variable(&self) { + unimplemented!(); + } + + fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> { + if self.get_declared_value("main").is_none() { + Some(self.declare_cfn("main", 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 + } + } + + fn compiler_used_statics(&self) -> &RefCell<Vec<RValue<'gcc>>> { + unimplemented!() + } + + fn create_compiler_used_variable(&self) { + unimplemented!() + } +} + +impl<'gcc, 'tcx> HasTyCtxt<'tcx> for CodegenCx<'gcc, 'tcx> { + fn tcx(&self) -> TyCtxt<'tcx> { + self.tcx + } +} + +impl<'gcc, 'tcx> HasDataLayout for CodegenCx<'gcc, 'tcx> { + fn data_layout(&self) -> &TargetDataLayout { + &self.tcx.data_layout + } +} + +impl<'gcc, 'tcx> HasTargetSpec for CodegenCx<'gcc, 'tcx> { + fn target_spec(&self) -> &Target { + &self.tcx.sess.target + } +} + +impl<'gcc, 'tcx> LayoutOfHelpers<'tcx> for CodegenCx<'gcc, '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().span_fatal(span, &err.to_string()) + } else { + span_bug!(span, "failed to get layout for `{}`: {}", ty, err) + } + } +} + +impl<'gcc, 'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'gcc, '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().span_fatal(span, &err.to_string()) + } else { + match fn_abi_request { + FnAbiRequest::OfFnPtr { sig, extra_args } => { + span_bug!( + span, + "`fn_abi_of_fn_ptr({}, {:?})` failed: {}", + sig, + extra_args, + err + ); + } + FnAbiRequest::OfInstance { instance, extra_args } => { + span_bug!( + span, + "`fn_abi_of_instance({}, {:?})` failed: {}", + instance, + extra_args, + err + ); + } + } + } + } +} + +impl<'tcx, 'gcc> HasParamEnv<'tcx> for CodegenCx<'gcc, 'tcx> { + fn param_env(&self) -> ParamEnv<'tcx> { + ParamEnv::reveal_all() + } +} + +impl<'b, 'tcx> CodegenCx<'b, 'tcx> { + /// 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_str("."); + base_n::push_str(idx as u128, base_n::ALPHANUMERIC_ONLY, &mut name); + name + } +} + +pub fn unit_name<'tcx>(codegen_unit: &CodegenUnit<'tcx>) -> String { + let name = &codegen_unit.name().to_string(); + mangle_name(&name.replace('-', "_")) +} + +fn to_gcc_tls_mode(tls_model: TlsModel) -> gccjit::TlsModel { + match tls_model { + TlsModel::GeneralDynamic => gccjit::TlsModel::GlobalDynamic, + TlsModel::LocalDynamic => gccjit::TlsModel::LocalDynamic, + TlsModel::InitialExec => gccjit::TlsModel::InitialExec, + TlsModel::LocalExec => gccjit::TlsModel::LocalExec, + } +} |