| // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| #![allow(non_camel_case_types, non_snake_case)] |
| |
| //! Code that is useful in various trans modules. |
| |
| use llvm; |
| use llvm::{ValueRef, ContextRef, TypeKind}; |
| use llvm::{True, False, Bool, OperandBundleDef}; |
| use rustc::hir::def_id::DefId; |
| use rustc::middle::lang_items::LangItem; |
| use abi; |
| use base; |
| use builder::Builder; |
| use consts; |
| use declare; |
| use type_::Type; |
| use type_of::LayoutLlvmExt; |
| use value::Value; |
| use rustc::traits; |
| use rustc::ty::{self, Ty, TyCtxt}; |
| use rustc::ty::layout::{HasDataLayout, LayoutOf}; |
| use rustc::ty::subst::Kind; |
| use rustc::hir; |
| |
| use libc::{c_uint, c_char}; |
| use std::iter; |
| |
| use syntax::abi::Abi; |
| use syntax::symbol::InternedString; |
| use syntax_pos::{Span, DUMMY_SP}; |
| |
| pub use context::{CrateContext, SharedCrateContext}; |
| |
| pub fn type_needs_drop<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool { |
| ty.needs_drop(tcx, ty::ParamEnv::empty(traits::Reveal::All)) |
| } |
| |
| pub fn type_is_sized<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool { |
| ty.is_sized(tcx, ty::ParamEnv::empty(traits::Reveal::All), DUMMY_SP) |
| } |
| |
| pub fn type_is_freeze<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool { |
| ty.is_freeze(tcx, ty::ParamEnv::empty(traits::Reveal::All), DUMMY_SP) |
| } |
| |
| /* |
| * A note on nomenclature of linking: "extern", "foreign", and "upcall". |
| * |
| * An "extern" is an LLVM symbol we wind up emitting an undefined external |
| * reference to. This means "we don't have the thing in this compilation unit, |
| * please make sure you link it in at runtime". This could be a reference to |
| * C code found in a C library, or rust code found in a rust crate. |
| * |
| * Most "externs" are implicitly declared (automatically) as a result of a |
| * user declaring an extern _module_ dependency; this causes the rust driver |
| * to locate an extern crate, scan its compilation metadata, and emit extern |
| * declarations for any symbols used by the declaring crate. |
| * |
| * A "foreign" is an extern that references C (or other non-rust ABI) code. |
| * There is no metadata to scan for extern references so in these cases either |
| * a header-digester like bindgen, or manual function prototypes, have to |
| * serve as declarators. So these are usually given explicitly as prototype |
| * declarations, in rust code, with ABI attributes on them noting which ABI to |
| * link via. |
| * |
| * An "upcall" is a foreign call generated by the compiler (not corresponding |
| * to any user-written call in the code) into the runtime library, to perform |
| * some helper task such as bringing a task to life, allocating memory, etc. |
| * |
| */ |
| |
| /// A structure representing an active landing pad for the duration of a basic |
| /// block. |
| /// |
| /// Each `Block` may contain an instance of this, indicating whether the block |
| /// is part of a landing pad or not. This is used to make decision about whether |
| /// to emit `invoke` instructions (e.g. in a landing pad we don't continue to |
| /// use `invoke`) and also about various function call metadata. |
| /// |
| /// For GNU exceptions (`landingpad` + `resume` instructions) this structure is |
| /// just a bunch of `None` instances (not too interesting), but for MSVC |
| /// exceptions (`cleanuppad` + `cleanupret` instructions) this contains data. |
| /// When inside of a landing pad, each function call in LLVM IR needs to be |
| /// annotated with which landing pad it's a part of. This is accomplished via |
| /// the `OperandBundleDef` value created for MSVC landing pads. |
| pub struct Funclet { |
| cleanuppad: ValueRef, |
| operand: OperandBundleDef, |
| } |
| |
| impl Funclet { |
| pub fn new(cleanuppad: ValueRef) -> Funclet { |
| Funclet { |
| cleanuppad, |
| operand: OperandBundleDef::new("funclet", &[cleanuppad]), |
| } |
| } |
| |
| pub fn cleanuppad(&self) -> ValueRef { |
| self.cleanuppad |
| } |
| |
| pub fn bundle(&self) -> &OperandBundleDef { |
| &self.operand |
| } |
| } |
| |
| pub fn val_ty(v: ValueRef) -> Type { |
| unsafe { |
| Type::from_ref(llvm::LLVMTypeOf(v)) |
| } |
| } |
| |
| // LLVM constant constructors. |
| pub fn C_null(t: Type) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstNull(t.to_ref()) |
| } |
| } |
| |
| pub fn C_undef(t: Type) -> ValueRef { |
| unsafe { |
| llvm::LLVMGetUndef(t.to_ref()) |
| } |
| } |
| |
| pub fn C_int(t: Type, i: i64) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstInt(t.to_ref(), i as u64, True) |
| } |
| } |
| |
| pub fn C_uint(t: Type, i: u64) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstInt(t.to_ref(), i, False) |
| } |
| } |
| |
| pub fn C_uint_big(t: Type, u: u128) -> ValueRef { |
| unsafe { |
| let words = [u as u64, (u >> 64) as u64]; |
| llvm::LLVMConstIntOfArbitraryPrecision(t.to_ref(), 2, words.as_ptr()) |
| } |
| } |
| |
| pub fn C_bool(ccx: &CrateContext, val: bool) -> ValueRef { |
| C_uint(Type::i1(ccx), val as u64) |
| } |
| |
| pub fn C_i32(ccx: &CrateContext, i: i32) -> ValueRef { |
| C_int(Type::i32(ccx), i as i64) |
| } |
| |
| pub fn C_u32(ccx: &CrateContext, i: u32) -> ValueRef { |
| C_uint(Type::i32(ccx), i as u64) |
| } |
| |
| pub fn C_u64(ccx: &CrateContext, i: u64) -> ValueRef { |
| C_uint(Type::i64(ccx), i) |
| } |
| |
| pub fn C_usize(ccx: &CrateContext, i: u64) -> ValueRef { |
| let bit_size = ccx.data_layout().pointer_size.bits(); |
| if bit_size < 64 { |
| // make sure it doesn't overflow |
| assert!(i < (1<<bit_size)); |
| } |
| |
| C_uint(ccx.isize_ty(), i) |
| } |
| |
| pub fn C_u8(ccx: &CrateContext, i: u8) -> ValueRef { |
| C_uint(Type::i8(ccx), i as u64) |
| } |
| |
| |
| // This is a 'c-like' raw string, which differs from |
| // our boxed-and-length-annotated strings. |
| pub fn C_cstr(cx: &CrateContext, s: InternedString, null_terminated: bool) -> ValueRef { |
| unsafe { |
| if let Some(&llval) = cx.const_cstr_cache().borrow().get(&s) { |
| return llval; |
| } |
| |
| let sc = llvm::LLVMConstStringInContext(cx.llcx(), |
| s.as_ptr() as *const c_char, |
| s.len() as c_uint, |
| !null_terminated as Bool); |
| let sym = cx.generate_local_symbol_name("str"); |
| let g = declare::define_global(cx, &sym[..], val_ty(sc)).unwrap_or_else(||{ |
| bug!("symbol `{}` is already defined", sym); |
| }); |
| llvm::LLVMSetInitializer(g, sc); |
| llvm::LLVMSetGlobalConstant(g, True); |
| llvm::LLVMRustSetLinkage(g, llvm::Linkage::InternalLinkage); |
| |
| cx.const_cstr_cache().borrow_mut().insert(s, g); |
| g |
| } |
| } |
| |
| // NB: Do not use `do_spill_noroot` to make this into a constant string, or |
| // you will be kicked off fast isel. See issue #4352 for an example of this. |
| pub fn C_str_slice(cx: &CrateContext, s: InternedString) -> ValueRef { |
| let len = s.len(); |
| let cs = consts::ptrcast(C_cstr(cx, s, false), |
| cx.layout_of(cx.tcx().mk_str()).llvm_type(cx).ptr_to()); |
| C_fat_ptr(cx, cs, C_usize(cx, len as u64)) |
| } |
| |
| pub fn C_fat_ptr(cx: &CrateContext, ptr: ValueRef, meta: ValueRef) -> ValueRef { |
| assert_eq!(abi::FAT_PTR_ADDR, 0); |
| assert_eq!(abi::FAT_PTR_EXTRA, 1); |
| C_struct(cx, &[ptr, meta], false) |
| } |
| |
| pub fn C_struct(cx: &CrateContext, elts: &[ValueRef], packed: bool) -> ValueRef { |
| C_struct_in_context(cx.llcx(), elts, packed) |
| } |
| |
| pub fn C_struct_in_context(llcx: ContextRef, elts: &[ValueRef], packed: bool) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstStructInContext(llcx, |
| elts.as_ptr(), elts.len() as c_uint, |
| packed as Bool) |
| } |
| } |
| |
| pub fn C_array(ty: Type, elts: &[ValueRef]) -> ValueRef { |
| unsafe { |
| return llvm::LLVMConstArray(ty.to_ref(), elts.as_ptr(), elts.len() as c_uint); |
| } |
| } |
| |
| pub fn C_vector(elts: &[ValueRef]) -> ValueRef { |
| unsafe { |
| return llvm::LLVMConstVector(elts.as_ptr(), elts.len() as c_uint); |
| } |
| } |
| |
| pub fn C_bytes(cx: &CrateContext, bytes: &[u8]) -> ValueRef { |
| C_bytes_in_context(cx.llcx(), bytes) |
| } |
| |
| pub fn C_bytes_in_context(llcx: ContextRef, bytes: &[u8]) -> ValueRef { |
| unsafe { |
| let ptr = bytes.as_ptr() as *const c_char; |
| return llvm::LLVMConstStringInContext(llcx, ptr, bytes.len() as c_uint, True); |
| } |
| } |
| |
| pub fn const_get_elt(v: ValueRef, idx: u64) -> ValueRef { |
| unsafe { |
| assert_eq!(idx as c_uint as u64, idx); |
| let us = &[idx as c_uint]; |
| let r = llvm::LLVMConstExtractValue(v, us.as_ptr(), us.len() as c_uint); |
| |
| debug!("const_get_elt(v={:?}, idx={}, r={:?})", |
| Value(v), idx, Value(r)); |
| |
| r |
| } |
| } |
| |
| pub fn const_to_uint(v: ValueRef) -> u64 { |
| unsafe { |
| llvm::LLVMConstIntGetZExtValue(v) |
| } |
| } |
| |
| pub fn is_const_integral(v: ValueRef) -> bool { |
| unsafe { |
| !llvm::LLVMIsAConstantInt(v).is_null() |
| } |
| } |
| |
| #[inline] |
| fn hi_lo_to_u128(lo: u64, hi: u64) -> u128 { |
| ((hi as u128) << 64) | (lo as u128) |
| } |
| |
| pub fn const_to_opt_u128(v: ValueRef, sign_ext: bool) -> Option<u128> { |
| unsafe { |
| if is_const_integral(v) { |
| let (mut lo, mut hi) = (0u64, 0u64); |
| let success = llvm::LLVMRustConstInt128Get(v, sign_ext, |
| &mut hi as *mut u64, &mut lo as *mut u64); |
| if success { |
| Some(hi_lo_to_u128(lo, hi)) |
| } else { |
| None |
| } |
| } else { |
| None |
| } |
| } |
| } |
| |
| pub fn langcall(tcx: TyCtxt, |
| span: Option<Span>, |
| msg: &str, |
| li: LangItem) |
| -> DefId { |
| match tcx.lang_items().require(li) { |
| Ok(id) => id, |
| Err(s) => { |
| let msg = format!("{} {}", msg, s); |
| match span { |
| Some(span) => tcx.sess.span_fatal(span, &msg[..]), |
| None => tcx.sess.fatal(&msg[..]), |
| } |
| } |
| } |
| } |
| |
| // To avoid UB from LLVM, these two functions mask RHS with an |
| // appropriate mask unconditionally (i.e. the fallback behavior for |
| // all shifts). For 32- and 64-bit types, this matches the semantics |
| // of Java. (See related discussion on #1877 and #10183.) |
| |
| pub fn build_unchecked_lshift<'a, 'tcx>( |
| bcx: &Builder<'a, 'tcx>, |
| lhs: ValueRef, |
| rhs: ValueRef |
| ) -> ValueRef { |
| let rhs = base::cast_shift_expr_rhs(bcx, hir::BinOp_::BiShl, lhs, rhs); |
| // #1877, #10183: Ensure that input is always valid |
| let rhs = shift_mask_rhs(bcx, rhs); |
| bcx.shl(lhs, rhs) |
| } |
| |
| pub fn build_unchecked_rshift<'a, 'tcx>( |
| bcx: &Builder<'a, 'tcx>, lhs_t: Ty<'tcx>, lhs: ValueRef, rhs: ValueRef |
| ) -> ValueRef { |
| let rhs = base::cast_shift_expr_rhs(bcx, hir::BinOp_::BiShr, lhs, rhs); |
| // #1877, #10183: Ensure that input is always valid |
| let rhs = shift_mask_rhs(bcx, rhs); |
| let is_signed = lhs_t.is_signed(); |
| if is_signed { |
| bcx.ashr(lhs, rhs) |
| } else { |
| bcx.lshr(lhs, rhs) |
| } |
| } |
| |
| fn shift_mask_rhs<'a, 'tcx>(bcx: &Builder<'a, 'tcx>, rhs: ValueRef) -> ValueRef { |
| let rhs_llty = val_ty(rhs); |
| bcx.and(rhs, shift_mask_val(bcx, rhs_llty, rhs_llty, false)) |
| } |
| |
| pub fn shift_mask_val<'a, 'tcx>( |
| bcx: &Builder<'a, 'tcx>, |
| llty: Type, |
| mask_llty: Type, |
| invert: bool |
| ) -> ValueRef { |
| let kind = llty.kind(); |
| match kind { |
| TypeKind::Integer => { |
| // i8/u8 can shift by at most 7, i16/u16 by at most 15, etc. |
| let val = llty.int_width() - 1; |
| if invert { |
| C_int(mask_llty, !val as i64) |
| } else { |
| C_uint(mask_llty, val) |
| } |
| }, |
| TypeKind::Vector => { |
| let mask = shift_mask_val(bcx, llty.element_type(), mask_llty.element_type(), invert); |
| bcx.vector_splat(mask_llty.vector_length(), mask) |
| }, |
| _ => bug!("shift_mask_val: expected Integer or Vector, found {:?}", kind), |
| } |
| } |
| |
| pub fn ty_fn_sig<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| ty: Ty<'tcx>) |
| -> ty::PolyFnSig<'tcx> |
| { |
| match ty.sty { |
| ty::TyFnDef(..) | |
| // Shims currently have type TyFnPtr. Not sure this should remain. |
| ty::TyFnPtr(_) => ty.fn_sig(ccx.tcx()), |
| ty::TyClosure(def_id, substs) => { |
| let tcx = ccx.tcx(); |
| let sig = substs.closure_sig(def_id, tcx); |
| |
| let env_ty = tcx.closure_env_ty(def_id, substs).unwrap(); |
| sig.map_bound(|sig| tcx.mk_fn_sig( |
| iter::once(*env_ty.skip_binder()).chain(sig.inputs().iter().cloned()), |
| sig.output(), |
| sig.variadic, |
| sig.unsafety, |
| sig.abi |
| )) |
| } |
| ty::TyGenerator(def_id, substs, _) => { |
| let tcx = ccx.tcx(); |
| let sig = substs.generator_poly_sig(def_id, ccx.tcx()); |
| |
| let env_region = ty::ReLateBound(ty::DebruijnIndex::new(1), ty::BrEnv); |
| let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty); |
| |
| sig.map_bound(|sig| { |
| let state_did = tcx.lang_items().gen_state().unwrap(); |
| let state_adt_ref = tcx.adt_def(state_did); |
| let state_substs = tcx.mk_substs([Kind::from(sig.yield_ty), |
| Kind::from(sig.return_ty)].iter()); |
| let ret_ty = tcx.mk_adt(state_adt_ref, state_substs); |
| |
| tcx.mk_fn_sig(iter::once(env_ty), |
| ret_ty, |
| false, |
| hir::Unsafety::Normal, |
| Abi::Rust |
| ) |
| }) |
| } |
| _ => bug!("unexpected type {:?} to ty_fn_sig", ty) |
| } |
| } |
| |