| // 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 session::Session; |
| use llvm; |
| use llvm::{ValueRef, BasicBlockRef, BuilderRef, ContextRef, TypeKind}; |
| use llvm::{True, False, Bool, OperandBundleDef}; |
| use rustc::cfg; |
| use rustc::hir::def::Def; |
| use rustc::hir::def_id::DefId; |
| use rustc::infer::TransNormalize; |
| use rustc::util::common::MemoizationMap; |
| use middle::lang_items::LangItem; |
| use rustc::ty::subst::Substs; |
| use abi::{Abi, FnType}; |
| use base; |
| use build; |
| use builder::Builder; |
| use callee::Callee; |
| use cleanup; |
| use consts; |
| use datum; |
| use debuginfo::{self, DebugLoc}; |
| use declare; |
| use machine; |
| use mir::CachedMir; |
| use monomorphize; |
| use type_::Type; |
| use value::Value; |
| use rustc::ty::{self, Ty, TyCtxt}; |
| use rustc::ty::layout::Layout; |
| use rustc::traits::{self, SelectionContext, ProjectionMode}; |
| use rustc::ty::fold::TypeFoldable; |
| use rustc::hir; |
| use util::nodemap::NodeMap; |
| |
| use arena::TypedArena; |
| use libc::{c_uint, c_char}; |
| use std::ops::Deref; |
| use std::ffi::CString; |
| use std::cell::{Cell, RefCell}; |
| |
| use syntax::ast; |
| use syntax::parse::token::InternedString; |
| use syntax::parse::token; |
| use syntax_pos::{DUMMY_SP, Span}; |
| |
| pub use context::{CrateContext, SharedCrateContext}; |
| |
| /// Is the type's representation size known at compile time? |
| pub fn type_is_sized<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool { |
| ty.is_sized(tcx, &tcx.empty_parameter_environment(), DUMMY_SP) |
| } |
| |
| pub fn type_is_fat_ptr<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool { |
| match ty.sty { |
| ty::TyRawPtr(ty::TypeAndMut{ty, ..}) | |
| ty::TyRef(_, ty::TypeAndMut{ty, ..}) | |
| ty::TyBox(ty) => { |
| !type_is_sized(tcx, ty) |
| } |
| _ => { |
| false |
| } |
| } |
| } |
| |
| pub fn type_is_immediate<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool { |
| use machine::llsize_of_alloc; |
| use type_of::sizing_type_of; |
| |
| let tcx = ccx.tcx(); |
| let simple = ty.is_scalar() || |
| ty.is_unique() || ty.is_region_ptr() || |
| ty.is_simd(); |
| if simple && !type_is_fat_ptr(tcx, ty) { |
| return true; |
| } |
| if !type_is_sized(tcx, ty) { |
| return false; |
| } |
| match ty.sty { |
| ty::TyStruct(..) | ty::TyEnum(..) | ty::TyTuple(..) | ty::TyArray(_, _) | |
| ty::TyClosure(..) => { |
| let llty = sizing_type_of(ccx, ty); |
| llsize_of_alloc(ccx, llty) <= llsize_of_alloc(ccx, ccx.int_type()) |
| } |
| _ => type_is_zero_size(ccx, ty) |
| } |
| } |
| |
| /// Returns Some([a, b]) if the type has a pair of fields with types a and b. |
| pub fn type_pair_fields<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) |
| -> Option<[Ty<'tcx>; 2]> { |
| match ty.sty { |
| ty::TyEnum(adt, substs) | ty::TyStruct(adt, substs) => { |
| assert_eq!(adt.variants.len(), 1); |
| let fields = &adt.variants[0].fields; |
| if fields.len() != 2 { |
| return None; |
| } |
| Some([monomorphize::field_ty(ccx.tcx(), substs, &fields[0]), |
| monomorphize::field_ty(ccx.tcx(), substs, &fields[1])]) |
| } |
| ty::TyClosure(_, ty::ClosureSubsts { upvar_tys: tys, .. }) | |
| ty::TyTuple(tys) => { |
| if tys.len() != 2 { |
| return None; |
| } |
| Some([tys[0], tys[1]]) |
| } |
| _ => None |
| } |
| } |
| |
| /// Returns true if the type is represented as a pair of immediates. |
| pub fn type_is_imm_pair<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) |
| -> bool { |
| let tcx = ccx.tcx(); |
| let layout = tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| { |
| match ty.layout(&infcx) { |
| Ok(layout) => layout, |
| Err(err) => { |
| bug!("type_is_imm_pair: layout for `{:?}` failed: {}", |
| ty, err); |
| } |
| } |
| }); |
| |
| match *layout { |
| Layout::FatPointer { .. } => true, |
| Layout::Univariant { ref variant, .. } => { |
| // There must be only 2 fields. |
| if variant.offset_after_field.len() != 2 { |
| return false; |
| } |
| |
| match type_pair_fields(ccx, ty) { |
| Some([a, b]) => { |
| type_is_immediate(ccx, a) && type_is_immediate(ccx, b) |
| } |
| None => false |
| } |
| } |
| _ => false |
| } |
| } |
| |
| /// Identify types which have size zero at runtime. |
| pub fn type_is_zero_size<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool { |
| use machine::llsize_of_alloc; |
| use type_of::sizing_type_of; |
| let llty = sizing_type_of(ccx, ty); |
| llsize_of_alloc(ccx, llty) == 0 |
| } |
| |
| /// Generates a unique symbol based off the name given. This is used to create |
| /// unique symbols for things like closures. |
| pub fn gensym_name(name: &str) -> ast::Name { |
| let num = token::gensym(name).0; |
| // use one colon which will get translated to a period by the mangler, and |
| // we're guaranteed that `num` is globally unique for this crate. |
| token::gensym(&format!("{}:{}", name, num)) |
| } |
| |
| /* |
| * 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. |
| * |
| */ |
| |
| use Disr; |
| |
| #[derive(Copy, Clone)] |
| pub struct NodeIdAndSpan { |
| pub id: ast::NodeId, |
| pub span: Span, |
| } |
| |
| pub fn expr_info(expr: &hir::Expr) -> NodeIdAndSpan { |
| NodeIdAndSpan { id: expr.id, span: expr.span } |
| } |
| |
| /// The concrete version of ty::FieldDef. The name is the field index if |
| /// the field is numeric. |
| pub struct Field<'tcx>(pub ast::Name, pub Ty<'tcx>); |
| |
| /// The concrete version of ty::VariantDef |
| pub struct VariantInfo<'tcx> { |
| pub discr: Disr, |
| pub fields: Vec<Field<'tcx>> |
| } |
| |
| impl<'a, 'tcx> VariantInfo<'tcx> { |
| pub fn from_ty(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| ty: Ty<'tcx>, |
| opt_def: Option<Def>) |
| -> Self |
| { |
| match ty.sty { |
| ty::TyStruct(adt, substs) | ty::TyEnum(adt, substs) => { |
| let variant = match opt_def { |
| None => adt.struct_variant(), |
| Some(def) => adt.variant_of_def(def) |
| }; |
| |
| VariantInfo { |
| discr: Disr::from(variant.disr_val), |
| fields: variant.fields.iter().map(|f| { |
| Field(f.name, monomorphize::field_ty(tcx, substs, f)) |
| }).collect() |
| } |
| } |
| |
| ty::TyTuple(ref v) => { |
| VariantInfo { |
| discr: Disr(0), |
| fields: v.iter().enumerate().map(|(i, &t)| { |
| Field(token::intern(&i.to_string()), t) |
| }).collect() |
| } |
| } |
| |
| _ => { |
| bug!("cannot get field types from the type {:?}", ty); |
| } |
| } |
| } |
| |
| /// Return the variant corresponding to a given node (e.g. expr) |
| pub fn of_node(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>, id: ast::NodeId) -> Self { |
| Self::from_ty(tcx, ty, Some(tcx.expect_def(id))) |
| } |
| |
| pub fn field_index(&self, name: ast::Name) -> usize { |
| self.fields.iter().position(|&Field(n,_)| n == name).unwrap_or_else(|| { |
| bug!("unknown field `{}`", name) |
| }) |
| } |
| } |
| |
| pub struct BuilderRef_res { |
| pub b: BuilderRef, |
| } |
| |
| impl Drop for BuilderRef_res { |
| fn drop(&mut self) { |
| unsafe { |
| llvm::LLVMDisposeBuilder(self.b); |
| } |
| } |
| } |
| |
| pub fn BuilderRef_res(b: BuilderRef) -> BuilderRef_res { |
| BuilderRef_res { |
| b: b |
| } |
| } |
| |
| pub fn validate_substs(substs: &Substs) { |
| assert!(!substs.types.needs_infer()); |
| } |
| |
| // work around bizarre resolve errors |
| type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>; |
| pub type LvalueDatum<'tcx> = datum::Datum<'tcx, datum::Lvalue>; |
| |
| #[derive(Clone, Debug)] |
| struct HintEntry<'tcx> { |
| // The datum for the dropflag-hint itself; note that many |
| // source-level Lvalues will be associated with the same |
| // dropflag-hint datum. |
| datum: cleanup::DropHintDatum<'tcx>, |
| } |
| |
| pub struct DropFlagHintsMap<'tcx> { |
| // Maps NodeId for expressions that read/write unfragmented state |
| // to that state's drop-flag "hint." (A stack-local hint |
| // indicates either that (1.) it is certain that no-drop is |
| // needed, or (2.) inline drop-flag must be consulted.) |
| node_map: NodeMap<HintEntry<'tcx>>, |
| } |
| |
| impl<'tcx> DropFlagHintsMap<'tcx> { |
| pub fn new() -> DropFlagHintsMap<'tcx> { DropFlagHintsMap { node_map: NodeMap() } } |
| pub fn has_hint(&self, id: ast::NodeId) -> bool { self.node_map.contains_key(&id) } |
| pub fn insert(&mut self, id: ast::NodeId, datum: cleanup::DropHintDatum<'tcx>) { |
| self.node_map.insert(id, HintEntry { datum: datum }); |
| } |
| pub fn hint_datum(&self, id: ast::NodeId) -> Option<cleanup::DropHintDatum<'tcx>> { |
| self.node_map.get(&id).map(|t|t.datum) |
| } |
| } |
| |
| // Function context. Every LLVM function we create will have one of |
| // these. |
| pub struct FunctionContext<'a, 'tcx: 'a> { |
| // The MIR for this function. At present, this is optional because |
| // we only have MIR available for things that are local to the |
| // crate. |
| pub mir: Option<CachedMir<'a, 'tcx>>, |
| |
| // The ValueRef returned from a call to llvm::LLVMAddFunction; the |
| // address of the first instruction in the sequence of |
| // instructions for this function that will go in the .text |
| // section of the executable we're generating. |
| pub llfn: ValueRef, |
| |
| // always an empty parameter-environment NOTE: @jroesch another use of ParamEnv |
| pub param_env: ty::ParameterEnvironment<'tcx>, |
| |
| // A pointer to where to store the return value. If the return type is |
| // immediate, this points to an alloca in the function. Otherwise, it's a |
| // pointer to the hidden first parameter of the function. After function |
| // construction, this should always be Some. |
| pub llretslotptr: Cell<Option<ValueRef>>, |
| |
| // These pub elements: "hoisted basic blocks" containing |
| // administrative activities that have to happen in only one place in |
| // the function, due to LLVM's quirks. |
| // A marker for the place where we want to insert the function's static |
| // allocas, so that LLVM will coalesce them into a single alloca call. |
| pub alloca_insert_pt: Cell<Option<ValueRef>>, |
| pub llreturn: Cell<Option<BasicBlockRef>>, |
| |
| // If the function has any nested return's, including something like: |
| // fn foo() -> Option<Foo> { Some(Foo { x: return None }) }, then |
| // we use a separate alloca for each return |
| pub needs_ret_allocas: bool, |
| |
| // When working with landingpad-based exceptions this value is alloca'd and |
| // later loaded when using the resume instruction. This ends up being |
| // critical to chaining landing pads and resuing already-translated |
| // cleanups. |
| // |
| // Note that for cleanuppad-based exceptions this is not used. |
| pub landingpad_alloca: Cell<Option<ValueRef>>, |
| |
| // Maps the DefId's for local variables to the allocas created for |
| // them in llallocas. |
| pub lllocals: RefCell<NodeMap<LvalueDatum<'tcx>>>, |
| |
| // Same as above, but for closure upvars |
| pub llupvars: RefCell<NodeMap<ValueRef>>, |
| |
| // Carries info about drop-flags for local bindings (longer term, |
| // paths) for the code being compiled. |
| pub lldropflag_hints: RefCell<DropFlagHintsMap<'tcx>>, |
| |
| // Describes the return/argument LLVM types and their ABI handling. |
| pub fn_ty: FnType, |
| |
| // If this function is being monomorphized, this contains the type |
| // substitutions used. |
| pub param_substs: &'tcx Substs<'tcx>, |
| |
| // The source span and nesting context where this function comes from, for |
| // error reporting and symbol generation. |
| pub span: Option<Span>, |
| |
| // The arena that blocks are allocated from. |
| pub block_arena: &'a TypedArena<BlockS<'a, 'tcx>>, |
| |
| // The arena that landing pads are allocated from. |
| pub lpad_arena: TypedArena<LandingPad>, |
| |
| // This function's enclosing crate context. |
| pub ccx: &'a CrateContext<'a, 'tcx>, |
| |
| // Used and maintained by the debuginfo module. |
| pub debug_context: debuginfo::FunctionDebugContext, |
| |
| // Cleanup scopes. |
| pub scopes: RefCell<Vec<cleanup::CleanupScope<'a, 'tcx>>>, |
| |
| pub cfg: Option<cfg::CFG>, |
| } |
| |
| impl<'a, 'tcx> FunctionContext<'a, 'tcx> { |
| pub fn mir(&self) -> CachedMir<'a, 'tcx> { |
| self.mir.clone().expect("fcx.mir was empty") |
| } |
| |
| pub fn cleanup(&self) { |
| unsafe { |
| llvm::LLVMInstructionEraseFromParent(self.alloca_insert_pt |
| .get() |
| .unwrap()); |
| } |
| } |
| |
| pub fn get_llreturn(&self) -> BasicBlockRef { |
| if self.llreturn.get().is_none() { |
| |
| self.llreturn.set(Some(unsafe { |
| llvm::LLVMAppendBasicBlockInContext(self.ccx.llcx(), self.llfn, |
| "return\0".as_ptr() as *const _) |
| })) |
| } |
| |
| self.llreturn.get().unwrap() |
| } |
| |
| pub fn get_ret_slot(&self, bcx: Block<'a, 'tcx>, name: &str) -> ValueRef { |
| if self.needs_ret_allocas { |
| base::alloca(bcx, self.fn_ty.ret.memory_ty(self.ccx), name) |
| } else { |
| self.llretslotptr.get().unwrap() |
| } |
| } |
| |
| pub fn new_block(&'a self, |
| name: &str, |
| opt_node_id: Option<ast::NodeId>) |
| -> Block<'a, 'tcx> { |
| unsafe { |
| let name = CString::new(name).unwrap(); |
| let llbb = llvm::LLVMAppendBasicBlockInContext(self.ccx.llcx(), |
| self.llfn, |
| name.as_ptr()); |
| BlockS::new(llbb, opt_node_id, self) |
| } |
| } |
| |
| pub fn new_id_block(&'a self, |
| name: &str, |
| node_id: ast::NodeId) |
| -> Block<'a, 'tcx> { |
| self.new_block(name, Some(node_id)) |
| } |
| |
| pub fn new_temp_block(&'a self, |
| name: &str) |
| -> Block<'a, 'tcx> { |
| self.new_block(name, None) |
| } |
| |
| pub fn join_blocks(&'a self, |
| id: ast::NodeId, |
| in_cxs: &[Block<'a, 'tcx>]) |
| -> Block<'a, 'tcx> { |
| let out = self.new_id_block("join", id); |
| let mut reachable = false; |
| for bcx in in_cxs { |
| if !bcx.unreachable.get() { |
| build::Br(*bcx, out.llbb, DebugLoc::None); |
| reachable = true; |
| } |
| } |
| if !reachable { |
| build::Unreachable(out); |
| } |
| return out; |
| } |
| |
| pub fn monomorphize<T>(&self, value: &T) -> T |
| where T: TransNormalize<'tcx> |
| { |
| monomorphize::apply_param_substs(self.ccx.tcx(), |
| self.param_substs, |
| value) |
| } |
| |
| /// This is the same as `common::type_needs_drop`, except that it |
| /// may use or update caches within this `FunctionContext`. |
| pub fn type_needs_drop(&self, ty: Ty<'tcx>) -> bool { |
| self.ccx.tcx().type_needs_drop_given_env(ty, &self.param_env) |
| } |
| |
| pub fn eh_personality(&self) -> ValueRef { |
| // The exception handling personality function. |
| // |
| // If our compilation unit has the `eh_personality` lang item somewhere |
| // within it, then we just need to translate 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". |
| let ccx = self.ccx; |
| let tcx = ccx.tcx(); |
| match tcx.lang_items.eh_personality() { |
| Some(def_id) if !base::wants_msvc_seh(ccx.sess()) => { |
| Callee::def(ccx, def_id, tcx.mk_substs(Substs::empty())).reify(ccx).val |
| } |
| _ => { |
| if let Some(llpersonality) = ccx.eh_personality().get() { |
| return llpersonality |
| } |
| let name = if base::wants_msvc_seh(ccx.sess()) { |
| "__CxxFrameHandler3" |
| } else { |
| "rust_eh_personality" |
| }; |
| let fty = Type::variadic_func(&[], &Type::i32(ccx)); |
| let f = declare::declare_cfn(ccx, name, fty); |
| ccx.eh_personality().set(Some(f)); |
| f |
| } |
| } |
| } |
| |
| // Returns a ValueRef of the "eh_unwind_resume" lang item if one is defined, |
| // otherwise declares it as an external function. |
| pub fn eh_unwind_resume(&self) -> Callee<'tcx> { |
| use attributes; |
| let ccx = self.ccx; |
| let tcx = ccx.tcx(); |
| assert!(ccx.sess().target.target.options.custom_unwind_resume); |
| if let Some(def_id) = tcx.lang_items.eh_unwind_resume() { |
| return Callee::def(ccx, def_id, tcx.mk_substs(Substs::empty())); |
| } |
| |
| let ty = tcx.mk_fn_ptr(tcx.mk_bare_fn(ty::BareFnTy { |
| unsafety: hir::Unsafety::Unsafe, |
| abi: Abi::C, |
| sig: ty::Binder(ty::FnSig { |
| inputs: vec![tcx.mk_mut_ptr(tcx.types.u8)], |
| output: ty::FnDiverging, |
| variadic: false |
| }), |
| })); |
| |
| let unwresume = ccx.eh_unwind_resume(); |
| if let Some(llfn) = unwresume.get() { |
| return Callee::ptr(datum::immediate_rvalue(llfn, ty)); |
| } |
| let llfn = declare::declare_fn(ccx, "rust_eh_unwind_resume", ty); |
| attributes::unwind(llfn, true); |
| unwresume.set(Some(llfn)); |
| Callee::ptr(datum::immediate_rvalue(llfn, ty)) |
| } |
| } |
| |
| // Basic block context. We create a block context for each basic block |
| // (single-entry, single-exit sequence of instructions) we generate from Rust |
| // code. Each basic block we generate is attached to a function, typically |
| // with many basic blocks per function. All the basic blocks attached to a |
| // function are organized as a directed graph. |
| pub struct BlockS<'blk, 'tcx: 'blk> { |
| // The BasicBlockRef returned from a call to |
| // llvm::LLVMAppendBasicBlock(llfn, name), which adds a basic |
| // block to the function pointed to by llfn. We insert |
| // instructions into that block by way of this block context. |
| // The block pointing to this one in the function's digraph. |
| pub llbb: BasicBlockRef, |
| pub terminated: Cell<bool>, |
| pub unreachable: Cell<bool>, |
| |
| // If this block part of a landing pad, then this is `Some` indicating what |
| // kind of landing pad its in, otherwise this is none. |
| pub lpad: Cell<Option<&'blk LandingPad>>, |
| |
| // AST node-id associated with this block, if any. Used for |
| // debugging purposes only. |
| pub opt_node_id: Option<ast::NodeId>, |
| |
| // The function context for the function to which this block is |
| // attached. |
| pub fcx: &'blk FunctionContext<'blk, 'tcx>, |
| } |
| |
| pub type Block<'blk, 'tcx> = &'blk BlockS<'blk, 'tcx>; |
| |
| impl<'blk, 'tcx> BlockS<'blk, 'tcx> { |
| pub fn new(llbb: BasicBlockRef, |
| opt_node_id: Option<ast::NodeId>, |
| fcx: &'blk FunctionContext<'blk, 'tcx>) |
| -> Block<'blk, 'tcx> { |
| fcx.block_arena.alloc(BlockS { |
| llbb: llbb, |
| terminated: Cell::new(false), |
| unreachable: Cell::new(false), |
| lpad: Cell::new(None), |
| opt_node_id: opt_node_id, |
| fcx: fcx |
| }) |
| } |
| |
| pub fn ccx(&self) -> &'blk CrateContext<'blk, 'tcx> { |
| self.fcx.ccx |
| } |
| pub fn fcx(&self) -> &'blk FunctionContext<'blk, 'tcx> { |
| self.fcx |
| } |
| pub fn tcx(&self) -> TyCtxt<'blk, 'tcx, 'tcx> { |
| self.fcx.ccx.tcx() |
| } |
| pub fn sess(&self) -> &'blk Session { self.fcx.ccx.sess() } |
| |
| pub fn lpad(&self) -> Option<&'blk LandingPad> { |
| self.lpad.get() |
| } |
| |
| pub fn set_lpad_ref(&self, lpad: Option<&'blk LandingPad>) { |
| // FIXME: use an IVar? |
| self.lpad.set(lpad); |
| } |
| |
| pub fn set_lpad(&self, lpad: Option<LandingPad>) { |
| self.set_lpad_ref(lpad.map(|p| &*self.fcx().lpad_arena.alloc(p))) |
| } |
| |
| pub fn mir(&self) -> CachedMir<'blk, 'tcx> { |
| self.fcx.mir() |
| } |
| |
| pub fn name(&self, name: ast::Name) -> String { |
| name.to_string() |
| } |
| |
| pub fn node_id_to_string(&self, id: ast::NodeId) -> String { |
| self.tcx().map.node_to_string(id).to_string() |
| } |
| |
| pub fn to_str(&self) -> String { |
| format!("[block {:p}]", self) |
| } |
| |
| pub fn monomorphize<T>(&self, value: &T) -> T |
| where T: TransNormalize<'tcx> |
| { |
| monomorphize::apply_param_substs(self.tcx(), |
| self.fcx.param_substs, |
| value) |
| } |
| |
| pub fn build(&'blk self) -> BlockAndBuilder<'blk, 'tcx> { |
| BlockAndBuilder::new(self, OwnedBuilder::new_with_ccx(self.ccx())) |
| } |
| } |
| |
| pub struct OwnedBuilder<'blk, 'tcx: 'blk> { |
| builder: Builder<'blk, 'tcx> |
| } |
| |
| impl<'blk, 'tcx> OwnedBuilder<'blk, 'tcx> { |
| pub fn new_with_ccx(ccx: &'blk CrateContext<'blk, 'tcx>) -> Self { |
| // Create a fresh builder from the crate context. |
| let llbuilder = unsafe { |
| llvm::LLVMCreateBuilderInContext(ccx.llcx()) |
| }; |
| OwnedBuilder { |
| builder: Builder { |
| llbuilder: llbuilder, |
| ccx: ccx, |
| } |
| } |
| } |
| } |
| |
| impl<'blk, 'tcx> Drop for OwnedBuilder<'blk, 'tcx> { |
| fn drop(&mut self) { |
| unsafe { |
| llvm::LLVMDisposeBuilder(self.builder.llbuilder); |
| } |
| } |
| } |
| |
| pub struct BlockAndBuilder<'blk, 'tcx: 'blk> { |
| bcx: Block<'blk, 'tcx>, |
| owned_builder: OwnedBuilder<'blk, 'tcx>, |
| } |
| |
| impl<'blk, 'tcx> BlockAndBuilder<'blk, 'tcx> { |
| pub fn new(bcx: Block<'blk, 'tcx>, owned_builder: OwnedBuilder<'blk, 'tcx>) -> Self { |
| // Set the builder's position to this block's end. |
| owned_builder.builder.position_at_end(bcx.llbb); |
| BlockAndBuilder { |
| bcx: bcx, |
| owned_builder: owned_builder, |
| } |
| } |
| |
| pub fn with_block<F, R>(&self, f: F) -> R |
| where F: FnOnce(Block<'blk, 'tcx>) -> R |
| { |
| let result = f(self.bcx); |
| self.position_at_end(self.bcx.llbb); |
| result |
| } |
| |
| pub fn map_block<F>(self, f: F) -> Self |
| where F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx> |
| { |
| let BlockAndBuilder { bcx, owned_builder } = self; |
| let bcx = f(bcx); |
| BlockAndBuilder::new(bcx, owned_builder) |
| } |
| |
| pub fn at_start<F, R>(&self, f: F) -> R |
| where F: FnOnce(&BlockAndBuilder<'blk, 'tcx>) -> R |
| { |
| self.position_at_start(self.bcx.llbb); |
| let r = f(self); |
| self.position_at_end(self.bcx.llbb); |
| r |
| } |
| |
| // Methods delegated to bcx |
| |
| pub fn is_unreachable(&self) -> bool { |
| self.bcx.unreachable.get() |
| } |
| |
| pub fn ccx(&self) -> &'blk CrateContext<'blk, 'tcx> { |
| self.bcx.ccx() |
| } |
| pub fn fcx(&self) -> &'blk FunctionContext<'blk, 'tcx> { |
| self.bcx.fcx() |
| } |
| pub fn tcx(&self) -> TyCtxt<'blk, 'tcx, 'tcx> { |
| self.bcx.tcx() |
| } |
| pub fn sess(&self) -> &'blk Session { |
| self.bcx.sess() |
| } |
| |
| pub fn llbb(&self) -> BasicBlockRef { |
| self.bcx.llbb |
| } |
| |
| pub fn mir(&self) -> CachedMir<'blk, 'tcx> { |
| self.bcx.mir() |
| } |
| |
| pub fn monomorphize<T>(&self, value: &T) -> T |
| where T: TransNormalize<'tcx> |
| { |
| self.bcx.monomorphize(value) |
| } |
| |
| pub fn set_lpad(&self, lpad: Option<LandingPad>) { |
| self.bcx.set_lpad(lpad) |
| } |
| |
| pub fn set_lpad_ref(&self, lpad: Option<&'blk LandingPad>) { |
| // FIXME: use an IVar? |
| self.bcx.set_lpad_ref(lpad); |
| } |
| |
| pub fn lpad(&self) -> Option<&'blk LandingPad> { |
| self.bcx.lpad() |
| } |
| } |
| |
| impl<'blk, 'tcx> Deref for BlockAndBuilder<'blk, 'tcx> { |
| type Target = Builder<'blk, 'tcx>; |
| fn deref(&self) -> &Self::Target { |
| &self.owned_builder.builder |
| } |
| } |
| |
| /// 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 LandingPad { |
| cleanuppad: Option<ValueRef>, |
| operand: Option<OperandBundleDef>, |
| } |
| |
| impl LandingPad { |
| pub fn gnu() -> LandingPad { |
| LandingPad { cleanuppad: None, operand: None } |
| } |
| |
| pub fn msvc(cleanuppad: ValueRef) -> LandingPad { |
| LandingPad { |
| cleanuppad: Some(cleanuppad), |
| operand: Some(OperandBundleDef::new("funclet", &[cleanuppad])), |
| } |
| } |
| |
| pub fn bundle(&self) -> Option<&OperandBundleDef> { |
| self.operand.as_ref() |
| } |
| |
| pub fn cleanuppad(&self) -> Option<ValueRef> { |
| self.cleanuppad |
| } |
| } |
| |
| impl Clone for LandingPad { |
| fn clone(&self) -> LandingPad { |
| LandingPad { |
| cleanuppad: self.cleanuppad, |
| operand: self.cleanuppad.map(|p| { |
| OperandBundleDef::new("funclet", &[p]) |
| }), |
| } |
| } |
| } |
| |
| pub struct Result<'blk, 'tcx: 'blk> { |
| pub bcx: Block<'blk, 'tcx>, |
| pub val: ValueRef |
| } |
| |
| impl<'b, 'tcx> Result<'b, 'tcx> { |
| pub fn new(bcx: Block<'b, 'tcx>, val: ValueRef) -> Result<'b, 'tcx> { |
| Result { |
| bcx: bcx, |
| val: val, |
| } |
| } |
| } |
| |
| 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_integral(t: Type, u: u64, sign_extend: bool) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstInt(t.to_ref(), u, sign_extend as Bool) |
| } |
| } |
| |
| pub fn C_floating(s: &str, t: Type) -> ValueRef { |
| unsafe { |
| let s = CString::new(s).unwrap(); |
| llvm::LLVMConstRealOfString(t.to_ref(), s.as_ptr()) |
| } |
| } |
| |
| pub fn C_floating_f64(f: f64, t: Type) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstReal(t.to_ref(), f) |
| } |
| } |
| |
| pub fn C_nil(ccx: &CrateContext) -> ValueRef { |
| C_struct(ccx, &[], false) |
| } |
| |
| pub fn C_bool(ccx: &CrateContext, val: bool) -> ValueRef { |
| C_integral(Type::i1(ccx), val as u64, false) |
| } |
| |
| pub fn C_i32(ccx: &CrateContext, i: i32) -> ValueRef { |
| C_integral(Type::i32(ccx), i as u64, true) |
| } |
| |
| pub fn C_u32(ccx: &CrateContext, i: u32) -> ValueRef { |
| C_integral(Type::i32(ccx), i as u64, false) |
| } |
| |
| pub fn C_u64(ccx: &CrateContext, i: u64) -> ValueRef { |
| C_integral(Type::i64(ccx), i, false) |
| } |
| |
| pub fn C_int<I: AsI64>(ccx: &CrateContext, i: I) -> ValueRef { |
| let v = i.as_i64(); |
| |
| let bit_size = machine::llbitsize_of_real(ccx, ccx.int_type()); |
| |
| if bit_size < 64 { |
| // make sure it doesn't overflow |
| assert!(v < (1<<(bit_size-1)) && v >= -(1<<(bit_size-1))); |
| } |
| |
| C_integral(ccx.int_type(), v as u64, true) |
| } |
| |
| pub fn C_uint<I: AsU64>(ccx: &CrateContext, i: I) -> ValueRef { |
| let v = i.as_u64(); |
| |
| let bit_size = machine::llbitsize_of_real(ccx, ccx.int_type()); |
| |
| if bit_size < 64 { |
| // make sure it doesn't overflow |
| assert!(v < (1<<bit_size)); |
| } |
| |
| C_integral(ccx.int_type(), v, false) |
| } |
| |
| pub trait AsI64 { fn as_i64(self) -> i64; } |
| pub trait AsU64 { fn as_u64(self) -> u64; } |
| |
| // FIXME: remove the intptr conversions, because they |
| // are host-architecture-dependent |
| impl AsI64 for i64 { fn as_i64(self) -> i64 { self as i64 }} |
| impl AsI64 for i32 { fn as_i64(self) -> i64 { self as i64 }} |
| impl AsI64 for isize { fn as_i64(self) -> i64 { self as i64 }} |
| |
| impl AsU64 for u64 { fn as_u64(self) -> u64 { self as u64 }} |
| impl AsU64 for u32 { fn as_u64(self) -> u64 { self as u64 }} |
| impl AsU64 for usize { fn as_u64(self) -> u64 { self as u64 }} |
| |
| pub fn C_u8(ccx: &CrateContext, i: u8) -> ValueRef { |
| C_integral(Type::i8(ccx), i as u64, false) |
| } |
| |
| |
| // 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 gsym = token::gensym("str"); |
| let sym = format!("str{}", gsym.0); |
| 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::LLVMSetLinkage(g, llvm::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), Type::i8p(cx)); |
| C_named_struct(cx.tn().find_type("str_slice").unwrap(), &[cs, C_uint(cx, len)]) |
| } |
| |
| 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_named_struct(t: Type, elts: &[ValueRef]) -> ValueRef { |
| unsafe { |
| llvm::LLVMConstNamedStruct(t.to_ref(), elts.as_ptr(), elts.len() as c_uint) |
| } |
| } |
| |
| 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, us: &[c_uint]) |
| -> ValueRef { |
| unsafe { |
| let r = llvm::LLVMConstExtractValue(v, us.as_ptr(), us.len() as c_uint); |
| |
| debug!("const_get_elt(v={:?}, us={:?}, r={:?})", |
| Value(v), us, Value(r)); |
| |
| r |
| } |
| } |
| |
| pub fn const_to_int(v: ValueRef) -> i64 { |
| unsafe { |
| llvm::LLVMConstIntGetSExtValue(v) |
| } |
| } |
| |
| pub fn const_to_uint(v: ValueRef) -> u64 { |
| unsafe { |
| llvm::LLVMConstIntGetZExtValue(v) |
| } |
| } |
| |
| fn is_const_integral(v: ValueRef) -> bool { |
| unsafe { |
| !llvm::LLVMIsAConstantInt(v).is_null() |
| } |
| } |
| |
| pub fn const_to_opt_int(v: ValueRef) -> Option<i64> { |
| unsafe { |
| if is_const_integral(v) { |
| Some(llvm::LLVMConstIntGetSExtValue(v)) |
| } else { |
| None |
| } |
| } |
| } |
| |
| pub fn const_to_opt_uint(v: ValueRef) -> Option<u64> { |
| unsafe { |
| if is_const_integral(v) { |
| Some(llvm::LLVMConstIntGetZExtValue(v)) |
| } else { |
| None |
| } |
| } |
| } |
| |
| pub fn is_undef(val: ValueRef) -> bool { |
| unsafe { |
| llvm::LLVMIsUndef(val) != False |
| } |
| } |
| |
| #[allow(dead_code)] // potentially useful |
| pub fn is_null(val: ValueRef) -> bool { |
| unsafe { |
| llvm::LLVMIsNull(val) != False |
| } |
| } |
| |
| pub fn monomorphize_type<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, t: Ty<'tcx>) -> Ty<'tcx> { |
| bcx.fcx.monomorphize(&t) |
| } |
| |
| pub fn node_id_type<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, id: ast::NodeId) -> Ty<'tcx> { |
| let tcx = bcx.tcx(); |
| let t = tcx.node_id_to_type(id); |
| monomorphize_type(bcx, t) |
| } |
| |
| pub fn expr_ty<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, ex: &hir::Expr) -> Ty<'tcx> { |
| node_id_type(bcx, ex.id) |
| } |
| |
| pub fn expr_ty_adjusted<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, ex: &hir::Expr) -> Ty<'tcx> { |
| monomorphize_type(bcx, bcx.tcx().expr_ty_adjusted(ex)) |
| } |
| |
| /// Attempts to resolve an obligation. The result is a shallow vtable resolution -- meaning that we |
| /// do not (necessarily) resolve all nested obligations on the impl. Note that type check should |
| /// guarantee to us that all nested obligations *could be* resolved if we wanted to. |
| pub fn fulfill_obligation<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| span: Span, |
| trait_ref: ty::PolyTraitRef<'tcx>) |
| -> traits::Vtable<'tcx, ()> |
| { |
| let tcx = scx.tcx(); |
| |
| // Remove any references to regions; this helps improve caching. |
| let trait_ref = tcx.erase_regions(&trait_ref); |
| |
| scx.trait_cache().memoize(trait_ref, || { |
| debug!("trans::fulfill_obligation(trait_ref={:?}, def_id={:?})", |
| trait_ref, trait_ref.def_id()); |
| |
| // Do the initial selection for the obligation. This yields the |
| // shallow result we are looking for -- that is, what specific impl. |
| tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| { |
| let mut selcx = SelectionContext::new(&infcx); |
| |
| let obligation_cause = traits::ObligationCause::misc(span, |
| ast::DUMMY_NODE_ID); |
| let obligation = traits::Obligation::new(obligation_cause, |
| trait_ref.to_poly_trait_predicate()); |
| |
| let selection = match selcx.select(&obligation) { |
| Ok(Some(selection)) => selection, |
| Ok(None) => { |
| // Ambiguity can happen when monomorphizing during trans |
| // expands to some humongo type that never occurred |
| // statically -- this humongo type can then overflow, |
| // leading to an ambiguous result. So report this as an |
| // overflow bug, since I believe this is the only case |
| // where ambiguity can result. |
| debug!("Encountered ambiguity selecting `{:?}` during trans, \ |
| presuming due to overflow", |
| trait_ref); |
| tcx.sess.span_fatal(span, |
| "reached the recursion limit during monomorphization \ |
| (selection ambiguity)"); |
| } |
| Err(e) => { |
| span_bug!(span, "Encountered error `{:?}` selecting `{:?}` during trans", |
| e, trait_ref) |
| } |
| }; |
| |
| debug!("fulfill_obligation: selection={:?}", selection); |
| |
| // Currently, we use a fulfillment context to completely resolve |
| // all nested obligations. This is because they can inform the |
| // inference of the impl's type parameters. |
| let mut fulfill_cx = traits::FulfillmentContext::new(); |
| let vtable = selection.map(|predicate| { |
| debug!("fulfill_obligation: register_predicate_obligation {:?}", predicate); |
| fulfill_cx.register_predicate_obligation(&infcx, predicate); |
| }); |
| let vtable = infcx.drain_fulfillment_cx_or_panic(span, &mut fulfill_cx, &vtable); |
| |
| info!("Cache miss: {:?} => {:?}", trait_ref, vtable); |
| vtable |
| }) |
| }) |
| } |
| |
| /// Normalizes the predicates and checks whether they hold. If this |
| /// returns false, then either normalize encountered an error or one |
| /// of the predicates did not hold. Used when creating vtables to |
| /// check for unsatisfiable methods. |
| pub fn normalize_and_test_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| predicates: Vec<ty::Predicate<'tcx>>) |
| -> bool |
| { |
| debug!("normalize_and_test_predicates(predicates={:?})", |
| predicates); |
| |
| tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| { |
| let mut selcx = SelectionContext::new(&infcx); |
| let mut fulfill_cx = traits::FulfillmentContext::new(); |
| let cause = traits::ObligationCause::dummy(); |
| let traits::Normalized { value: predicates, obligations } = |
| traits::normalize(&mut selcx, cause.clone(), &predicates); |
| for obligation in obligations { |
| fulfill_cx.register_predicate_obligation(&infcx, obligation); |
| } |
| for predicate in predicates { |
| let obligation = traits::Obligation::new(cause.clone(), predicate); |
| fulfill_cx.register_predicate_obligation(&infcx, obligation); |
| } |
| |
| infcx.drain_fulfillment_cx(&mut fulfill_cx, &()).is_ok() |
| }) |
| } |
| |
| 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[..]), |
| } |
| } |
| } |
| } |
| |
| /// Return the VariantDef corresponding to an inlined variant node |
| pub fn inlined_variant_def<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| inlined_vid: ast::NodeId) |
| -> ty::VariantDef<'tcx> |
| { |
| let ctor_ty = ccx.tcx().node_id_to_type(inlined_vid); |
| debug!("inlined_variant_def: ctor_ty={:?} inlined_vid={:?}", ctor_ty, |
| inlined_vid); |
| let adt_def = match ctor_ty.sty { |
| ty::TyFnDef(_, _, &ty::BareFnTy { sig: ty::Binder(ty::FnSig { |
| output: ty::FnConverging(ty), .. |
| }), ..}) => ty, |
| _ => ctor_ty |
| }.ty_adt_def().unwrap(); |
| let variant_def_id = if ccx.tcx().map.is_inlined(inlined_vid) { |
| ccx.defid_for_inlined_node(inlined_vid).unwrap() |
| } else { |
| ccx.tcx().map.local_def_id(inlined_vid) |
| }; |
| |
| adt_def.variants |
| .iter() |
| .find(|v| variant_def_id == v.did) |
| .unwrap_or_else(|| { |
| bug!("no variant for {:?}::{}", adt_def, inlined_vid) |
| }) |
| } |
| |
| // 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<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
| lhs: ValueRef, |
| rhs: ValueRef, |
| binop_debug_loc: DebugLoc) -> 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, binop_debug_loc); |
| build::Shl(bcx, lhs, rhs, binop_debug_loc) |
| } |
| |
| pub fn build_unchecked_rshift<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
| lhs_t: Ty<'tcx>, |
| lhs: ValueRef, |
| rhs: ValueRef, |
| binop_debug_loc: DebugLoc) -> 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, binop_debug_loc); |
| let is_signed = lhs_t.is_signed(); |
| if is_signed { |
| build::AShr(bcx, lhs, rhs, binop_debug_loc) |
| } else { |
| build::LShr(bcx, lhs, rhs, binop_debug_loc) |
| } |
| } |
| |
| fn shift_mask_rhs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
| rhs: ValueRef, |
| debug_loc: DebugLoc) -> ValueRef { |
| let rhs_llty = val_ty(rhs); |
| build::And(bcx, rhs, shift_mask_val(bcx, rhs_llty, rhs_llty, false), debug_loc) |
| } |
| |
| pub fn shift_mask_val<'blk, 'tcx>(bcx: Block<'blk, '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_integral(mask_llty, !val, true) |
| } else { |
| C_integral(mask_llty, val, false) |
| } |
| }, |
| TypeKind::Vector => { |
| let mask = shift_mask_val(bcx, llty.element_type(), mask_llty.element_type(), invert); |
| build::VectorSplat(bcx, mask_llty.vector_length(), mask) |
| }, |
| _ => bug!("shift_mask_val: expected Integer or Vector, found {:?}", kind), |
| } |
| } |
