compiler/rustc_codegen_ssa/src/mono_item.rs

   1 use crate::base;
   2 use crate::common;
   3 use crate::traits::*;
   4 use rustc_hir as hir;
   5 use rustc_middle::mir::mono::MonoItem;
   6 use rustc_middle::mir::mono::{Linkage, Visibility};
   7 use rustc_middle::ty::layout::HasTyCtxt;
   8 use rustc_target::abi::LayoutOf;
   9
  10 pub trait MonoItemExt<'a, 'tcx> {
  11     fn define<Bx: BuilderMethods<'a, 'tcx>>(&self, cx: &'a Bx::CodegenCx);
  12     fn predefine<Bx: BuilderMethods<'a, 'tcx>>(
  13         &self,
  14         cx: &'a Bx::CodegenCx,
  15         linkage: Linkage,
  16         visibility: Visibility,
  17     );
  18     fn to_raw_string(&self) -> String;
  19 }
  20
  21 impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
  22     fn define<Bx: BuilderMethods<'a, 'tcx>>(&self, cx: &'a Bx::CodegenCx) {
  23         debug!(
  24             "BEGIN IMPLEMENTING '{} ({})' in cgu {}",
  25             self,
  26             self.to_raw_string(),
  27             cx.codegen_unit().name()
  28         );
  29
  30         match *self {
  31             MonoItem::Static(def_id) => {
  32                 cx.codegen_static(def_id, cx.tcx().is_mutable_static(def_id));
  33             }
  34             MonoItem::GlobalAsm(item_id) => {
  35                 let item = cx.tcx().hir().item(item_id);
  36                 if let hir::ItemKind::GlobalAsm(ref asm) = item.kind {
  37                     let operands: Vec<_> = asm
  38                         .operands
  39                         .iter()
  40                         .map(|(op, op_sp)| match *op {
  41                             hir::InlineAsmOperand::Const { ref anon_const } => {
  42                                 let anon_const_def_id =
  43                                     cx.tcx().hir().local_def_id(anon_const.hir_id).to_def_id();
  44                                 let const_value =
  45                                     cx.tcx().const_eval_poly(anon_const_def_id).unwrap_or_else(
  46                                         |_| span_bug!(*op_sp, "asm const cannot be resolved"),
  47                                     );
  48                                 let ty = cx
  49                                     .tcx()
  50                                     .typeck_body(anon_const.body)
  51                                     .node_type(anon_const.hir_id);
  52                                 let string = common::asm_const_to_str(
  53                                     cx.tcx(),
  54                                     *op_sp,
  55                                     const_value,
  56                                     cx.layout_of(ty),
  57                                 );
  58                                 GlobalAsmOperandRef::Const { string }
  59                             }
  60                             _ => span_bug!(*op_sp, "invalid operand type for global_asm!"),
  61                         })
  62                         .collect();
  63
  64                     cx.codegen_global_asm(asm.template, &operands, asm.options, asm.line_spans);
  65                 } else {
  66                     span_bug!(item.span, "Mismatch between hir::Item type and MonoItem type")
  67                 }
  68             }
  69             MonoItem::Fn(instance) => {
  70                 base::codegen_instance::<Bx>(&cx, instance);
  71             }
  72         }
  73
  74         debug!(
  75             "END IMPLEMENTING '{} ({})' in cgu {}",
  76             self,
  77             self.to_raw_string(),
  78             cx.codegen_unit().name()
  79         );
  80     }
  81
  82     fn predefine<Bx: BuilderMethods<'a, 'tcx>>(
  83         &self,
  84         cx: &'a Bx::CodegenCx,
  85         linkage: Linkage,
  86         visibility: Visibility,
  87     ) {
  88         debug!(
  89             "BEGIN PREDEFINING '{} ({})' in cgu {}",
  90             self,
  91             self.to_raw_string(),
  92             cx.codegen_unit().name()
  93         );
  94
  95         let symbol_name = self.symbol_name(cx.tcx()).name;
  96
  97         debug!("symbol {}", &symbol_name);
  98
  99         match *self {
 100             MonoItem::Static(def_id) => {
 101                 cx.predefine_static(def_id, linkage, visibility, &symbol_name);
 102             }
 103             MonoItem::Fn(instance) => {
 104                 cx.predefine_fn(instance, linkage, visibility, &symbol_name);
 105             }
 106             MonoItem::GlobalAsm(..) => {}
 107         }
 108
 109         debug!(
 110             "END PREDEFINING '{} ({})' in cgu {}",
 111             self,
 112             self.to_raw_string(),
 113             cx.codegen_unit().name()
 114         );
 115     }
 116
 117     fn to_raw_string(&self) -> String {
 118         match *self {
 119             MonoItem::Fn(instance) => {
 120                 format!("Fn({:?}, {})", instance.def, instance.substs.as_ptr() as usize)
 121             }
 122             MonoItem::Static(id) => format!("Static({:?})", id),
 123             MonoItem::GlobalAsm(id) => format!("GlobalAsm({:?})", id),
 124         }
 125     }
 126 }