src/librustc_codegen_ssa/mir/statement.rs

   1 use rustc::mir;
   2
   3 use crate::traits::BuilderMethods;
   4 use super::FunctionCx;
   5 use super::LocalRef;
   6 use super::OperandValue;
   7 use crate::traits::*;
   8
   9 impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
  10     pub fn codegen_statement(
  11         &mut self,
  12         mut bx: Bx,
  13         statement: &mir::Statement<'tcx>
  14     ) -> Bx {
  15         debug!("codegen_statement(statement={:?})", statement);
  16
  17         self.set_debug_loc(&mut bx, statement.source_info);
  18         match statement.kind {
  19             mir::StatementKind::Assign(ref place, ref rvalue) => {
  20                 if let mir::Place::Local(index) = *place {
  21                     match self.locals[index] {
  22                         LocalRef::Place(cg_dest) => {
  23                             self.codegen_rvalue(bx, cg_dest, rvalue)
  24                         }
  25                         LocalRef::UnsizedPlace(cg_indirect_dest) => {
  26                             self.codegen_rvalue_unsized(bx, cg_indirect_dest, rvalue)
  27                         }
  28                         LocalRef::Operand(None) => {
  29                             let (bx, operand) = self.codegen_rvalue_operand(bx, rvalue);
  30                             self.locals[index] = LocalRef::Operand(Some(operand));
  31                             bx
  32                         }
  33                         LocalRef::Operand(Some(op)) => {
  34                             if !op.layout.is_zst() {
  35                                 span_bug!(statement.source_info.span,
  36                                           "operand {:?} already assigned",
  37                                           rvalue);
  38                             }
  39
  40                             // If the type is zero-sized, it's already been set here,
  41                             // but we still need to make sure we codegen the operand
  42                             self.codegen_rvalue_operand(bx, rvalue).0
  43                         }
  44                     }
  45                 } else {
  46                     let cg_dest = self.codegen_place(&mut bx, place);
  47                     self.codegen_rvalue(bx, cg_dest, rvalue)
  48                 }
  49             }
  50             mir::StatementKind::SetDiscriminant{ref place, variant_index} => {
  51                 self.codegen_place(&mut bx, place)
  52                     .codegen_set_discr(&mut bx, variant_index);
  53                 bx
  54             }
  55             mir::StatementKind::StorageLive(local) => {
  56                 if let LocalRef::Place(cg_place) = self.locals[local] {
  57                     cg_place.storage_live(&mut bx);
  58                 } else if let LocalRef::UnsizedPlace(cg_indirect_place) = self.locals[local] {
  59                     cg_indirect_place.storage_live(&mut bx);
  60                 }
  61                 bx
  62             }
  63             mir::StatementKind::StorageDead(local) => {
  64                 if let LocalRef::Place(cg_place) = self.locals[local] {
  65                     cg_place.storage_dead(&mut bx);
  66                 } else if let LocalRef::UnsizedPlace(cg_indirect_place) = self.locals[local] {
  67                     cg_indirect_place.storage_dead(&mut bx);
  68                 }
  69                 bx
  70             }
  71             mir::StatementKind::InlineAsm { ref asm, ref outputs, ref inputs } => {
  72                 let outputs = outputs.iter().map(|output| {
  73                     self.codegen_place(&mut bx, output)
  74                 }).collect();
  75
  76                 let input_vals = inputs.iter()
  77                     .fold(Vec::with_capacity(inputs.len()), |mut acc, (span, input)| {
  78                         let op = self.codegen_operand(&mut bx, input);
  79                         if let OperandValue::Immediate(_) = op.val {
  80                             acc.push(op.immediate());
  81                         } else {
  82                             span_err!(bx.sess(), span.to_owned(), E0669,
  83                                      "invalid value for constraint in inline assembly");
  84                         }
  85                         acc
  86                 });
  87
  88                 if input_vals.len() == inputs.len() {
  89                     let res = bx.codegen_inline_asm(asm, outputs, input_vals);
  90                     if !res {
  91                         span_err!(bx.sess(), statement.source_info.span, E0668,
  92                                   "malformed inline assembly");
  93                     }
  94                 }
  95                 bx
  96             }
  97             mir::StatementKind::FakeRead(..) |
  98             mir::StatementKind::Retag { .. } |
  99             mir::StatementKind::AscribeUserType(..) |
 100             mir::StatementKind::Nop => bx,
 101         }
 102     }
 103 }