src/librustc_codegen_ssa/mir/statement.rs

   1 use rustc::mir;
   2 use rustc_errors::struct_span_err;
   3
   4 use super::FunctionCx;
   5 use super::LocalRef;
   6 use super::OperandValue;
   7 use crate::traits::BuilderMethods;
   8 use crate::traits::*;
   9
  10 use rustc_error_codes::*;
  11
  12 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
  13     pub fn codegen_statement(&mut self, mut bx: Bx, statement: &mir::Statement<'tcx>) -> Bx {
  14         debug!("codegen_statement(statement={:?})", statement);
  15
  16         self.set_debug_loc(&mut bx, statement.source_info);
  17         match statement.kind {
  18             mir::StatementKind::Assign(box (ref place, ref rvalue)) => {
  19                 if let Some(index) = place.as_local() {
  20                     match self.locals[index] {
  21                         LocalRef::Place(cg_dest) => self.codegen_rvalue(bx, cg_dest, rvalue),
  22                         LocalRef::UnsizedPlace(cg_indirect_dest) => {
  23                             self.codegen_rvalue_unsized(bx, cg_indirect_dest, rvalue)
  24                         }
  25                         LocalRef::Operand(None) => {
  26                             let (mut bx, operand) = self.codegen_rvalue_operand(bx, rvalue);
  27                             self.locals[index] = LocalRef::Operand(Some(operand));
  28                             self.debug_introduce_local(&mut bx, index);
  29                             bx
  30                         }
  31                         LocalRef::Operand(Some(op)) => {
  32                             if !op.layout.is_zst() {
  33                                 span_bug!(
  34                                     statement.source_info.span,
  35                                     "operand {:?} already assigned",
  36                                     rvalue
  37                                 );
  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.as_ref());
  47                     self.codegen_rvalue(bx, cg_dest, rvalue)
  48                 }
  49             }
  50             mir::StatementKind::SetDiscriminant { box ref place, variant_index } => {
  51                 self.codegen_place(&mut bx, &place.as_ref())
  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) => {
  72                 let outputs = asm
  73                     .outputs
  74                     .iter()
  75                     .map(|output| self.codegen_place(&mut bx, &output.as_ref()))
  76                     .collect();
  77
  78                 let input_vals = asm.inputs.iter().fold(
  79                     Vec::with_capacity(asm.inputs.len()),
  80                     |mut acc, (span, input)| {
  81                         let op = self.codegen_operand(&mut bx, input);
  82                         if let OperandValue::Immediate(_) = op.val {
  83                             acc.push(op.immediate());
  84                         } else {
  85                             struct_span_err!(
  86                                 bx.sess(),
  87                                 span.to_owned(),
  88                                 E0669,
  89                                 "invalid value for constraint in inline assembly"
  90                             )
  91                             .emit();
  92                         }
  93                         acc
  94                     },
  95                 );
  96
  97                 if input_vals.len() == asm.inputs.len() {
  98                     let res = bx.codegen_inline_asm(
  99                         &asm.asm,
 100                         outputs,
 101                         input_vals,
 102                         statement.source_info.span,
 103                     );
 104                     if !res {
 105                         struct_span_err!(
 106                             bx.sess(),
 107                             statement.source_info.span,
 108                             E0668,
 109                             "malformed inline assembly"
 110                         )
 111                         .emit();
 112                     }
 113                 }
 114                 bx
 115             }
 116             mir::StatementKind::FakeRead(..)
 117             | mir::StatementKind::Retag { .. }
 118             | mir::StatementKind::AscribeUserType(..)
 119             | mir::StatementKind::Nop => bx,
 120         }
 121     }
 122 }