src/librustc_codegen_llvm/mir/statement.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use rustc::mir;
  12
  13 use asm;
  14 use builder::Builder;
  15
  16 use super::FunctionCx;
  17 use super::LocalRef;
  18
  19 impl<'a, 'tcx> FunctionCx<'a, 'tcx> {
  20     pub fn codegen_statement(&mut self,
  21                            bx: Builder<'a, 'tcx>,
  22                            statement: &mir::Statement<'tcx>)
  23                            -> Builder<'a, 'tcx> {
  24         debug!("codegen_statement(statement={:?})", statement);
  25
  26         self.set_debug_loc(&bx, statement.source_info);
  27         match statement.kind {
  28             mir::StatementKind::Assign(ref place, ref rvalue) => {
  29                 if let mir::Place::Local(index) = *place {
  30                     match self.locals[index] {
  31                         LocalRef::Place(cg_dest) => {
  32                             self.codegen_rvalue(bx, cg_dest, rvalue)
  33                         }
  34                         LocalRef::Operand(None) => {
  35                             let (bx, operand) = self.codegen_rvalue_operand(bx, rvalue);
  36                             self.locals[index] = LocalRef::Operand(Some(operand));
  37                             bx
  38                         }
  39                         LocalRef::Operand(Some(op)) => {
  40                             if !op.layout.is_zst() {
  41                                 span_bug!(statement.source_info.span,
  42                                           "operand {:?} already assigned",
  43                                           rvalue);
  44                             }
  45
  46                             // If the type is zero-sized, it's already been set here,
  47                             // but we still need to make sure we codegen the operand
  48                             self.codegen_rvalue_operand(bx, rvalue).0
  49                         }
  50                     }
  51                 } else {
  52                     let cg_dest = self.codegen_place(&bx, place);
  53                     self.codegen_rvalue(bx, cg_dest, rvalue)
  54                 }
  55             }
  56             mir::StatementKind::SetDiscriminant{ref place, variant_index} => {
  57                 self.codegen_place(&bx, place)
  58                     .codegen_set_discr(&bx, variant_index);
  59                 bx
  60             }
  61             mir::StatementKind::StorageLive(local) => {
  62                 if let LocalRef::Place(cg_place) = self.locals[local] {
  63                     cg_place.storage_live(&bx);
  64                 }
  65                 bx
  66             }
  67             mir::StatementKind::StorageDead(local) => {
  68                 if let LocalRef::Place(cg_place) = self.locals[local] {
  69                     cg_place.storage_dead(&bx);
  70                 }
  71                 bx
  72             }
  73             mir::StatementKind::InlineAsm { ref asm, ref outputs, ref inputs } => {
  74                 let outputs = outputs.iter().map(|output| {
  75                     self.codegen_place(&bx, output)
  76                 }).collect();
  77
  78                 let input_vals = inputs.iter().map(|input| {
  79                     self.codegen_operand(&bx, input).immediate()
  80                 }).collect();
  81
  82                 asm::codegen_inline_asm(&bx, asm, outputs, input_vals);
  83                 bx
  84             }
  85             mir::StatementKind::ReadForMatch(_) |
  86             mir::StatementKind::EndRegion(_) |
  87             mir::StatementKind::Validate(..) |
  88             mir::StatementKind::UserAssertTy(..) |
  89             mir::StatementKind::Nop => bx,
  90         }
  91     }
  92 }