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 use super::OperandValue;
  19 use value::Value;
  20
  21 impl FunctionCx<'a, 'll, 'tcx, &'ll Value> {
  22     pub fn codegen_statement(&mut self,
  23                            bx: Builder<'a, 'll, 'tcx>,
  24                            statement: &mir::Statement<'tcx>)
  25                            -> Builder<'a, 'll, 'tcx> {
  26         debug!("codegen_statement(statement={:?})", statement);
  27
  28         self.set_debug_loc(&bx, statement.source_info);
  29         match statement.kind {
  30             mir::StatementKind::Assign(ref place, ref rvalue) => {
  31                 if let mir::Place::Local(index) = *place {
  32                     match self.locals[index] {
  33                         LocalRef::Place(cg_dest) => {
  34                             self.codegen_rvalue(bx, cg_dest, rvalue)
  35                         }
  36                         LocalRef::UnsizedPlace(cg_indirect_dest) => {
  37                             self.codegen_rvalue_unsized(bx, cg_indirect_dest, rvalue)
  38                         }
  39                         LocalRef::Operand(None) => {
  40                             let (bx, operand) = self.codegen_rvalue_operand(bx, rvalue);
  41                             self.locals[index] = LocalRef::Operand(Some(operand));
  42                             bx
  43                         }
  44                         LocalRef::Operand(Some(op)) => {
  45                             if !op.layout.is_zst() {
  46                                 span_bug!(statement.source_info.span,
  47                                           "operand {:?} already assigned",
  48                                           rvalue);
  49                             }
  50
  51                             // If the type is zero-sized, it's already been set here,
  52                             // but we still need to make sure we codegen the operand
  53                             self.codegen_rvalue_operand(bx, rvalue).0
  54                         }
  55                     }
  56                 } else {
  57                     let cg_dest = self.codegen_place(&bx, place);
  58                     self.codegen_rvalue(bx, cg_dest, rvalue)
  59                 }
  60             }
  61             mir::StatementKind::SetDiscriminant{ref place, variant_index} => {
  62                 self.codegen_place(&bx, place)
  63                     .codegen_set_discr(&bx, variant_index);
  64                 bx
  65             }
  66             mir::StatementKind::StorageLive(local) => {
  67                 if let LocalRef::Place(cg_place) = self.locals[local] {
  68                     cg_place.storage_live(&bx);
  69                 } else if let LocalRef::UnsizedPlace(cg_indirect_place) = self.locals[local] {
  70                     cg_indirect_place.storage_live(&bx);
  71                 }
  72                 bx
  73             }
  74             mir::StatementKind::StorageDead(local) => {
  75                 if let LocalRef::Place(cg_place) = self.locals[local] {
  76                     cg_place.storage_dead(&bx);
  77                 } else if let LocalRef::UnsizedPlace(cg_indirect_place) = self.locals[local] {
  78                     cg_indirect_place.storage_dead(&bx);
  79                 }
  80                 bx
  81             }
  82             mir::StatementKind::InlineAsm { ref asm, ref outputs, ref inputs } => {
  83                 let outputs = outputs.iter().map(|output| {
  84                     self.codegen_place(&bx, output)
  85                 }).collect();
  86
  87                 let input_vals = inputs.iter()
  88                     .fold(Vec::with_capacity(inputs.len()), |mut acc, (span, input)| {
  89                         let op = self.codegen_operand(&bx, input);
  90                         if let OperandValue::Immediate(_) = op.val {
  91                             acc.push(op.immediate());
  92                         } else {
  93                             span_err!(bx.sess(), span.to_owned(), E0669,
  94                                      "invalid value for constraint in inline assembly");
  95                         }
  96                         acc
  97                 });
  98
  99                 if input_vals.len() == inputs.len() {
 100                     let res = asm::codegen_inline_asm(&bx, asm, outputs, input_vals);
 101                     if !res {
 102                         span_err!(bx.sess(), statement.source_info.span, E0668,
 103                                   "malformed inline assembly");
 104                     }
 105                 }
 106                 bx
 107             }
 108             mir::StatementKind::FakeRead(..) |
 109             mir::StatementKind::EndRegion(..) |
 110             mir::StatementKind::Retag { .. } |
 111             mir::StatementKind::EscapeToRaw { .. } |
 112             mir::StatementKind::AscribeUserType(..) |
 113             mir::StatementKind::Nop => bx,
 114         }
 115     }
 116 }