Subzero: Add Non-SFI support for x86-32.

src/IceAssemblerX86BaseImpl.h

 //===- subzero/src/IceAssemblerX86BaseImpl.h - base x86 assembler -*- C++ -*-=//
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        The Subzero Code Generator
@@ skipping 105 matching lines @@
   emitRex(RexTypeIrrelevant, address, RexRegIrrelevant);
   emitUint8(0xFF);
   emitOperand(2, address);
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::call(const ConstantRelocatable *label) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   intptr_t call_start = Buffer.getPosition();
   emitUint8(0xE8);
-  emitFixup(this->createFixup(Traits::PcRelFixup, label));
+  emitFixup(this->createFixup(Traits::FK_PcRel, label));
   emitInt32(-4);
   assert((Buffer.getPosition() - call_start) == kCallExternalLabelSize);
   (void)call_start;
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::call(const Immediate &abs_address) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   intptr_t call_start = Buffer.getPosition();
   emitUint8(0xE8);
-  emitFixup(this->createFixup(Traits::PcRelFixup, AssemblerFixup::NullSymbol));
+  emitFixup(this->createFixup(Traits::FK_PcRel, AssemblerFixup::NullSymbol));
   emitInt32(abs_address.value() - 4);
   assert((Buffer.getPosition() - call_start) == kCallExternalLabelSize);
   (void)call_start;
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::pushl(typename Traits::GPRRegister reg) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitRexB(RexTypeIrrelevant, reg);
   emitUint8(0x50 + gprEncoding(reg));
@@ skipping 3069 matching lines @@
     emitLabelLink(label);
   }
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::j(typename Traits::Cond::BrCond condition,
                                   const ConstantRelocatable *label) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitUint8(0x0F);
   emitUint8(0x80 + condition);
-  emitFixup(this->createFixup(Traits::PcRelFixup, label));
+  assert(0 && "Untested - please verify and then remove this assert.");

[John, 2016/01/04 21:33:51]

Why isn't this codepath exercised yet? If this instruction can ever be emitted,
then we should figure a test to emit this and ensure it works -- otherwise we
risk releasing a broken binary that will silently do the wrong thing in release
mode.

[Jim Stichnoth, 2016/01/04 23:32:12]

We don't (yet) have a way to produce a conditional or unconditional branch into
a different function.

Good point about MINIMAL mode - changed the assert to a report_fatal_error.

+  emitFixup(this->createFixup(Traits::FK_PcRel, label));
   emitInt32(-4);
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::jmp(typename Traits::GPRRegister reg) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitRexB(RexTypeIrrelevant, reg);
   emitUint8(0xFF);
   emitRegisterOperand(4, gprEncoding(reg));
 }
@@ skipping 19 matching lines @@
   } else {
     emitUint8(0xE9);
     emitLabelLink(label);
   }
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::jmp(const ConstantRelocatable *label) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitUint8(0xE9);
-  emitFixup(this->createFixup(Traits::PcRelFixup, label));
+  assert(0 && "Untested - please verify and then remove this assert.");
+  emitFixup(this->createFixup(Traits::FK_PcRel, label));
   emitInt32(-4);
 }
 
 template <class Machine> void AssemblerX86Base<Machine>::mfence() {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitUint8(0x0F);
   emitUint8(0xAE);
   emitUint8(0xF0);
 }
 
@@ skipping 311 matching lines @@
   (void)shifter;
   if (Ty == IceType_i16)
     emitOperandSizeOverride();
   emitRexB(Ty, operand.rm());
   emitUint8(isByteSizedArithType(Ty) ? 0xD2 : 0xD3);
   emitOperand(rm, operand);
 }
 
 } // end of namespace X86Internal
 } // end of namespace Ice