Subzero: Add locking to prepare for multithreaded translation.

src/IceCfg.cpp

 //===- subzero/src/IceCfg.cpp - Control flow graph implementation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Cfg class, including constant pool
@@ skipping 38 matching lines @@
   // TODO(stichnot,kschimpf): Set CurrentCfg=nullptr in the dtor for
   // safety.  This can't be done currently because the translator
   // manages the Cfg by creating a new Cfg (which sets CurrentCfg to
   // the new value), then deleting the old Cfg (which would then reset
   // CurrentCfg to nullptr).
 }
 
 void Cfg::setError(const IceString &Message) {
   HasError = true;
   ErrorMessage = Message;
+  OstreamLocker L(Ctx);
   Ctx->getStrDump() << "ICE translation error: " << ErrorMessage << "\n";
 }
 
 CfgNode *Cfg::makeNode() {
   SizeT LabelIndex = Nodes.size();
   CfgNode *Node = CfgNode::create(this, LabelIndex);
   Nodes.push_back(Node);
   return Node;
 }
 
@@ skipping 259 matching lines @@
       Node->livenessAddIntervals(getLiveness(), FirstInstNum, LastInstNum);
     }
   }
 }
 
 // Traverse every Variable of every Inst and verify that it
 // appears within the Variable's computed live range.
 bool Cfg::validateLiveness() const {
   TimerMarker T(TimerStack::TT_validateLiveness, this);
   bool Valid = true;
+  OstreamLocker L(Ctx);
   Ostream &Str = Ctx->getStrDump();
   for (CfgNode *Node : Nodes) {
     Inst *FirstInst = nullptr;
     for (Inst &Inst : Node->getInsts()) {
       if (Inst.isDeleted())
         continue;
       if (FirstInst == nullptr)
         FirstInst = &Inst;
       InstNumberT InstNumber = Inst.getNumber();
       if (Variable *Dest = Inst.getDest()) {
@@ skipping 87 matching lines @@
 void Cfg::emit() {
   if (!ALLOW_DUMP)
     return;
   TimerMarker T(TimerStack::TT_emit, this);
   if (Ctx->getFlags().DecorateAsm) {
     renumberInstructions();
     getVMetadata()->init(VMK_Uses);
     liveness(Liveness_Basic);
     dump("After recomputing liveness for -decorate-asm");
   }
+  OstreamLocker L(Ctx);
   Ostream &Str = Ctx->getStrEmit();
   IceString MangledName = getContext()->mangleName(getFunctionName());
   emitTextHeader(MangledName);
   for (CfgNode *Node : Nodes)
     Node->emit(this);
   Str << "\n";
 }
 
 void Cfg::emitIAS() {
   TimerMarker T(TimerStack::TT_emit, this);
   assert(!Ctx->getFlags().DecorateAsm);
   IceString MangledName = getContext()->mangleName(getFunctionName());
-  if (!Ctx->getFlags().UseELFWriter)
-    emitTextHeader(MangledName);
+  // The emitIAS() routines emit into the internal assembler buffer,
+  // so there's no need to lock the streams until we're ready to call
+  // emitIASBytes().
   for (CfgNode *Node : Nodes)
     Node->emitIAS(this);
   // Now write the function to the file and track.
   if (Ctx->getFlags().UseELFWriter) {
     getAssembler<Assembler>()->alignFunction();
     Ctx->getObjectWriter()->writeFunctionCode(MangledName, getInternal(),
                                               getAssembler<Assembler>());
   } else {
+    OstreamLocker L(Ctx);
+    emitTextHeader(MangledName);
     getAssembler<Assembler>()->emitIASBytes(Ctx);
   }
 }
 
 // Dumps the IR with an optional introductory message.
 void Cfg::dump(const IceString &Message) {
   if (!ALLOW_DUMP)
     return;
   if (!Ctx->isVerbose())
     return;
+  OstreamLocker L(Ctx);
   Ostream &Str = Ctx->getStrDump();
   if (!Message.empty())
     Str << "================ " << Message << " ================\n";
   setCurrentNode(getEntryNode());
   // Print function name+args
   if (getContext()->isVerbose(IceV_Instructions)) {
     Str << "define ";
     if (getInternal() && !Ctx->getFlags().DisableInternal)
       Str << "internal ";
     Str << ReturnType << " @" << Ctx->mangleName(getFunctionName()) << "(";
@@ skipping 20 matching lines @@
     }
   }
   // Print each basic block
   for (CfgNode *Node : Nodes)
     Node->dump(this);
   if (getContext()->isVerbose(IceV_Instructions))
     Str << "}\n";
 }
 
 } // end of namespace Ice