Subzero: Add locking to prepare for multithreaded translation.

src/IceCfg.cpp

Index: src/IceCfg.cpp
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index e8c74bacc3a08c3e44c460092ed950edfea76395..8eac918b69d671de8fb9e15b511b27b157456b71 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -56,6 +56,7 @@ Cfg::~Cfg() {
 void Cfg::setError(const IceString &Message) {
   HasError = true;
   ErrorMessage = Message;
+  OstreamLocker L(Ctx);
   Ctx->getStrDump() << "ICE translation error: " << ErrorMessage << "\n";
 }
 
@@ -335,6 +336,7 @@ void Cfg::liveness(LivenessMode Mode) {
 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;
@@ -442,6 +444,7 @@ void Cfg::emit() {
     liveness(Liveness_Basic);
     dump("After recomputing liveness for -decorate-asm");
   }
+  OstreamLocker L(Ctx);
   Ostream &Str = Ctx->getStrEmit();
   IceString MangledName = getContext()->mangleName(getFunctionName());
   emitTextHeader(MangledName);
@@ -454,6 +457,7 @@ void Cfg::emitIAS() {
   TimerMarker T(TimerStack::TT_emit, this);
   assert(!Ctx->getFlags().DecorateAsm);
   IceString MangledName = getContext()->mangleName(getFunctionName());
+  OstreamLocker L(Ctx);
   if (!Ctx->getFlags().UseELFWriter)

[jvoung (off chromium), 2015/01/15 18:20:40]

Technically, the lock doesn't need to be held this long. The loop through
CfgNodes can be done without the lock, and just the emitTextHeader /
writeFunctionCode and emitIASBytes need it.

It might be okay to do the loop first, and move the emitTextHeader to be after,
since the .s fallback only writes in bulk via emitIASBytes.

[Jim Stichnoth, 2015/01/17 18:44:16]

Done.

     emitTextHeader(MangledName);
   for (CfgNode *Node : Nodes)
@@ -474,6 +478,7 @@ void Cfg::dump(const IceString &Message) {
     return;
   if (!Ctx->isVerbose())
     return;
+  OstreamLocker L(Ctx);
   Ostream &Str = Ctx->getStrDump();
   if (!Message.empty())
     Str << "================ " << Message << " ================\n";