[ORC] Add support for emulated TLS to ORCv2.

This commit adds a ManglingOptions struct to IRMaterializationUnit, and replaces
IRCompileLayer::CompileFunction with a new IRCompileLayer::IRCompiler class. The
ManglingOptions struct defines the emulated-TLS state (via a bool member,
EmulatedTLS, which is true if emulated-TLS is enabled and false otherwise). The
IRCompileLayer::IRCompiler class wraps an IRCompiler (the same way that the
CompileFunction typedef used to), but adds a method to return the
IRCompileLayer::ManglingOptions that the compiler will use.

These changes allow us to correctly determine the symbols that will be produced
when a thread local global variable defined at the IR level is compiled with or
without emulated TLS. This is required for ORCv2, where MaterializationUnits
must declare their interface up-front.

Most ORCv2 clients should not require any changes. Clients writing custom IR
compilers will need to wrap their compiler in an IRCompileLayer::IRCompiler,
rather than an IRCompileLayer::CompileFunction, however this should be a
straightforward change (see modifications to CompileUtils.* in this patch for an
example).

1 files changed, 20 insertions, 11 deletions

diff --git a/llvm/lib/ExecutionEngine/Orc/CompileUtils.cpp b/llvm/lib/ExecutionEngine/Orc/CompileUtils.cpp
index f5671d9..8d2c2d9 100644
--- a/llvm/lib/ExecutionEngine/Orc/CompileUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/CompileUtils.cpp
@@ -24,8 +24,17 @@
 namespace llvm {
 namespace orc {
 
+IRMaterializationUnit::ManglingOptions
+irManglingOptionsFromTargetOptions(const TargetOptions &Opts) {
+  IRMaterializationUnit::ManglingOptions MO;
+
+  MO.EmulatedTLS = Opts.EmulatedTLS;
+
+  return MO;
+}
+
 /// Compile a Module to an ObjectFile.
-SimpleCompiler::CompileResult SimpleCompiler::operator()(Module &M) {
+Expected<SimpleCompiler::CompileResult> SimpleCompiler::operator()(Module &M) {
   CompileResult CachedObject = tryToLoadFromObjectCache(M);
   if (CachedObject)
     return CachedObject;
@@ -38,7 +47,8 @@ SimpleCompiler::CompileResult SimpleCompiler::operator()(Module &M) {
     legacy::PassManager PM;
     MCContext *Ctx;
     if (TM.addPassesToEmitMC(PM, Ctx, ObjStream))
-      llvm_unreachable("Target does not support MC emission.");
+      return make_error<StringError>("Target does not support MC emission",
+                                     inconvertibleErrorCode());
     PM.run(M);
   }
 
@@ -47,14 +57,11 @@ SimpleCompiler::CompileResult SimpleCompiler::operator()(Module &M) {
 
   auto Obj = object::ObjectFile::createObjectFile(ObjBuffer->getMemBufferRef());
 
-  if (Obj) {
-    notifyObjectCompiled(M, *ObjBuffer);
-    return std::move(ObjBuffer);
-  }
+  if (!Obj)
+    return Obj.takeError();
 
-  // TODO: Actually report errors helpfully.
-  consumeError(Obj.takeError());
-  return nullptr;
+  notifyObjectCompiled(M, *ObjBuffer);
+  return std::move(ObjBuffer);
 }
 
 SimpleCompiler::CompileResult
@@ -73,9 +80,11 @@ void SimpleCompiler::notifyObjectCompiled(const Module &M,
 
 ConcurrentIRCompiler::ConcurrentIRCompiler(JITTargetMachineBuilder JTMB,
                                            ObjectCache *ObjCache)
-    : JTMB(std::move(JTMB)), ObjCache(ObjCache) {}
+    : IRCompiler(irManglingOptionsFromTargetOptions(JTMB.getOptions())),
+      JTMB(std::move(JTMB)), ObjCache(ObjCache) {}
 
-std::unique_ptr<MemoryBuffer> ConcurrentIRCompiler::operator()(Module &M) {
+Expected<std::unique_ptr<MemoryBuffer>>
+ConcurrentIRCompiler::operator()(Module &M) {
   auto TM = cantFail(JTMB.createTargetMachine());
   SimpleCompiler C(*TM, ObjCache);
   return C(M);