[NFC] Clean up performLLVM a bit

The only non-trivial bit is making the DiagnosticEngine parameter to swift::performLLVM required. No callers were taking advantage of this parameter allowing NULL.

Author: CodaFi

include/swift/Subsystems.h

@@ -61,6 +61,7 @@ namespace swift {
   class SILModule;
   class SILParserTUState;
   class SourceFile;
+  enum class SourceFileKind;
   class SourceManager;
   class SyntaxParseActions;
   class SyntaxParsingCache;
@@ -70,7 +71,6 @@ namespace swift {
   class TypeCheckerOptions;
   struct TypeLoc;
   class UnifiedStatsReporter;
-  enum class SourceFileKind;
 
   namespace Lowering {
     class TypeConverter;
@@ -286,29 +286,31 @@ namespace swift {
                                    StringRef OutputPath);
 
   /// Turn the given LLVM module into native code and return true on error.
-  bool performLLVM(const IRGenOptions &Opts, ASTContext &Ctx, llvm::Module *Module,
-                   StringRef OutputFilename,
-                   UnifiedStatsReporter *Stats=nullptr);
+  bool performLLVM(const IRGenOptions &Opts,
+                   ASTContext &Ctx,
+                   llvm::Module *Module,
+                   StringRef OutputFilename);
 
   /// Run the LLVM passes. In multi-threaded compilation this will be done for
   /// multiple LLVM modules in parallel.
-  /// \param Diags may be null if LLVM code gen diagnostics are not required.
-  /// \param DiagMutex may also be null if a mutex around \p Diags is not
-  ///                  required.
+  /// \param Diags The Diagnostic Engine.
+  /// \param DiagMutex in contexts that require parallel codegen, a mutex that the
+  ///                  diagnostic engine uses to synchronize emission.
   /// \param HashGlobal used with incremental LLVMCodeGen to know if a module
   ///                   was already compiled, may be null if not desired.
   /// \param Module LLVM module to code gen, required.
   /// \param TargetMachine target of code gen, required.
   /// \param effectiveLanguageVersion version of the language, effectively.
   /// \param OutputFilename Filename for output.
-  bool performLLVM(const IRGenOptions &Opts, DiagnosticEngine *Diags,
+  bool performLLVM(const IRGenOptions &Opts,
+                   DiagnosticEngine &Diags,
                    llvm::sys::Mutex *DiagMutex,
                    llvm::GlobalVariable *HashGlobal,
                    llvm::Module *Module,
                    llvm::TargetMachine *TargetMachine,
                    const version::Version &effectiveLanguageVersion,
                    StringRef OutputFilename,
-                   UnifiedStatsReporter *Stats=nullptr);
+                   UnifiedStatsReporter *Stats);
 
   /// Dump YAML describing all fixed-size types imported from the given module.
   bool performDumpTypeInfo(const IRGenOptions &Opts,

lib/AST/ASTContext.cpp

@@ -617,13 +617,12 @@ llvm::BumpPtrAllocator &ASTContext::getAllocator(AllocationArena arena) const {
 
 /// Set a new stats reporter.
 void ASTContext::setStatsReporter(UnifiedStatsReporter *stats) {
-  Stats = stats;
-  evaluator.setStatsReporter(stats);
-
   if (stats) {
     stats->getFrontendCounters().NumASTBytesAllocated =
         getAllocator().getBytesAllocated();
   }
+  evaluator.setStatsReporter(stats);
+  Stats = stats;
 }
 
 RC<syntax::SyntaxArena> ASTContext::getSyntaxArena() const {

lib/IRGen/IRGen.cpp

@@ -454,23 +454,22 @@ static void countStatsPostIRGen(UnifiedStatsReporter &Stats,
 
 template<typename ...ArgTypes>
 void
-diagnoseSync(DiagnosticEngine *Diags, llvm::sys::Mutex *DiagMutex,
+diagnoseSync(DiagnosticEngine &Diags, llvm::sys::Mutex *DiagMutex,
              SourceLoc Loc, Diag<ArgTypes...> ID,
              typename swift::detail::PassArgument<ArgTypes>::type... Args) {
-  if (!Diags)
-    return;
   if (DiagMutex)
     DiagMutex->lock();
 
-  Diags->diagnose(Loc, ID, std::move(Args)...);
+  Diags.diagnose(Loc, ID, std::move(Args)...);
 
   if (DiagMutex)
     DiagMutex->unlock();
 }
 
 /// Run the LLVM passes. In multi-threaded compilation this will be done for
 /// multiple LLVM modules in parallel.
-bool swift::performLLVM(const IRGenOptions &Opts, DiagnosticEngine *Diags,
+bool swift::performLLVM(const IRGenOptions &Opts,
+                        DiagnosticEngine &Diags,
                         llvm::sys::Mutex *DiagMutex,
                         llvm::GlobalVariable *HashGlobal,
                         llvm::Module *Module,
@@ -975,7 +974,7 @@ performIRGeneration(const IRGenOptions &Opts, ModuleDecl *M,
     FrontendStatsTracer tracer(Ctx.Stats, "LLVM pipeline");
 
     // Since no out module hash was set, we need to performLLVM.
-    if (performLLVM(Opts, &IGM.Context.Diags, nullptr, IGM.ModuleHash,
+    if (performLLVM(Opts, IGM.Context.Diags, nullptr, IGM.ModuleHash,
                     IGM.getModule(), IGM.TargetMachine.get(),
                     IGM.Context.LangOpts.EffectiveLanguageVersion,
                     IGM.OutputFilename, IGM.Context.Stats))
@@ -1010,7 +1009,7 @@ struct LLVMCodeGenThreads {
                           << IGM->OutputFilename << "\n";
                    diagMutex->unlock(););
         embedBitcode(IGM->getModule(), parent.irgen->Opts);
-        performLLVM(parent.irgen->Opts, &IGM->Context.Diags, diagMutex,
+        performLLVM(parent.irgen->Opts, IGM->Context.Diags, diagMutex,
                     IGM->ModuleHash, IGM->getModule(), IGM->TargetMachine.get(),
                     IGM->Context.LangOpts.EffectiveLanguageVersion,
                     IGM->OutputFilename, IGM->Context.Stats);
@@ -1363,15 +1362,14 @@ swift::createSwiftModuleObjectFile(SILModule &SILMod, StringRef Buffer,
   }
   ASTSym->setSection(Section);
   ASTSym->setAlignment(llvm::MaybeAlign(serialization::SWIFTMODULE_ALIGNMENT));
-  ::performLLVM(Opts, &Ctx.Diags, nullptr, nullptr, IGM.getModule(),
+  ::performLLVM(Opts, Ctx.Diags, nullptr, nullptr, IGM.getModule(),
                 IGM.TargetMachine.get(),
                 Ctx.LangOpts.EffectiveLanguageVersion,
-                OutputPath);
+                OutputPath, Ctx.Stats);
 }
 
 bool swift::performLLVM(const IRGenOptions &Opts, ASTContext &Ctx,
-                        llvm::Module *Module, StringRef OutputFilename,
-                        UnifiedStatsReporter *Stats) {
+                        llvm::Module *Module, StringRef OutputFilename) {
   // Build TargetMachine.
   auto TargetMachine = createTargetMachine(Opts, Ctx);
   if (!TargetMachine)
@@ -1382,10 +1380,10 @@ bool swift::performLLVM(const IRGenOptions &Opts, ASTContext &Ctx,
   Module->setDataLayout(Clang->getTargetInfo().getDataLayout());
 
   embedBitcode(Module, Opts);
-  if (::performLLVM(Opts, &Ctx.Diags, nullptr, nullptr, Module,
+  if (::performLLVM(Opts, Ctx.Diags, nullptr, nullptr, Module,
                     TargetMachine.get(),
                     Ctx.LangOpts.EffectiveLanguageVersion,
-                    OutputFilename, Stats))
+                    OutputFilename, Ctx.Stats))
     return true;
   return false;
 }