SILGen: Simplify prepareEpilog() utility method

Author: slavapestov

lib/SILGen/SILGen.cpp

@@ -1536,7 +1536,7 @@ class SourceFileScope {
       sgm.TopLevelSGF = new SILGenFunction(sgm, *toplevel, sf);
       sgm.TopLevelSGF->MagicFunctionName = sgm.SwiftModule->getName();
       auto moduleCleanupLoc = CleanupLocation::getModuleCleanupLocation();
-      sgm.TopLevelSGF->prepareEpilog(Type(), true, moduleCleanupLoc);
+      sgm.TopLevelSGF->prepareEpilog(false, true, moduleCleanupLoc);
 
       // Create the argc and argv arguments.
       auto prologueLoc = RegularLocation::getModuleLocation();

lib/SILGen/SILGenConstructor.cpp

@@ -281,7 +281,7 @@ void SILGenFunction::emitValueConstructor(ConstructorDecl *ctor) {
   // Create a basic block to jump to for the implicit 'self' return.
   // We won't emit this until after we've emitted the body.
   // The epilog takes a void return because the return of 'self' is implicit.
-  prepareEpilog(Type(), ctor->hasThrows(), CleanupLocation(ctor));
+  prepareEpilog(false, ctor->hasThrows(), CleanupLocation(ctor));
 
   // If the constructor can fail, set up an alternative epilog for constructor
   // failure.
@@ -659,7 +659,7 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
 
   // Create a basic block to jump to for the implicit 'self' return.
   // We won't emit the block until after we've emitted the body.
-  prepareEpilog(Type(), ctor->hasThrows(),
+  prepareEpilog(false, ctor->hasThrows(),
                 CleanupLocation::get(endOfInitLoc));
 
   auto resultType = ctor->mapTypeIntoContext(ctor->getResultInterfaceType());
@@ -1000,7 +1000,7 @@ void SILGenFunction::emitIVarInitializer(SILDeclRef ivarInitializer) {
   VarLocs[selfDecl] = VarLoc::get(selfArg);
 
   auto cleanupLoc = CleanupLocation::get(loc);
-  prepareEpilog(TupleType::getEmpty(getASTContext()), false, cleanupLoc);
+  prepareEpilog(false, false, cleanupLoc);
 
   // Emit the initializers.
   emitMemberInitializers(cd, selfDecl, cd);

lib/SILGen/SILGenDestructor.cpp

@@ -33,7 +33,7 @@ void SILGenFunction::emitDestroyingDestructor(DestructorDecl *dd) {
   // Create a basic block to jump to for the implicit destruction behavior
   // of releasing the elements and calling the superclass destructor.
   // We won't actually emit the block until we finish with the destructor body.
-  prepareEpilog(Type(), false, CleanupLocation::get(Loc));
+  prepareEpilog(false, false, CleanupLocation::get(Loc));
 
   emitProfilerIncrement(dd->getBody());
   // Emit the destructor body.
@@ -166,7 +166,7 @@ void SILGenFunction::emitIVarDestroyer(SILDeclRef ivarDestroyer) {
       emitSelfDecl(cd->getDestructor()->getImplicitSelfDecl()));
 
   auto cleanupLoc = CleanupLocation::get(loc);
-  prepareEpilog(TupleType::getEmpty(getASTContext()), false, cleanupLoc);
+  prepareEpilog(false, false, cleanupLoc);
   {
     Scope S(*this, cleanupLoc);
     emitClassMemberDestruction(selfValue, cd, cleanupLoc);
@@ -206,7 +206,7 @@ void SILGenFunction::emitObjCDestructor(SILDeclRef dtor) {
   // Create a basic block to jump to for the implicit destruction behavior
   // of releasing the elements and calling the superclass destructor.
   // We won't actually emit the block until we finish with the destructor body.
-  prepareEpilog(Type(), false, CleanupLocation::get(loc));
+  prepareEpilog(false, false, CleanupLocation::get(loc));
 
   emitProfilerIncrement(dd->getBody());
   // Emit the destructor body.

lib/SILGen/SILGenEpilog.cpp

@@ -18,13 +18,12 @@
 using namespace swift;
 using namespace Lowering;
 
-void SILGenFunction::prepareEpilog(Type resultType, bool isThrowing,
+void SILGenFunction::prepareEpilog(bool hasDirectResults, bool isThrowing,
                                    CleanupLocation CleanupL) {
   auto *epilogBB = createBasicBlock();
 
   // If we have any direct results, receive them via BB arguments.
-  // But callers can disable this by passing a null result type.
-  if (resultType) {
+  if (hasDirectResults) {
     auto fnConv = F.getConventions();
     // Set NeedsReturn for indirect or direct results. This ensures that SILGen
     // emits unreachable if there is no source level return.

lib/SILGen/SILGenFunction.cpp

@@ -487,8 +487,7 @@ void SILGenFunction::emitFunction(FuncDecl *fd) {
   auto captureInfo = SGM.M.Types.getLoweredLocalCaptures(SILDeclRef(fd));
   emitProlog(captureInfo, fd->getParameters(), fd->getImplicitSelfDecl(), fd,
              fd->getResultInterfaceType(), fd->hasThrows(), fd->getThrowsLoc());
-  Type resultTy = fd->mapTypeIntoContext(fd->getResultInterfaceType());
-  prepareEpilog(resultTy, fd->hasThrows(), CleanupLocation(fd));
+  prepareEpilog(true, fd->hasThrows(), CleanupLocation(fd));
 
   emitProfilerIncrement(fd->getBody());
   emitStmt(fd->getBody());
@@ -506,8 +505,7 @@ void SILGenFunction::emitClosure(AbstractClosureExpr *ace) {
     SILDeclRef(ace));
   emitProlog(captureInfo, ace->getParameters(), /*selfParam=*/nullptr,
              ace, resultIfaceTy, ace->isBodyThrowing(), ace->getLoc());
-  prepareEpilog(ace->getResultType(), ace->isBodyThrowing(),
-                CleanupLocation(ace));
+  prepareEpilog(true, ace->isBodyThrowing(), CleanupLocation(ace));
   emitProfilerIncrement(ace);
   if (auto *ce = dyn_cast<ClosureExpr>(ace)) {
     emitStmt(ce->getBody());
@@ -773,7 +771,7 @@ void SILGenFunction::emitGeneratorFunction(SILDeclRef function, Expr *value,
              dc, interfaceType, /*throws=*/false, SourceLoc());
   if (EmitProfilerIncrement)
     emitProfilerIncrement(value);
-  prepareEpilog(value->getType(), false, CleanupLocation::get(Loc));
+  prepareEpilog(true, false, CleanupLocation::get(Loc));
 
   {
     llvm::Optional<SILGenFunction::OpaqueValueRAII> opaqueValue;
@@ -806,21 +804,19 @@ void SILGenFunction::emitGeneratorFunction(SILDeclRef function, VarDecl *var) {
   auto decl = function.getAbstractFunctionDecl();
   auto *dc = decl->getInnermostDeclContext();
   auto interfaceType = var->getValueInterfaceType();
-  auto varType = var->getType();
 
   // If this is the backing storage for a property with an attached
   // wrapper that was initialized with '=', the stored property initializer
   // will be in terms of the original property's type.
   if (auto originalProperty = var->getOriginalWrappedProperty()) {
     if (originalProperty->isPropertyMemberwiseInitializedWithWrappedType()) {
       interfaceType = originalProperty->getValueInterfaceType();
-      varType = originalProperty->getType();
     }
   }
 
   emitProlog(/*paramList*/ nullptr, /*selfParam*/ nullptr, interfaceType, dc,
              /*throws=*/false, SourceLoc());
-  prepareEpilog(varType, false, CleanupLocation::get(loc));
+  prepareEpilog(true, false, CleanupLocation::get(loc));
 
   auto pbd = var->getParentPatternBinding();
   const auto i = pbd->getPatternEntryIndexForVarDecl(var);

lib/SILGen/SILGenFunction.h

@@ -828,13 +828,12 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
   /// Create (but do not emit) the epilog branch, and save the
   /// current cleanups depth as the destination for return statement branches.
   ///
-  /// \param returnType  If non-null, the epilog block will be created with an
-  ///                    argument of this type to receive the return value for
-  ///                    the function.
+  /// \param hasDirectResults  If true, the epilog block will be created with
+  ///                    arguments for each direct result of this function.
   /// \param isThrowing  If true, create an error epilog block.
   /// \param L           The SILLocation which should be associated with
   ///                    cleanup instructions.
-  void prepareEpilog(Type returnType, bool isThrowing, CleanupLocation L);
+  void prepareEpilog(bool hasDirectResults, bool isThrowing, CleanupLocation L);
   void prepareRethrowEpilog(CleanupLocation l);
   void prepareCoroutineUnwindEpilog(CleanupLocation l);