[SILGen] Move all top-level emission code to SILGenTopLevel.cpp

Author: Zak Kent

lib/SILGen/SILGen.cpp

@@ -1928,171 +1928,6 @@ void SILGenModule::visitPoundDiagnosticDecl(PoundDiagnosticDecl *PDD) {
   // Nothing to do for #error/#warning; they've already been emitted.
 }
 
-void SILGenModule::emitEntryPoint(SourceFile *SF, SILFunction *TopLevel) {
-
-  auto EntryRef = SILDeclRef::getMainFileEntryPoint(SF);
-  bool isAsyncTopLevel = false;
-  if (SF->isAsyncContext()) {
-    isAsyncTopLevel = true;
-    auto asyncEntryRef = SILDeclRef::getAsyncMainFileEntryPoint(SF);
-    auto *asyncTopLevel = getFunction(asyncEntryRef, ForDefinition);
-    SILGenFunction(*this, *TopLevel, SF)
-        .emitAsyncMainThreadStart(asyncEntryRef);
-    TopLevel = asyncTopLevel;
-    EntryRef = asyncEntryRef;
-  }
-
-  TopLevel->createProfiler(EntryRef);
-
-  SILGenFunction TopLevelSGF(*this, *TopLevel, SF, true);
-  TopLevelSGF.MagicFunctionName = SwiftModule->getName();
-  auto moduleCleanupLoc = CleanupLocation::getModuleCleanupLocation();
-
-  TopLevelSGF.prepareEpilog(llvm::None, true, moduleCleanupLoc);
-
-  auto prologueLoc = RegularLocation::getModuleLocation();
-  prologueLoc.markAsPrologue();
-  if (SF->isAsyncContext()) {
-    // emitAsyncMainThreadStart will create argc and argv.
-    // Just set the main actor as the expected executor; we should
-    // already be running on it.
-    SILValue executor = TopLevelSGF.emitMainExecutor(prologueLoc);
-    TopLevelSGF.ExpectedExecutor = TopLevelSGF.B.createOptionalSome(
-        prologueLoc, executor, SILType::getOptionalType(executor->getType()));
-  } else {
-    // Create the argc and argv arguments.
-    auto entry = TopLevelSGF.B.getInsertionBB();
-    auto context = TopLevelSGF.getTypeExpansionContext();
-    auto paramTypeIter =
-        TopLevelSGF.F.getConventions().getParameterSILTypes(context).begin();
-
-    entry->createFunctionArgument(*paramTypeIter);
-    entry->createFunctionArgument(*std::next(paramTypeIter));
-  }
-
-  {
-    Scope S(TopLevelSGF.Cleanups, moduleCleanupLoc);
-    SILGenTopLevel(TopLevelSGF).visitSourceFile(SF);
-  }
-
-  // Unregister the top-level function emitter.
-  TopLevelSGF.stopEmittingTopLevelCode();
-
-  // Write out the epilog.
-  auto moduleLoc = RegularLocation::getModuleLocation();
-  moduleLoc.markAutoGenerated();
-  auto returnInfo = TopLevelSGF.emitEpilogBB(moduleLoc);
-  auto returnLoc = returnInfo.second;
-  returnLoc.markAutoGenerated();
-
-  SILFunction *exitFunc = nullptr;
-
-  SILType returnType;
-  if (isAsyncTopLevel) {
-    FuncDecl *exitFuncDecl = getExit();
-    assert(exitFuncDecl && "Failed to find exit function declaration");
-    exitFunc = getFunction(
-        SILDeclRef(exitFuncDecl, SILDeclRef::Kind::Func, /*isForeign*/ true),
-        NotForDefinition);
-    SILFunctionType &funcType =
-        *exitFunc->getLoweredType().getAs<SILFunctionType>();
-    returnType = SILType::getPrimitiveObjectType(
-        funcType.getParameters().front().getInterfaceType());
-  } else {
-    returnType = TopLevelSGF.F.getConventions().getSingleSILResultType(
-        TopLevelSGF.getTypeExpansionContext());
-  }
-
-  auto emitTopLevelReturnValue = [&](unsigned value) -> SILValue {
-    // Create an integer literal for the value.
-    auto litType = SILType::getBuiltinIntegerType(32, getASTContext());
-    SILValue retValue =
-        TopLevelSGF.B.createIntegerLiteral(moduleLoc, litType, value);
-
-    // Wrap that in a struct if necessary.
-    if (litType != returnType) {
-      retValue = TopLevelSGF.B.createStruct(moduleLoc, returnType, retValue);
-    }
-    return retValue;
-  };
-
-  // Fallthrough should signal a normal exit by returning 0.
-  SILValue returnValue;
-  if (TopLevelSGF.B.hasValidInsertionPoint())
-    returnValue = emitTopLevelReturnValue(0);
-
-  // Handle the implicit rethrow block.
-  auto rethrowBB = TopLevelSGF.ThrowDest.getBlock();
-  TopLevelSGF.ThrowDest = JumpDest::invalid();
-
-  // If the rethrow block wasn't actually used, just remove it.
-  if (rethrowBB->pred_empty()) {
-    TopLevelSGF.eraseBasicBlock(rethrowBB);
-
-    // Otherwise, we need to produce a unified return block.
-  } else {
-    auto returnBB = TopLevelSGF.createBasicBlock();
-    if (TopLevelSGF.B.hasValidInsertionPoint())
-      TopLevelSGF.B.createBranch(returnLoc, returnBB, returnValue);
-    returnValue = returnBB->createPhiArgument(returnType, OwnershipKind::Owned);
-    TopLevelSGF.B.emitBlock(returnBB);
-
-    // Emit the rethrow block.
-    SILGenSavedInsertionPoint savedIP(TopLevelSGF, rethrowBB,
-                                      FunctionSection::Postmatter);
-
-    // Log the error.
-    SILValue error = rethrowBB->getArgument(0);
-    TopLevelSGF.B.createBuiltin(moduleLoc,
-                                getASTContext().getIdentifier("errorInMain"),
-                                Types.getEmptyTupleType(), {}, {error});
-
-    // Then end the lifetime of the error.
-    //
-    // We do this to appease the ownership verifier. We do not care about
-    // actually destroying the value since we are going to immediately exit,
-    // so this saves us a slight bit of code-size since end_lifetime is
-    // stripped out after ownership is removed.
-    TopLevelSGF.B.createEndLifetime(moduleLoc, error);
-
-    // Signal an abnormal exit by returning 1.
-    TopLevelSGF.Cleanups.emitCleanupsForReturn(CleanupLocation(moduleLoc),
-                                               IsForUnwind);
-    TopLevelSGF.B.createBranch(returnLoc, returnBB, emitTopLevelReturnValue(1));
-  }
-
-  // Return.
-  if (TopLevelSGF.B.hasValidInsertionPoint()) {
-
-    if (isAsyncTopLevel) {
-      SILValue exitCall = TopLevelSGF.B.createFunctionRef(moduleLoc, exitFunc);
-      TopLevelSGF.B.createApply(moduleLoc, exitCall, {}, {returnValue});
-      TopLevelSGF.B.createUnreachable(moduleLoc);
-    } else {
-      TopLevelSGF.B.createReturn(returnLoc, returnValue);
-    }
-  }
-
-  // Okay, we're done emitting the top-level function; destroy the
-  // emitter and verify the result.
-  SILFunction &toplevel = TopLevelSGF.getFunction();
-
-  LLVM_DEBUG(llvm::dbgs() << "lowered toplevel sil:\n";
-             toplevel.print(llvm::dbgs()));
-  toplevel.verifyIncompleteOSSA();
-  emitLazyConformancesForFunction(&toplevel);
-}
-
-void SILGenModule::emitEntryPoint(SourceFile *SF) {
-  assert(!M.lookUpFunction(getASTContext().getEntryPointFunctionName()) &&
-         "already emitted toplevel?!");
-
-  auto mainEntryRef = SILDeclRef::getMainFileEntryPoint(SF);
-  SILFunction *TopLevel = getFunction(mainEntryRef, ForDefinition);
-  TopLevel->setBare(IsBare);
-  emitEntryPoint(SF, TopLevel);
-}
-
 namespace {
 
 // An RAII object that constructs a \c SILGenModule instance.

lib/SILGen/SILGenGlobalVariable.cpp

@@ -133,24 +133,6 @@ SILGenFunction::emitGlobalVariableRef(SILLocation loc, VarDecl *var,
   return ManagedValue::forLValue(addr);
 }
 
-void SILGenFunction::emitMarkFunctionEscapeForTopLevelCodeGlobals(
-    SILLocation Loc, CaptureInfo CaptureInfo) {
-
-  llvm::SmallVector<SILValue, 4> Captures;
-
-  for (auto Capture : CaptureInfo.getCaptures()) {
-    // Decls captured by value don't escape.
-    auto It = VarLocs.find(Capture.getDecl());
-    if (It == VarLocs.end() || !It->getSecond().value->getType().isAddress())
-      continue;
-
-    Captures.push_back(It->second.value);
-  }
-
-  if (!Captures.empty())
-    B.createMarkFunctionEscape(Loc, Captures);
-}
-
 //===----------------------------------------------------------------------===//
 // Global initialization
 //===----------------------------------------------------------------------===//

lib/SILGen/SILGenStmt.cpp

@@ -907,11 +907,10 @@ void StmtEmitter::visitDeferStmt(DeferStmt *S) {
   // If the defer is at the top-level code, insert 'mark_escape_inst'
   // to the top-level code to check initialization of any captured globals.
   FuncDecl *deferDecl = S->getTempDecl();
-  auto declCtxKind = deferDecl->getDeclContext()->getContextKind();
-  if (declCtxKind == DeclContextKind::TopLevelCodeDecl &&
-      SGF.isEmittingTopLevelCode()) {
-      SGF.emitMarkFunctionEscapeForTopLevelCodeGlobals(
-          S, deferDecl->getCaptureInfo());
+  auto *Ctx = deferDecl->getDeclContext();
+  if (isa<TopLevelCodeDecl>(Ctx) && SGF.isEmittingTopLevelCode()) {
+      auto Captures = deferDecl->getCaptureInfo();
+      SGF.emitMarkFunctionEscapeForTopLevelCodeGlobals(S, std::move(Captures));
   }
   SGF.visitFuncDecl(deferDecl);