Remove "StartElem" from perform{SIL,IR}Generation

This was only used by the integrated REPL, and is now a dead option.

The "StartElem" option for performTypeChecking is still used for
reading SIL files, which have AST and SIL blocks alternate.

Author: jrose-apple

include/swift/SIL/SILModule.h

@@ -343,10 +343,9 @@ class SILModule {
   /// should contain source files.
   ///
   /// If a source file is provided, SIL will only be emitted for decls in that
-  /// source file, starting from the specified element number.
+  /// source file.
   static std::unique_ptr<SILModule>
   constructSIL(ModuleDecl *M, SILOptions &Options, FileUnit *sf = nullptr,
-               Optional<unsigned> startElem = None,
                bool isWholeModule = false);
 
   /// \brief Create and return an empty SIL module that we can

include/swift/Subsystems.h

@@ -246,12 +246,8 @@ namespace swift {
                        bool wholeModuleCompilation = false);
 
   /// Turn a source file into SIL IR.
-  ///
-  /// If \p StartElem is provided, the module is assumed to be only part of the
-  /// SourceFile, and any optimizations should take that into account.
   std::unique_ptr<SILModule>
-  performSILGeneration(FileUnit &SF, SILOptions &options,
-                       Optional<unsigned> StartElem = None);
+  performSILGeneration(FileUnit &SF, SILOptions &options);
 
   using ModuleOrSourceFile = PointerUnion<ModuleDecl *, SourceFile *>;
 
@@ -283,7 +279,6 @@ namespace swift {
                       std::unique_ptr<SILModule> SILMod,
                       StringRef ModuleName, const PrimarySpecificPaths &PSPs,
                       llvm::LLVMContext &LLVMContext,
-                      unsigned StartElem = 0,
                       llvm::GlobalVariable **outModuleHash = nullptr);
 
   /// Given an already created LLVM module, construct a pass pipeline and run

lib/FrontendTool/FrontendTool.cpp

@@ -832,7 +832,7 @@ generateSILModules(CompilerInvocation &Invocation, CompilerInstance &Instance) {
   // once for each such input.
   std::deque<PostSILGenInputs> PSGIs;
   for (auto *PrimaryFile : Instance.getPrimarySourceFiles()) {
-    auto SM = performSILGeneration(*PrimaryFile, SILOpts, None);
+    auto SM = performSILGeneration(*PrimaryFile, SILOpts);
     const PrimarySpecificPaths PSPs =
         Instance.getPrimarySpecificPathsForSourceFile(*PrimaryFile);
     PSGIs.push_back(PostSILGenInputs{std::move(SM), true, PrimaryFile, PSPs});
@@ -846,7 +846,7 @@ generateSILModules(CompilerInvocation &Invocation, CompilerInstance &Instance) {
       if (Invocation.getFrontendOptions().InputsAndOutputs.isInputPrimary(
               SASTF->getFilename())) {
         assert(PSGIs.empty() && "Can only handle one primary AST input");
-        auto SM = performSILGeneration(*SASTF, SILOpts, None);
+        auto SM = performSILGeneration(*SASTF, SILOpts);
         const PrimarySpecificPaths &PSPs =
             Instance.getPrimarySpecificPathsForPrimary(SASTF->getFilename());
         PSGIs.push_back(
@@ -1130,7 +1130,7 @@ static void generateIR(IRGenOptions &IRGenOpts, std::unique_ptr<SILModule> SM,
   IRModule = MSF.is<SourceFile *>()
                  ? performIRGeneration(IRGenOpts, *MSF.get<SourceFile *>(),
                                        std::move(SM), OutputFilename, PSPs,
-                                       LLVMContext, 0, &HashGlobal)
+                                       LLVMContext, &HashGlobal)
                  : performIRGeneration(IRGenOpts, MSF.get<ModuleDecl *>(),
                                        std::move(SM), OutputFilename, PSPs,
                                        LLVMContext, parallelOutputFilenames,

lib/IRGen/GenDecl.cpp

@@ -467,13 +467,13 @@ class PrettySourceFileEmission : public llvm::PrettyStackTraceEntry {
 } // end anonymous namespace
 
 /// Emit all the top-level code in the source file.
-void IRGenModule::emitSourceFile(SourceFile &SF, unsigned StartElem) {
+void IRGenModule::emitSourceFile(SourceFile &SF) {
   PrettySourceFileEmission StackEntry(SF);
   llvm::SaveAndRestore<SourceFile *> SetCurSourceFile(CurSourceFile, &SF);
 
   // Emit types and other global decls.
-  for (unsigned i = StartElem, e = SF.Decls.size(); i != e; ++i)
-    emitGlobalDecl(SF.Decls[i]);
+  for (auto *decl : SF.Decls)
+    emitGlobalDecl(decl);
   for (auto *localDecl : SF.LocalTypeDecls)
     emitGlobalDecl(localDecl);
 

lib/IRGen/IRGen.cpp

@@ -762,15 +762,12 @@ static void runIRGenPreparePasses(SILModule &Module,
 
 /// Generates LLVM IR, runs the LLVM passes and produces the output file.
 /// All this is done in a single thread.
-static std::unique_ptr<llvm::Module> performIRGeneration(IRGenOptions &Opts,
-                                                         swift::ModuleDecl *M,
-                                            std::unique_ptr<SILModule> SILMod,
-                                                         StringRef ModuleName,
-                                              const PrimarySpecificPaths &PSPs,
-                                                 llvm::LLVMContext &LLVMContext,
-                                                       SourceFile *SF = nullptr,
-                                 llvm::GlobalVariable **outModuleHash = nullptr,
-                                                       unsigned StartElem = 0) {
+static std::unique_ptr<llvm::Module>
+performIRGeneration(IRGenOptions &Opts, ModuleDecl *M,
+                    std::unique_ptr<SILModule> SILMod, StringRef ModuleName,
+                    const PrimarySpecificPaths &PSPs,
+                    llvm::LLVMContext &LLVMContext, SourceFile *SF = nullptr,
+                    llvm::GlobalVariable **outModuleHash = nullptr) {
   auto &Ctx = M->getASTContext();
   assert(!Ctx.hadError());
 
@@ -795,13 +792,12 @@ static std::unique_ptr<llvm::Module> performIRGeneration(IRGenOptions &Opts,
     irgen.emitGlobalTopLevel();
 
     if (SF) {
-      IGM.emitSourceFile(*SF, StartElem);
+      IGM.emitSourceFile(*SF);
     } else {
-      assert(StartElem == 0 && "no explicit source file provided");
       for (auto *File : M->getFiles()) {
         if (auto *nextSF = dyn_cast<SourceFile>(File)) {
           if (nextSF->ASTStage >= SourceFile::TypeChecked)
-            IGM.emitSourceFile(*nextSF, 0);
+            IGM.emitSourceFile(*nextSF);
         } else {
           File->collectLinkLibraries([&IGM](LinkLibrary LinkLib) {
             IGM.addLinkLibrary(LinkLib);
@@ -972,7 +968,7 @@ static void performParallelIRGeneration(
   for (auto *File : M->getFiles()) {
     if (auto *SF = dyn_cast<SourceFile>(File)) {
       IRGenModule *IGM = irgen.getGenModule(SF);
-      IGM->emitSourceFile(*SF, 0);
+      IGM->emitSourceFile(*SF);
     } else {
       File->collectLinkLibraries([&](LinkLibrary LinkLib) {
         irgen.getPrimaryIGM()->addLinkLibrary(LinkLib);
@@ -1116,12 +1112,10 @@ performIRGeneration(IRGenOptions &Opts, SourceFile &SF,
                     std::unique_ptr<SILModule> SILMod,
                     StringRef ModuleName, const PrimarySpecificPaths &PSPs,
                     llvm::LLVMContext &LLVMContext,
-                    unsigned StartElem,
                     llvm::GlobalVariable **outModuleHash) {
-  return ::performIRGeneration(Opts, SF.getParentModule(),
-                               std::move(SILMod), ModuleName,
-                               PSPs,
-                               LLVMContext, &SF, outModuleHash, StartElem);
+  return ::performIRGeneration(Opts, SF.getParentModule(), std::move(SILMod),
+                               ModuleName, PSPs, LLVMContext, &SF,
+                               outModuleHash);
 }
 
 void

lib/IRGen/IRGenModule.h

@@ -1095,7 +1095,7 @@ private:                            \
 
   llvm::LLVMContext &getLLVMContext() const { return LLVMContext; }
 
-  void emitSourceFile(SourceFile &SF, unsigned StartElem);
+  void emitSourceFile(SourceFile &SF);
   void addLinkLibrary(const LinkLibrary &linkLib);
 
   /// Attempt to finalize the module.

lib/SILGen/SILGen.cpp

@@ -1579,10 +1579,10 @@ class SourceFileScope {
 
 } // end anonymous namespace
 
-void SILGenModule::emitSourceFile(SourceFile *sf, unsigned startElem) {
+void SILGenModule::emitSourceFile(SourceFile *sf) {
   SourceFileScope scope(*this, sf);
   FrontendStatsTracer StatsTracer(getASTContext().Stats, "SILgen-file", sf);
-  for (Decl *D : llvm::makeArrayRef(sf->Decls).slice(startElem)) {
+  for (Decl *D : sf->Decls) {
     FrontendStatsTracer StatsTracer(getASTContext().Stats, "SILgen-decl", D);
     visit(D);
   }
@@ -1603,16 +1603,10 @@ void SILGenModule::emitSourceFile(SourceFile *sf, unsigned startElem) {
 
 std::unique_ptr<SILModule>
 SILModule::constructSIL(ModuleDecl *mod, SILOptions &options, FileUnit *SF,
-                        Optional<unsigned> startElem,
                         bool isWholeModule) {
   SharedTimer timer("SILGen");
   const DeclContext *DC;
-  if (startElem) {
-    assert(SF && "cannot have a start element without a source file");
-    // Because more decls may be added to the SourceFile, we can't assume
-    // anything about the compilation context.
-    DC = nullptr;
-  } else if (SF) {
+  if (SF) {
     DC = SF;
   } else {
     DC = mod;
@@ -1624,7 +1618,7 @@ SILModule::constructSIL(ModuleDecl *mod, SILOptions &options, FileUnit *SF,
 
   if (SF) {
     if (auto *file = dyn_cast<SourceFile>(SF)) {
-      SGM.emitSourceFile(file, startElem.getValueOr(0));
+      SGM.emitSourceFile(file);
     } else if (auto *file = dyn_cast<SerializedASTFile>(SF)) {
       if (file->isSIB())
         M->getSILLoader()->getAllForModule(mod->getName(), file);
@@ -1634,7 +1628,7 @@ SILModule::constructSIL(ModuleDecl *mod, SILOptions &options, FileUnit *SF,
       auto nextSF = dyn_cast<SourceFile>(file);
       if (!nextSF || nextSF->ASTStage != SourceFile::TypeChecked)
         continue;
-      SGM.emitSourceFile(nextSF, 0);
+      SGM.emitSourceFile(nextSF);
     }
 
     // Also make sure to process any intermediate files that may contain SIL
@@ -1679,13 +1673,10 @@ std::unique_ptr<SILModule>
 swift::performSILGeneration(ModuleDecl *mod,
                             SILOptions &options,
                             bool wholeModuleCompilation) {
-  return SILModule::constructSIL(mod, options, nullptr, None,
-                                 wholeModuleCompilation);
+  return SILModule::constructSIL(mod, options, nullptr, wholeModuleCompilation);
 }
 
 std::unique_ptr<SILModule>
-swift::performSILGeneration(FileUnit &sf, SILOptions &options,
-                            Optional<unsigned> startElem) {
-  return SILModule::constructSIL(sf.getParentModule(), options, &sf, startElem,
-                                 false);
+swift::performSILGeneration(FileUnit &sf, SILOptions &options) {
+  return SILModule::constructSIL(sf.getParentModule(), options, &sf, false);
 }

lib/SILGen/SILGen.h

@@ -222,7 +222,7 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
   void emitAbstractFuncDecl(AbstractFunctionDecl *AFD);
 
   /// Generate code for a source file of the module.
-  void emitSourceFile(SourceFile *sf, unsigned startElem);
+  void emitSourceFile(SourceFile *sf);
 
   /// Generates code for the given FuncDecl and adds the
   /// SILFunction to the current SILModule under the name SILDeclRef(decl). For