Simplify use of formatted_raw_ostream.

formatted_raw_ostream is a wrapper over another stream to add column and line
number tracking.

It is used only for asm printing.

This patch moves the its creation down to where we know we are printing
assembly. This has the following advantages:

* Simpler lifetime management: std::unique_ptr
* We don't compute column and line number of object files :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234535 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCStreamer.h

@@ -746,7 +746,8 @@ MCStreamer *createNullStreamer(MCContext &Ctx);
 ///
 /// \param ShowInst - Whether to show the MCInst representation inline with
 /// the assembly.
-MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
+MCStreamer *createAsmStreamer(MCContext &Ctx,
+                              std::unique_ptr<formatted_raw_ostream> OS,
                               bool isVerboseAsm, bool useDwarfDirectory,
                               MCInstPrinter *InstPrint, MCCodeEmitter *CE,
                               MCAsmBackend *TAB, bool ShowInst);

include/llvm/Support/FormattedStream.h

@@ -25,27 +25,11 @@ namespace llvm {
 /// boundaries and querying the number of lines written to the stream.
 ///
 class formatted_raw_ostream : public raw_ostream {
-public:
-  /// DELETE_STREAM - Tell the destructor to delete the held stream.
-  ///
-  static const bool DELETE_STREAM = true;
-
-  /// PRESERVE_STREAM - Tell the destructor to not delete the held
-  /// stream.
-  ///
-  static const bool PRESERVE_STREAM = false;
-
-private:
   /// TheStream - The real stream we output to. We set it to be
   /// unbuffered, since we're already doing our own buffering.
   ///
   raw_ostream *TheStream;
 
-  /// DeleteStream - Do we need to delete TheStream in the
-  /// destructor?
-  ///
-  bool DeleteStream;
-
   /// Position - The current output column and line of the data that's
   /// been flushed and the portion of the buffer that's been
   /// scanned.  The line and column scheme is zero-based.
@@ -73,6 +57,24 @@ class formatted_raw_ostream : public raw_ostream {
   ///
   void ComputePosition(const char *Ptr, size_t size);
 
+  void setStream(raw_ostream &Stream) {
+    releaseStream();
+
+    TheStream = &Stream;
+
+    // This formatted_raw_ostream inherits from raw_ostream, so it'll do its
+    // own buffering, and it doesn't need or want TheStream to do another
+    // layer of buffering underneath. Resize the buffer to what TheStream
+    // had been using, and tell TheStream not to do its own buffering.
+    if (size_t BufferSize = TheStream->GetBufferSize())
+      SetBufferSize(BufferSize);
+    else
+      SetUnbuffered();
+    TheStream->SetUnbuffered();
+
+    Scanned = nullptr;
+  }
+
 public:
   /// formatted_raw_ostream - Open the specified file for
   /// writing. If an error occurs, information about the error is
@@ -84,12 +86,11 @@ class formatted_raw_ostream : public raw_ostream {
   /// so it doesn't want another layer of buffering to be happening
   /// underneath it.
   ///
-  formatted_raw_ostream(raw_ostream &Stream, bool Delete = false)
-      : TheStream(nullptr), DeleteStream(false), Position(0, 0) {
-    setStream(Stream, Delete);
+  formatted_raw_ostream(raw_ostream &Stream)
+      : TheStream(nullptr), Position(0, 0) {
+    setStream(Stream);
   }
-  explicit formatted_raw_ostream()
-      : TheStream(nullptr), DeleteStream(false), Position(0, 0) {
+  explicit formatted_raw_ostream() : TheStream(nullptr), Position(0, 0) {
     Scanned = nullptr;
   }
 
@@ -98,25 +99,6 @@ class formatted_raw_ostream : public raw_ostream {
     releaseStream();
   }
 
-  void setStream(raw_ostream &Stream, bool Delete = false) {
-    releaseStream();
-
-    TheStream = &Stream;
-    DeleteStream = Delete;
-
-    // This formatted_raw_ostream inherits from raw_ostream, so it'll do its
-    // own buffering, and it doesn't need or want TheStream to do another
-    // layer of buffering underneath. Resize the buffer to what TheStream
-    // had been using, and tell TheStream not to do its own buffering.
-    if (size_t BufferSize = TheStream->GetBufferSize())
-      SetBufferSize(BufferSize);
-    else
-      SetUnbuffered();
-    TheStream->SetUnbuffered();
-
-    Scanned = nullptr;
-  }
-
   /// PadToColumn - Align the output to some column number.  If the current
   /// column is already equal to or more than NewCol, PadToColumn inserts one
   /// space.
@@ -151,13 +133,11 @@ class formatted_raw_ostream : public raw_ostream {
 
 private:
   void releaseStream() {
-    // Delete the stream if needed. Otherwise, transfer the buffer
-    // settings from this raw_ostream back to the underlying stream.
+    // Transfer the buffer settings from this raw_ostream back to the underlying
+    // stream.
     if (!TheStream)
       return;
-    if (DeleteStream)
-      delete TheStream;
-    else if (size_t BufferSize = GetBufferSize())
+    if (size_t BufferSize = GetBufferSize())
       TheStream->SetBufferSize(BufferSize);
     else
       TheStream->SetUnbuffered();

include/llvm/Support/TargetRegistry.h

@@ -22,6 +22,7 @@
 #include "llvm-c/Disassembler.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/CodeGen.h"
+#include "llvm/Support/FormattedStream.h"
 #include <cassert>
 #include <memory>
 #include <string>
@@ -52,7 +53,8 @@ namespace llvm {
   class formatted_raw_ostream;
 
   MCStreamer *createNullStreamer(MCContext &Ctx);
-  MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
+  MCStreamer *createAsmStreamer(MCContext &Ctx,
+                                std::unique_ptr<formatted_raw_ostream> OS,
                                 bool isVerboseAsm, bool useDwarfDirectory,
                                 MCInstPrinter *InstPrint, MCCodeEmitter *CE,
                                 MCAsmBackend *TAB, bool ShowInst);
@@ -469,14 +471,16 @@ namespace llvm {
       return S;
     }
 
-    MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
+    MCStreamer *createAsmStreamer(MCContext &Ctx,
+                                  std::unique_ptr<formatted_raw_ostream> OS,
                                   bool IsVerboseAsm, bool UseDwarfDirectory,
                                   MCInstPrinter *InstPrint, MCCodeEmitter *CE,
                                   MCAsmBackend *TAB, bool ShowInst) const {
-      MCStreamer *S =
-          llvm::createAsmStreamer(Ctx, OS, IsVerboseAsm, UseDwarfDirectory,
-                                  InstPrint, CE, TAB, ShowInst);
-      createAsmTargetStreamer(*S, OS, InstPrint, IsVerboseAsm);
+      formatted_raw_ostream &OSRef = *OS;
+      MCStreamer *S = llvm::createAsmStreamer(Ctx, std::move(OS), IsVerboseAsm,
+                                              UseDwarfDirectory, InstPrint, CE,
+                                              TAB, ShowInst);
+      createAsmTargetStreamer(*S, OSRef, InstPrint, IsVerboseAsm);
       return S;
     }
 

include/llvm/Target/TargetMachine.h

@@ -207,8 +207,7 @@ class TargetMachine {
   /// emitted.  Typically this will involve several steps of code generation.
   /// This method should return true if emission of this file type is not
   /// supported, or false on success.
-  virtual bool addPassesToEmitFile(PassManagerBase &,
-                                   formatted_raw_ostream &,
+  virtual bool addPassesToEmitFile(PassManagerBase &, raw_ostream &,
                                    CodeGenFileType,
                                    bool /*DisableVerify*/ = true,
                                    AnalysisID /*StartAfter*/ = nullptr,
@@ -257,7 +256,7 @@ class LLVMTargetMachine : public TargetMachine {
 
   /// Add passes to the specified pass manager to get the specified file
   /// emitted.  Typically this will involve several steps of code generation.
-  bool addPassesToEmitFile(PassManagerBase &PM, formatted_raw_ostream &Out,
+  bool addPassesToEmitFile(PassManagerBase &PM, raw_ostream &Out,
                            CodeGenFileType FileType, bool DisableVerify = true,
                            AnalysisID StartAfter = nullptr,
                            AnalysisID StopAfter = nullptr) override;

lib/CodeGen/LLVMTargetMachine.cpp

@@ -140,12 +140,9 @@ static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
   return &MMI->getContext();
 }
 
-bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
-                                            formatted_raw_ostream &Out,
-                                            CodeGenFileType FileType,
-                                            bool DisableVerify,
-                                            AnalysisID StartAfter,
-                                            AnalysisID StopAfter) {
+bool LLVMTargetMachine::addPassesToEmitFile(
+    PassManagerBase &PM, raw_ostream &Out, CodeGenFileType FileType,
+    bool DisableVerify, AnalysisID StartAfter, AnalysisID StopAfter) {
   // Add common CodeGen passes.
   MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
                                                StartAfter, StopAfter);
@@ -184,8 +181,9 @@ bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
 
     MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
                                                        TargetCPU);
+    auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
     MCStreamer *S = getTarget().createAsmStreamer(
-        *Context, Out, Options.MCOptions.AsmVerbose,
+        *Context, std::move(FOut), Options.MCOptions.AsmVerbose,
         Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
         Options.MCOptions.ShowMCInst);
     AsmStreamer.reset(S);

lib/LTO/LTOCodeGenerator.cpp

@@ -38,7 +38,6 @@
 #include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
-#include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Signals.h"
@@ -574,13 +573,11 @@ bool LTOCodeGenerator::compileOptimized(raw_ostream &out, std::string &errMsg) {
 
   legacy::PassManager codeGenPasses;
 
-  formatted_raw_ostream Out(out);
-
   // If the bitcode files contain ARC code and were compiled with optimization,
   // the ObjCARCContractPass must be run, so do it unconditionally here.
   codeGenPasses.add(createObjCARCContractPass());
 
-  if (TargetMach->addPassesToEmitFile(codeGenPasses, Out,
+  if (TargetMach->addPassesToEmitFile(codeGenPasses, out,
                                       TargetMachine::CGFT_ObjectFile)) {
     errMsg = "target file type not supported";
     return false;

lib/MC/MCAsmStreamer.cpp

@@ -37,6 +37,7 @@ using namespace llvm;
 namespace {
 
 class MCAsmStreamer final : public MCStreamer {
+  std::unique_ptr<formatted_raw_ostream> OSOwner;
   formatted_raw_ostream &OS;
   const MCAsmInfo *MAI;
   std::unique_ptr<MCInstPrinter> InstPrinter;
@@ -55,14 +56,15 @@ class MCAsmStreamer final : public MCStreamer {
   void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
 
 public:
-  MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
+  MCAsmStreamer(MCContext &Context, std::unique_ptr<formatted_raw_ostream> os,
                 bool isVerboseAsm, bool useDwarfDirectory,
                 MCInstPrinter *printer, MCCodeEmitter *emitter,
                 MCAsmBackend *asmbackend, bool showInst)
-      : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
-        InstPrinter(printer), Emitter(emitter), AsmBackend(asmbackend),
-        CommentStream(CommentToEmit), IsVerboseAsm(isVerboseAsm),
-        ShowInst(showInst), UseDwarfDirectory(useDwarfDirectory) {
+      : MCStreamer(Context), OSOwner(std::move(os)), OS(*OSOwner),
+        MAI(Context.getAsmInfo()), InstPrinter(printer), Emitter(emitter),
+        AsmBackend(asmbackend), CommentStream(CommentToEmit),
+        IsVerboseAsm(isVerboseAsm), ShowInst(showInst),
+        UseDwarfDirectory(useDwarfDirectory) {
     if (InstPrinter && IsVerboseAsm)
       InstPrinter->setCommentStream(CommentStream);
   }
@@ -1312,10 +1314,10 @@ void MCAsmStreamer::FinishImpl() {
 }
 
 MCStreamer *llvm::createAsmStreamer(MCContext &Context,
-                                    formatted_raw_ostream &OS,
+                                    std::unique_ptr<formatted_raw_ostream> OS,
                                     bool isVerboseAsm, bool useDwarfDirectory,
                                     MCInstPrinter *IP, MCCodeEmitter *CE,
                                     MCAsmBackend *MAB, bool ShowInst) {
-  return new MCAsmStreamer(Context, OS, isVerboseAsm, useDwarfDirectory, IP, CE,
-                           MAB, ShowInst);
+  return new MCAsmStreamer(Context, std::move(OS), isVerboseAsm,
+                           useDwarfDirectory, IP, CE, MAB, ShowInst);
 }

lib/Target/CppBackend/CPPBackend.cpp

@@ -15,6 +15,7 @@
 #include "CPPTargetMachine.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/config.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Constants.h"
@@ -91,6 +92,7 @@ namespace {
   /// CppWriter - This class is the main chunk of code that converts an LLVM
   /// module to a C++ translation unit.
   class CppWriter : public ModulePass {
+    std::unique_ptr<formatted_raw_ostream> OutOwner;
     formatted_raw_ostream &Out;
     const Module *TheModule;
     uint64_t uniqueNum;
@@ -105,8 +107,9 @@ namespace {
 
   public:
     static char ID;
-    explicit CppWriter(formatted_raw_ostream &o) :
-      ModulePass(ID), Out(o), uniqueNum(0), is_inline(false), indent_level(0){}
+    explicit CppWriter(std::unique_ptr<formatted_raw_ostream> o)
+        : ModulePass(ID), OutOwner(std::move(o)), Out(*OutOwner), uniqueNum(0),
+          is_inline(false), indent_level(0) {}
 
     const char *getPassName() const override { return "C++ backend"; }
 
@@ -2146,13 +2149,14 @@ char CppWriter::ID = 0;
 //                       External Interface declaration
 //===----------------------------------------------------------------------===//
 
-bool CPPTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
-                                           formatted_raw_ostream &o,
+bool CPPTargetMachine::addPassesToEmitFile(PassManagerBase &PM, raw_ostream &o,
                                            CodeGenFileType FileType,
                                            bool DisableVerify,
                                            AnalysisID StartAfter,
                                            AnalysisID StopAfter) {
-  if (FileType != TargetMachine::CGFT_AssemblyFile) return true;
-  PM.add(new CppWriter(o));
+  if (FileType != TargetMachine::CGFT_AssemblyFile)
+    return true;
+  auto FOut = llvm::make_unique<formatted_raw_ostream>(o);
+  PM.add(new CppWriter(std::move(FOut)));
   return false;
 }

lib/Target/CppBackend/CPPTargetMachine.h

@@ -29,7 +29,7 @@ struct CPPTargetMachine : public TargetMachine {
       : TargetMachine(T, "", TT, CPU, FS, Options) {}
 
 public:
-  bool addPassesToEmitFile(PassManagerBase &PM, formatted_raw_ostream &Out,
+  bool addPassesToEmitFile(PassManagerBase &PM, raw_ostream &Out,
                            CodeGenFileType FileType, bool DisableVerify,
                            AnalysisID StartAfter,
                            AnalysisID StopAfter) override;

lib/Target/TargetMachineC.cpp

@@ -183,7 +183,7 @@ void LLVMSetTargetMachineAsmVerbosity(LLVMTargetMachineRef T,
 }
 
 static LLVMBool LLVMTargetMachineEmit(LLVMTargetMachineRef T, LLVMModuleRef M,
-                                      formatted_raw_ostream &OS,
+                                      raw_ostream &OS,
                                       LLVMCodeGenFileType codegen,
                                       char **ErrorMessage) {
   TargetMachine* TM = unwrap(T);
@@ -231,8 +231,7 @@ LLVMBool LLVMTargetMachineEmitToFile(LLVMTargetMachineRef T, LLVMModuleRef M,
     *ErrorMessage = strdup(EC.message().c_str());
     return true;
   }
-  formatted_raw_ostream destf(dest);
-  bool Result = LLVMTargetMachineEmit(T, M, destf, codegen, ErrorMessage);
+  bool Result = LLVMTargetMachineEmit(T, M, dest, codegen, ErrorMessage);
   dest.flush();
   return Result;
 }
@@ -242,8 +241,7 @@ LLVMBool LLVMTargetMachineEmitToMemoryBuffer(LLVMTargetMachineRef T,
   LLVMMemoryBufferRef *OutMemBuf) {
   SmallString<0> CodeString;
   raw_svector_ostream OStream(CodeString);
-  formatted_raw_ostream Out(OStream);
-  bool Result = LLVMTargetMachineEmit(T, M, Out, codegen, ErrorMessage);
+  bool Result = LLVMTargetMachineEmit(T, M, OStream, codegen, ErrorMessage);
   OStream.flush();
 
   StringRef Data = OStream.str();

tools/gold/gold-plugin.cpp

@@ -31,7 +31,7 @@
 #include "llvm/Linker/Linker.h"
 #include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Object/IRObjectFile.h"
-#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -804,9 +804,8 @@ static void codegen(Module &M) {
 
   {
     raw_fd_ostream OS(FD, true);
-    formatted_raw_ostream FOS(OS);
 
-    if (TM->addPassesToEmitFile(CodeGenPasses, FOS,
+    if (TM->addPassesToEmitFile(CodeGenPasses, OS,
                                 TargetMachine::CGFT_ObjectFile))
       message(LDPL_FATAL, "Failed to setup codegen");
     CodeGenPasses.run(M);

tools/llc/llc.cpp

@@ -335,8 +335,6 @@ static int compileModule(char **argv, LLVMContext &Context) {
              << ": warning: ignoring -mc-relax-all because filetype != obj";
 
   {
-    formatted_raw_ostream FOS(Out->os());
-
     AnalysisID StartAfterID = nullptr;
     AnalysisID StopAfterID = nullptr;
     const PassRegistry *PR = PassRegistry::getPassRegistry();
@@ -358,7 +356,7 @@ static int compileModule(char **argv, LLVMContext &Context) {
     }
 
     // Ask the target to add backend passes as necessary.
-    if (Target->addPassesToEmitFile(PM, FOS, FileType, NoVerify,
+    if (Target->addPassesToEmitFile(PM, Out->os(), FileType, NoVerify,
                                     StartAfterID, StopAfterID)) {
       errs() << argv[0] << ": target does not support generation of this"
              << " file type!\n";