misc cleanup of Compiler::run

src/IceCompiler.cpp

 //===- subzero/src/IceCompiler.cpp - Driver for bitcode translation -------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 18 matching lines @@
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-parameter"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Bitcode/NaCl/NaClReaderWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/StreamingMemoryObject.h"
+
+#include <regex>
+
 #pragma clang diagnostic pop
 
 namespace Ice {
 
 namespace {
 
 struct {
   const char *FlagName;
   bool FlagValue;
 } ConditionalBuildAttributes[] = {
     {"dump", BuildDefs::dump()},
     {"llvm_cl", BuildDefs::llvmCl()},
     {"llvm_ir", BuildDefs::llvmIr()},
     {"llvm_ir_as_input", BuildDefs::llvmIrAsInput()},
     {"minimal_build", BuildDefs::minimal()},
     {"browser_mode", BuildDefs::browser()}};
 
 /// Dumps values of build attributes to Stream if Stream is non-null.
-void dumpBuildAttributes(Ostream *Stream) {
-  if (Stream == nullptr)
-    return;
+void dumpBuildAttributes(Ostream &Str) {
 // List the supported targets.
-#define SUBZERO_TARGET(TARGET) *Stream << "target_" #TARGET << "\n";
+#define SUBZERO_TARGET(TARGET) Str << "target_" #TARGET << "\n";
 #include "llvm/Config/SZTargets.def"
   const char *Prefix[2] = {"no", "allow"};
   for (size_t i = 0; i < llvm::array_lengthof(ConditionalBuildAttributes);
        ++i) {
     const auto &A = ConditionalBuildAttributes[i];
-    *Stream << Prefix[A.FlagValue] << "_" << A.FlagName << "\n";
+    Str << Prefix[A.FlagValue] << "_" << A.FlagName << "\n";
   }
 }
+bool llvmIRInput(const IceString &Filename) {
+  return BuildDefs::llvmIrAsInput() &&
+         std::regex_match(Filename, std::regex(".*\\.ll"));
+}
 
 } // end of anonymous namespace
 
 void Compiler::run(const Ice::ClFlagsExtra &ExtraFlags, GlobalContext &Ctx,
                    std::unique_ptr<llvm::DataStreamer> &&InputStream) {
-  dumpBuildAttributes(ExtraFlags.getGenerateBuildAtts() ? &Ctx.getStrDump()
-                                                        : nullptr);
-  if (ExtraFlags.getGenerateBuildAtts())
-    return Ctx.getErrorStatus()->assign(EC_None);
-
+  if (ExtraFlags.getGenerateBuildAtts()) {
+    dumpBuildAttributes(Ctx.getStrDump());
+    Ctx.getErrorStatus()->assign(EC_None);
+    return;
+  }
   // The Minimal build (specifically, when dump()/emit() are not implemented)
   // allows only --filetype=obj. Check here to avoid cryptic error messages
   // downstream.
   if (!BuildDefs::dump() && Ctx.getFlags().getOutFileType() != FT_Elf) {
     // TODO(stichnot): Access the actual command-line argument via
     // llvm::Option.ArgStr and .ValueStr .
     Ctx.getStrError()
         << "Error: only --filetype=obj is supported in this build.\n";
-    return Ctx.getErrorStatus()->assign(EC_Args);
+    Ctx.getErrorStatus()->assign(EC_Args);
+    return;
   }
 
-  // Force -build-on-read=0 for .ll files.
-  const std::string LLSuffix = ".ll";
-  const IceString &IRFilename = ExtraFlags.getIRFilename();
-  bool BuildOnRead = ExtraFlags.getBuildOnRead();
-  if (BuildDefs::llvmIrAsInput() && IRFilename.length() >= LLSuffix.length() &&
-      IRFilename.compare(IRFilename.length() - LLSuffix.length(),
-                         LLSuffix.length(), LLSuffix) == 0)
-    BuildOnRead = false;
-
   TimerMarker T(Ice::TimerStack::TT_szmain, &Ctx);
 
   Ctx.emitFileHeader();
   Ctx.startWorkerThreads();
 
   std::unique_ptr<Translator> Translator;
+  const IceString &IRFilename = ExtraFlags.getIRFilename();
+  bool BuildOnRead = ExtraFlags.getBuildOnRead() && !llvmIRInput(IRFilename);
   if (BuildOnRead) {
     std::unique_ptr<PNaClTranslator> PTranslator(new PNaClTranslator(&Ctx));
     std::unique_ptr<llvm::StreamingMemoryObject> MemObj(
         new llvm::StreamingMemoryObjectImpl(InputStream.release()));
     PTranslator->translate(IRFilename, std::move(MemObj));
     Translator.reset(PTranslator.release());
   } else if (BuildDefs::llvmIr()) {
     if (BuildDefs::browser()) {
       Ctx.getStrError()
           << "non BuildOnRead is not supported w/ PNACL_BROWSER_TRANSLATOR\n";
-      return Ctx.getErrorStatus()->assign(EC_Args);
+      Ctx.getErrorStatus()->assign(EC_Args);
+      return;
     }
     // Parse the input LLVM IR file into a module.
     llvm::SMDiagnostic Err;
     TimerMarker T1(Ice::TimerStack::TT_parse, &Ctx);
     llvm::DiagnosticHandlerFunction DiagnosticHandler =
         ExtraFlags.getLLVMVerboseErrors()
             ? redirectNaClDiagnosticToStream(llvm::errs())
             : nullptr;
     std::unique_ptr<llvm::Module> Mod =
         NaClParseIRFile(IRFilename, ExtraFlags.getInputFileFormat(), Err,
                         llvm::getGlobalContext(), DiagnosticHandler);
     if (!Mod) {
       Err.print(ExtraFlags.getAppName().c_str(), llvm::errs());
-      return Ctx.getErrorStatus()->assign(EC_Bitcode);
+      Ctx.getErrorStatus()->assign(EC_Bitcode);
+      return;
     }
 
     std::unique_ptr<Converter> Converter(new class Converter(Mod.get(), &Ctx));
     Converter->convertToIce();
     Translator.reset(Converter.release());
   } else {
     Ctx.getStrError() << "Error: Build doesn't allow LLVM IR, "
                       << "--build-on-read=0 not allowed\n";
-    return Ctx.getErrorStatus()->assign(EC_Args);
+    Ctx.getErrorStatus()->assign(EC_Args);
+    return;
   }
 
   Ctx.waitForWorkerThreads();
   if (Translator->getErrorStatus()) {
     Ctx.getErrorStatus()->assign(Translator->getErrorStatus().value());
   } else {
     Ctx.lowerGlobals("last");
     Ctx.lowerProfileData();
     Ctx.lowerConstants();
     Ctx.lowerJumpTables();
@@ skipping 10 matching lines @@
 
   if (Ctx.getFlags().getTimeEachFunction()) {
     constexpr bool DumpCumulative = false;
     Ctx.dumpTimers(GlobalContext::TSK_Funcs, DumpCumulative);
   }
   constexpr bool FinalStats = true;
   Ctx.dumpStats("_FINAL_", FinalStats);
 }
 
 } // end of namespace Ice