Do not use errs() or outs() directly. Instead use message(), log() or error()

LLD is a multi-threaded program. errs() or outs() are not guaranteed
to be thread-safe (they are actually not).

LLD's message(), log() or error() are thread-safe. We should use them.

llvm-svn: 295787

lld/COFF/Chunks.cpp

@@ -227,7 +227,7 @@ void SectionChunk::printDiscardedMessage() const {
   // Removed by dead-stripping. If it's removed by ICF, ICF already
   // printed out the name, so don't repeat that here.
   if (Sym && this == Repl)
-    outs() << "Discarded " << Sym->getName() << "\n";
+    message("Discarded " + Sym->getName());
 }
 
 StringRef SectionChunk::getDebugName() {

lld/COFF/Driver.cpp

@@ -164,8 +164,7 @@ void LinkerDriver::addArchiveBuffer(MemoryBufferRef MB, StringRef SymName,
 
   Obj->ParentName = ParentName;
   Symtab.addFile(Obj);
-  if (Config->Verbose)
-    outs() << "Loaded " << toString(Obj) << " for " << SymName << "\n";
+  log("Loaded " + toString(Obj) + " for " + SymName);
 }
 
 void LinkerDriver::enqueueArchiveMember(const Archive::Child &C,
@@ -472,8 +471,8 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
     if (ErrOrWriter) {
       Tar = std::move(*ErrOrWriter);
     } else {
-      errs() << "/linkrepro: failed to open " << Path << ": "
-             << toString(ErrOrWriter.takeError()) << '\n';
+      error("/linkrepro: failed to open " + Path + ": " +
+            toString(ErrOrWriter.takeError()));
     }
   }
 
@@ -696,7 +695,7 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   // We should have inferred a machine type by now from the input files, but if
   // not we assume x64.
   if (Config->Machine == IMAGE_FILE_MACHINE_UNKNOWN) {
-    errs() << "warning: /machine is not specified. x64 is assumed.\n";
+    warn("/machine is not specified. x64 is assumed");
     Config->Machine = AMD64;
   }
 
@@ -733,8 +732,7 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
     if (S.empty())
       fatal("entry point must be defined");
     Config->Entry = addUndefined(S);
-    if (Config->Verbose)
-      outs() << "Entry name inferred: " << S << "\n";
+    log("Entry name inferred: " + S);
   }
 
   // Handle /export

lld/COFF/DriverUtils.cpp

@@ -44,39 +44,35 @@ namespace {
 class Executor {
 public:
   explicit Executor(StringRef S) : Saver(Alloc), Prog(Saver.save(S)) {}
-  void add(StringRef S) { Args.push_back(Saver.save(S).data()); }
-  void add(std::string &S) { Args.push_back(Saver.save(S).data()); }
-  void add(Twine S) { Args.push_back(Saver.save(S).data()); }
-  void add(const char *S) { Args.push_back(Saver.save(S).data()); }
+  void add(StringRef S) { Args.push_back(Saver.save(S)); }
+  void add(std::string &S) { Args.push_back(Saver.save(S)); }
+  void add(Twine S) { Args.push_back(Saver.save(S)); }
+  void add(const char *S) { Args.push_back(Saver.save(S)); }
 
   void run() {
-    if (Config->Verbose) {
-      outs() << Prog;
-      for (const char *Arg : Args)
-        outs() << " " << Arg;
-      outs() << '\n';
-    }
+    log(Prog + " " + llvm::join(Args.begin(), Args.end(), " "));
 
     ErrorOr<std::string> ExeOrErr = sys::findProgramByName(Prog);
     if (auto EC = ExeOrErr.getError())
       fatal(EC, "unable to find " + Prog + " in PATH: ");
-    const char *Exe = Saver.save(*ExeOrErr).data();
-
+    StringRef Exe = Saver.save(*ExeOrErr);
     Args.insert(Args.begin(), Exe);
-    Args.push_back(nullptr);
-    if (sys::ExecuteAndWait(Args[0], Args.data()) != 0) {
-      for (const char *S : Args)
-        if (S)
-          errs() << S << " ";
-      fatal("ExecuteAndWait failed");
-    }
+
+    std::vector<const char *> Vec;
+    for (StringRef S : Args)
+      Vec.push_back(S.data());
+    Vec.push_back(nullptr);
+
+    if (sys::ExecuteAndWait(Args[0], Vec.data()) != 0)
+      fatal("ExecuteAndWait failed: " +
+            llvm::join(Args.begin(), Args.end(), " "));
   }
 
 private:
   BumpPtrAllocator Alloc;
   StringSaver Saver;
   StringRef Prog;
-  std::vector<const char *> Args;
+  std::vector<StringRef> Args;
 };
 
 } // anonymous namespace
@@ -175,8 +171,7 @@ void parseMerge(StringRef S) {
   if (!Inserted) {
     StringRef Existing = Pair.first->second;
     if (Existing != To)
-      errs() << "warning: " << S << ": already merged into " << Existing
-             << "\n";
+      warn(S + ": already merged into " + Existing);
   }
 }
 
@@ -558,7 +553,7 @@ void fixupExports() {
     Export *Existing = Pair.first->second;
     if (E == *Existing || E.Name != Existing->Name)
       continue;
-    errs() << "warning: duplicate /export option: " << E.Name << "\n";
+    warn("duplicate /export option: " + E.Name);
   }
   Config->Exports = std::move(V);
 
@@ -677,8 +672,7 @@ void runMSVCLinker(opt::InputArgList &Args, ArrayRef<StringRef> Objects) {
     }
   }
 
-  if (Config->Verbose)
-    outs() << "link.exe " << Rsp << "\n";
+  log("link.exe " + Rsp);
 
   // Run MSVC link.exe.
   Temps.emplace_back("lto", "rsp", Rsp);
@@ -723,16 +717,16 @@ opt::InputArgList ArgParser::parse(ArrayRef<const char *> ArgsArr) {
 
   // Print the real command line if response files are expanded.
   if (Args.hasArg(OPT_verbose) && ArgsArr.size() != Argv.size()) {
-    outs() << "Command line:";
+    std::string Msg = "Command line:";
     for (const char *S : Argv)
-      outs() << " " << S;
-    outs() << "\n";
+      Msg += " " + std::string(S);
+    message(Msg);
   }
 
   if (MissingCount)
     fatal(Twine(Args.getArgString(MissingIndex)) + ": missing argument");
   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
-    errs() << "ignoring unknown argument: " << Arg->getSpelling() << "\n";
+    warn("ignoring unknown argument: " + Arg->getSpelling());
   return Args;
 }
 

lld/COFF/Error.cpp

@@ -55,6 +55,19 @@ static void print(StringRef S, raw_ostream::Colors C) {
   }
 }
 
+void log(const Twine &Msg) {
+  if (Config->Verbose) {
+    std::lock_guard<std::mutex> Lock(Mu);
+    outs() << Argv0 << ": " << Msg << "\n";
+  }
+}
+
+void message(const Twine &Msg) {
+  std::lock_guard<std::mutex> Lock(Mu);
+  outs() << Msg << "\n";
+  outs().flush();
+}
+
 void error(const Twine &Msg) {
   std::lock_guard<std::mutex> Lock(Mu);
 

lld/COFF/Error.h

@@ -20,6 +20,8 @@ extern uint64_t ErrorCount;
 extern llvm::raw_ostream *ErrorOS;
 extern llvm::StringRef Argv0;
 
+void log(const Twine &Msg);
+void message(const Twine &Msg);
 void warn(const Twine &Msg);
 void error(const Twine &Msg);
 LLVM_ATTRIBUTE_NORETURN void fatal(const Twine &Msg);

lld/COFF/ICF.cpp

@@ -231,19 +231,16 @@ void ICF::run(const std::vector<Chunk *> &Vec) {
     ++Cnt;
   } while (Repeat);
 
-  if (Config->Verbose)
-    outs() << "\nICF needed " << Cnt << " iterations\n";
+  log("ICF needed " + Twine(Cnt) + " iterations");
 
   // Merge sections in the same colors.
   forEachColor([&](size_t Begin, size_t End) {
     if (End - Begin == 1)
       return;
 
-    if (Config->Verbose)
-      outs() << "Selected " << Chunks[Begin]->getDebugName() << "\n";
+    log("Selected " + Chunks[Begin]->getDebugName());
     for (size_t I = Begin + 1; I < End; ++I) {
-      if (Config->Verbose)
-        outs() << "  Removed " << Chunks[I]->getDebugName() << "\n";
+      log("  Removed " + Chunks[I]->getDebugName());
       Chunks[Begin]->replace(Chunks[I]);
     }
   });

lld/COFF/SymbolTable.cpp

@@ -57,8 +57,7 @@ static SymbolPreference compareDefined(Symbol *S, bool WasInserted,
 SymbolTable *Symtab;
 
 void SymbolTable::addFile(InputFile *File) {
-  if (Config->Verbose)
-    outs() << "Reading " << toString(File) << "\n";
+  log("Reading " + toString(File));
   File->parse();
 
   MachineTypes MT = File->getMachineType();
@@ -81,8 +80,7 @@ void SymbolTable::addFile(InputFile *File) {
   if (S.empty())
     return;
 
-  if (Config->Verbose)
-    outs() << "Directives: " << toString(File) << ": " << S << "\n";
+  log("Directives: " + toString(File) + ": " + S);
   Driver->parseDirectives(S);
 }
 
@@ -136,12 +134,11 @@ void SymbolTable::reportRemainingUndefines() {
     return;
   for (SymbolBody *B : Config->GCRoot)
     if (Undefs.count(B))
-      errs() << "<root>: undefined symbol: " << B->getName() << "\n";
+      warn("<root>: undefined symbol: " + B->getName());
   for (ObjectFile *File : ObjectFiles)
     for (SymbolBody *Sym : File->getSymbols())
       if (Undefs.count(Sym))
-        errs() << toString(File) << ": undefined symbol: " << Sym->getName()
-               << "\n";
+        warn(toString(File) + ": undefined symbol: " + Sym->getName());
   if (!Config->Force)
     fatal("link failed");
 }

lld/ELF/Driver.cpp

@@ -299,7 +299,7 @@ void LinkerDriver::main(ArrayRef<const char *> ArgsArr, bool CanExitEarly) {
   // in help to print the version information, GNU ld just normally exits,
   // while gold can continue linking. We are compatible with ld.bfd here.
   if (Args.hasArg(OPT_version) || Args.hasArg(OPT_v))
-    outs() << getLLDVersion() << "\n";
+    message(getLLDVersion());
   if (Args.hasArg(OPT_version))
     return;
 

lld/ELF/Error.cpp

@@ -45,9 +45,16 @@ static void print(StringRef S, raw_ostream::Colors C) {
 }
 
 void elf::log(const Twine &Msg) {
-  std::lock_guard<std::mutex> Lock(Mu);
-  if (Config->Verbose)
+  if (Config->Verbose) {
+    std::lock_guard<std::mutex> Lock(Mu);
     outs() << Argv0 << ": " << Msg << "\n";
+  }
+}
+
+void elf::message(const Twine &Msg) {
+  std::lock_guard<std::mutex> Lock(Mu);
+  outs() << Msg << "\n";
+  outs().flush();
 }
 
 void elf::warn(const Twine &Msg) {

lld/ELF/Error.h

@@ -36,6 +36,7 @@ extern llvm::raw_ostream *ErrorOS;
 extern llvm::StringRef Argv0;
 
 void log(const Twine &Msg);
+void message(const Twine &Msg);
 void warn(const Twine &Msg);
 void error(const Twine &Msg);
 LLVM_ATTRIBUTE_NORETURN void fatal(const Twine &Msg);

lld/ELF/InputFiles.cpp

@@ -56,14 +56,13 @@ public:
 }
 
 Optional<MemoryBufferRef> elf::readFile(StringRef Path) {
-  if (Config->Verbose)
-    outs() << Path << "\n";
-
+  log(Path);
   auto MBOrErr = MemoryBuffer::getFile(Path);
   if (auto EC = MBOrErr.getError()) {
     error("cannot open " + Path + ": " + EC.message());
     return None;
   }
+
   std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
   MemoryBufferRef MBRef = MB->getMemBufferRef();
   make<std::unique_ptr<MemoryBuffer>>(std::move(MB)); // take MB ownership

lld/ELF/OutputSections.cpp

@@ -568,8 +568,8 @@ static bool canMergeToProgbits(unsigned Type) {
 template <class ELFT> static void reportDiscarded(InputSectionBase<ELFT> *IS) {
   if (!Config->PrintGcSections)
     return;
-  errs() << "removing unused section from '" << IS->Name << "' in file '"
-         << IS->getFile()->getName() << "'\n";
+  message("removing unused section from '" + IS->Name + "' in file '" +
+          IS->getFile()->getName());
 }
 
 template <class ELFT>

lld/ELF/SymbolTable.cpp

@@ -75,7 +75,7 @@ template <class ELFT> void SymbolTable<ELFT>::addFile(InputFile *File) {
   }
 
   if (Config->Trace)
-    outs() << toString(File) << "\n";
+    message(toString(File));
 
   // .so file
   if (auto *F = dyn_cast<SharedFile<ELFT>>(File)) {

lld/ELF/Symbols.cpp

@@ -293,15 +293,15 @@ bool Symbol::includeInDynsym() const {
 // Print out a log message for --trace-symbol.
 void elf::printTraceSymbol(Symbol *Sym) {
   SymbolBody *B = Sym->body();
-  outs() << toString(B->File);
-
+  std::string S;
   if (B->isUndefined())
-    outs() << ": reference to ";
+    S = ": reference to ";
   else if (B->isCommon())
-    outs() << ": common definition of ";
+    S = ": common definition of ";
   else
-    outs() << ": definition of ";
-  outs() << B->getName() << "\n";
+    S = ": definition of ";
+
+  message(toString(B->File) + S + B->getName());
 }
 
 // Returns a symbol for an error message.