Refactor: Avoid `std::endl` where it's not necessary (part 1)

The `std::endl` manupulator, except inserting `\n` character, also
performs `os.flush()`, which may leads to undesired effects (like
disk I/O in the middle of forming data strings). For the
`std::stringstream` it also has no meaning.

9 files changed, 101 insertions, 111 deletions

diff --git a/Source/cmCacheManager.cxx b/Source/cmCacheManager.cxx
index 8789f6e..cfa8dc7 100644
--- a/Source/cmCacheManager.cxx
+++ b/Source/cmCacheManager.cxx
@@ -77,7 +77,7 @@ bool cmCacheManager::LoadCache(const std::string& path, bool internal,
     }
     while (realbuffer[0] == '/' && realbuffer[1] == '/') {
       if ((realbuffer[2] == '\\') && (realbuffer[3] == 'n')) {
-        helpString += "\n";
+        helpString += '\n';
         helpString += &realbuffer[4];
       } else {
         helpString += &realbuffer[2];
@@ -117,8 +117,8 @@ bool cmCacheManager::LoadCache(const std::string& path, bool internal,
       }
     } else {
       std::ostringstream error;
-      error << "Parse error in cache file " << cacheFile;
-      error << " on line " << lineno << ". Offending entry: " << realbuffer;
+      error << "Parse error in cache file " << cacheFile << " on line "
+            << lineno << ". Offending entry: " << realbuffer;
       cmSystemTools::Error(error.str());
     }
   }
@@ -217,7 +217,7 @@ void cmCacheManager::WritePropertyEntries(std::ostream& os, CacheIterator i,
       cmCacheManager::OutputKey(os, key);
       os << ":INTERNAL=";
       cmCacheManager::OutputValue(os, *value);
-      os << "\n";
+      os << '\n';
       cmCacheManager::OutputNewlineTruncationWarning(os, key, *value,
                                                      messenger);
     }
@@ -268,31 +268,29 @@ bool cmCacheManager::SaveCache(const std::string& path, cmMessenger* messenger)
 
   /* clang-format off */
   fout << "# This is the CMakeCache file.\n"
-       << "# For build in directory: " << currentcwd << "\n"
-       << "# It was generated by CMake: "
-       << cmSystemTools::GetCMakeCommand() << std::endl;
+          "# For build in directory: " << currentcwd << "\n"
+          "# It was generated by CMake: "
+       << cmSystemTools::GetCMakeCommand()
+       << "\n"
+          "# You can edit this file to change values found and used by cmake."
+          "\n"
+          "# If you do not want to change any of the values, simply exit the "
+          "editor.\n"
+          "# If you do want to change a value, simply edit, save, and exit "
+          "the editor.\n"
+          "# The syntax for the file is as follows:\n"
+          "# KEY:TYPE=VALUE\n"
+          "# KEY is the name of a variable in the cache.\n"
+          "# TYPE is a hint to GUIs for the type of VALUE, DO NOT EDIT TYPE!."
+          "\n"
+          "# VALUE is the current value for the KEY.\n"
+          "\n"
+          "########################\n"
+          "# EXTERNAL cache entries\n"
+          "########################\n"
+          "\n";
   /* clang-format on */
 
-  /* clang-format off */
-  fout << "# You can edit this file to change values found and used by cmake."
-       << std::endl
-       << "# If you do not want to change any of the values, simply exit the "
-       "editor." << std::endl
-       << "# If you do want to change a value, simply edit, save, and exit "
-       "the editor." << std::endl
-       << "# The syntax for the file is as follows:\n"
-       << "# KEY:TYPE=VALUE\n"
-       << "# KEY is the name of a variable in the cache.\n"
-       << "# TYPE is a hint to GUIs for the type of VALUE, DO NOT EDIT "
-       "TYPE!." << std::endl
-       << "# VALUE is the current value for the KEY.\n\n";
-  /* clang-format on */
-
-  fout << "########################\n";
-  fout << "# EXTERNAL cache entries\n";
-  fout << "########################\n";
-  fout << "\n";
-
   for (auto const& i : this->Cache) {
     CacheEntry const& ce = i.second;
     cmStateEnums::CacheEntryType t = ce.Type;
@@ -309,20 +307,20 @@ bool cmCacheManager::SaveCache(const std::string& path, cmMessenger* messenger)
         cmCacheManager::OutputHelpString(fout, "Missing description");
       }
       cmCacheManager::OutputKey(fout, i.first);
-      fout << ":" << cmState::CacheEntryTypeToString(t) << "=";
+      fout << ':' << cmState::CacheEntryTypeToString(t) << '=';
       cmCacheManager::OutputValue(fout, ce.Value);
-      fout << "\n";
+      fout << '\n';
       cmCacheManager::OutputNewlineTruncationWarning(fout, i.first, ce.Value,
                                                      messenger);
-      fout << "\n";
+      fout << '\n';
     }
   }
 
-  fout << "\n";
-  fout << "########################\n";
-  fout << "# INTERNAL cache entries\n";
-  fout << "########################\n";
-  fout << "\n";
+  fout << "\n"
+          "########################\n"
+          "# INTERNAL cache entries\n"
+          "########################\n"
+          "\n";
 
   for (cmCacheManager::CacheIterator i = this->NewIterator(); !i.IsAtEnd();
        i.Next()) {
@@ -338,14 +336,14 @@ bool cmCacheManager::SaveCache(const std::string& path, cmMessenger* messenger)
         cmCacheManager::OutputHelpString(fout, *help);
       }
       cmCacheManager::OutputKey(fout, i.GetName());
-      fout << ":" << cmState::CacheEntryTypeToString(t) << "=";
+      fout << ':' << cmState::CacheEntryTypeToString(t) << '=';
       cmCacheManager::OutputValue(fout, i.GetValue());
-      fout << "\n";
+      fout << '\n';
       cmCacheManager::OutputNewlineTruncationWarning(fout, i.GetName(),
                                                      i.GetValue(), messenger);
     }
   }
-  fout << "\n";
+  fout << '\n';
   fout.Close();
   std::string checkCacheFile = cmStrCat(path, "/CMakeFiles");
   cmSystemTools::MakeDirectory(checkCacheFile);
@@ -428,7 +426,7 @@ void cmCacheManager::OutputHelpString(std::ostream& fout,
         fout << "\\n";
       }
       oneLine = helpString.substr(pos, i - pos);
-      fout << oneLine << "\n";
+      fout << oneLine << '\n';
       pos = i;
     }
   }
@@ -450,7 +448,7 @@ void cmCacheManager::OutputWarningComment(std::ostream& fout,
         fout << "\\n";
       }
       oneLine = message.substr(pos, i - pos);
-      fout << oneLine << "\n";
+      fout << oneLine << '\n';
       pos = i;
     }
   }
@@ -517,17 +515,17 @@ cmProp cmCacheManager::GetInitializedCacheValue(const std::string& key) const
 
 void cmCacheManager::PrintCache(std::ostream& out) const
 {
-  out << "=================================================" << std::endl;
-  out << "CMakeCache Contents:" << std::endl;
+  out << "=================================================\n"
+         "CMakeCache Contents:\n";
   for (auto const& i : this->Cache) {
     if (i.second.Type != cmStateEnums::INTERNAL) {
-      out << i.first << " = " << i.second.Value << std::endl;
+      out << i.first << " = " << i.second.Value << '\n';
     }
   }
-  out << "\n\n";
-  out << "To change values in the CMakeCache, " << std::endl
-      << "edit CMakeCache.txt in your output directory.\n";
-  out << "=================================================" << std::endl;
+  out << "\n\n"
+         "To change values in the CMakeCache, \n"
+         "edit CMakeCache.txt in your output directory.\n"
+         "=================================================\n";
 }
 
 void cmCacheManager::AddCacheEntry(const std::string& key, const char* value,
diff --git a/Source/cmCallVisualStudioMacro.cxx b/Source/cmCallVisualStudioMacro.cxx
index 9e152ff..94b6e18 100644
--- a/Source/cmCallVisualStudioMacro.cxx
+++ b/Source/cmCallVisualStudioMacro.cxx
@@ -43,8 +43,7 @@ static bool LogErrorsAsMessages;
       if (LogErrorsAsMessages) {                                              \
         std::ostringstream _hresult_oss;                                      \
         _hresult_oss.flags(std::ios::hex);                                    \
-        _hresult_oss << context << " failed HRESULT, hr = 0x" << hr           \
-                     << std::endl;                                            \
+        _hresult_oss << context << " failed HRESULT, hr = 0x" << hr << '\n';  \
         _hresult_oss.flags(std::ios::dec);                                    \
         _hresult_oss << __FILE__ << "(" << __LINE__ << ")";                   \
         cmSystemTools::Message(_hresult_oss.str());                           \
@@ -98,32 +97,37 @@ HRESULT InstanceCallMacro(IDispatch* vsIDE, const std::string& macro,
                          DISPATCH_METHOD, &params, &result, &excep, &arg);
 
       std::ostringstream oss;
-      oss << std::endl;
-      oss << "Invoke(ExecuteCommand)" << std::endl;
-      oss << "  Macro: " << macro << std::endl;
-      oss << "  Args: " << args << std::endl;
+      /* clang-format off */
+      oss << "\nInvoke(ExecuteCommand)\n"
+             "  Macro: " << macro << "\n"
+             "  Args: " << args << '\n';
+      /* clang-format on */
 
       if (DISP_E_EXCEPTION == hr) {
-        oss << "DISP_E_EXCEPTION EXCEPINFO:" << excep.wCode << std::endl;
-        oss << "  wCode: " << excep.wCode << std::endl;
-        oss << "  wReserved: " << excep.wReserved << std::endl;
+        /* clang-format off */
+        oss << "DISP_E_EXCEPTION EXCEPINFO:" << excep.wCode << "\n"
+               "  wCode: " << excep.wCode << "\n"
+               "  wReserved: " << excep.wReserved << '\n';
+        /* clang-format on */
         if (excep.bstrSource) {
           oss << "  bstrSource: " << (const char*)(_bstr_t)excep.bstrSource
-              << std::endl;
+              << '\n';
         }
         if (excep.bstrDescription) {
           oss << "  bstrDescription: "
-              << (const char*)(_bstr_t)excep.bstrDescription << std::endl;
+              << (const char*)(_bstr_t)excep.bstrDescription << '\n';
         }
         if (excep.bstrHelpFile) {
           oss << "  bstrHelpFile: " << (const char*)(_bstr_t)excep.bstrHelpFile
-              << std::endl;
+              << '\n';
         }
-        oss << "  dwHelpContext: " << excep.dwHelpContext << std::endl;
-        oss << "  pvReserved: " << excep.pvReserved << std::endl;
-        oss << "  pfnDeferredFillIn: "
-            << reinterpret_cast<void*>(excep.pfnDeferredFillIn) << std::endl;
-        oss << "  scode: " << excep.scode << std::endl;
+        /* clang-format off */
+        oss << "  dwHelpContext: " << excep.dwHelpContext << "\n"
+               "  pvReserved: " << excep.pvReserved << "\n"
+               "  pfnDeferredFillIn: "
+            << reinterpret_cast<void*>(excep.pfnDeferredFillIn) << "\n"
+               "  scode: " << excep.scode << '\n';
+        /* clang-format on */
       }
 
       std::string exstr(oss.str());
diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 003019a..ea31417 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -276,8 +276,7 @@ static bool checkInterfaceDirs(const std::string& prepro,
                 << "\"\nhowever it is also "
                    "a subdirectory of the "
                 << (inBinary ? "build" : "source") << " tree:\n    \""
-                << (inBinary ? topBinaryDir : topSourceDir) << "\""
-                << std::endl;
+                << (inBinary ? topBinaryDir : topSourceDir) << "\"\n";
               target->GetLocalGenerator()->IssueMessage(
                 MessageType::AUTHOR_WARNING, s.str());
               CM_FALLTHROUGH;
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index d58113c..44b2749 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -1011,7 +1011,7 @@ void cmGlobalNinjaGenerator::AddCXXCompileCommand(
       cm::make_unique<cmGeneratedFileStream>(buildFilePath);
     *this->CompileCommandsStream << "[";
   } else {
-    *this->CompileCommandsStream << "," << std::endl;
+    *this->CompileCommandsStream << ",\n";
   }
 
   std::string sourceFileName = sourceFile;
diff --git a/Source/cmGlobalUnixMakefileGenerator3.cxx b/Source/cmGlobalUnixMakefileGenerator3.cxx
index 7daca74..bebd4e0 100644
--- a/Source/cmGlobalUnixMakefileGenerator3.cxx
+++ b/Source/cmGlobalUnixMakefileGenerator3.cxx
@@ -159,7 +159,7 @@ void cmGlobalUnixMakefileGenerator3::Generate()
   this->WriteMainCMakefile();
 
   if (this->CommandDatabase) {
-    *this->CommandDatabase << std::endl << "]";
+    *this->CommandDatabase << "\n]";
     this->CommandDatabase.reset();
   }
 }
@@ -174,21 +174,20 @@ void cmGlobalUnixMakefileGenerator3::AddCXXCompileCommand(
       "/compile_commands.json";
     this->CommandDatabase =
       cm::make_unique<cmGeneratedFileStream>(commandDatabaseName);
-    *this->CommandDatabase << "[" << std::endl;
+    *this->CommandDatabase << "[\n";
   } else {
-    *this->CommandDatabase << "," << std::endl;
+    *this->CommandDatabase << ",\n";
   }
-  *this->CommandDatabase << "{" << std::endl
+  *this->CommandDatabase << "{\n"
                          << R"(  "directory": ")"
                          << cmGlobalGenerator::EscapeJSON(workingDirectory)
-                         << "\"," << std::endl
+                         << "\",\n"
                          << R"(  "command": ")"
                          << cmGlobalGenerator::EscapeJSON(compileCommand)
-                         << "\"," << std::endl
+                         << "\",\n"
                          << R"(  "file": ")"
-                         << cmGlobalGenerator::EscapeJSON(sourceFile) << "\""
-                         << std::endl
-                         << "}";
+                         << cmGlobalGenerator::EscapeJSON(sourceFile)
+                         << "\"\n}";
 }
 
 void cmGlobalUnixMakefileGenerator3::WriteMainMakefile2()
diff --git a/Source/cmLocalNinjaGenerator.cxx b/Source/cmLocalNinjaGenerator.cxx
index be1dd0d..43232d0 100644
--- a/Source/cmLocalNinjaGenerator.cxx
+++ b/Source/cmLocalNinjaGenerator.cxx
@@ -206,9 +206,8 @@ void cmLocalNinjaGenerator::WriteBuildFileTop()
 void cmLocalNinjaGenerator::WriteProjectHeader(std::ostream& os)
 {
   cmGlobalNinjaGenerator::WriteDivider(os);
-  os << "# Project: " << this->GetProjectName() << std::endl
-     << "# Configurations: " << cmJoin(this->GetConfigNames(), ", ")
-     << std::endl;
+  os << "# Project: " << this->GetProjectName() << '\n'
+     << "# Configurations: " << cmJoin(this->GetConfigNames(), ", ") << '\n';
   cmGlobalNinjaGenerator::WriteDivider(os);
 }
 
@@ -235,8 +234,7 @@ void cmLocalNinjaGenerator::WriteNinjaRequiredVersion(std::ostream& os)
 
   cmGlobalNinjaGenerator::WriteComment(
     os, "Minimal version of Ninja required by this file");
-  os << "ninja_required_version = " << requiredVersion << std::endl
-     << std::endl;
+  os << "ninja_required_version = " << requiredVersion << "\n\n";
 }
 
 void cmLocalNinjaGenerator::WriteNinjaConfigurationVariable(
@@ -265,9 +263,8 @@ void cmLocalNinjaGenerator::WritePools(std::ostream& os)
       unsigned int jobs;
       if (eq != std::string::npos &&
           sscanf(pool.c_str() + eq, "=%u", &jobs) == 1) {
-        os << "pool " << pool.substr(0, eq) << std::endl;
-        os << "  depth = " << jobs << std::endl;
-        os << std::endl;
+        os << "pool " << pool.substr(0, eq) << "\n  depth = " << jobs
+           << "\n\n";
       } else {
         cmSystemTools::Error("Invalid pool defined by property 'JOB_POOLS': " +
                              pool);
@@ -279,8 +276,7 @@ void cmLocalNinjaGenerator::WritePools(std::ostream& os)
 void cmLocalNinjaGenerator::WriteNinjaFilesInclusionConfig(std::ostream& os)
 {
   cmGlobalNinjaGenerator::WriteDivider(os);
-  os << "# Include auxiliary files.\n"
-     << "\n";
+  os << "# Include auxiliary files.\n\n";
   cmGlobalNinjaGenerator* ng = this->GetGlobalNinjaGenerator();
   std::string const ninjaCommonFile =
     ng->NinjaOutputPath(cmGlobalNinjaMultiGenerator::NINJA_COMMON_FILE);
@@ -293,8 +289,7 @@ void cmLocalNinjaGenerator::WriteNinjaFilesInclusionConfig(std::ostream& os)
 void cmLocalNinjaGenerator::WriteNinjaFilesInclusionCommon(std::ostream& os)
 {
   cmGlobalNinjaGenerator::WriteDivider(os);
-  os << "# Include auxiliary files.\n"
-     << "\n";
+  os << "# Include auxiliary files.\n\n";
   cmGlobalNinjaGenerator* ng = this->GetGlobalNinjaGenerator();
   std::string const ninjaRulesFile =
     ng->NinjaOutputPath(cmGlobalNinjaGenerator::NINJA_RULES_FILE);
@@ -307,14 +302,14 @@ void cmLocalNinjaGenerator::WriteNinjaFilesInclusionCommon(std::ostream& os)
 void cmLocalNinjaGenerator::WriteProcessedMakefile(std::ostream& os)
 {
   cmGlobalNinjaGenerator::WriteDivider(os);
-  os << "# Write statements declared in CMakeLists.txt:" << std::endl
+  os << "# Write statements declared in CMakeLists.txt:\n"
      << "# " << this->Makefile->GetDefinition("CMAKE_CURRENT_LIST_FILE")
-     << std::endl;
+     << '\n';
   if (this->IsRootMakefile()) {
-    os << "# Which is the root file." << std::endl;
+    os << "# Which is the root file.\n";
   }
   cmGlobalNinjaGenerator::WriteDivider(os);
-  os << std::endl;
+  os << '\n';
 }
 
 void cmLocalNinjaGenerator::AppendTargetOutputs(cmGeneratorTarget* target,
diff --git a/Source/cmLocalUnixMakefileGenerator3.cxx b/Source/cmLocalUnixMakefileGenerator3.cxx
index 53bd1d5..a4b9e76 100644
--- a/Source/cmLocalUnixMakefileGenerator3.cxx
+++ b/Source/cmLocalUnixMakefileGenerator3.cxx
@@ -1328,10 +1328,9 @@ bool cmLocalUnixMakefileGenerator3::UpdateDependencies(
     int result;
     if (!ftc->Compare(internalDependFile, tgtInfo, &result) || result < 0) {
       if (verbose) {
-        std::ostringstream msg;
-        msg << "Dependee \"" << tgtInfo << "\" is newer than depender \""
-            << internalDependFile << "\"." << std::endl;
-        cmSystemTools::Stdout(msg.str());
+        cmSystemTools::Stdout(cmStrCat("Dependee \"", tgtInfo,
+                                       "\" is newer than depender \"",
+                                       internalDependFile, "\".\n"));
       }
       needRescanDependInfo = true;
     }
@@ -1348,10 +1347,9 @@ bool cmLocalUnixMakefileGenerator3::UpdateDependencies(
     if (!ftc->Compare(internalDependFile, dirInfoFile, &result) ||
         result < 0) {
       if (verbose) {
-        std::ostringstream msg;
-        msg << "Dependee \"" << dirInfoFile << "\" is newer than depender \""
-            << internalDependFile << "\"." << std::endl;
-        cmSystemTools::Stdout(msg.str());
+        cmSystemTools::Stdout(cmStrCat("Dependee \"", dirInfoFile,
+                                       "\" is newer than depender \"",
+                                       internalDependFile, "\".\n"));
       }
       needRescanDirInfo = true;
     }
@@ -1517,11 +1515,9 @@ void cmLocalUnixMakefileGenerator3::CheckMultipleOutputs(bool verbose)
     if (cmSystemTools::FileExists(dependee) &&
         !cmSystemTools::FileExists(depender)) {
       if (verbose) {
-        std::ostringstream msg;
-        msg << "Deleting primary custom command output \"" << dependee
-            << "\" because another output \"" << depender
-            << "\" does not exist." << std::endl;
-        cmSystemTools::Stdout(msg.str());
+        cmSystemTools::Stdout(cmStrCat(
+          "Deleting primary custom command output \"", dependee,
+          "\" because another output \"", depender, "\" does not exist.\n"));
       }
       cmSystemTools::RemoveFile(dependee);
     }
@@ -1969,7 +1965,7 @@ std::string cmLocalUnixMakefileGenerator3::GetRecursiveMakeCall(
 void cmLocalUnixMakefileGenerator3::WriteDivider(std::ostream& os)
 {
   os << "#======================================"
-     << "=======================================\n";
+        "=======================================\n";
 }
 
 void cmLocalUnixMakefileGenerator3::WriteCMakeArgument(std::ostream& os,
@@ -1977,7 +1973,7 @@ void cmLocalUnixMakefileGenerator3::WriteCMakeArgument(std::ostream& os,
 {
   // Write the given string to the stream with escaping to get it back
   // into CMake through the lexical scanner.
-  os << "\"";
+  os << '"';
   for (char c : s) {
     if (c == '\\') {
       os << "\\\\";
@@ -1987,7 +1983,7 @@ void cmLocalUnixMakefileGenerator3::WriteCMakeArgument(std::ostream& os,
       os << c;
     }
   }
-  os << "\"";
+  os << '"';
 }
 
 std::string cmLocalUnixMakefileGenerator3::ConvertToQuotedOutputPath(
diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index f95d233..c7ab452 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -300,8 +300,7 @@ void cmMakefileTargetGenerator::WriteCommonCodeRules()
       dependFileNameFull, false, this->GlobalGenerator->GetMakefileEncoding());
     depFileStream << "# Empty dependencies file for "
                   << this->GeneratorTarget->GetName() << ".\n"
-                  << "# This may be replaced when dependencies are built."
-                  << std::endl;
+                  << "# This may be replaced when dependencies are built.\n";
   }
 
   // Open the flags file.  This should be copy-if-different because the
diff --git a/Source/cmWriteFileCommand.cxx b/Source/cmWriteFileCommand.cxx
index 34e21b2..666ba87 100644
--- a/Source/cmWriteFileCommand.cxx
+++ b/Source/cmWriteFileCommand.cxx
@@ -72,7 +72,7 @@ bool cmWriteFileCommand(std::vector<std::string> const& args,
     status.SetError(error);
     return false;
   }
-  file << message << std::endl;
+  file << message << '\n';
   file.close();
   if (mode && !writable) {
     cmSystemTools::SetPermissions(fileName.c_str(), mode);