Simplify boolean expressions

Use clang-tidy's readability-simplify-boolean-expr checker.
After applying the fix-its, revise all changes *very* carefully.
Be aware of false positives and invalid changes.

37 files changed, 73 insertions, 169 deletions

diff --git a/Source/CPack/IFW/cmCPackIFWRepository.cxx b/Source/CPack/IFW/cmCPackIFWRepository.cxx
index b149f81..1838005 100644
--- a/Source/CPack/IFW/cmCPackIFWRepository.cxx
+++ b/Source/CPack/IFW/cmCPackIFWRepository.cxx
@@ -45,16 +45,16 @@ bool cmCPackIFWRepository::IsValid() const
 
   switch (Update) {
     case None:
-      valid = Url.empty() ? false : true;
+      valid = !Url.empty();
       break;
     case Add:
-      valid = Url.empty() ? false : true;
+      valid = !Url.empty();
       break;
     case Remove:
-      valid = Url.empty() ? false : true;
+      valid = !Url.empty();
       break;
     case Replace:
-      valid = (OldUrl.empty() || NewUrl.empty()) ? false : true;
+      valid = !OldUrl.empty() && !NewUrl.empty();
       break;
   }
 
@@ -244,11 +244,7 @@ bool cmCPackIFWRepository::PatchUpdatesXml()
 
   fout.Close();
 
-  if (!cmSystemTools::RenameFile(updatesPatchXml.data(), updatesXml.data())) {
-    return false;
-  }
-
-  return true;
+  return cmSystemTools::RenameFile(updatesPatchXml.data(), updatesXml.data());
 }
 
 void cmCPackIFWRepository::WriteRepositoryConfig(cmXMLWriter& xout)
diff --git a/Source/CPack/cmCPackArchiveGenerator.cxx b/Source/CPack/cmCPackArchiveGenerator.cxx
index 7db20a4..baf6719 100644
--- a/Source/CPack/cmCPackArchiveGenerator.cxx
+++ b/Source/CPack/cmCPackArchiveGenerator.cxx
@@ -269,9 +269,5 @@ bool cmCPackArchiveGenerator::SupportsComponentInstallation() const
   // The Component installation support should only
   // be activated if explicitly requested by the user
   // (for backward compatibility reason)
-  if (IsOn("CPACK_ARCHIVE_COMPONENT_INSTALL")) {
-    return true;
-  } else {
-    return false;
-  }
+  return IsOn("CPACK_ARCHIVE_COMPONENT_INSTALL");
 }
diff --git a/Source/CPack/cmCPackDebGenerator.cxx b/Source/CPack/cmCPackDebGenerator.cxx
index 1ad4152..ddaa483 100644
--- a/Source/CPack/cmCPackDebGenerator.cxx
+++ b/Source/CPack/cmCPackDebGenerator.cxx
@@ -675,11 +675,7 @@ int cmCPackDebGenerator::createDeb()
 
 bool cmCPackDebGenerator::SupportsComponentInstallation() const
 {
-  if (IsOn("CPACK_DEB_COMPONENT_INSTALL")) {
-    return true;
-  } else {
-    return false;
-  }
+  return IsOn("CPACK_DEB_COMPONENT_INSTALL");
 }
 
 std::string cmCPackDebGenerator::GetComponentInstallDirNameSuffix(
diff --git a/Source/CPack/cmCPackRPMGenerator.cxx b/Source/CPack/cmCPackRPMGenerator.cxx
index 9827b70..bc10111 100644
--- a/Source/CPack/cmCPackRPMGenerator.cxx
+++ b/Source/CPack/cmCPackRPMGenerator.cxx
@@ -228,11 +228,7 @@ int cmCPackRPMGenerator::PackageFiles()
 
 bool cmCPackRPMGenerator::SupportsComponentInstallation() const
 {
-  if (IsOn("CPACK_RPM_COMPONENT_INSTALL")) {
-    return true;
-  } else {
-    return false;
-  }
+  return IsOn("CPACK_RPM_COMPONENT_INSTALL");
 }
 
 std::string cmCPackRPMGenerator::GetComponentInstallDirNameSuffix(
diff --git a/Source/CPack/cpack.cxx b/Source/CPack/cpack.cxx
index 94e1615..425afd9 100644
--- a/Source/CPack/cpack.cxx
+++ b/Source/CPack/cpack.cxx
@@ -209,11 +209,7 @@ int main(int argc, char const* const* argv)
    * should launch cpack using "cpackConfigFile" if it exists
    * in the current directory.
    */
-  if ((doc.CheckOptions(argc, argv, "-G")) && !(argc == 1)) {
-    help = true;
-  } else {
-    help = false;
-  }
+  help = doc.CheckOptions(argc, argv, "-G") && argc != 1;
 
   // This part is used for cpack documentation lookup as well.
   cminst.AddCMakePaths();
diff --git a/Source/CTest/cmCTestCoverageHandler.cxx b/Source/CTest/cmCTestCoverageHandler.cxx
index daefb59..ba9e546 100644
--- a/Source/CTest/cmCTestCoverageHandler.cxx
+++ b/Source/CTest/cmCTestCoverageHandler.cxx
@@ -90,11 +90,8 @@ public:
     cmsysProcess_Execute(this->Process);
     this->PipeState = cmsysProcess_GetState(this->Process);
     // if the process is running or exited return true
-    if (this->PipeState == cmsysProcess_State_Executing ||
-        this->PipeState == cmsysProcess_State_Exited) {
-      return true;
-    }
-    return false;
+    return this->PipeState == cmsysProcess_State_Executing ||
+      this->PipeState == cmsysProcess_State_Exited;
   }
   void SetStdoutFile(const char* fname)
   {
@@ -705,13 +702,8 @@ bool IsFileInDir(const std::string& infile, const std::string& indir)
   std::string file = cmSystemTools::CollapseFullPath(infile);
   std::string dir = cmSystemTools::CollapseFullPath(indir);
 
-  if (file.size() > dir.size() &&
-      (fnc(file.substr(0, dir.size())) == fnc(dir)) &&
-      file[dir.size()] == '/') {
-    return true;
-  }
-
-  return false;
+  return file.size() > dir.size() &&
+    fnc(file.substr(0, dir.size())) == fnc(dir) && file[dir.size()] == '/';
 }
 
 int cmCTestCoverageHandler::HandlePHPCoverage(
diff --git a/Source/CTest/cmCTestLaunch.cxx b/Source/CTest/cmCTestLaunch.cxx
index 4a408a2..99fa9e7 100644
--- a/Source/CTest/cmCTestLaunch.cxx
+++ b/Source/CTest/cmCTestLaunch.cxx
@@ -594,12 +594,8 @@ bool cmCTestLaunch::Match(std::string const& line,
 
 bool cmCTestLaunch::MatchesFilterPrefix(std::string const& line) const
 {
-  if (!this->OptionFilterPrefix.empty() &&
-      cmSystemTools::StringStartsWith(line.c_str(),
-                                      this->OptionFilterPrefix.c_str())) {
-    return true;
-  }
-  return false;
+  return !this->OptionFilterPrefix.empty() &&
+    cmSystemTools::StringStartsWith(line, this->OptionFilterPrefix.c_str());
 }
 
 int cmCTestLaunch::Main(int argc, const char* const argv[])
diff --git a/Source/CTest/cmCTestMemCheckHandler.cxx b/Source/CTest/cmCTestMemCheckHandler.cxx
index 5ae98af..f8ffd43 100644
--- a/Source/CTest/cmCTestMemCheckHandler.cxx
+++ b/Source/CTest/cmCTestMemCheckHandler.cxx
@@ -722,10 +722,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckSanitizerOutput(
     ostr << *i << std::endl;
   }
   log = ostr.str();
-  if (defects) {
-    return false;
-  }
-  return true;
+  return defects == 0;
 }
 bool cmCTestMemCheckHandler::ProcessMemCheckPurifyOutput(
   const std::string& str, std::string& log, std::vector<int>& results)
@@ -766,10 +763,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckPurifyOutput(
   }
 
   log = ostr.str();
-  if (defects) {
-    return false;
-  }
-  return true;
+  return defects == 0;
 }
 
 bool cmCTestMemCheckHandler::ProcessMemCheckValgrindOutput(
@@ -904,10 +898,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckValgrindOutput(
                        << (cmSystemTools::GetTime() - sttime) << std::endl,
                      this->Quiet);
   log = ostr.str();
-  if (defects) {
-    return false;
-  }
-  return true;
+  return defects == 0;
 }
 
 bool cmCTestMemCheckHandler::ProcessMemCheckBoundsCheckerOutput(
diff --git a/Source/CTest/cmCTestSubmitHandler.cxx b/Source/CTest/cmCTestSubmitHandler.cxx
index f373348..32975df 100644
--- a/Source/CTest/cmCTestSubmitHandler.cxx
+++ b/Source/CTest/cmCTestSubmitHandler.cxx
@@ -845,10 +845,7 @@ bool cmCTestSubmitHandler::SubmitUsingSCP(const std::string& scp_command,
     }
   }
   cmsysProcess_Delete(cp);
-  if (problems) {
-    return false;
-  }
-  return true;
+  return problems == 0;
 }
 
 bool cmCTestSubmitHandler::SubmitUsingCP(const std::string& localprefix,
@@ -870,7 +867,6 @@ bool cmCTestSubmitHandler::SubmitUsingCP(const std::string& localprefix,
   }
 
   cmCTest::SetOfStrings::const_iterator file;
-  bool problems = false;
   for (file = files.begin(); file != files.end(); ++file) {
     std::string lfname = localprefix;
     cmSystemTools::ConvertToUnixSlashes(lfname);
@@ -883,9 +879,6 @@ bool cmCTestSubmitHandler::SubmitUsingCP(const std::string& localprefix,
   }
   std::string tagDoneFile = destination + "/" + remoteprefix + "DONE";
   cmSystemTools::Touch(tagDoneFile, true);
-  if (problems) {
-    return false;
-  }
   return true;
 }
 
diff --git a/Source/CTest/cmCTestTestHandler.cxx b/Source/CTest/cmCTestTestHandler.cxx
index 20ef693..55a6518 100644
--- a/Source/CTest/cmCTestTestHandler.cxx
+++ b/Source/CTest/cmCTestTestHandler.cxx
@@ -1406,7 +1406,7 @@ void cmCTestTestHandler::UseIncludeRegExp()
 void cmCTestTestHandler::UseExcludeRegExp()
 {
   this->UseExcludeRegExpFlag = true;
-  this->UseExcludeRegExpFirst = this->UseIncludeRegExpFlag ? false : true;
+  this->UseExcludeRegExpFirst = !this->UseIncludeRegExpFlag;
 }
 
 const char* cmCTestTestHandler::GetTestStatus(int status)
diff --git a/Source/CTest/cmParsePHPCoverage.cxx b/Source/CTest/cmParsePHPCoverage.cxx
index eb0d962..5ec2718 100644
--- a/Source/CTest/cmParsePHPCoverage.cxx
+++ b/Source/CTest/cmParsePHPCoverage.cxx
@@ -27,10 +27,7 @@ bool cmParsePHPCoverage::ReadUntil(std::istream& in, char until)
   char c = 0;
   while (in.get(c) && c != until) {
   }
-  if (c != until) {
-    return false;
-  }
-  return true;
+  return c == until;
 }
 bool cmParsePHPCoverage::ReadCoverageArray(std::istream& in,
                                            std::string const& fileName)
diff --git a/Source/CursesDialog/cmCursesBoolWidget.cxx b/Source/CursesDialog/cmCursesBoolWidget.cxx
index 0055e88..9bcf050 100644
--- a/Source/CursesDialog/cmCursesBoolWidget.cxx
+++ b/Source/CursesDialog/cmCursesBoolWidget.cxx
@@ -54,9 +54,5 @@ void cmCursesBoolWidget::SetValueAsBool(bool value)
 
 bool cmCursesBoolWidget::GetValueAsBool()
 {
-  if (this->Value == "ON") {
-    return true;
-  } else {
-    return false;
-  }
+  return this->Value == "ON";
 }
diff --git a/Source/cmCacheManager.cxx b/Source/cmCacheManager.cxx
index d143193..676e84a 100644
--- a/Source/cmCacheManager.cxx
+++ b/Source/cmCacheManager.cxx
@@ -642,5 +642,5 @@ void cmCacheManager::CacheIterator::SetProperty(const std::string& p, bool v)
 bool cmCacheManager::CacheIterator::PropertyExists(
   const std::string& prop) const
 {
-  return this->GetProperty(prop) ? true : false;
+  return this->GetProperty(prop) != NULL;
 }
diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index e1a7bee..1eefbb1 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -274,8 +274,7 @@ cmComputeLinkInformation::cmComputeLinkInformation(
 
   // Check whether we should use an import library for linking a target.
   this->UseImportLibrary =
-    this->Makefile->GetDefinition("CMAKE_IMPORT_LIBRARY_SUFFIX") ? true
-                                                                 : false;
+    this->Makefile->IsDefinitionSet("CMAKE_IMPORT_LIBRARY_SUFFIX");
 
   // Check whether we should skip dependencies on shared library files.
   this->LinkDependsNoShared =
diff --git a/Source/cmCustomCommand.cxx b/Source/cmCustomCommand.cxx
index 7c00c80..4c5bd03 100644
--- a/Source/cmCustomCommand.cxx
+++ b/Source/cmCustomCommand.cxx
@@ -38,7 +38,7 @@ cmCustomCommand::cmCustomCommand(cmMakefile const* mf,
   , Backtrace()
   , Comment(comment ? comment : "")
   , WorkingDirectory(workingDirectory ? workingDirectory : "")
-  , HaveComment(comment ? true : false)
+  , HaveComment(comment != NULL)
   , EscapeAllowMakeVars(false)
   , EscapeOldStyle(true)
 {
diff --git a/Source/cmDependsC.cxx b/Source/cmDependsC.cxx
index 78bb1b2..5be527c 100644
--- a/Source/cmDependsC.cxx
+++ b/Source/cmDependsC.cxx
@@ -278,21 +278,21 @@ void cmDependsC::ReadCacheFile()
       continue;
     }
     // the first line after an empty line is the name of the parsed file
-    if (haveFileName == false) {
+    if (!haveFileName) {
       haveFileName = true;
       int newer = 0;
       cmFileTimeComparison comp;
       bool res = comp.FileTimeCompare(this->CacheFileName.c_str(),
                                       line.c_str(), &newer);
 
-      if ((res == true) && (newer == 1)) // cache is newer than the parsed file
+      if (res && newer == 1) // cache is newer than the parsed file
       {
         cacheEntry = new cmIncludeLines;
         this->FileCache[line] = cacheEntry;
       }
       // file doesn't exist, check that the regular expressions
       // haven't changed
-      else if (res == false) {
+      else if (!res) {
         if (line.find(INCLUDE_REGEX_LINE_MARKER) == 0) {
           if (line != this->IncludeRegexLineString) {
             return;
diff --git a/Source/cmDependsFortran.cxx b/Source/cmDependsFortran.cxx
index 38e319d..a20fb98 100644
--- a/Source/cmDependsFortran.cxx
+++ b/Source/cmDependsFortran.cxx
@@ -654,10 +654,9 @@ bool cmDependsFortran::ModulesDiffer(const char* modFile,
     // but also do not include a date so we can fall through to
     // compare them without skipping any prefix.
     unsigned char hdr[2];
-    bool okay =
-      finModFile.read(reinterpret_cast<char*>(hdr), 2) ? true : false;
+    bool okay = !finModFile.read(reinterpret_cast<char*>(hdr), 2).fail();
     finModFile.seekg(0);
-    if (!(okay && hdr[0] == 0x1f && hdr[1] == 0x8b)) {
+    if (!okay || hdr[0] != 0x1f || hdr[1] != 0x8b) {
       const char seq[1] = { '\n' };
       const int seqlen = 1;
 
diff --git a/Source/cmELF.cxx b/Source/cmELF.cxx
index 26f1a44..c7f8a2d 100644
--- a/Source/cmELF.cxx
+++ b/Source/cmELF.cxx
@@ -143,7 +143,7 @@ public:
   {
     this->Stream.seekg(pos);
     this->Stream.read(buf, size);
-    return this->Stream ? true : false;
+    return !this->Stream.fail();
   }
 
   // Lookup the SONAME in the DYNAMIC section.
@@ -497,7 +497,7 @@ private:
         this->NeedSwap) {
       ByteSwap(x);
     }
-    return this->Stream ? true : false;
+    return !this->Stream.fail();
   }
   bool Read(ELF_Dyn& x)
   {
@@ -505,7 +505,7 @@ private:
         this->NeedSwap) {
       ByteSwap(x);
     }
-    return this->Stream ? true : false;
+    return !this->Stream.fail();
   }
 
   bool LoadSectionHeader(ELF_Half i)
diff --git a/Source/cmExtraCodeBlocksGenerator.cxx b/Source/cmExtraCodeBlocksGenerator.cxx
index 2070b1f..40cff78 100644
--- a/Source/cmExtraCodeBlocksGenerator.cxx
+++ b/Source/cmExtraCodeBlocksGenerator.cxx
@@ -655,11 +655,11 @@ std::string cmExtraCodeBlocksGenerator::GetCBCompilerId(const cmMakefile* mf)
   // projects with C/C++ and Fortran are handled as C/C++ projects
   bool pureFortran = false;
   std::string compilerIdVar;
-  if (this->GlobalGenerator->GetLanguageEnabled("CXX") == true) {
+  if (this->GlobalGenerator->GetLanguageEnabled("CXX")) {
     compilerIdVar = "CMAKE_CXX_COMPILER_ID";
-  } else if (this->GlobalGenerator->GetLanguageEnabled("C") == true) {
+  } else if (this->GlobalGenerator->GetLanguageEnabled("C")) {
     compilerIdVar = "CMAKE_C_COMPILER_ID";
-  } else if (this->GlobalGenerator->GetLanguageEnabled("Fortran") == true) {
+  } else if (this->GlobalGenerator->GetLanguageEnabled("Fortran")) {
     compilerIdVar = "CMAKE_Fortran_COMPILER_ID";
     pureFortran = true;
   }
@@ -667,7 +667,7 @@ std::string cmExtraCodeBlocksGenerator::GetCBCompilerId(const cmMakefile* mf)
   std::string compilerId = mf->GetSafeDefinition(compilerIdVar);
   std::string compiler = "gcc"; // default to gcc
   if (compilerId == "MSVC") {
-    if (mf->IsDefinitionSet("MSVC10") == true) {
+    if (mf->IsDefinitionSet("MSVC10")) {
       compiler = "msvc10";
     } else {
       compiler = "msvc8";
diff --git a/Source/cmExtraCodeLiteGenerator.cxx b/Source/cmExtraCodeLiteGenerator.cxx
index ba58767..dd10b65 100644
--- a/Source/cmExtraCodeLiteGenerator.cxx
+++ b/Source/cmExtraCodeLiteGenerator.cxx
@@ -407,7 +407,7 @@ std::string cmExtraCodeLiteGenerator::GetCodeLiteCompilerName(
   // figure out which language to use
   // for now care only for C and C++
   std::string compilerIdVar = "CMAKE_CXX_COMPILER_ID";
-  if (this->GlobalGenerator->GetLanguageEnabled("CXX") == false) {
+  if (!this->GlobalGenerator->GetLanguageEnabled("CXX")) {
     compilerIdVar = "CMAKE_C_COMPILER_ID";
   }
 
diff --git a/Source/cmExtraEclipseCDT4Generator.cxx b/Source/cmExtraEclipseCDT4Generator.cxx
index f24e7fb..bc217af 100644
--- a/Source/cmExtraEclipseCDT4Generator.cxx
+++ b/Source/cmExtraEclipseCDT4Generator.cxx
@@ -129,7 +129,7 @@ void cmExtraEclipseCDT4Generator::Generate()
     (this->IsOutOfSourceBuild &&
      mf->IsOn("CMAKE_ECLIPSE_GENERATE_SOURCE_PROJECT"));
 
-  if ((this->GenerateSourceProject == false) &&
+  if (!this->GenerateSourceProject &&
       (mf->IsOn("ECLIPSE_CDT4_GENERATE_SOURCE_PROJECT"))) {
     mf->IssueMessage(
       cmake::WARNING,
diff --git a/Source/cmGeneratedFileStream.cxx b/Source/cmGeneratedFileStream.cxx
index 2c05913..dee174b 100644
--- a/Source/cmGeneratedFileStream.cxx
+++ b/Source/cmGeneratedFileStream.cxx
@@ -42,7 +42,7 @@ cmGeneratedFileStream::~cmGeneratedFileStream()
   // stream will be destroyed which will close the temporary file.
   // Finally the base destructor will be called to replace the
   // destination file.
-  this->Okay = (*this) ? true : false;
+  this->Okay = !this->fail();
 }
 
 cmGeneratedFileStream& cmGeneratedFileStream::Open(const char* name,
@@ -71,7 +71,7 @@ cmGeneratedFileStream& cmGeneratedFileStream::Open(const char* name,
 bool cmGeneratedFileStream::Close()
 {
   // Save whether the temporary output file is valid before closing.
-  this->Okay = (*this) ? true : false;
+  this->Okay = !this->fail();
 
   // Close the temporary output file.
   this->Stream::close();
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 3856091..1607dd9 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -1306,11 +1306,7 @@ bool cmGeneratorTarget::MacOSXRpathInstallNameDirDefault() const
       this->GetName());
   }
 
-  if (cmp0042 == cmPolicies::NEW) {
-    return true;
-  }
-
-  return false;
+  return cmp0042 == cmPolicies::NEW;
 }
 
 std::string cmGeneratorTarget::GetSOName(const std::string& config) const
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index a1764a3..fc34b8b 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -180,8 +180,7 @@ void cmGlobalGenerator::ResolveLanguageCompiler(const std::string& lang,
   } else {
     path = name;
   }
-  if ((path.empty() || !cmSystemTools::FileExists(path.c_str())) &&
-      (optional == false)) {
+  if (!optional && (path.empty() || !cmSystemTools::FileExists(path))) {
     return;
   }
   const char* cname =
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index 143ad92..3abcba3 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -1227,9 +1227,9 @@ std::string cmGlobalNinjaGenerator::ninjaCmd() const
 
 bool cmGlobalNinjaGenerator::SupportsConsolePool() const
 {
-  return cmSystemTools::VersionCompare(
-           cmSystemTools::OP_LESS, this->NinjaVersion.c_str(),
-           RequiredNinjaVersionForConsolePool().c_str()) == false;
+  return !cmSystemTools::VersionCompare(
+    cmSystemTools::OP_LESS, this->NinjaVersion.c_str(),
+    RequiredNinjaVersionForConsolePool().c_str());
 }
 
 void cmGlobalNinjaGenerator::WriteTargetClean(std::ostream& os)
diff --git a/Source/cmGraphVizWriter.cxx b/Source/cmGraphVizWriter.cxx
index 20cd171..6b3a870 100644
--- a/Source/cmGraphVizWriter.cxx
+++ b/Source/cmGraphVizWriter.cxx
@@ -140,7 +140,7 @@ void cmGraphVizWriter::ReadSettings(const char* settingsFileName,
 // which other targets depend on it.
 void cmGraphVizWriter::WriteTargetDependersFiles(const char* fileName)
 {
-  if (this->GenerateDependers == false) {
+  if (!this->GenerateDependers) {
     return;
   }
 
@@ -153,7 +153,7 @@ void cmGraphVizWriter::WriteTargetDependersFiles(const char* fileName)
       continue;
     }
 
-    if (this->GenerateForTargetType(ptrIt->second->GetType()) == false) {
+    if (!this->GenerateForTargetType(ptrIt->second->GetType())) {
       continue;
     }
 
@@ -184,7 +184,7 @@ void cmGraphVizWriter::WriteTargetDependersFiles(const char* fileName)
 // on which targets it depends.
 void cmGraphVizWriter::WritePerTargetFiles(const char* fileName)
 {
-  if (this->GeneratePerTarget == false) {
+  if (!this->GeneratePerTarget) {
     return;
   }
 
@@ -197,7 +197,7 @@ void cmGraphVizWriter::WritePerTargetFiles(const char* fileName)
       continue;
     }
 
-    if (this->GenerateForTargetType(ptrIt->second->GetType()) == false) {
+    if (!this->GenerateForTargetType(ptrIt->second->GetType())) {
       continue;
     }
 
@@ -243,7 +243,7 @@ void cmGraphVizWriter::WriteGlobalFile(const char* fileName)
       continue;
     }
 
-    if (this->GenerateForTargetType(ptrIt->second->GetType()) == false) {
+    if (!this->GenerateForTargetType(ptrIt->second->GetType())) {
       continue;
     }
 
@@ -344,7 +344,7 @@ void cmGraphVizWriter::WriteDependerConnections(
       continue;
     }
 
-    if (this->GenerateForTargetType(dependerIt->second->GetType()) == false) {
+    if (!this->GenerateForTargetType(dependerIt->second->GetType())) {
       continue;
     }
 
@@ -403,7 +403,7 @@ void cmGraphVizWriter::WriteNode(const std::string& targetName,
 
 void cmGraphVizWriter::CollectTargetsAndLibs()
 {
-  if (this->HaveTargetsAndLibs == false) {
+  if (!this->HaveTargetsAndLibs) {
     this->HaveTargetsAndLibs = true;
     int cnt = this->CollectAllTargets();
     if (this->GenerateForExternals) {
diff --git a/Source/cmListFileCache.cxx b/Source/cmListFileCache.cxx
index f47e9b6..33731e0 100644
--- a/Source/cmListFileCache.cxx
+++ b/Source/cmListFileCache.cxx
@@ -202,10 +202,7 @@ bool cmListFile::ParseFile(const char* filename, bool topLevel, cmMakefile* mf)
       this->Functions.insert(this->Functions.begin(), project);
     }
   }
-  if (parseError) {
-    return false;
-  }
-  return true;
+  return !parseError;
 }
 
 bool cmListFileParser::ParseFunction(const char* name, long line)
diff --git a/Source/cmLocalUnixMakefileGenerator3.cxx b/Source/cmLocalUnixMakefileGenerator3.cxx
index f60a595..4b5af8b 100644
--- a/Source/cmLocalUnixMakefileGenerator3.cxx
+++ b/Source/cmLocalUnixMakefileGenerator3.cxx
@@ -1322,7 +1322,7 @@ bool cmLocalUnixMakefileGenerator3::UpdateDependencies(const char* tgtInfo,
   // not be considered.
   std::map<std::string, cmDepends::DependencyVector> validDependencies;
   bool needRescanDependencies = false;
-  if (needRescanDirInfo == false) {
+  if (!needRescanDirInfo) {
     cmDependsC checker;
     checker.SetVerbose(verbose);
     checker.SetFileComparison(ftc);
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index e684689..45fb7cf 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -2124,20 +2124,11 @@ bool cmMakefile::CanIWriteThisFile(const char* fileName) const
   // If we are doing an in-source build, then the test will always fail
   if (cmSystemTools::SameFile(this->GetHomeDirectory(),
                               this->GetHomeOutputDirectory())) {
-    if (this->IsOn("CMAKE_DISABLE_IN_SOURCE_BUILD")) {
-      return false;
-    }
-    return true;
+    return !this->IsOn("CMAKE_DISABLE_IN_SOURCE_BUILD");
   }
 
-  // Check if this is a subdirectory of the source tree but not a
-  // subdirectory of the build tree
-  if (cmSystemTools::IsSubDirectory(fileName, this->GetHomeDirectory()) &&
-      !cmSystemTools::IsSubDirectory(fileName,
-                                     this->GetHomeOutputDirectory())) {
-    return false;
-  }
-  return true;
+  return !cmSystemTools::IsSubDirectory(fileName, this->GetHomeDirectory()) ||
+    cmSystemTools::IsSubDirectory(fileName, this->GetHomeOutputDirectory());
 }
 
 const char* cmMakefile::GetRequiredDefinition(const std::string& name) const
@@ -2166,7 +2157,7 @@ bool cmMakefile::IsDefinitionSet(const std::string& name) const
     }
   }
 #endif
-  return def ? true : false;
+  return def != NULL;
 }
 
 const char* cmMakefile::GetDefinition(const std::string& name) const
diff --git a/Source/cmMakefileLibraryTargetGenerator.cxx b/Source/cmMakefileLibraryTargetGenerator.cxx
index 8f7dd7e..128291d 100644
--- a/Source/cmMakefileLibraryTargetGenerator.cxx
+++ b/Source/cmMakefileLibraryTargetGenerator.cxx
@@ -454,8 +454,7 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules(
   std::vector<std::string> archiveFinishCommands;
   std::string::size_type archiveCommandLimit = std::string::npos;
   if (this->GeneratorTarget->GetType() == cmState::STATIC_LIBRARY) {
-    haveStaticLibraryRule =
-      this->Makefile->GetDefinition(linkRuleVar) ? true : false;
+    haveStaticLibraryRule = this->Makefile->IsDefinitionSet(linkRuleVar);
     std::string arCreateVar = "CMAKE_";
     arCreateVar += linkLanguage;
     arCreateVar += "_ARCHIVE_CREATE";
diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 1aa2ddb..b0f0d9b 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -130,8 +130,7 @@ void cmNinjaTargetGenerator::AddIncludeFlags(std::string& languageFlags,
   // Add include directory flags.
   std::string includeFlags = this->LocalGenerator->GetIncludeFlags(
     includes, this->GeneratorTarget, language,
-    language == "RC" ? true : false, // full include paths for RC
-    // needed by cmcldeps
+    language == "RC", // full include paths for RC needed by cmcldeps
     false, this->GetConfigName());
   if (this->GetGlobalGenerator()->IsGCCOnWindows())
     std::replace(includeFlags.begin(), includeFlags.end(), '\\', '/');
diff --git a/Source/cmPropertyDefinitionMap.cxx b/Source/cmPropertyDefinitionMap.cxx
index ebc2caa..0ba35e7 100644
--- a/Source/cmPropertyDefinitionMap.cxx
+++ b/Source/cmPropertyDefinitionMap.cxx
@@ -31,12 +31,7 @@ void cmPropertyDefinitionMap::DefineProperty(const std::string& name,
 
 bool cmPropertyDefinitionMap::IsPropertyDefined(const std::string& name) const
 {
-  cmPropertyDefinitionMap::const_iterator it = this->find(name);
-  if (it == this->end()) {
-    return false;
-  }
-
-  return true;
+  return this->find(name) != this->end();
 }
 
 bool cmPropertyDefinitionMap::IsPropertyChained(const std::string& name) const
diff --git a/Source/cmQtAutoGenerators.cxx b/Source/cmQtAutoGenerators.cxx
index ac64397..dc44f3e 100644
--- a/Source/cmQtAutoGenerators.cxx
+++ b/Source/cmQtAutoGenerators.cxx
@@ -636,14 +636,14 @@ void cmQtAutoGenerators::ParseCppFile(
         }
       } else {
         std::string fileToMoc = absFilename;
-        if ((basename != scannedFileBasename) || (requiresMoc == false)) {
+        if (!requiresMoc || basename != scannedFileBasename) {
           std::string mocSubDir = extractSubDir(absPath, currentMoc);
           std::string headerToMoc =
             findMatchingHeader(absPath, mocSubDir, basename, headerExtensions);
           if (!headerToMoc.empty()) {
             // this is for KDE4 compatibility:
             fileToMoc = headerToMoc;
-            if ((requiresMoc == false) && (basename == scannedFileBasename)) {
+            if (!requiresMoc && basename == scannedFileBasename) {
               std::stringstream err;
               err << "AUTOGEN: warning: " << absFilename
                   << ": The file "
@@ -696,8 +696,8 @@ void cmQtAutoGenerators::ParseCppFile(
   // If this is the case, the moc_foo.cpp should probably be generated from
   // foo.cpp instead of foo.h, because otherwise it won't build.
   // But warn, since this is not how it is supposed to be used.
-  if ((dotMocIncluded == false) && (requiresMoc == true)) {
-    if (mocUnderscoreIncluded == true) {
+  if (!dotMocIncluded && requiresMoc) {
+    if (mocUnderscoreIncluded) {
       // this is for KDE4 compatibility:
       std::stringstream err;
       err << "AUTOGEN: warning: " << absFilename << ": The file "
@@ -833,8 +833,7 @@ void cmQtAutoGenerators::StrictParseCppFile(
   // foo.cpp instead of foo.h, because otherwise it won't build.
   // But warn, since this is not how it is supposed to be used.
   std::string macroName;
-  if ((dotMocIncluded == false) &&
-      (requiresMocing(contentsString, macroName))) {
+  if (!dotMocIncluded && requiresMocing(contentsString, macroName)) {
     // otherwise always error out since it will not compile:
     std::stringstream err;
     err << "AUTOGEN: error: " << absFilename << ": The file "
diff --git a/Source/cmSourceFileLocation.cxx b/Source/cmSourceFileLocation.cxx
index 3219f36..a89d1e8 100644
--- a/Source/cmSourceFileLocation.cxx
+++ b/Source/cmSourceFileLocation.cxx
@@ -177,10 +177,7 @@ bool cmSourceFileLocation::MatchesAmbiguousExtension(
   }
   std::vector<std::string> hdrExts =
     mf->GetCMakeInstance()->GetHeaderExtensions();
-  if (std::find(hdrExts.begin(), hdrExts.end(), ext) != hdrExts.end()) {
-    return true;
-  }
-  return false;
+  return std::find(hdrExts.begin(), hdrExts.end(), ext) != hdrExts.end();
 }
 
 bool cmSourceFileLocation::Matches(cmSourceFileLocation const& loc)
diff --git a/Source/cmSourceGroup.cxx b/Source/cmSourceGroup.cxx
index 394b33a..f27b572 100644
--- a/Source/cmSourceGroup.cxx
+++ b/Source/cmSourceGroup.cxx
@@ -86,11 +86,7 @@ bool cmSourceGroup::MatchesRegex(const char* name)
 
 bool cmSourceGroup::MatchesFiles(const char* name)
 {
-  std::set<std::string>::const_iterator i = this->GroupFiles.find(name);
-  if (i != this->GroupFiles.end()) {
-    return true;
-  }
-  return false;
+  return this->GroupFiles.find(name) != this->GroupFiles.end();
 }
 
 void cmSourceGroup::AssignSource(const cmSourceFile* sf)
diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 7dece47..7156948 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -2108,11 +2108,8 @@ bool cmSystemTools::GuessLibrarySOName(std::string const& fullPath,
   // If the symlink points at an extended version of the same name
   // assume it is the soname.
   std::string name = cmSystemTools::GetFilenameName(fullPath);
-  if (soname.length() > name.length() &&
-      soname.substr(0, name.length()) == name) {
-    return true;
-  }
-  return false;
+  return soname.length() > name.length() &&
+    soname.compare(0, name.length(), name) == 0;
 }
 
 bool cmSystemTools::GuessLibraryInstallName(std::string const& fullPath,
diff --git a/Source/cmcmd.cxx b/Source/cmcmd.cxx
index 471028a..535dead 100644
--- a/Source/cmcmd.cxx
+++ b/Source/cmcmd.cxx
@@ -1027,11 +1027,7 @@ int cmcmd::ExecuteEchoColor(std::vector<std::string>& args)
       // Enable or disable color based on the switch value.
       std::string value = args[i].substr(9);
       if (!value.empty()) {
-        if (cmSystemTools::IsOn(value.c_str())) {
-          enabled = true;
-        } else {
-          enabled = false;
-        }
+        enabled = cmSystemTools::IsOn(value.c_str());
       }
     } else if (cmHasLiteralPrefix(args[i], "--progress-dir=")) {
       progressDir = args[i].substr(15);
@@ -1226,7 +1222,7 @@ int cmcmd::VisualStudioLink(std::vector<std::string>& args, int type)
   if (args.size() < 2) {
     return -1;
   }
-  bool verbose = cmSystemTools::GetEnv("VERBOSE") ? true : false;
+  bool verbose = cmSystemTools::GetEnv("VERBOSE") != NULL;
   std::vector<std::string> expandedArgs;
   for (std::vector<std::string>::iterator i = args.begin(); i != args.end();
        ++i) {