Improve string find: prefer character overloads.

Apply fix-its from clang-tidy's performance-faster-string-find checker.
Ignore findings in kwsys.

Source/CPack/IFW/cmCPackIFWPackage.cxx

@@ -56,13 +56,13 @@ cmCPackIFWPackage::DependenceStruct::DependenceStruct(
   } else if ((pos = dependence.find(">=")) != std::string::npos) {
     Compare.Type = CompareGreaterOrEqual;
     Compare.Value = dependence.substr(pos + 2);
-  } else if ((pos = dependence.find("<")) != std::string::npos) {
+  } else if ((pos = dependence.find('<')) != std::string::npos) {
     Compare.Type = CompareLess;
     Compare.Value = dependence.substr(pos + 1);
-  } else if ((pos = dependence.find("=")) != std::string::npos) {
+  } else if ((pos = dependence.find('=')) != std::string::npos) {
     Compare.Type = CompareEqual;
     Compare.Value = dependence.substr(pos + 1);
-  } else if ((pos = dependence.find(">")) != std::string::npos) {
+  } else if ((pos = dependence.find('>')) != std::string::npos) {
     Compare.Type = CompareGreater;
     Compare.Value = dependence.substr(pos + 1);
   }

Source/CPack/cpack.cxx

@@ -68,7 +68,7 @@ int cpackDefinitionArgument(const char* argument, const char* cValue,
   (void)argument;
   cpackDefinitions* def = static_cast<cpackDefinitions*>(call_data);
   std::string value = cValue;
-  size_t pos = value.find_first_of("=");
+  size_t pos = value.find_first_of('=');
   if (pos == std::string::npos) {
     cmCPack_Log(def->Log, cmCPackLog::LOG_ERROR,
                 "Please specify CPack definitions as: KEY=VALUE" << std::endl);

Source/CTest/cmCTestBuildHandler.cxx

@@ -617,7 +617,7 @@ void cmCTestBuildHandler::GenerateXMLLogScraped(cmXMLWriter& xml)
           cmSystemTools::ConvertToUnixSlashes(cm->SourceFile);
           if (cm->SourceFile.find("/.../") != cm->SourceFile.npos) {
             cmSystemTools::ReplaceString(cm->SourceFile, "/.../", "");
-            std::string::size_type p = cm->SourceFile.find("/");
+            std::string::size_type p = cm->SourceFile.find('/');
             if (p != cm->SourceFile.npos) {
               cm->SourceFile =
                 cm->SourceFile.substr(p + 1, cm->SourceFile.size() - p);

Source/CTest/cmCTestCoverageHandler.cxx

@@ -1238,7 +1238,7 @@ int cmCTestCoverageHandler::HandleGCovCoverage(
               // Initially all entries are -1 (not used). If we get coverage
               // information, increment it to 0 first.
               if (vec[lineIdx] < 0) {
-                if (cov > 0 || prefix.find("#") != prefix.npos) {
+                if (cov > 0 || prefix.find('#') != prefix.npos) {
                   vec[lineIdx] = 0;
                 }
               }
@@ -1543,7 +1543,7 @@ int cmCTestCoverageHandler::HandleLCovCoverage(
                 // Initially all entries are -1 (not used). If we get coverage
                 // information, increment it to 0 first.
                 if (vec[lineIdx] < 0) {
-                  if (cov > 0 || prefix.find("#") != prefix.npos) {
+                  if (cov > 0 || prefix.find('#') != prefix.npos) {
                     vec[lineIdx] = 0;
                   }
                 }

Source/CTest/cmCTestSubmitHandler.cxx

@@ -417,7 +417,7 @@ bool cmCTestSubmitHandler::SubmitUsingHTTP(const std::string& localprefix,
         }
       }
       std::string upload_as = url +
-        ((url.find("?", 0) == std::string::npos) ? "?" : "&") + "FileName=" +
+        ((url.find('?') == std::string::npos) ? '?' : '&') + "FileName=" +
         ofile;
 
       upload_as += "&MD5=";
@@ -706,7 +706,7 @@ bool cmCTestSubmitHandler::TriggerUsingHTTP(const std::set<std::string>& files,
         }
       }
       std::string turl = url +
-        ((url.find("?", 0) == std::string::npos) ? "?" : "&") + "xmlfile=" +
+        ((url.find('?') == std::string::npos) ? '?' : '&') + "xmlfile=" +
         ofile;
       *this->LogFile << "Trigger url: " << turl << std::endl;
       cmCTestOptionalLog(this->CTest, HANDLER_VERBOSE_OUTPUT,

Source/CTest/cmCTestTestHandler.cxx

@@ -1869,7 +1869,7 @@ bool cmCTestTestHandler::SetTestsProperties(
             cmSystemTools::ExpandListArgument(val, rtit->Labels);
           }
           if (key == "MEASUREMENT") {
-            size_t pos = val.find_first_of("=");
+            size_t pos = val.find_first_of('=');
             if (pos != val.npos) {
               std::string mKey = val.substr(0, pos);
               const char* mVal = val.c_str() + pos + 1;

Source/CTest/cmParseDelphiCoverage.cxx

@@ -171,7 +171,7 @@ public:
       }
 
       lastoffset = line.find("class=");
-      endcovpos = line.find(">", lastoffset);
+      endcovpos = line.find('>', lastoffset);
       lineresult = line.substr(lastoffset + 7, (endcovpos - 8) - lastoffset);
 
       if (lineresult == "covered") {

Source/CursesDialog/cmCursesMainForm.cxx

@@ -729,7 +729,7 @@ void cmCursesMainForm::FillCacheManagerFromUI()
 void cmCursesMainForm::FixValue(cmState::CacheEntryType type,
                                 const std::string& in, std::string& out) const
 {
-  out = in.substr(0, in.find_last_not_of(" ") + 1);
+  out = in.substr(0, in.find_last_not_of(' ') + 1);
   if (type == cmState::PATH || type == cmState::FILEPATH) {
     cmSystemTools::ConvertToUnixSlashes(out);
   }

Source/cmCTest.cxx

@@ -721,7 +721,7 @@ bool cmCTest::UpdateCTestConfiguration()
       if (line[0] == '#') {
         continue;
       }
-      std::string::size_type cpos = line.find_first_of(":");
+      std::string::size_type cpos = line.find_first_of(':');
       if (cpos == line.npos) {
         continue;
       }
@@ -2480,7 +2480,7 @@ void cmCTest::AddSubmitFile(Part part, const char* name)
 
 void cmCTest::AddCTestConfigurationOverwrite(const std::string& overStr)
 {
-  size_t epos = overStr.find("=");
+  size_t epos = overStr.find('=');
   if (epos == overStr.npos) {
     cmCTestLog(this, ERROR_MESSAGE,
                "CTest configuration overwrite specified in the wrong format."

Source/cmDependsFortran.cxx

@@ -77,7 +77,7 @@ cmDependsFortran::cmDependsFortran(cmLocalGenerator* lg)
   for (std::vector<std::string>::const_iterator it = definitions.begin();
        it != definitions.end(); ++it) {
     std::string def = *it;
-    std::string::size_type assignment = def.find("=");
+    std::string::size_type assignment = def.find('=');
     if (assignment != std::string::npos) {
       def = it->substr(0, assignment);
     }

Source/cmExportFileGenerator.cxx

@@ -608,8 +608,8 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
   while ((pos = input.find("$<TARGET_PROPERTY:", lastPos)) != input.npos) {
     std::string::size_type nameStartPos =
       pos + sizeof("$<TARGET_PROPERTY:") - 1;
-    std::string::size_type closePos = input.find(">", nameStartPos);
-    std::string::size_type commaPos = input.find(",", nameStartPos);
+    std::string::size_type closePos = input.find('>', nameStartPos);
+    std::string::size_type commaPos = input.find(',', nameStartPos);
     std::string::size_type nextOpenPos = input.find("$<", nameStartPos);
     if (commaPos == input.npos     // Implied 'this' target
         || closePos == input.npos  // Imcomplete expression.
@@ -634,7 +634,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
   lastPos = pos;
   while ((pos = input.find("$<TARGET_NAME:", lastPos)) != input.npos) {
     std::string::size_type nameStartPos = pos + sizeof("$<TARGET_NAME:") - 1;
-    std::string::size_type endPos = input.find(">", nameStartPos);
+    std::string::size_type endPos = input.find('>', nameStartPos);
     if (endPos == input.npos) {
       errorString = "$<TARGET_NAME:...> expression incomplete";
       break;
@@ -659,7 +659,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
   while (errorString.empty() &&
          (pos = input.find("$<LINK_ONLY:", lastPos)) != input.npos) {
     std::string::size_type nameStartPos = pos + sizeof("$<LINK_ONLY:") - 1;
-    std::string::size_type endPos = input.find(">", nameStartPos);
+    std::string::size_type endPos = input.find('>', nameStartPos);
     if (endPos == input.npos) {
       errorString = "$<LINK_ONLY:...> expression incomplete";
       break;

Source/cmGeneratorExpression.cxx

@@ -300,7 +300,7 @@ void cmGeneratorExpression::Split(const std::string& input,
     std::string part = input.substr(lastPos, pos - lastPos);
     std::string preGenex;
     if (!part.empty()) {
-      std::string::size_type startPos = input.rfind(";", pos);
+      std::string::size_type startPos = input.rfind(';', pos);
       if (startPos == std::string::npos) {
         preGenex = part;
         part = "";
@@ -364,7 +364,7 @@ std::string::size_type cmGeneratorExpression::Find(const std::string& input)
 {
   const std::string::size_type openpos = input.find("$<");
   if (openpos != std::string::npos &&
-      input.find(">", openpos) != std::string::npos) {
+      input.find('>', openpos) != std::string::npos) {
     return openpos;
   }
   return std::string::npos;

Source/cmGeneratorTarget.cxx

@@ -145,7 +145,7 @@ struct DoAccept<true>
     // where the user supplied the file name and Visual Studio
     // appended the suffix.
     std::string resx = f->GetFullPath();
-    std::string hFileName = resx.substr(0, resx.find_last_of(".")) + ".h";
+    std::string hFileName = resx.substr(0, resx.find_last_of('.')) + ".h";
     data.ExpectedResxHeaders.insert(hFileName);
     data.ResxSources.push_back(f);
   }

Source/cmLocalGenerator.cxx

@@ -640,7 +640,7 @@ std::string cmLocalGenerator::ExpandRuleVariable(
       if (variable == "TARGET_BASE") {
         // Strip the last extension off the target name.
         std::string targetBase = replaceValues.Target;
-        std::string::size_type pos = targetBase.rfind(".");
+        std::string::size_type pos = targetBase.rfind('.');
         if (pos != targetBase.npos) {
           return targetBase.substr(0, pos);
         } else {
@@ -2306,7 +2306,7 @@ std::string& cmLocalGenerator::CreateSafeUniqueObjectFileName(
     std::string ssin = sin;
 
     // Avoid full paths by removing leading slashes.
-    ssin.erase(0, ssin.find_first_not_of("/"));
+    ssin.erase(0, ssin.find_first_not_of('/'));
 
     // Avoid full paths by removing colons.
     std::replace(ssin.begin(), ssin.end(), ':', '_');
@@ -2464,7 +2464,7 @@ std::string cmLocalGenerator::GetObjectFileNameWithoutTarget(
     // Remove the source extension if it is to be replaced.
     if (replaceExt) {
       keptSourceExtension = false;
-      std::string::size_type dot_pos = objectName.rfind(".");
+      std::string::size_type dot_pos = objectName.rfind('.');
       if (dot_pos != std::string::npos) {
         objectName = objectName.substr(0, dot_pos);
       }
@@ -2603,7 +2603,7 @@ bool cmLocalGenerator::CheckDefinition(std::string const& define) const
   }
 
   // Many compilers do not support # in the value so we disable it.
-  if (define.find_first_of("#") != define.npos) {
+  if (define.find_first_of('#') != define.npos) {
     std::ostringstream e;
     /* clang-format off */
     e << "WARNING: Preprocessor definitions containing '#' may not be "

Source/cmLocalNinjaGenerator.cxx

@@ -205,7 +205,7 @@ void cmLocalNinjaGenerator::WritePools(std::ostream& os)
     cmSystemTools::ExpandListArgument(jobpools, pools);
     for (size_t i = 0; i < pools.size(); ++i) {
       const std::string pool = pools[i];
-      const std::string::size_type eq = pool.find("=");
+      const std::string::size_type eq = pool.find('=');
       unsigned int jobs;
       if (eq != std::string::npos &&
           sscanf(pool.c_str() + eq, "=%u", &jobs) == 1) {

Source/cmLocalUnixMakefileGenerator3.cxx

@@ -71,7 +71,7 @@ private:
 static std::string cmSplitExtension(std::string const& in, std::string& base)
 {
   std::string ext;
-  std::string::size_type dot_pos = in.rfind(".");
+  std::string::size_type dot_pos = in.rfind('.');
   if (dot_pos != std::string::npos) {
     // Remove the extension first in case &base == &in.
     ext = in.substr(dot_pos, std::string::npos);
@@ -949,11 +949,11 @@ void cmLocalUnixMakefileGenerator3::AppendCustomCommand(
       cmSystemTools::ReplaceString(cmd, "/./", "/");
       // Convert the command to a relative path only if the current
       // working directory will be the start-output directory.
-      bool had_slash = cmd.find("/") != cmd.npos;
+      bool had_slash = cmd.find('/') != cmd.npos;
       if (workingDir.empty()) {
         cmd = this->Convert(cmd, START_OUTPUT);
       }
-      bool has_slash = cmd.find("/") != cmd.npos;
+      bool has_slash = cmd.find('/') != cmd.npos;
       if (had_slash && !has_slash) {
         // This command was specified as a path to a file in the
         // current directory.  Add a leading "./" so it can run
@@ -975,9 +975,9 @@ void cmLocalUnixMakefileGenerator3::AppendCustomCommand(
         // must be written {{} instead of just {.  Otherwise some
         // curly braces are removed.  The hack can be skipped if the
         // first curly brace is the last character.
-        std::string::size_type lcurly = cmd.find("{");
+        std::string::size_type lcurly = cmd.find('{');
         if (lcurly != cmd.npos && lcurly < (cmd.size() - 1)) {
-          std::string::size_type rcurly = cmd.find("}");
+          std::string::size_type rcurly = cmd.find('}');
           if (rcurly == cmd.npos || rcurly > lcurly) {
             // The first curly is a left curly.  Use the hack.
             std::string hack_cmd = cmd.substr(0, lcurly);

Source/cmMakefileTargetGenerator.cxx

@@ -661,9 +661,9 @@ void cmMakefileTargetGenerator::WriteObjectBuildFile(
   if (do_preprocess_rules || do_assembly_rules) {
     std::vector<std::string> force_depends;
     force_depends.push_back("cmake_force");
-    std::string::size_type dot_pos = relativeObj.rfind(".");
+    std::string::size_type dot_pos = relativeObj.rfind('.');
     std::string relativeObjBase = relativeObj.substr(0, dot_pos);
-    dot_pos = obj.rfind(".");
+    dot_pos = obj.rfind('.');
     std::string objBase = obj.substr(0, dot_pos);
 
     if (do_preprocess_rules) {
@@ -1479,7 +1479,7 @@ void cmMakefileTargetGenerator::CreateLinkLibs(
                                             useResponseFile, useWatcomQuote);
   linkLibs = frameworkPath + linkPath + linkLibs;
 
-  if (useResponseFile && linkLibs.find_first_not_of(" ") != linkLibs.npos) {
+  if (useResponseFile && linkLibs.find_first_not_of(' ') != linkLibs.npos) {
     // Lookup the response file reference flag.
     std::string responseFlagVar = "CMAKE_";
     responseFlagVar +=

Source/cmSystemTools.cxx

@@ -1298,7 +1298,7 @@ cmSystemTools::SaveRestoreEnvironment::~SaveRestoreEnvironment()
        eit != currentEnv.end(); ++eit) {
     std::string var(*eit);
 
-    std::string::size_type pos = var.find("=");
+    std::string::size_type pos = var.find('=');
     if (pos != std::string::npos) {
       var = var.substr(0, pos);
     }

Source/cmcmd.cxx

@@ -386,7 +386,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
           std::cerr << "cmake -E env: unknown option '" << a << "'"
                     << std::endl;
           return 1;
-        } else if (a.find("=") != a.npos) {
+        } else if (a.find('=') != a.npos) {
           // Set environment variable.
           cmSystemTools::PutEnv(a);
         } else {