Autogen: Modernize cmQtAutoGen methods using cm::string_view

Source/cmQtAutoGen.cxx

@@ -12,6 +12,7 @@
 
 #include <algorithm>
 #include <array>
+#include <initializer_list>
 #include <sstream>
 #include <utility>
 
@@ -21,7 +22,7 @@
 /// @arg valueOpts list of options that accept a value
 void MergeOptions(std::vector<std::string>& baseOpts,
                   std::vector<std::string> const& newOpts,
-                  std::vector<std::string> const& valueOpts, bool isQt5)
+                  std::initializer_list<cm::string_view> valueOpts, bool isQt5)
 {
   typedef std::vector<std::string>::iterator Iter;
   typedef std::vector<std::string>::const_iterator CIter;
@@ -117,60 +118,42 @@ std::string const& cmQtAutoGen::GeneratorNameUpper(GenT genType)
 
 std::string cmQtAutoGen::Tools(bool moc, bool uic, bool rcc)
 {
-  std::string res;
-  std::vector<std::string> lst;
+  std::array<cm::string_view, 3> lst;
+  decltype(lst)::size_type num = 0;
   if (moc) {
-    lst.emplace_back("AUTOMOC");
+    lst.at(num++) = "AUTOMOC";
   }
   if (uic) {
-    lst.emplace_back("AUTOUIC");
+    lst.at(num++) = "AUTOUIC";
   }
   if (rcc) {
-    lst.emplace_back("AUTORCC");
+    lst.at(num++) = "AUTORCC";
   }
-  switch (lst.size()) {
+  switch (num) {
     case 1:
-      res += lst.at(0);
-      break;
+      return std::string(lst[0]);
     case 2:
-      res += lst.at(0);
-      res += " and ";
-      res += lst.at(1);
-      break;
+      return cmStrCat(lst[0], " and ", lst[1]);
     case 3:
-      res += lst.at(0);
-      res += ", ";
-      res += lst.at(1);
-      res += " and ";
-      res += lst.at(2);
-      break;
+      return cmStrCat(lst[0], ", ", lst[1], " and ", lst[2]);
     default:
       break;
   }
-  return res;
+  return std::string();
 }
 
-std::string cmQtAutoGen::Quoted(std::string const& text)
+std::string cmQtAutoGen::Quoted(cm::string_view text)
 {
-  const std::array<std::pair<const char*, const char*>, 9> replaces = {
-    { { "\\", "\\\\" },
-      { "\"", "\\\"" },
-      { "\a", "\\a" },
-      { "\b", "\\b" },
-      { "\f", "\\f" },
-      { "\n", "\\n" },
-      { "\r", "\\r" },
-      { "\t", "\\t" },
-      { "\v", "\\v" } }
-  };
+  static std::initializer_list<std::pair<const char*, const char*>> const
+    replacements = { { "\\", "\\\\" }, { "\"", "\\\"" }, { "\a", "\\a" },
+                     { "\b", "\\b" },  { "\f", "\\f" },  { "\n", "\\n" },
+                     { "\r", "\\r" },  { "\t", "\\t" },  { "\v", "\\v" } };
 
-  std::string res = text;
-  for (auto const& pair : replaces) {
+  std::string res(text);
+  for (auto const& pair : replacements) {
     cmSystemTools::ReplaceString(res, pair.first, pair.second);
   }
-  res = '"' + res;
-  res += '"';
-  return res;
+  return cmStrCat('"', res, '"');
 }
 
 std::string cmQtAutoGen::QuotedCommand(std::vector<std::string> const& command)
@@ -191,37 +174,31 @@ std::string cmQtAutoGen::QuotedCommand(std::vector<std::string> const& command)
   return res;
 }
 
-std::string cmQtAutoGen::SubDirPrefix(std::string const& filename)
+std::string cmQtAutoGen::SubDirPrefix(cm::string_view filename)
 {
-  std::string::size_type slash_pos = filename.rfind('/');
-  if (slash_pos == std::string::npos) {
+  auto slashPos = filename.rfind('/');
+  if (slashPos == cm::string_view::npos) {
     return std::string();
   }
-  return filename.substr(0, slash_pos + 1);
+  return std::string(filename.substr(0, slashPos + 1));
 }
 
-std::string cmQtAutoGen::AppendFilenameSuffix(std::string const& filename,
-                                              std::string const& suffix)
+std::string cmQtAutoGen::AppendFilenameSuffix(cm::string_view filename,
+                                              cm::string_view suffix)
 {
-  std::string res;
-  auto pos = filename.rfind('.');
-  if (pos != std::string::npos) {
-    const auto it_dot = filename.begin() + pos;
-    res.assign(filename.begin(), it_dot);
-    res.append(suffix);
-    res.append(it_dot, filename.end());
-  } else {
-    res = filename;
-    res.append(suffix);
+  auto dotPos = filename.rfind('.');
+  if (dotPos == cm::string_view::npos) {
+    return cmStrCat(filename, suffix);
   }
-  return res;
+  return cmStrCat(filename.substr(0, dotPos), suffix,
+                  filename.substr(dotPos, filename.size() - dotPos));
 }
 
 void cmQtAutoGen::UicMergeOptions(std::vector<std::string>& baseOpts,
                                   std::vector<std::string> const& newOpts,
                                   bool isQt5)
 {
-  static std::vector<std::string> const valueOpts = {
+  static std::initializer_list<cm::string_view> const valueOpts = {
     "tr",      "translate", "postfix", "generator",
     "include", // Since Qt 5.3
     "g"
@@ -233,9 +210,9 @@ void cmQtAutoGen::RccMergeOptions(std::vector<std::string>& baseOpts,
                                   std::vector<std::string> const& newOpts,
                                   bool isQt5)
 {
-  static std::vector<std::string> const valueOpts = { "name", "root",
-                                                      "compress",
-                                                      "threshold" };
+  static std::initializer_list<cm::string_view> const valueOpts = {
+    "name", "root", "compress", "threshold"
+  };
   MergeOptions(baseOpts, newOpts, valueOpts, isQt5);
 }
 
@@ -349,9 +326,8 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
 
       // Log command
       if (verbose) {
-        std::string msg =
-          cmStrCat("Running command:\n", QuotedCommand(cmd), '\n');
-        cmSystemTools::Stdout(msg);
+        cmSystemTools::Stdout(
+          cmStrCat("Running command:\n", QuotedCommand(cmd), '\n'));
       }
 
       result = cmSystemTools::RunSingleCommand(
@@ -362,12 +338,10 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
       error =
         cmStrCat("The rcc list process failed for ", Quoted(qrcFile), '\n');
       if (!rccStdOut.empty()) {
-        error += rccStdOut;
-        error += "\n";
+        error += cmStrCat(rccStdOut, '\n');
       }
       if (!rccStdErr.empty()) {
-        error += rccStdErr;
-        error += "\n";
+        error += cmStrCat(rccStdErr, '\n');
       }
       return false;
     }

Source/cmQtAutoGen.h

@@ -5,6 +5,8 @@
 
 #include "cmConfigure.h" // IWYU pragma: keep
 
+#include "cm_string_view.hxx"
+
 #include <memory>
 #include <string>
 #include <vector>
@@ -74,16 +76,16 @@ public:
   static std::string Tools(bool moc, bool uic, bool rcc);
 
   /// @brief Returns the string escaped and enclosed in quotes
-  static std::string Quoted(std::string const& text);
+  static std::string Quoted(cm::string_view text);
 
   static std::string QuotedCommand(std::vector<std::string> const& command);
 
   /// @brief Returns the parent directory of the file with a "/" suffix
-  static std::string SubDirPrefix(std::string const& filename);
+  static std::string SubDirPrefix(cm::string_view filename);
 
   /// @brief Appends the suffix to the filename before the last dot
-  static std::string AppendFilenameSuffix(std::string const& filename,
-                                          std::string const& suffix);
+  static std::string AppendFilenameSuffix(cm::string_view filename,
+                                          cm::string_view suffix);
 
   /// @brief Merges newOpts into baseOpts
   static void UicMergeOptions(std::vector<std::string>& baseOpts,