cmLocalGenerator::AppendDefines: Remove const char* overloads

Accept const std::string& arguments only

Source/cmListFileCache.cxx

@@ -481,7 +481,7 @@ std::ostream& operator<<(std::ostream& os, BT<std::string> const& s)
 }
 
 std::vector<BT<std::string>> ExpandListWithBacktrace(
-  const char* list, cmListFileBacktrace const& bt)
+  std::string const& list, cmListFileBacktrace const& bt)
 {
   std::vector<BT<std::string>> result;
   std::vector<std::string> tmp;

Source/cmListFileCache.h

@@ -199,7 +199,8 @@ public:
 std::ostream& operator<<(std::ostream& os, BT<std::string> const& s);
 
 std::vector<BT<std::string>> ExpandListWithBacktrace(
-  const char* list, cmListFileBacktrace const& bt = cmListFileBacktrace());
+  std::string const& list,
+  cmListFileBacktrace const& bt = cmListFileBacktrace());
 
 struct cmListFile
 {

Source/cmLocalGenerator.cxx

@@ -2108,7 +2108,7 @@ void cmLocalGenerator::AppendIncludeDirectories(
 }
 
 void cmLocalGenerator::AppendDefines(std::set<std::string>& defines,
-                                     const char* defines_list) const
+                                     std::string const& defines_list) const
 {
   std::set<BT<std::string>> tmp;
   this->AppendDefines(tmp, ExpandListWithBacktrace(defines_list));
@@ -2118,10 +2118,10 @@ void cmLocalGenerator::AppendDefines(std::set<std::string>& defines,
 }
 
 void cmLocalGenerator::AppendDefines(std::set<BT<std::string>>& defines,
-                                     const char* defines_list) const
+                                     std::string const& defines_list) const
 {
   // Short-circuit if there are no definitions.
-  if (!defines_list) {
+  if (defines_list.empty()) {
     return;
   }
 

Source/cmLocalGenerator.h

@@ -169,19 +169,9 @@ public:
    * command line.
    */
   void AppendDefines(std::set<std::string>& defines,
-                     const char* defines_list) const;
-  void AppendDefines(std::set<std::string>& defines,
-                     std::string const& defines_list) const
-  {
-    this->AppendDefines(defines, defines_list.c_str());
-  }
+                     std::string const& defines_list) const;
   void AppendDefines(std::set<BT<std::string>>& defines,
-                     const char* defines_list) const;
-  void AppendDefines(std::set<BT<std::string>>& defines,
-                     std::string const& defines_list) const
-  {
-    this->AppendDefines(defines, defines_list.c_str());
-  }
+                     std::string const& defines_list) const;
   void AppendDefines(std::set<BT<std::string>>& defines,
                      const std::vector<BT<std::string>>& defines_vec) const;