cmDefinitions: Remove const char* based Set method

- Removes `cmDefinitions::Set` method overload that takes a `const char*`
  value argument.
- Updates calls to `cmDefinitions::Set` to use the `cm::string_view` based
  version instead.

Source/cmDefinitions.h

@@ -32,16 +32,6 @@ public:
 
   static bool HasKey(const std::string& key, StackIter begin, StackIter end);
 
-  /** Set (or unset if null) a value associated with a key.  */
-  void Set(const std::string& key, const char* value)
-  {
-    if (value) {
-      this->Set(key, cm::string_view(value));
-    } else {
-      this->Unset(key);
-    }
-  }
-
   /** Set a value associated with a key.  */
   void Set(const std::string& key, cm::string_view value);
 

Source/cmState.cxx

@@ -308,8 +308,8 @@ cmStateSnapshot cmState::Reset()
     pos->Parent = this->VarTree.Root();
     pos->Root = this->VarTree.Root();
 
-    pos->Vars->Set("CMAKE_SOURCE_DIR", srcDir.c_str());
-    pos->Vars->Set("CMAKE_BINARY_DIR", binDir.c_str());
+    pos->Vars->Set("CMAKE_SOURCE_DIR", srcDir);
+    pos->Vars->Set("CMAKE_BINARY_DIR", binDir);
   }
 
   this->DefineProperty("RULE_LAUNCH_COMPILE", cmProperty::DIRECTORY, "", "",

Source/cmStateSnapshot.cxx

@@ -222,14 +222,14 @@ bool cmStateSnapshot::IsInitialized(std::string const& name) const
 }
 
 void cmStateSnapshot::SetDefinition(std::string const& name,
-                                    std::string const& value)
+                                    cm::string_view value)
 {
-  this->Position->Vars->Set(name, value.c_str());
+  this->Position->Vars->Set(name, value);
 }
 
 void cmStateSnapshot::RemoveDefinition(std::string const& name)
 {
-  this->Position->Vars->Set(name, nullptr);
+  this->Position->Vars->Unset(name);
 }
 
 std::vector<std::string> cmStateSnapshot::UnusedKeys() const
@@ -264,7 +264,11 @@ bool cmStateSnapshot::RaiseScope(std::string const& var, const char* varDef)
   cmDefinitions::Raise(var, this->Position->Vars, this->Position->Root);
 
   // Now update the definition in the parent scope.
-  this->Position->Parent->Set(var, varDef);
+  if (varDef) {
+    this->Position->Parent->Set(var, varDef);
+  } else {
+    this->Position->Parent->Unset(var);
+  }
   return true;
 }
 

Source/cmStateSnapshot.h

@@ -9,6 +9,8 @@
 #include <string>
 #include <vector>
 
+#include "cm_string_view.hxx"
+
 #include "cmLinkedTree.h"
 #include "cmPolicies.h"
 #include "cmStateTypes.h"
@@ -24,7 +26,7 @@ public:
 
   std::string const* GetDefinition(std::string const& name) const;
   bool IsInitialized(std::string const& name) const;
-  void SetDefinition(std::string const& name, std::string const& value);
+  void SetDefinition(std::string const& name, cm::string_view value);
   void RemoveDefinition(std::string const& name);
   std::vector<std::string> UnusedKeys() const;
   std::vector<std::string> ClosureKeys() const;