cmMakefile: Use enumeration for policy scope

Create `cmPolicyScope` to describe whether `ReadDependentFile` creates a
policy scope, rather than a bare `bool`. Replace a local enumeration in
`cmFindPackageCommand` serving the same purpose with this new, global
one.

Source/cmFindPackageCommand.cxx

@@ -1581,7 +1581,7 @@ bool cmFindPackageCommand::FindModule(bool& found)
     found = true;
     std::string const var = cmStrCat(this->Name, "_FIND_MODULE");
     this->Makefile->AddDefinition(var, "1");
-    bool result = this->ReadListFile(mfile, DoPolicyScope);
+    bool result = this->ReadListFile(mfile, cm::PolicyScope::Local);
     this->Makefile->RemoveDefinition(var);
 
     std::string const foundVar = cmStrCat(this->Name, "_FOUND");
@@ -1705,7 +1705,7 @@ bool cmFindPackageCommand::HandlePackageMode(
       // The package has been found.
       found = true;
       result = this->ReadPackage();
-    } else if (this->ReadListFile(this->FileFound, DoPolicyScope)) {
+    } else if (this->ReadListFile(this->FileFound, cm::PolicyScope::Local)) {
       // The package has been found.
       found = true;
 
@@ -2071,9 +2071,11 @@ cmFindPackageCommand::AppendixMap cmFindPackageCommand::FindAppendices(
 }
 
 bool cmFindPackageCommand::ReadListFile(std::string const& f,
-                                        PolicyScopeRule const psr)
+                                        cm::PolicyScope ps)
 {
-  bool const noPolicyScope = !this->PolicyScope || psr == NoPolicyScope;
+  if (!this->PolicyScope) {
+    ps = cm::PolicyScope::None;
+  }
 
   using ITScope = cmMakefile::ImportedTargetScope;
   ITScope scope = this->GlobalScope ? ITScope::Global : ITScope::Local;
@@ -2084,7 +2086,7 @@ bool cmFindPackageCommand::ReadListFile(std::string const& f,
   // This allows child snapshots to inherit the CAN_UNWIND state from us, we'll
   // reset it immediately after the dependent file is done
   this->Makefile->GetStateSnapshot().SetUnwindType(cmStateEnums::CAN_UNWIND);
-  bool result = this->Makefile->ReadDependentFile(f, noPolicyScope);
+  bool result = this->Makefile->ReadDependentFile(f, ps);
 
   this->Makefile->GetStateSnapshot().SetUnwindType(oldUnwind);
   this->Makefile->GetStateSnapshot().SetUnwindState(
@@ -3205,7 +3207,7 @@ bool cmFindPackageCommand::CheckVersionFile(std::string const& version_file,
   // Load the version check file.
   // Pass NoPolicyScope because we do our own policy push/pop.
   bool suitable = false;
-  if (this->ReadListFile(version_file, NoPolicyScope)) {
+  if (this->ReadListFile(version_file, cm::PolicyScope::None)) {
     // Check the output variables.
     bool okay = this->Makefile->IsOn("PACKAGE_VERSION_EXACT");
     bool const unsuitable = this->Makefile->IsOn("PACKAGE_VERSION_UNSUITABLE");

Source/cmFindPackageCommand.h

@@ -32,6 +32,10 @@ namespace std {
 /* clang-format on */
 #endif
 
+namespace cm {
+enum class PolicyScope : bool;
+}
+
 class cmExecutionStatus;
 class cmPackageState;
 class cmSearchPath;
@@ -139,12 +143,7 @@ private:
   bool FindFrameworkConfig();
   bool FindAppBundleConfig();
   bool FindEnvironmentConfig();
-  enum PolicyScopeRule
-  {
-    NoPolicyScope,
-    DoPolicyScope
-  };
-  bool ReadListFile(std::string const& f, PolicyScopeRule psr);
+  bool ReadListFile(std::string const& f, cm::PolicyScope ps);
   bool ReadPackage();
 
   struct Appendix

Source/cmIncludeCommand.cxx

@@ -48,7 +48,7 @@ bool cmIncludeCommand(std::vector<std::string> const& args,
   }
 
   bool optional = false;
-  bool noPolicyScope = false;
+  cm::PolicyScope policyScope = cm::PolicyScope::Local;
   std::string fname = args[0];
   std::string resultVarName;
 
@@ -72,7 +72,7 @@ bool cmIncludeCommand(std::vector<std::string> const& args,
         return false;
       }
     } else if (args[i] == "NO_POLICY_SCOPE") {
-      noPolicyScope = true;
+      policyScope = cm::PolicyScope::None;
     } else if (i > 1) // compat.: in previous cmake versions the second
                       // parameter was ignored if it wasn't "OPTIONAL"
     {
@@ -161,8 +161,7 @@ bool cmIncludeCommand(std::vector<std::string> const& args,
     }
   }
 
-  bool readit =
-    status.GetMakefile().ReadDependentFile(listFile, noPolicyScope);
+  bool readit = status.GetMakefile().ReadDependentFile(listFile, policyScope);
 
   // add the location of the included file if a result variable was given
   if (!resultVarName.empty()) {

Source/cmMakefile.cxx

@@ -620,7 +620,7 @@ class cmMakefile::IncludeScope : public FileScopeBase
 {
 public:
   IncludeScope(cmMakefile* mf, std::string const& filenametoread,
-               bool noPolicyScope);
+               cm::PolicyScope policyScope);
   ~IncludeScope();
   void Quiet() { this->ReportError = false; }
 
@@ -628,15 +628,15 @@ public:
   IncludeScope& operator=(IncludeScope const&) = delete;
 
 private:
-  bool NoPolicyScope;
+  cm::PolicyScope PolicyScope;
   bool ReportError = true;
 };
 
 cmMakefile::IncludeScope::IncludeScope(cmMakefile* mf,
                                        std::string const& filenametoread,
-                                       bool noPolicyScope)
+                                       cm::PolicyScope policyScope)
   : FileScopeBase(mf)
-  , NoPolicyScope(noPolicyScope)
+  , PolicyScope(policyScope)
 {
   this->Makefile->Backtrace = this->Makefile->Backtrace.Push(
     cmListFileContext::FromListFilePath(filenametoread));
@@ -646,7 +646,7 @@ cmMakefile::IncludeScope::IncludeScope(cmMakefile* mf,
   this->Makefile->StateSnapshot =
     this->Makefile->GetState()->CreateIncludeFileSnapshot(
       this->Makefile->StateSnapshot, filenametoread);
-  if (!this->NoPolicyScope) {
+  if (this->PolicyScope == cm::PolicyScope::Local) {
     this->Makefile->PushPolicy();
   }
   this->PushListFileVars(filenametoread);
@@ -655,7 +655,7 @@ cmMakefile::IncludeScope::IncludeScope(cmMakefile* mf,
 cmMakefile::IncludeScope::~IncludeScope()
 {
   this->PopListFileVars();
-  if (!this->NoPolicyScope) {
+  if (this->PolicyScope == cm::PolicyScope::Local) {
     // Pop the scope we pushed for the script.
     this->Makefile->PopPolicy();
   }
@@ -667,12 +667,12 @@ cmMakefile::IncludeScope::~IncludeScope()
 }
 
 bool cmMakefile::ReadDependentFile(std::string const& filename,
-                                   bool noPolicyScope)
+                                   cm::PolicyScope policyScope)
 {
   std::string filenametoread = cmSystemTools::CollapseFullPath(
     filename, this->GetCurrentSourceDirectory());
 
-  IncludeScope incScope(this, filenametoread, noPolicyScope);
+  IncludeScope incScope(this, filenametoread, policyScope);
 
 #ifdef CMake_ENABLE_DEBUGGER
   if (this->GetCMakeInstance()->GetDebugAdapter()) {

Source/cmMakefile.h

@@ -64,6 +64,14 @@ class cmTestGenerator;
 class cmVariableWatch;
 class cmake;
 
+namespace cm {
+enum class PolicyScope : bool
+{
+  None,
+  Local,
+};
+}
+
 /** A type-safe wrapper for a string representing a directory id.  */
 class cmDirectoryId
 {
@@ -109,7 +117,7 @@ public:
                             std::string const& virtualFileName);
 
   bool ReadDependentFile(std::string const& filename,
-                         bool noPolicyScope = true);
+                         cm::PolicyScope policyScope = cm::PolicyScope::None);
 
   /**
    * Add a function blocker to this makefile