ENH: Isolate policy changes in included scripts

Isolation of policy changes inside scripts is important for protecting
the including context.  This teaches include() and find_package() to
imply a cmake_policy(PUSH) and cmake_policy(POP) around the scripts they
load, with a NO_POLICY_SCOPE option to disable the behavior.  This also
creates CMake Policy CMP0011 to provide compatibility.  See issue #8192.

1 files changed, 3 insertions, 1 deletions

diff --git a/Source/cmFindPackageCommand.h b/Source/cmFindPackageCommand.h
index 3fc8f65..faeb04d 100644
--- a/Source/cmFindPackageCommand.h
+++ b/Source/cmFindPackageCommand.h
@@ -82,7 +82,8 @@ private:
   bool FindPrefixedConfig();
   bool FindFrameworkConfig();
   bool FindAppBundleConfig();
-  bool ReadListFile(const char* f);
+  enum PolicyScopeRule { NoPolicyScope, DoPolicyScope };
+  bool ReadListFile(const char* f, PolicyScopeRule psr);
   void StoreVersionFound();
 
   void ComputePrefixes();
@@ -132,6 +133,7 @@ private:
   bool NoBuilds;
   bool DebugMode;
   bool UseLib64Paths;
+  bool PolicyScope;
   std::vector<std::string> Names;
   std::vector<std::string> Configs;
 };