Remove CMake Policy CMP0015 until it is revised

We revert commit "Create CMake Policy CMP0015 to fix set(CACHE)" because
the NEW behavior of the policy breaks a valid use case:

  # CMakeLists.txt
  option(BUILD_SHARED_LIBS "..." ON)
  add_library(mylib ...)
  set(BUILD_SHARED_LIBS OFF) # we want only mylib to be shared
  add_subdirectory(ThirdParty)

  # ThirdParty/CMakeLists.txt
  option(BUILD_SHARED_LIBS "..." ON)
  # uh, oh, with NEW behavior this dir uses shared libs!!!

We'll re-introduce the policy later with a different change in behavior
to resolve the motivating case, which was more subtle but less common.

See issue #9008.

1 files changed, 0 insertions, 51 deletions

diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 6fc0dd4..88c8c7b 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -1642,57 +1642,6 @@ void cmMakefile::AddDefinition(const char* name, const char* value)
 #endif
 }
 
-//----------------------------------------------------------------------------
-void cmMakefile::UseCacheDefinition(cmCacheManager::CacheIterator const& it)
-{
-  // Check for a local definition that might hide the cache value.
-  const char* name = it.GetName();
-  const char* def = this->Internal->VarStack.top().Get(name);
-  if(!def)
-    {
-    return;
-    }
-
-  // If the visible value will change then check policy CMP0015.
-  const char* cache = it.GetValue();
-  if(strcmp(def, cache) != 0)
-    {
-    cmOStringStream e;
-    switch (this->GetPolicyStatus(cmPolicies::CMP0015))
-      {
-      case cmPolicies::WARN:
-        e << "Local variable \"" << name << "\" is set to\n"
-          << "  " << def << "\n"
-          << "but the CACHE entry of the same name is set to\n"
-          << "  " << cache << "\n"
-          << "The local variable is hiding the cache value."
-          << "\n"
-          << this->GetPolicies()->GetPolicyWarning(cmPolicies::CMP0015);
-        this->IssueMessage(cmake::AUTHOR_WARNING, e.str());
-      case cmPolicies::OLD:
-        // OLD behavior is to leave local definition.
-        return;
-      case cmPolicies::REQUIRED_IF_USED:
-      case cmPolicies::REQUIRED_ALWAYS:
-        e << "Local variable \"" << name << "\" is set to\n"
-          << "  " << def << "\n"
-          << "but the CACHE entry of the same name is set to\n"
-          << "  " << cache << "\n"
-          << "This command is removing the local variable to expose "
-          << "the cache value."
-          << "\n"
-          << this->GetPolicies()->GetRequiredPolicyError(cmPolicies::CMP0015);
-        this->IssueMessage(cmake::FATAL_ERROR, e.str());
-      case cmPolicies::NEW:
-        // NEW behavior is to remove local definition (done below).
-        break;
-      }
-    }
-
-  // Remove the local definition to make the cache value visible.
-  this->RemoveDefinition(name);
-}
-
 
 void cmMakefile::AddCacheDefinition(const char* name, const char* value,
                                     const char* doc,