CMP0047: Remove support for OLD behavior

Help/policy/CMP0047.rst

@@ -1,6 +1,9 @@
 CMP0047
 -------
 
+.. |REMOVED_IN_CMAKE_VERSION| replace:: 4.0
+.. include:: REMOVED_PROLOGUE.txt
+
 Use ``QCC`` compiler id for the qcc drivers on QNX.
 
 CMake 3.0 and above recognize that the QNX qcc compiler driver is
@@ -20,11 +23,9 @@ for the qcc and QCC compiler drivers. The ``NEW`` behavior for this policy
 is to use the ``QCC`` compiler id for those drivers.
 
 .. |INTRODUCED_IN_CMAKE_VERSION| replace:: 3.0
-.. |WARNS_OR_DOES_NOT_WARN| replace:: does *not* warn by default
-.. include:: STANDARD_ADVICE.txt
+.. |WARNED_OR_DID_NOT_WARN| replace:: did *not* warn by default
+.. include:: REMOVED_EPILOGUE.txt
 
 See documentation of the
 :variable:`CMAKE_POLICY_WARNING_CMP0047 <CMAKE_POLICY_WARNING_CMP<NNNN>>`
-variable to control the warning.
-
-.. include:: DEPRECATED.txt
+variable to control the warning in CMake versions before 4.0.

Help/variable/CMAKE_POLICY_WARNING_CMPNNNN.rst

@@ -8,8 +8,8 @@ only for the policies that do not warn by default:
 
 * ``CMAKE_POLICY_WARNING_CMP0025`` controlled the warning for
   policy :policy:`CMP0025` in CMake versions before 4.0.
-* ``CMAKE_POLICY_WARNING_CMP0047`` controls the warning for
-  policy :policy:`CMP0047`.
+* ``CMAKE_POLICY_WARNING_CMP0047`` controlled the warning for
+  policy :policy:`CMP0047` in CMake versions before 4.0.
 * ``CMAKE_POLICY_WARNING_CMP0056`` controls the warning for
   policy :policy:`CMP0056`.
 * ``CMAKE_POLICY_WARNING_CMP0060`` controls the warning for

Source/cmGlobalGenerator.cxx

@@ -1010,36 +1010,6 @@ void cmGlobalGenerator::CheckCompilerIdCompatibility(
   std::string compilerIdVar = cmStrCat("CMAKE_", lang, "_COMPILER_ID");
   std::string const compilerId = mf->GetSafeDefinition(compilerIdVar);
 
-  if (compilerId == "QCC") {
-    switch (mf->GetPolicyStatus(cmPolicies::CMP0047)) {
-      case cmPolicies::WARN:
-        if (!this->CMakeInstance->GetIsInTryCompile() &&
-            mf->PolicyOptionalWarningEnabled("CMAKE_POLICY_WARNING_CMP0047")) {
-          std::ostringstream w;
-          /* clang-format off */
-          w << cmPolicies::GetPolicyWarning(cmPolicies::CMP0047) << "\n"
-            "Converting " << lang <<
-            R"( compiler id "QCC" to "GNU" for compatibility.)"
-            ;
-          /* clang-format on */
-          mf->IssueMessage(MessageType::AUTHOR_WARNING, w.str());
-        }
-        CM_FALLTHROUGH;
-      case cmPolicies::OLD:
-        // OLD behavior is to convert QCC to GNU.
-        mf->AddDefinition(compilerIdVar, "GNU");
-        if (lang == "C") {
-          mf->AddDefinition("CMAKE_COMPILER_IS_GNUCC", "1");
-        } else if (lang == "CXX") {
-          mf->AddDefinition("CMAKE_COMPILER_IS_GNUCXX", "1");
-        }
-        break;
-      case cmPolicies::NEW:
-        // NEW behavior is to keep QCC.
-        break;
-    }
-  }
-
   if (compilerId == "XLClang") {
     switch (mf->GetPolicyStatus(cmPolicies::CMP0089)) {
       case cmPolicies::WARN:

Source/cmPolicies.h

@@ -143,7 +143,7 @@ class cmMakefile;
          "Error on non-existent dependency in add_dependencies.", 3, 0, 0,    \
          NEW)                                                                 \
   SELECT(POLICY, CMP0047, "Use QCC compiler id for the qcc drivers on QNX.",  \
-         3, 0, 0, WARN)                                                       \
+         3, 0, 0, NEW)                                                        \
   SELECT(POLICY, CMP0048, "project() command manages VERSION variables.", 3,  \
          0, 0, WARN)                                                          \
   SELECT(POLICY, CMP0049,                                                     \