cmFindPackageCommand: Refactor CMP0074 logic to de-duplicate lookups

1 files changed, 22 insertions, 8 deletions

diff --git a/Source/cmFindPackageCommand.cxx b/Source/cmFindPackageCommand.cxx
index 16e0986..dd00419 100644
--- a/Source/cmFindPackageCommand.cxx
+++ b/Source/cmFindPackageCommand.cxx
@@ -1814,26 +1814,40 @@ void cmFindPackageCommand::PushFindPackageRootPathStack()
 
   // Add root paths from <PackageName>_ROOT CMake and environment variables,
   // subject to CMP0074.
+  std::string const rootVar = this->Name + "_ROOT";
+  cmValue rootDef = this->Makefile->GetDefinition(rootVar);
+  if (rootDef && rootDef.IsEmpty()) {
+    rootDef = nullptr;
+  }
+  cm::optional<std::string> rootEnv = cmSystemTools::GetEnvVar(rootVar);
+  if (rootEnv && rootEnv->empty()) {
+    rootEnv = cm::nullopt;
+  }
   switch (this->Makefile->GetPolicyStatus(cmPolicies::CMP0074)) {
     case cmPolicies::WARN:
-      this->Makefile->MaybeWarnCMP0074(this->Name);
+      this->Makefile->MaybeWarnCMP0074(rootVar, rootDef, rootEnv);
       CM_FALLTHROUGH;
     case cmPolicies::OLD:
-      // OLD behavior is to ignore the <pkg>_ROOT variables.
-      break;
+      // OLD behavior is to ignore the <PackageName>_ROOT variables.
+      return;
     case cmPolicies::REQUIRED_IF_USED:
     case cmPolicies::REQUIRED_ALWAYS:
       this->Makefile->IssueMessage(
         MessageType::FATAL_ERROR,
         cmPolicies::GetRequiredPolicyError(cmPolicies::CMP0074));
-      break;
+      return;
     case cmPolicies::NEW: {
-      // NEW behavior is to honor the <pkg>_ROOT variables.
-      std::string const rootVar = this->Name + "_ROOT";
-      this->Makefile->GetDefExpandList(rootVar, rootPaths, false);
-      cmSystemTools::GetPath(rootPaths, rootVar.c_str());
+      // NEW behavior is to honor the <PackageName>_ROOT variables.
     } break;
   }
+
+  if (rootDef) {
+    cmExpandList(*rootDef, rootPaths);
+  }
+  if (rootEnv) {
+    std::vector<std::string> p = cmSystemTools::SplitEnvPath(*rootEnv);
+    std::move(p.begin(), p.end(), std::back_inserter(rootPaths));
+  }
 }
 
 void cmFindPackageCommand::PopFindPackageRootPathStack()