GenEx: Add support for custom transitive compile properties

Teach the `$<TARGET_PROPERTY:...>` generator expression to check for a
new `TRANSITIVE_COMPILE_PROPERTIES` property in the target's link
closure to enable transitive evaluation of named properties through
the link closure, excluding entries guarded by `$<LINK_ONLY:...>`.

Issue: #20416

1 files changed, 19 insertions, 0 deletions

diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 9bd7f49..a7d0d7e 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -604,6 +604,25 @@ void cmExportFileGenerator::PopulateCompatibleInterfaceProperties(
   }
 }
 
+void cmExportFileGenerator::PopulateCustomTransitiveInterfaceProperties(
+  cmGeneratorTarget const* target,
+  cmGeneratorExpression::PreprocessContext preprocessRule,
+  ImportPropertyMap& properties)
+{
+  this->PopulateInterfaceProperty("TRANSITIVE_COMPILE_PROPERTIES", target,
+                                  properties);
+  std::set<std::string> ifaceProperties;
+  for (std::string const& config : this->Configurations) {
+    for (auto const& i : target->GetCustomTransitiveProperties(
+           config, cmGeneratorTarget::PropertyFor::Interface)) {
+      ifaceProperties.emplace(i.second.InterfaceName);
+    }
+  }
+  for (std::string const& ip : ifaceProperties) {
+    this->PopulateInterfaceProperty(ip, target, preprocessRule, properties);
+  }
+}
+
 void cmExportFileGenerator::GenerateInterfaceProperties(
   const cmGeneratorTarget* target, std::ostream& os,
   const ImportPropertyMap& properties)