Genex: Optimize build setting TARGET_PROPERTY evaluation

For each build setting property (such as `COMPILE_DEFINITIONS` or
`INCLUDE_DIRECTORIES`), the value of `$<TARGET_PROPERTY:target,prop>`
includes the values of the corresponding `INTERFACE_*` usage requirement
property from the transitive closure of link libraries of the target.

Previously we computed this by constructing a generator expression
string like `$<TARGET_PROPERTY:lib,INTERFACE_COMPILE_DEFINITIONS>` and
recursively evaluating it with the generator expression engine.  Avoid
the string construction and parsing by using the dedicated evaluation
method `cmGeneratorTarget::EvaluateInterfaceProperty`.

Issue: #18964, #18965

1 files changed, 8 insertions, 14 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 21da2fd..b22d8b6 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -1227,23 +1227,17 @@ void AddInterfaceEntries(cmGeneratorTarget const* headTarget,
         headTarget->GetLinkImplementationLibraries(config)) {
     for (cmLinkImplItem const& lib : impl->Libraries) {
       if (lib.Target) {
-        std::string uniqueName =
-          headTarget->GetGlobalGenerator()->IndexGeneratorTargetUniquely(
-            lib.Target);
-        std::string genex =
-          "$<TARGET_PROPERTY:" + std::move(uniqueName) + "," + prop + ">";
-        cmGeneratorExpression ge(lib.Backtrace);
-        std::unique_ptr<cmCompiledGeneratorExpression> cge = ge.Parse(genex);
-        cge->SetEvaluateForBuildsystem(true);
-
         EvaluatedTargetPropertyEntry ee(lib, lib.Backtrace);
+        // Pretend $<TARGET_PROPERTY:lib.Target,prop> appeared in our
+        // caller's property and hand-evaluate it as if it were compiled.
+        // Create a context as cmCompiledGeneratorExpression::Evaluate does.
+        cmGeneratorExpressionContext context(
+          headTarget->GetLocalGenerator(), config, false, headTarget,
+          headTarget, true, lib.Backtrace, lang);
         cmSystemTools::ExpandListArgument(
-          cge->Evaluate(headTarget->GetLocalGenerator(), config, false,
-                        headTarget, dagChecker, lang),
+          lib.Target->EvaluateInterfaceProperty(prop, &context, dagChecker),
           ee.Values);
-        if (cge->GetHadContextSensitiveCondition()) {
-          ee.ContextDependent = true;
-        }
+        ee.ContextDependent = context.HadContextSensitiveCondition;
         entries.emplace_back(std::move(ee));
       }
     }