Merge topic 'restore-link-interface-objlib-with-unity' into release-3.29

5b8e9e068f Restore support for TARGET_OBJECTS in link interfaces with unity builds
1313c78a9c Tests: Update RunCMake.TargetObjects cmake_minimum_required version

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9279

3 files changed, 8 insertions, 6 deletions

diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index fb56a0d..fd4b2ec 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -727,7 +727,10 @@ public:
    */
   void ClearSourcesCache();
 
-  // Do not use.  This is only for a specific call site with a FIXME comment.
+  /**
+   * Clears cached evaluations of INTERFACE_LINK_LIBRARIES.
+   * They will be recomputed on demand.
+   */
   void ClearLinkInterfaceCache();
 
   void AddSource(const std::string& src, bool before = false);
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 71ab2a6..185bff9 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1922,9 +1922,13 @@ bool cmGlobalGenerator::AddAutomaticSources()
   // Clear the source list and classification cache (KindedSources) of all
   // targets so that it will be recomputed correctly by the generators later
   // now that the above transformations are done for all targets.
+  // Also clear the link interface cache to support $<TARGET_OBJECTS:objlib>
+  // in INTERFACE_LINK_LIBRARIES because the list of object files may have
+  // been changed by conversion to a unity build or addition of a PCH source.
   for (const auto& lg : this->LocalGenerators) {
     for (const auto& gt : lg->GetGeneratorTargets()) {
       gt->ClearSourcesCache();
+      gt->ClearLinkInterfaceCache();
     }
   }
   return true;
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 0e539fe..4afed43 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2864,15 +2864,10 @@ void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
                   cm::nullopt, true);
               } else if (reuseTarget->GetType() ==
                          cmStateEnums::OBJECT_LIBRARY) {
-                // FIXME: This can propagate more than one level, unlike
-                // the rest of the object files in an object library.
-                // Find another way to do this.
                 target->Target->AppendProperty(
                   "INTERFACE_LINK_LIBRARIES",
                   cmStrCat("$<$<CONFIG:", config,
                            ">:$<LINK_ONLY:", pchSourceObj, ">>"));
-                // We updated the link interface, so ensure it is recomputed.
-                target->ClearLinkInterfaceCache();
               }
             }
           } else {