LinkItem: track `cmSourceFile` instances for external objects

The target may be required in order to provide Fortran modules, so track
the source file so that the target may be looked up when needed.

6 files changed, 30 insertions, 13 deletions

diff --git a/Source/cmComputeLinkDepends.cxx b/Source/cmComputeLinkDepends.cxx
index 1b1f640..320c57c 100644
--- a/Source/cmComputeLinkDepends.cxx
+++ b/Source/cmComputeLinkDepends.cxx
@@ -515,6 +515,7 @@ void cmComputeLinkDepends::AddLinkObject(cmLinkItem const& item)
   LinkEntry& entry = this->EntryList[index];
   entry.Item = BT<std::string>(item.AsStr(), item.Backtrace);
   entry.Kind = LinkEntry::Object;
+  entry.ObjectSource = item.ObjectSource;
 
   // Record explicitly linked object files separately.
   this->ObjectEntries.emplace_back(index);
diff --git a/Source/cmComputeLinkDepends.h b/Source/cmComputeLinkDepends.h
index 22c4e2a..3233217 100644
--- a/Source/cmComputeLinkDepends.h
+++ b/Source/cmComputeLinkDepends.h
@@ -22,6 +22,7 @@
 class cmGeneratorTarget;
 class cmGlobalGenerator;
 class cmMakefile;
+class cmSourceFile;
 class cmake;
 
 /** \class cmComputeLinkDepends
@@ -63,6 +64,9 @@ public:
 
     BT<std::string> Item;
     cmGeneratorTarget const* Target = nullptr;
+    // The source file representing the external object (used when linking
+    // `$<TARGET_OBJECTS>`)
+    cmSourceFile const* ObjectSource = nullptr;
     EntryKind Kind = Library;
     // The following member is for the management of items specified
     // through genex $<LINK_LIBRARY:...>
diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index 297ae1d..c58dc68 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -1176,7 +1176,7 @@ void cmComputeLinkInformation::AddItem(LinkEntry const& entry)
         : cmStateEnums::RuntimeBinaryArtifact;
       std::string exe = tgt->GetFullPath(config, artifact, true);
       this->Items.emplace_back(
-        BT<std::string>(exe, item.Backtrace), ItemIsPath::Yes, tgt,
+        BT<std::string>(exe, item.Backtrace), ItemIsPath::Yes, tgt, nullptr,
         this->FindLibraryFeature(entry.Feature == DEFAULT
                                    ? "__CMAKE_LINK_EXECUTABLE"
                                    : entry.Feature));
@@ -1197,7 +1197,7 @@ void cmComputeLinkInformation::AddItem(LinkEntry const& entry)
     } else if (this->GlobalGenerator->IsXcode() &&
                !tgt->GetImportedXcFrameworkPath(config).empty()) {
       this->Items.emplace_back(
-        tgt->GetImportedXcFrameworkPath(config), ItemIsPath::Yes, tgt,
+        tgt->GetImportedXcFrameworkPath(config), ItemIsPath::Yes, tgt, nullptr,
         this->FindLibraryFeature(entry.Feature == DEFAULT
                                    ? "__CMAKE_LINK_XCFRAMEWORK"
                                    : entry.Feature));
@@ -1679,15 +1679,15 @@ void cmComputeLinkInformation::AddTargetItem(LinkEntry const& entry)
       if (isImportedFrameworkFolderOnApple) {
         if (entry.Feature == DEFAULT) {
           this->AddLibraryFeature("FRAMEWORK");
-          this->Items.emplace_back(item, ItemIsPath::Yes, target,
+          this->Items.emplace_back(item, ItemIsPath::Yes, target, nullptr,
                                    this->FindLibraryFeature("FRAMEWORK"));
         } else {
-          this->Items.emplace_back(item, ItemIsPath::Yes, target,
+          this->Items.emplace_back(item, ItemIsPath::Yes, target, nullptr,
                                    this->FindLibraryFeature(entry.Feature));
         }
       } else {
         this->Items.emplace_back(
-          item, ItemIsPath::Yes, target,
+          item, ItemIsPath::Yes, target, nullptr,
           this->FindLibraryFeature(entry.Feature == DEFAULT
                                      ? "__CMAKE_LINK_FRAMEWORK"
                                      : entry.Feature));
@@ -1695,17 +1695,17 @@ void cmComputeLinkInformation::AddTargetItem(LinkEntry const& entry)
     } else {
       if (cmHasSuffix(entry.Feature, "FRAMEWORK"_s)) {
         this->Items.emplace_back(fwDescriptor->GetLinkName(), ItemIsPath::Yes,
-                                 target,
+                                 target, nullptr,
                                  this->FindLibraryFeature(entry.Feature));
       } else if (entry.Feature == DEFAULT &&
                  isImportedFrameworkFolderOnApple) {
         this->AddLibraryFeature("FRAMEWORK");
         this->Items.emplace_back(fwDescriptor->GetLinkName(), ItemIsPath::Yes,
-                                 target,
+                                 target, nullptr,
                                  this->FindLibraryFeature("FRAMEWORK"));
       } else {
         this->Items.emplace_back(
-          item, ItemIsPath::Yes, target,
+          item, ItemIsPath::Yes, target, nullptr,
           this->FindLibraryFeature(entry.Feature == DEFAULT
                                      ? "__CMAKE_LINK_LIBRARY"
                                      : entry.Feature));
@@ -1714,7 +1714,7 @@ void cmComputeLinkInformation::AddTargetItem(LinkEntry const& entry)
   } else {
     // Now add the full path to the library.
     this->Items.emplace_back(
-      item, ItemIsPath::Yes, target,
+      item, ItemIsPath::Yes, target, nullptr,
       this->FindLibraryFeature(
         entry.Feature == DEFAULT ? "__CMAKE_LINK_LIBRARY" : entry.Feature));
   }
@@ -1774,7 +1774,7 @@ void cmComputeLinkInformation::AddFullItem(LinkEntry const& entry)
 
   // Now add the full path to the library.
   this->Items.emplace_back(
-    item, ItemIsPath::Yes, nullptr,
+    item, ItemIsPath::Yes, nullptr, entry.ObjectSource,
     this->FindLibraryFeature(
       entry.Feature == DEFAULT
         ? (entry.Kind == cmComputeLinkDepends::LinkEntry::Object
@@ -2000,13 +2000,13 @@ void cmComputeLinkInformation::AddFrameworkItem(LinkEntry const& entry)
   if (this->GlobalGenerator->IsXcode()) {
     // Add framework path - it will be handled by Xcode after it's added to
     // "Link Binary With Libraries" build phase
-    this->Items.emplace_back(item, ItemIsPath::Yes, nullptr,
+    this->Items.emplace_back(item, ItemIsPath::Yes, nullptr, nullptr,
                              this->FindLibraryFeature(entry.Feature == DEFAULT
                                                         ? "FRAMEWORK"
                                                         : entry.Feature));
   } else {
     this->Items.emplace_back(
-      fwDescriptor->GetLinkName(), ItemIsPath::Yes, nullptr,
+      fwDescriptor->GetLinkName(), ItemIsPath::Yes, nullptr, nullptr,
       this->FindLibraryFeature(entry.Feature == DEFAULT ? "FRAMEWORK"
                                                         : entry.Feature));
   }
@@ -2024,7 +2024,7 @@ void cmComputeLinkInformation::AddXcFrameworkItem(LinkEntry const& entry)
         plist->SelectSuitableLibrary(*this->Makefile, entry.Item.Backtrace)) {
     if (this->GlobalGenerator->IsXcode()) {
       this->Items.emplace_back(
-        entry.Item.Value, ItemIsPath::Yes, nullptr,
+        entry.Item.Value, ItemIsPath::Yes, nullptr, nullptr,
         this->FindLibraryFeature(entry.Feature == DEFAULT
                                    ? "__CMAKE_LINK_XCFRAMEWORK"
                                    : entry.Feature));
diff --git a/Source/cmComputeLinkInformation.h b/Source/cmComputeLinkInformation.h
index 1e8556d..3ee995f 100644
--- a/Source/cmComputeLinkInformation.h
+++ b/Source/cmComputeLinkInformation.h
@@ -22,6 +22,7 @@ class cmGeneratorTarget;
 class cmGlobalGenerator;
 class cmMakefile;
 class cmOrderDirectories;
+class cmSourceFile;
 class cmake;
 
 /** \class cmComputeLinkInformation
@@ -51,16 +52,21 @@ public:
   {
     Item(BT<std::string> v, ItemIsPath isPath,
          cmGeneratorTarget const* target = nullptr,
+         cmSourceFile const* objectSource = nullptr,
          FeatureDescriptor const* feature = nullptr)
       : Value(std::move(v))
       , IsPath(isPath)
       , Target(target)
+      , ObjectSource(objectSource)
       , Feature(feature)
     {
     }
     BT<std::string> Value;
     ItemIsPath IsPath = ItemIsPath::No;
     cmGeneratorTarget const* Target = nullptr;
+    // The source file representing the external object (used when linking
+    // `$<TARGET_OBJECTS>`)
+    cmSourceFile const* ObjectSource = nullptr;
 
     bool HasFeature() const { return this->Feature != nullptr; }
     const std::string& GetFeatureName() const
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 146319a..8d21e63 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -6898,6 +6898,7 @@ void cmGeneratorTarget::ExpandLinkItems(
             cmSourceFile const* sf =
               mf->GetSource(maybeObj, cmSourceFileLocationKind::Known);
             if (sf && sf->GetPropertyAsBool("EXTERNAL_OBJECT")) {
+              item.ObjectSource = sf;
               iface.Objects.emplace_back(std::move(item));
               continue;
             }
@@ -8489,6 +8490,7 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
           cmSourceFile const* sf =
             mf->GetSource(maybeObj, cmSourceFileLocationKind::Known);
           if (sf && sf->GetPropertyAsBool("EXTERNAL_OBJECT")) {
+            item.ObjectSource = sf;
             impl.Objects.emplace_back(std::move(item));
             continue;
           }
diff --git a/Source/cmLinkItem.h b/Source/cmLinkItem.h
index 262728b..e4444d3 100644
--- a/Source/cmLinkItem.h
+++ b/Source/cmLinkItem.h
@@ -17,6 +17,7 @@
 #include "cmTargetLinkLibraryType.h"
 
 class cmGeneratorTarget;
+class cmSourceFile;
 
 // Basic information about each link item.
 class cmLinkItem
@@ -29,6 +30,9 @@ public:
   cmLinkItem(cmGeneratorTarget const* t, bool c, cmListFileBacktrace bt);
   std::string const& AsStr() const;
   cmGeneratorTarget const* Target = nullptr;
+  // The source file representing the external object (used when linking
+  // `$<TARGET_OBJECTS>`)
+  cmSourceFile const* ObjectSource = nullptr;
   bool Cross = false;
   cmListFileBacktrace Backtrace;
   friend bool operator<(cmLinkItem const& l, cmLinkItem const& r);