Eclipse: add switch to disable linked resources (#13189)

Eclipse may get confused by these linked resources, because it sees
the same source file multiple times then and doesn't recognize
that it's the same file actually.

Alex

Source/cmExtraEclipseCDT4Generator.cxx

@@ -38,6 +38,7 @@ cmExtraEclipseCDT4Generator
   this->SupportedGlobalGenerators.push_back("Unix Makefiles");
 
   this->SupportsVirtualFolders = true;
+  this->GenerateLinkedResources = true;
 }
 
 //----------------------------------------------------------------------------
@@ -83,6 +84,9 @@ void cmExtraEclipseCDT4Generator::Generate()
   this->HomeDirectory       = mf->GetHomeDirectory();
   this->HomeOutputDirectory = mf->GetHomeOutputDirectory();
 
+  this->GenerateLinkedResources = mf->IsOn(
+                                    "CMAKE_ECLIPSE_GENERATE_LINKED_RESOURCES");
+
   this->IsOutOfSourceBuild = (this->HomeDirectory!=this->HomeOutputDirectory);
 
   this->GenerateSourceProject = (this->IsOutOfSourceBuild &&
@@ -501,6 +505,10 @@ void cmExtraEclipseCDT4Generator::CreateLinksForTargets(
           linkName2 += ti->first;
           this->AppendLinkedResource(fout, linkName2, "virtual:/virtual",
                                      VirtualFolder);
+          if (!this->GenerateLinkedResources)
+            {
+            break; // skip generating the linked resources to the source files
+            }
           std::vector<cmSourceGroup> sourceGroups=makefile->GetSourceGroups();
           // get the files from the source lists then add them to the groups
           cmTarget* tgt = const_cast<cmTarget*>(&ti->second);
@@ -555,6 +563,11 @@ void cmExtraEclipseCDT4Generator::CreateLinksForTargets(
 void cmExtraEclipseCDT4Generator::CreateLinksToSubprojects(
                        cmGeneratedFileStream& fout, const std::string& baseDir)
 {
+  if (!this->GenerateLinkedResources)
+    {
+    return;
+    }
+
   // for each sub project create a linked resource to the source dir
   // - only if it is an out-of-source build
   this->AppendLinkedResource(fout, "[Subprojects]",

Source/cmExtraEclipseCDT4Generator.h

@@ -109,6 +109,7 @@ private:
   std::string HomeOutputDirectory;
   bool IsOutOfSourceBuild;
   bool GenerateSourceProject;
+  bool GenerateLinkedResources;
   bool SupportsVirtualFolders;
 
 };