cmTarget: Refactor LinkImplementation to allow more information

Create a cmLinkImplItem class derived from cmLinkItem so more
information can be added to link implementation entries than link
interface entries.  Convert the LinkImplementation Libraries member to
hold it.  Update client sites accordingly.

Source/cmComputeTargetDepends.cxx

@@ -255,7 +255,7 @@ void cmComputeTargetDepends::CollectTargetDepends(int depender_index)
 
     // A target should not depend on itself.
     emitted.insert(depender->GetName());
-    for(std::vector<cmLinkItem>::const_iterator
+    for(std::vector<cmLinkImplItem>::const_iterator
           lib = impl->Libraries.begin();
         lib != impl->Libraries.end(); ++lib)
       {

Source/cmGeneratorExpressionEvaluator.cxx

@@ -844,7 +844,7 @@ getLinkedTargetsContent(
 
 std::string
 getLinkedTargetsContent(
-  std::vector<cmLinkItem> const &libraries,
+  std::vector<cmLinkImplItem> const &libraries,
   cmTarget const* target,
   cmTarget const* headTarget,
   cmGeneratorExpressionContext *context,
@@ -852,7 +852,7 @@ getLinkedTargetsContent(
   const std::string &interfacePropertyName)
 {
   std::vector<cmTarget const*> tgts;
-  for (std::vector<cmLinkItem>::const_iterator
+  for (std::vector<cmLinkImplItem>::const_iterator
       it = libraries.begin();
       it != libraries.end(); ++it)
     {

Source/cmGeneratorTarget.cxx

@@ -475,8 +475,8 @@ bool cmGeneratorTarget::IsSystemIncludeDirectory(const std::string& dir,
       }
 
     std::set<cmTarget const*> uniqueDeps;
-    for(std::vector<cmLinkItem>::const_iterator li = impl->Libraries.begin();
-        li != impl->Libraries.end(); ++li)
+    for(std::vector<cmLinkImplItem>::const_iterator
+          li = impl->Libraries.begin(); li != impl->Libraries.end(); ++li)
       {
       cmTarget const* tgt = li->Target;
       if (!tgt)

Source/cmTarget.cxx

@@ -2281,7 +2281,7 @@ cmTarget::GetIncludeDirectories(const std::string& config) const
     if(this->Makefile->IsOn("APPLE"))
       {
       LinkImplementation const* impl = this->GetLinkImplementation(config);
-      for(std::vector<cmLinkItem>::const_iterator
+      for(std::vector<cmLinkImplItem>::const_iterator
           it = impl->Libraries.begin();
           it != impl->Libraries.end(); ++it)
         {
@@ -3675,7 +3675,8 @@ void cmTarget::ComputeLinkClosure(const std::string& config,
 
   // Add interface languages from linked targets.
   cmTargetCollectLinkLanguages cll(this, config, languages, this);
-  for(std::vector<cmLinkItem>::const_iterator li = impl->Libraries.begin();
+  for(std::vector<cmLinkImplItem>::const_iterator
+        li = impl->Libraries.begin();
       li != impl->Libraries.end(); ++li)
     {
     cll.Visit(*li);
@@ -6242,7 +6243,8 @@ cmTarget::GetLinkImplementationClosure(const std::string& config) const
     cmTarget::LinkImplementation const* impl
       = this->GetLinkImplementationLibraries(config);
 
-    for(std::vector<cmLinkItem>::const_iterator it = impl->Libraries.begin();
+    for(std::vector<cmLinkImplItem>::const_iterator
+          it = impl->Libraries.begin();
         it != impl->Libraries.end(); ++it)
       {
       processILibs(config, this, *it, tgts , emitted);
@@ -6383,7 +6385,8 @@ const char* cmTarget::ComputeLinkInterfaceLibraries(const std::string& config,
     // The link implementation is the default link interface.
     LinkImplementation const* impl =
         this->GetLinkImplementationLibrariesInternal(config, headTarget);
-    iface.Libraries = impl->Libraries;
+    std::copy(impl->Libraries.begin(), impl->Libraries.end(),
+              std::back_inserter(iface.Libraries));
     if(this->PolicyStatusCMP0022 == cmPolicies::WARN &&
        !this->Internal->PolicyWarnedCMP0022 && !usage_requirements_only)
       {
@@ -6397,12 +6400,12 @@ const char* cmTarget::ComputeLinkInterfaceLibraries(const std::string& config,
                               headTarget, usage_requirements_only,
                               ifaceLibs);
         }
-      if (ifaceLibs != impl->Libraries)
+      if (ifaceLibs != iface.Libraries)
         {
         std::string oldLibraries;
         std::string newLibraries;
         const char *sep = "";
-        for(std::vector<cmLinkItem>::const_iterator it
+        for(std::vector<cmLinkImplItem>::const_iterator it
               = impl->Libraries.begin(); it != impl->Libraries.end(); ++it)
           {
           oldLibraries += sep;
@@ -6470,7 +6473,7 @@ void cmTargetInternals::ComputeLinkInterface(cmTarget const* thisTarget,
         {
         cmTarget::LinkImplementation const* impl =
             thisTarget->GetLinkImplementation(config);
-        for(std::vector<cmLinkItem>::const_iterator
+        for(std::vector<cmLinkImplItem>::const_iterator
               li = impl->Libraries.begin(); li != impl->Libraries.end(); ++li)
           {
           if(emitted.insert(*li).second)
@@ -6674,7 +6677,7 @@ void cmTarget::ComputeLinkImplementation(const std::string& config,
 
       // The entry is meant for this configuration.
       impl.Libraries.push_back(
-        cmLinkItem(name, this->FindTargetToLink(name)));
+        cmLinkImplItem(name, this->FindTargetToLink(name)));
       }
 
     std::set<std::string> const& seenProps = cge->GetSeenTargetProperties();

Source/cmTarget.h

@@ -54,6 +54,16 @@ public:
   cmLinkItem(cmLinkItem const& r): std_string(r), Target(r.Target) {}
   cmTarget const* Target;
 };
+class cmLinkImplItem: public cmLinkItem
+{
+public:
+  cmLinkImplItem(): cmLinkItem() {}
+  cmLinkImplItem(std::string const& n,
+                 cmTarget const* t):
+    cmLinkItem(n, t) {}
+  cmLinkImplItem(cmLinkImplItem const& r):
+    cmLinkItem(r) {}
+};
 
 struct cmTargetLinkInformationMap:
   public std::map<std::string, cmComputeLinkInformation*>
@@ -296,7 +306,7 @@ public:
     std::vector<std::string> Languages;
 
     // Libraries linked directly in this configuration.
-    std::vector<cmLinkItem> Libraries;
+    std::vector<cmLinkImplItem> Libraries;
 
     // Libraries linked directly in other configurations.
     // Needed only for OLD behavior of CMP0003.