3 files changed, 75 insertions, 3 deletions

diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index 0c72e4f..119248e 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -1131,6 +1131,10 @@ bool cmComputeLinkInformation::CheckImplicitDirItem(std::string const& item)
   // portion.  This will allow the system linker to locate the proper
   // library for the architecture at link time.
   this->AddUserItem(file, false);
+
+  // Make sure the link directory ordering will find the library.
+  this->OrderLinkerSearchPath->AddLinkLibrary(item);
+
   return true;
 }
 
diff --git a/Source/cmOrderDirectories.cxx b/Source/cmOrderDirectories.cxx
index c618a57..54f23f7 100644
--- a/Source/cmOrderDirectories.cxx
+++ b/Source/cmOrderDirectories.cxx
@@ -69,6 +69,29 @@ public:
         }
       }
     }
+
+  void FindImplicitConflicts(cmOStringStream& w)
+    {
+    bool first = true;
+    for(unsigned int i=0; i < this->OD->OriginalDirectories.size(); ++i)
+      {
+      // Check if this directory conflicts with the entry.
+      std::string const& dir = this->OD->OriginalDirectories[i];
+      if(dir != this->Directory && this->FindConflict(dir))
+        {
+        // The library will be found in this directory but it is
+        // supposed to be found in an implicit search directory.
+        if(first)
+          {
+          first = false;
+          w << "  ";
+          this->Report(w);
+          w << " in " << this->Directory << " may be hidden by files in:\n";
+          }
+        w << "    " << dir << "\n";
+        }
+      }
+    }
 protected:
   virtual bool FindConflict(std::string const& dir) = 0;
 
@@ -258,6 +281,12 @@ cmOrderDirectories::~cmOrderDirectories()
     {
     delete *i;
     }
+  for(std::vector<cmOrderDirectoriesConstraint*>::iterator
+        i = this->ImplicitDirEntries.begin();
+      i != this->ImplicitDirEntries.end(); ++i)
+    {
+    delete *i;
+    }
 }
 
 //----------------------------------------------------------------------------
@@ -280,13 +309,15 @@ void cmOrderDirectories::AddRuntimeLibrary(std::string const& fullPath,
   // Add the runtime library at most once.
   if(this->EmmittedConstraintSOName.insert(fullPath).second)
     {
-    // Avoid dealing with implicit directories.
+    // Implicit link directories need special handling.
     if(!this->ImplicitDirectories.empty())
       {
       std::string dir = cmSystemTools::GetFilenamePath(fullPath);
       if(this->ImplicitDirectories.find(dir) !=
          this->ImplicitDirectories.end())
         {
+        this->ImplicitDirEntries.push_back(
+          new cmOrderDirectoriesConstraintSOName(this, fullPath, soname));
         return;
         }
       }
@@ -313,13 +344,15 @@ void cmOrderDirectories::AddLinkLibrary(std::string const& fullPath)
   // Add the link library at most once.
   if(this->EmmittedConstraintLibrary.insert(fullPath).second)
     {
-    // Avoid dealing with implicit directories.
+    // Implicit link directories need special handling.
     if(!this->ImplicitDirectories.empty())
       {
       std::string dir = cmSystemTools::GetFilenamePath(fullPath);
       if(this->ImplicitDirectories.find(dir) !=
          this->ImplicitDirectories.end())
         {
+        this->ImplicitDirEntries.push_back(
+          new cmOrderDirectoriesConstraintLibrary(this, fullPath));
         return;
         }
       }
@@ -367,7 +400,7 @@ void cmOrderDirectories::CollectOriginalDirectories()
         di = this->UserDirectories.begin();
       di != this->UserDirectories.end(); ++di)
     {
-    // Avoid dealing with implicit directories.
+    // We never explicitly specify implicit link directories.
     if(this->ImplicitDirectories.find(*di) !=
        this->ImplicitDirectories.end())
       {
@@ -450,6 +483,39 @@ void cmOrderDirectories::FindConflicts()
       std::unique(i->begin(), i->end(), cmOrderDirectoriesCompare());
     i->erase(last, i->end());
     }
+
+  // Check items in implicit link directories.
+  this->FindImplicitConflicts();
+}
+
+//----------------------------------------------------------------------------
+void cmOrderDirectories::FindImplicitConflicts()
+{
+  // Check for items in implicit link directories that have conflicts
+  // in the explicit directories.
+  cmOStringStream conflicts;
+  for(unsigned int i=0; i < this->ImplicitDirEntries.size(); ++i)
+    {
+    this->ImplicitDirEntries[i]->FindImplicitConflicts(conflicts);
+    }
+
+  // Skip warning if there were no conflicts.
+  std::string text = conflicts.str();
+  if(text.empty())
+    {
+    return;
+    }
+
+  // Warn about the conflicts.
+  cmOStringStream w;
+  w << "Cannot generate a safe " << this->Purpose
+    << " for target " << this->Target->GetName()
+    << " because files in some directories may conflict with "
+    << " libraries in implicit directories:\n"
+    << text
+    << "Some of these libraries may not be found correctly.";
+  this->GlobalGenerator->GetCMakeInstance()
+    ->IssueMessage(cmake::WARNING, w.str(), this->Target->GetBacktrace());
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmOrderDirectories.h b/Source/cmOrderDirectories.h
index aa09a4e..5407733 100644
--- a/Source/cmOrderDirectories.h
+++ b/Source/cmOrderDirectories.h
@@ -54,6 +54,7 @@ private:
 
   bool OrderedDirectoriesComputed;
   std::vector<cmOrderDirectoriesConstraint*> ConstraintEntries;
+  std::vector<cmOrderDirectoriesConstraint*> ImplicitDirEntries;
   std::vector<std::string> UserDirectories;
   cmsys::RegularExpression RemoveLibraryExtension;
   std::vector<std::string> LinkExtensions;
@@ -66,6 +67,7 @@ private:
   void CollectOriginalDirectories();
   int AddOriginalDirectory(std::string const& dir);
   void FindConflicts();
+  void FindImplicitConflicts();
   void OrderDirectories();
   void VisitDirectory(unsigned int i);
   void DiagnoseCycle();