ENH: add a new library path ordering algorithm to make sure -L paths will pick the correct libraries if possible

1 files changed, 126 insertions, 0 deletions

diff --git a/Source/cmOrderLinkDirectories.h b/Source/cmOrderLinkDirectories.h
new file mode 100644
index 0000000..234a343
--- /dev/null
+++ b/Source/cmOrderLinkDirectories.h
@@ -0,0 +1,126 @@
+/*=========================================================================
+
+  Program:   CMake - Cross-Platform Makefile Generator
+  Module:    $RCSfile$
+  Language:  C++
+  Date:      $Date$
+  Version:   $Revision$
+
+  Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
+  See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even 
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#ifndef cmOrderLinkDirectories_h
+#define cmOrderLinkDirectories_h
+
+#include <cmStandardIncludes.h>
+#include <map>
+#include <vector>
+#include "cmTarget.h"
+#include "cmsys/RegularExpression.hxx"
+
+
+/** \class cmOrderLinkDirectories
+ * \brief Compute the best -L path order
+ *
+ * This class computes the best order for -L paths.
+ * It tries to make sure full path specified libraries are 
+ * used.  For example if you have /usr/mylib/libfoo.a on as
+ * a link library for a target, and you also have /usr/lib/libbar.a
+ * and you also have /usr/lib/libfoo.a, then you would
+ * want -L/usr/mylib -L/usr/lib to make sure the correct libfoo.a is 
+ * found by the linker.  The algorithm is as follows:
+ * - foreach library create a vector of directories it exists in.
+ * - foreach directory create a vector of directories that must come
+ *   after it, put this in a map<dir, vector<dir>> mapping from a directory
+ *   to the vector of directories that it must be before.
+ * - put all directories into a vector
+ * - sort the vector with a compare function CanBeBefore
+ *   CanBeBefore returns true if a directory is OK to be before
+ *   another directory.  This is determined by looking at the 
+ *   map<dir vector<dir>> and seeing if d1 is in the vector for d2.
+ */
+class cmOrderLinkDirectories
+{
+public:
+  ///! set link information from the target
+  void SetLinkInformation(const cmTarget&, cmTarget::LinkLibraryType,
+                          const char* targetLibrary);
+  ///! Compute the best order for -L paths from GetLinkLibraries
+  bool DetermineLibraryPathOrder();
+  ///! Get the results from DetermineLibraryPathOrder
+  void GetLinkerInformation(std::vector<cmStdString>& searchPaths,
+                            std::vector<cmStdString>& linkItems)
+  {
+    linkItems = m_LinkItems;
+    searchPaths = m_SortedSearchPaths;
+  }
+  // should be set from CMAKE_STATIC_LIBRARY_SUFFIX,
+  // CMAKE_SHARED_LIBRARY_SUFFIX
+  // CMAKE_LINK_LIBRARY_SUFFIX
+  void AddLinkExtension(const char* e)
+  {
+    m_LinkExtensions.push_back(e);
+  }
+  // Return any warnings if the exist
+  std::string GetWarnings();
+
+  // structure to hold a full path library link item
+  struct Library
+  {
+    cmStdString FullPath;
+    cmStdString File;
+    cmStdString Path;
+  };
+  friend struct cmOrderLinkDirectoriesCompare;
+private:
+  void CreateRegularExpressions();
+  void DetermineLibraryPathOrder(std::vector<cmStdString>& searchPaths,
+                                 std::vector<cmStdString>& libs,
+                                 std::vector<cmStdString>& sortedPaths);
+  void PrepareLinkTargets();
+  bool LibraryInDirectory(const char* dir, const char* lib);
+  void FindLibrariesInSeachPaths();
+  void FindIndividualLibraryOrders();
+  void PrintMap(const char* name,
+                std::map<cmStdString, std::vector<cmStdString> >& m);
+  void OrderPaths(std::vector<cmStdString>& paths);
+  bool CanBeBefore(const cmStdString& d1,
+                   const cmStdString& d2);
+  void AddImpossible(const cmStdString& ,
+                     const cmStdString& );
+private:
+  // map from library to directories that it is in other than its full path
+  std::map<cmStdString, std::vector<cmStdString> > m_LibraryToDirectories;
+  // map from directory to vector of directories that must be after it
+  std::map<cmStdString, std::vector<cmStdString> > m_DirectoryToAfterList;
+  // map from full path to a Library struct
+  std::map<cmStdString, Library> m_FullPathLibraries;
+  // libraries that are found in multiple directories
+  std::vector<Library> m_MultiDirectoryLibraries;
+  // libraries that are only found in one directory
+  std::vector<Library> m_SingleDirectoryLibraries;
+  // This is a vector of all the link objects -lm or m
+  std::vector<cmStdString> m_LinkItems;
+  // Unprocessed link items
+  std::vector<cmStdString> m_RawLinkItems;
+  // This vector holds the sorted -L paths
+  std::vector<cmStdString> m_SortedSearchPaths;
+  // This is the set of -L paths unsorted, but unique
+  std::set<cmStdString> m_LinkPathSet;
+  // the names of link extensions
+  std::vector<cmStdString> m_LinkExtensions;
+  // set of directories that can not be put in the correct order
+  std::set<cmStdString> m_ImposibleDirectories;
+  // library regular expressions
+  cmsys::RegularExpression m_RemoveLibraryExtension;
+  cmsys::RegularExpression m_ExtractBaseLibraryName;
+  cmsys::RegularExpression m_ExtractBaseLibraryNameNoPrefix;
+  
+};
+
+#endif