ENH: SUBDIR_DEPENDS command now does nothing. The parallel build functionality is now automatic. Dependencies are setup to force the same build order as a single threaded build, but multiple files in the same directory can be built simultaneously. Also fixed bug with inheriting CMakeLists.txt files when a directory level is skipped.

Source/cmMakefile.cxx

@@ -560,12 +560,6 @@ void cmMakefile::AddSubDirectory(const char* sub)
   m_SubDirectories.push_back(sub);
 }
 
-void cmMakefile::AddSubdirDependency(const char* subdir,
-                                     const char* dependency)
-{
-  m_SubdirDepends[subdir].insert(dependency);
-}
-
 void cmMakefile::AddIncludeDirectory(const char* inc, bool before)
 {
   // Don't add an include directory that is already present.  Yes,
@@ -812,12 +806,26 @@ std::string cmMakefile::GetParentListFileName(const char *currentFileName)
   // is there a CMakeLists.txt file in the parent directory ?
   parentFile = listsDir;
   parentFile += "/CMakeLists.txt";
-  if(!cmSystemTools::FileExists(parentFile.c_str()))
+  while(!cmSystemTools::FileExists(parentFile.c_str()))
     {
-    parentFile = "";
-    return parentFile;
+    // There is no CMakeLists.txt file in the parent directory.  This
+    // can occur when coming out of a subdirectory resulting from a
+    // SUBDIRS(Foo/Bar) command (coming out of Bar into Foo).  Try
+    // walking up until a CMakeLists.txt is found or the home
+    // directory is hit.
+    
+    // if we are in the home directory then stop, return 0
+    if(m_cmHomeDirectory == listsDir) { return ""; }
+    
+    // is there a parent directory we can check
+    pos = listsDir.rfind('/');
+    // if we could not find the directory return 0
+    if(pos == std::string::npos) { return ""; }
+    listsDir = listsDir.substr(0, pos);
+    parentFile = listsDir;
+    parentFile += "/CMakeLists.txt";
     }
-  
+    
   return parentFile;
 }
 

Source/cmMakefile.h

@@ -210,11 +210,6 @@ public:
    */
   void AddSubDirectory(const char*);
 
-  /**
-   * Add a subdirectory dependency.
-   */
-  void AddSubdirDependency(const char* subdir, const char* dependency);
-
   /**
    * Add an include directory to the build.
    */
@@ -404,14 +399,6 @@ public:
     return m_SubDirectories;
     }
 
-  /**
-   * Get the subdirectory dependencies for the given subdirectory.
-   */
-  const std::set<cmStdString>& GetSubdirDepends(const char* subdir)
-    { 
-    return m_SubdirDepends[subdir];
-    }
-
   /**
    * Get a list of include directories in the build.
    */
@@ -571,8 +558,6 @@ protected:
   {
   };
   
-  std::map<cmStdString, StringSet >  m_SubdirDepends;
-  
   // The include and link-library paths.  These may have order
   // dependency, so they must be vectors (not set).
   std::vector<std::string> m_IncludeDirectories;

Source/cmSubdirDependsCommand.cxx

@@ -43,18 +43,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 // cmSubdirDependsCommand
 bool cmSubdirDependsCommand::InitialPass(std::vector<std::string> const& args)
 {
-  if(args.size() < 2)
-    {
-    this->SetError("called with incorrect number of arguments");
-    return false;
-    }
-  std::vector<std::string>::const_iterator i = args.begin();
-  std::string subdir = *i;
-  
-  for(++i; i != args.end(); ++i)
-    {
-    m_Makefile->AddSubdirDependency(subdir.c_str(), i->c_str());
-    }
   return true;
 }
 

Source/cmSubdirDependsCommand.h

@@ -45,15 +45,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "cmCommand.h"
 
 /** \class cmSubdirDependsCommand
- * \brief Specify a set of subdirectories which must be built before the
- * given subdirectory.
+ * \brief Legacy command.  Do not use.
  *
- * cmSubdirDependsCommand specifies for one entry of a SUBDIRS command
- * a set of the other entries that must be built before it.  CMake
- * will still walk the subdirectories in the order in which they
- * appear in a SUBDIRS command, but the generated makefiles will be
- * setup to be sure one directory is finished before another begins.
- * This allows parallel builds to work correctly.
+ * cmSubdirDependsCommand has been left in CMake for compatability with
+ * projects already using it.  Its functionality in supporting parallel
+ * builds is now automatic.  The command does not do anything.
  */
 class cmSubdirDependsCommand : public cmCommand
 {
@@ -82,7 +78,7 @@ public:
    */
   virtual const char* GetTerseDocumentation() 
     {
-    return "Add a set of subdirectories on which another subdirectory depends.";
+    return "Legacy command.  Does nothing.";
     }
   
   /**
@@ -92,9 +88,8 @@ public:
     {
     return
       "SUBDIR_DEPENDS(subdir dep1 dep2 ...)\n"
-      "Add a set of subdirectories on which \"subdir\" depends.\n"
-      "This sets up the generated makefiles to build the subdirectries dep1, "
-      "dep2, ... before \"subdir\" itself.";
+      "Does not do anything.  This command used to help projects order\n"
+      "parallel builds correctly.  This functionality is now automatic.";
     }
   
   cmTypeMacro(cmSubdirDependsCommand, cmCommand);

Source/cmUnixMakefileGenerator.cxx

@@ -1013,18 +1013,22 @@ OutputSubDirectoryVars(std::ostream& fout,
       }
     }
   fout << "# Targets for making " << target << " in subdirectories.\n";
+  std::string last = "";
   for(unsigned int i =0; i < SubDirectories.size(); i++)
     {
     std::string subdir = FixDirectoryName(SubDirectories[i].c_str());
     fout << target << "_" << subdir.c_str() << ":";
-    const std::set<cmStdString>& subdirDepends = m_Makefile->GetSubdirDepends(SubDirectories[i].c_str());
-    for(std::set<cmStdString>::const_iterator d = subdirDepends.begin();
-        d != subdirDepends.end(); ++d)
+    
+    // Make each subdirectory depend on previous one.  This forces
+    // parallel builds (make -j 2) to build in same order as a single
+    // threaded build to avoid dependency problems.
+    if(i > 0)
       {
-      std::string fixed_d = FixDirectoryName(d->c_str());
-      fout << " " << target << "_" << fixed_d.c_str();
+      fout << " " << target << "_" << last.c_str();
       }
+    
     fout << "\n";
+    last = subdir;
     this->BuildInSubDirectory(fout, SubDirectories[i].c_str(),
                               target1, target2);
     }