ENH: Add relative tag and add test for relative tag

Source/cmFileCommand.cxx

@@ -210,6 +210,17 @@ bool cmFileCommand::HandleGlobCommand(std::vector<std::string> const& args,
   bool first = true;
   for ( ; i != args.end(); ++i )
     {
+    if ( *i == "RELATIVE" )
+      {
+      ++i; // skip RELATIVE
+      if ( i == args.end() )
+        {
+        this->SetError("GLOB requires a directory after the RELATIVE tag");
+        return false;
+        }
+      g.SetRelative(i->c_str());
+      ++i;
+      }
     if ( !cmsys::SystemTools::FileIsFullPath(i->c_str()) )
       {
       std::string expr = this->Makefile->GetCurrentDirectory();

Source/cmFileCommand.h

@@ -67,8 +67,8 @@ public:
       "  FILE(WRITE filename \"message to write\"... )\n"
       "  FILE(APPEND filename \"message to write\"... )\n"
       "  FILE(READ filename variable)\n"
-      "  FILE(GLOB variable [globbing expressions]...)\n"
-      "  FILE(GLOB_RECURSE variable [globbing expressions]...)\n"
+      "  FILE(GLOB variable [RELATIVE path] [globbing expressions]...)\n"
+      "  FILE(GLOB_RECURSE variable [RELATIVE path] [globbing expressions]...)\n"
       "  FILE(REMOVE [directory]...)\n"
       "  FILE(REMOVE_RECURSE [directory]...)\n"
       "  FILE(MAKE_DIRECTORY [directory]...)\n"
@@ -87,7 +87,9 @@ public:
       "variable.\n"
       "GLOB will generate a list of all files that match the globbing "
       "expressions and store it into the variable. Globbing expressions "
-      "are similar to regular expressions, but much simpler.\n"
+      "are similar to regular expressions, but much simpler. If RELATIVE "
+      "flag is specified for an expression, the results will be returned "
+      "as a relative path to the given path.\n"
       "Examples of globbing expressions include:\n"
       "   *.cxx      - match all files with extension cxx\n"
       "   *.vt?      - match all files with extension vta,...,vtz\n"

Tests/StringFileTest/CMakeLists.txt

@@ -91,9 +91,12 @@ SET(expr "${CMAKE_CURRENT_SOURCE_DIR}/[sS][!a-su-zA-Z0-9][^a-qs-zA-Z0-9]ing?ile*
 MESSAGE("Glob expression is [${expr}].")
 FILE(GLOB src_files "${expr}")
 MESSAGE("Globbed files [${src_files}].")
-
 ADD_EXECUTABLE(StringFileTest ${src_files})
 
+SET(expr "${CMAKE_CURRENT_SOURCE_DIR}/../*.cxx")
+FILE(GLOB_RECURSE rel_src_files RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/.." "${expr}")
+MESSAGE("Globbed files [${rel_src_files}].")
+
 # Test FOREACH range
 MESSAGE("Cheack if FOREACH with RANGE works")
 MACRO(TEST_RANGE ARGS CHECK)