Enhance DESTDIR documentation. Fixes #0012374.

3 files changed, 22 insertions, 5 deletions

diff --git a/Source/CPack/cmCPackDocumentVariables.cxx b/Source/CPack/cmCPackDocumentVariables.cxx
index edbef45..7fa401c 100644
--- a/Source/CPack/cmCPackDocumentVariables.cxx
+++ b/Source/CPack/cmCPackDocumentVariables.cxx
@@ -45,17 +45,18 @@ void cmCPackDocumentVariables::DefineVariables(cmake* cm)
            " packaging.", "DESTDIR means DESTination DIRectory."
            " It is commonly used by makefile "
            "users in order to install software at non-default location. It "
-           "is a basic relocation mechanism. "
+           "is a basic relocation mechanism that should not be used on"
+           " Windows (see CMAKE_INSTALL_PREFIX documentation). "
            "It is usually invoked like this:\n"
            " make DESTDIR=/home/john install\n"
            "which will install the concerned software using the"
-           " installation prefix, e.g. \"/usr/local\" prepended with "
+           " installation prefix, e.g. \"/usr/local\" pre-pended with "
            "the DESTDIR value which finally gives \"/home/john/usr/local\"."
            " When preparing a package, CPack first installs the items to be "
            "packaged in a local (to the build tree) directory by using the "
            "same DESTDIR mechanism. Nevertheless, if "
            "CPACK_SET_DESTDIR is set then CPack will set DESTDIR before"
-           " doing the local install. The most  noticeable difference is"
+           " doing the local install. The most noticeable difference is"
            " that without CPACK_SET_DESTDIR, CPack uses "
            "CPACK_PACKAGING_INSTALL_PREFIX as a prefix whereas with "
            "CPACK_SET_DESTDIR set, CPack will use CMAKE_INSTALL_PREFIX as"
diff --git a/Source/cmDocumentVariables.cxx b/Source/cmDocumentVariables.cxx
index 05ef8fc..c2197f2 100644
--- a/Source/cmDocumentVariables.cxx
+++ b/Source/cmDocumentVariables.cxx
@@ -595,7 +595,21 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
      "If \"make install\" is invoked or INSTALL is built"
      ", this directory is pre-pended onto all install "
      "directories. This variable defaults to /usr/local"
-     " on UNIX and c:/Program Files on Windows.",false,
+     " on UNIX and c:/Program Files on Windows.\n"
+     "On UNIX one can use the DESTDIR mechanism in order"
+     " to relocate the whole installation. "
+     "DESTDIR means DESTination DIRectory. It is "
+     "commonly used by makefile users "
+     "in order to install software at non-default location. "
+     "It is usually invoked like this:\n"
+     " make DESTDIR=/home/john install\n"
+     "which will install the concerned software using the"
+     " installation prefix, e.g. \"/usr/local\" pre-pended with "
+     "the DESTDIR value which finally gives \"/home/john/usr/local\".\n"
+     "WARNING: DESTDIR may not be used on Windows because installation"
+     " prefix usually contains a drive letter like in \"C:/Program Files\""
+     " which cannot be pre-pended with some other prefix."
+     ,false,
      "Variables That Change Behavior");
 
   cm->DefineProperty
diff --git a/Source/cmInstallCommand.h b/Source/cmInstallCommand.h
index 76e622e..7c06009 100644
--- a/Source/cmInstallCommand.h
+++ b/Source/cmInstallCommand.h
@@ -70,7 +70,9 @@ public:
       "the directory on disk to which a file will be installed.  "
       "If a full path (with a leading slash or drive letter) is given it "
       "is used directly.  If a relative path is given it is interpreted "
-      "relative to the value of CMAKE_INSTALL_PREFIX.\n"
+      "relative to the value of CMAKE_INSTALL_PREFIX. The prefix can "
+      "be relocated at install time using DESTDIR mechanism explained in the "
+      "CMAKE_INSTALL_PREFIX variable documentation.\n"
       "PERMISSIONS arguments specify permissions for installed files.  "
       "Valid permissions are "
       "OWNER_READ, OWNER_WRITE, OWNER_EXECUTE, "