Utilities: Add BoostScanDeps script

This script scans Boost headers in order to determine inter-library
dependencies, using the "autolink" information embedded in the
headers for automatic linking on Windows.  This information is then
output in a form suitable for use in FindBoost.cmake.

Utilities/Scripts/BoostScanDeps.cmake

@@ -0,0 +1,217 @@
+# Scan the Boost headers and determine the library dependencies.  Note
+# that this script only scans one Boost version at once; invoke once
+# for each Boost release.  Note that this does require the headers for
+# a given component to match the library name, since this computes
+# inter-library dependencies.  Library components for which this
+# assumption does not hold true and which have dependencies on other
+# Boost libraries will require special-casing.  It also doesn't handle
+# private dependencies not described in the headers, for static
+# library dependencies--this is also a limitation of auto-linking, and
+# I'm unaware of any specific instances where this would be
+# problematic.
+#
+# Invoke in script mode, defining these variables:
+# BOOST_DIR - the root of the boost includes
+#
+# The script will process each directory under the root as a
+# "component".  For each component, all the headers will be scanned to
+# determine the components it depends upon by following all the
+# possible includes from this component.  This is to match the
+# behaviour of autolinking.
+
+# Written by Roger Leigh <[email protected]>
+
+#=============================================================================
+# Copyright 2014-2015 University of Dundee
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+# Determine header dependencies on libraries using the embedded dependency information.
+#
+# component - the component to check (uses all headers from boost/${component})
+# includedir - the path to the Boost headers
+# _ret_libs - list of library dependencies
+#
+function(_Boost_FIND_COMPONENT_DEPENDENCIES component includedir _ret_libs)
+  # _boost_unprocessed_headers - list of headers requiring parsing
+  # _boost_processed_headers - headers already parsed (or currently being parsed)
+  # _boost_new_headers - new headers discovered for future processing
+
+  set(library_component FALSE)
+
+  # Start by finding all headers for the component; header
+  # dependencies via #include will be solved by future passes
+
+  # Special-case since it is part of mpi; look only in boost/mpi/python*
+  if(component STREQUAL "mpi_python")
+    set(_boost_DEPS "python")
+    set(library_component TRUE)
+    file(GLOB_RECURSE _boost_unprocessed_headers
+         RELATIVE "${includedir}"
+         "${includedir}/boost/mpi/python/*")
+    list(INSERT _boost_unprocessed_headers 0 "${includedir}/boost/mpi/python.hpp")
+  # Special-case since it is a serialization variant; look in boost/serialization
+  elseif(component STREQUAL "wserialization")
+    set(library_component TRUE)
+    file(GLOB_RECURSE _boost_unprocessed_headers
+         RELATIVE "${includedir}"
+         "${includedir}/boost/serialization/*")
+    list(INSERT _boost_unprocessed_headers 0 "${includedir}/boost/serialization.hpp")
+  # Not really a library in its own right, but treat it as one
+  elseif(component STREQUAL "math")
+    set(library_component TRUE)
+    file(GLOB_RECURSE _boost_unprocessed_headers
+         RELATIVE "${includedir}"
+         "${includedir}/boost/math/*")
+    list(INSERT _boost_unprocessed_headers 0 "${includedir}/boost/math.hpp")
+  # Single test header
+  elseif(component STREQUAL "unit_test_framework")
+    set(library_component TRUE)
+    set(_boost_unprocessed_headers "${BOOST_DIR}/test/unit_test.hpp")
+  # Single test header
+  elseif(component STREQUAL "prg_exec_monitor")
+    set(library_component TRUE)
+    set(_boost_unprocessed_headers "${BOOST_DIR}/test/prg_exec_monitor.hpp")
+  # Single test header
+  elseif(component STREQUAL "test_exec_monitor")
+    set(library_component TRUE)
+    set(_boost_unprocessed_headers "${BOOST_DIR}/test/test_exec_monitor.hpp")
+  else()
+    # Default behaviour where header directory is the same as the library name.
+    file(GLOB_RECURSE _boost_unprocessed_headers
+         RELATIVE "${includedir}"
+         "${includedir}/boost/${component}/*")
+    list(INSERT _boost_unprocessed_headers 0 "${includedir}/boost/${component}.hpp")
+  endif()
+
+  while(_boost_unprocessed_headers)
+    list(APPEND _boost_processed_headers ${_boost_unprocessed_headers})
+    foreach(header ${_boost_unprocessed_headers})
+      if(EXISTS "${includedir}/${header}")
+        file(STRINGS "${includedir}/${header}" _boost_header_includes REGEX "^#[ \t]*include[ \t]*<boost/[^>][^>]*>")
+        # The optional whitespace before "#" is intentional
+        # (boost/serialization/config.hpp bug).
+        file(STRINGS "${includedir}/${header}" _boost_header_deps REGEX "^[ \t]*#[ \t]*define[ \t][ \t]*BOOST_LIB_NAME[ \t][ \t]*boost_")
+
+        foreach(line ${_boost_header_includes})
+          string(REGEX REPLACE "^#[ \t]*include[ \t]*<(boost/[^>][^>]*)>.*" "\\1" _boost_header_match "${line}")
+          list(FIND _boost_processed_headers "${_boost_header_match}" _boost_header_processed)
+          list(FIND _boost_new_headers "${_boost_header_match}" _boost_header_new)
+          if (_boost_header_processed EQUAL -1 AND _boost_header_new EQUAL -1)
+            list(APPEND _boost_new_headers ${_boost_header_match})
+          endif()
+        endforeach()
+
+        foreach(line ${_boost_header_deps})
+          string(REGEX REPLACE "^[ \t]*#[ \t]*define[ \t][ \t]*BOOST_LIB_NAME[ \t][ \t]*boost_([^ \t][^ \t]*).*" "\\1" _boost_component_match "${line}")
+          list(FIND _boost_DEPS "${_boost_component_match}" _boost_dep_found)
+          if(_boost_component_match STREQUAL "bzip2" OR
+             _boost_component_match STREQUAL "zlib")
+            # These components may or may not be required; not
+            # possible to tell without knowing where and when
+            # BOOST_BZIP2_BINARY and BOOST_ZLIB_BINARY are defined.
+            # If building against an external zlib or bzip2, this is
+            # undesirable.
+            continue()
+          endif()
+          if(component STREQUAL "mpi" AND
+             (_boost_component_match STREQUAL "mpi_python" OR
+              _boost_component_match STREQUAL "python"))
+            # Optional python dependency; skip to avoid making it a
+            # hard dependency (handle as special-case for mpi_python).
+            continue()
+          endif()
+          if (_boost_dep_found EQUAL -1 AND
+              NOT "${_boost_component_match}" STREQUAL "${component}")
+            list(APPEND _boost_DEPS "${_boost_component_match}")
+          endif()
+          if("${_boost_component_match}" STREQUAL "${component}")
+            set(library_component TRUE)
+          endif()
+        endforeach()
+      endif()
+    endforeach()
+    set(_boost_unprocessed_headers ${_boost_new_headers})
+    unset(_boost_new_headers)
+  endwhile()
+
+  # message(STATUS "Unfiltered dependencies for Boost::${component}: ${_boost_DEPS}")
+
+  if(NOT library_component)
+    unset(_boost_DEPS)
+  endif()
+  set(${_ret_libs} ${_boost_DEPS} PARENT_SCOPE)
+
+  #string(REGEX REPLACE ";" " " _boost_DEPS_STRING "${_boost_DEPS}")
+  #if (NOT _boost_DEPS_STRING)
+  #  set(_boost_DEPS_STRING "(none)")
+  #endif()
+  #message(STATUS "Dependencies for Boost::${component}: ${_boost_DEPS_STRING}")
+endfunction()
+
+
+message(STATUS "Scanning ${BOOST_DIR}")
+
+# List of all directories and files
+file(GLOB boost_contents RELATIVE "${BOOST_DIR}/boost" "${BOOST_DIR}/boost/*")
+
+# Components as directories
+foreach(component ${boost_contents})
+  if(IS_DIRECTORY "${BOOST_DIR}/boost/${component}")
+    list(APPEND boost_components "${component}")
+  endif()
+endforeach()
+
+# The following components are not top-level directories, so require
+# special-casing:
+
+# Special-case mpi_python, since it's a part of mpi
+if(IS_DIRECTORY "${BOOST_DIR}/boost/mpi" AND
+   IS_DIRECTORY "${BOOST_DIR}/boost/python")
+ list(APPEND boost_components "mpi_python")
+endif()
+# Special-case wserialization, which is a variant of serialization
+if(IS_DIRECTORY "${BOOST_DIR}/boost/serialization")
+ list(APPEND boost_components "wserialization")
+endif()
+# Special-case math* since there are six libraries, but no actual math
+# library component.  Handle specially when scanning above.
+#
+# Special-case separate test libraries, which are all part of test
+if(EXISTS "${BOOST_DIR}/test/unit_test.hpp")
+ list(APPEND boost_components "unit_test_framework")
+endif()
+if(EXISTS "${BOOST_DIR}/test/prg_exec_monitor.hpp")
+ list(APPEND boost_components "prg_exec_monitor")
+endif()
+if(EXISTS "${BOOST_DIR}/test/test_exec_monitor.hpp")
+ list(APPEND boost_components "test_exec_monitor")
+endif()
+
+if(boost_components)
+  list(SORT boost_components)
+endif()
+
+# Process each component defined above
+foreach(component ${boost_components})
+  string(TOUPPER ${component} UPPERCOMPONENT)
+  _Boost_FIND_COMPONENT_DEPENDENCIES("${component}" "${BOOST_DIR}"
+                                     _Boost_${UPPERCOMPONENT}_LIBRARY_DEPENDENCIES)
+endforeach()
+
+# Output results
+foreach(component ${boost_components})
+  string(TOUPPER ${component} UPPERCOMPONENT)
+  if(_Boost_${UPPERCOMPONENT}_LIBRARY_DEPENDENCIES)
+    string(REGEX REPLACE ";" " " _boost_DEPS_STRING "${_Boost_${UPPERCOMPONENT}_LIBRARY_DEPENDENCIES}")
+    message(STATUS "set(_Boost_${UPPERCOMPONENT}_DEPENDENCIES ${_boost_DEPS_STRING})")
+  endif()
+endforeach()