From Pere:

For ROOT's Makefile we have intentionally disentangled CINT and dictionaries
by using order dependencies: when CINT gets changed, none of the dictionaries
get rebuilt, unless cint/cint/inc/cintdictversion.h is touched. This allows us
to maintain CINT without pain from the build system - in almost 100% of all
cases the dictionaries are unchanged after patching CINT. The difference is
drastic: 8 seconds (Makefile) compared to more than 5 minutes (CMake).

This change apply the technique to CMake. It still re-links all the libraries since
they depend on libCint.so but the time has been reduced from 7-8 minutes to
about 14 seconds on my Mac.


git-svn-id: http://root.cern.ch/svn/root/trunk@42930 27541ba8-7e3a-0410-8455-c3a389f83636

cint/ROOT/CMakeLists.txt

@@ -95,7 +95,7 @@ foreach(_name ${CINTSTLDLLNAMES})
   add_Custom_Command(OUTPUT ${OutFileName} 
                      COMMAND cint_tmp -w1 -z${_name} -n${OutFileName} ${AdditionalFlags} -D__MAKECINT__ -DG__MAKECINT ${IncludeDirs} -c-1 -A -Z0 ${InFileName} ${AdditionalHeaderFiles}
                      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-                     DEPENDS cint_tmp
+                     DEPENDS ${CINTDEP}
                     ) 
                     
   list(FIND CINTBUILDLOADER ${_name} _position)
@@ -119,7 +119,20 @@ foreach(_name ${CINTSTLDLLNAMES})
     endif()
     set(linkdeffile "${CMAKE_SOURCE_DIR}/core/metautils/src/${_name}Linkdef.h")
     
-    ROOT_GENERATE_DICTIONARY( ${Dictionary} ${_name1} LINKDEF ${linkdeffile})
+    #ROOT_GENERATE_DICTIONARY( ${Dictionary} ${_name1} LINKDEF ${linkdeffile})
+    add_custom_command(OUTPUT ${Dictionary}.cxx ${Dictionary}.h
+                       COMMAND rootcint_tmp -cint -f ${Dictionary}.cxx -c 
+                               -I${CMAKE_CURRENT_SOURCE_DIR}/inc 
+                               -I${CMAKE_BINARY_DIR}/include
+                               -I${CMAKE_SOURCE_DIR}/cint/cint/include 
+                               -I${CMAKE_SOURCE_DIR}/cint/cint/stl 
+                               -I${CMAKE_SOURCE_DIR}/cint/cint/lib
+                               -I${CMAKE_SOURCE_DIR}/core/base/inc
+                               -I${CMAKE_SOURCE_DIR}/core/meta/inc 
+                               -I${CMAKE_SOURCE_DIR}/core/clib/inc 
+                               ${_name1} ${linkdeffile} 
+                       DEPENDS ${linkdeffile} ${ROOTCINTDEP})
+
     set_source_files_properties(${Dictionary}.cxx 
                                  COMPILE_FLAGS "${CINTDLLCXXFLAGS} -DG__CINTBODY -I${HEADER_OUTPUT_PATH}"
                                 )                                
@@ -161,7 +174,7 @@ foreach(_name ${CINTINCDLLNAMES})
     add_custom_command(OUTPUT ${OutFileName} 
                        COMMAND cint_tmp -K -w1 -z${_name} -n${OutFileName} -D__MAKECINT__ -DG__MAKECINT ${IncludeDirs} -c-2 -Z0 ${InFileName} ${AdditionalHeaderFiles}
                        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-                       DEPENDS cint_tmp
+                       DEPENDS ${CINTDEP}
                       ) 
 
     set_source_files_properties(${OutFileName} 
@@ -178,7 +191,7 @@ foreach(_name ${CINTINCDLLNAMES})
     add_custom_command(OUTPUT ${OutFileName} 
                        COMMAND cint_tmp -K -w1 -z${_name} -n${OutFileName} -D__MAKECINT__ -DG__MAKECINT ${IncludeDirs} -c-2 -Z0 ${InFileName} ${AdditionalHeaderFiles}
                        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-                       DEPENDS ${CMAKE_BINARY_DIR}/cint/cint/include/sys/types.h cint_tmp
+                       DEPENDS ${CMAKE_BINARY_DIR}/cint/cint/include/sys/types.h ${CINTDEP}
                       ) 
 
     set_source_files_properties(${OutFileName} 
@@ -216,7 +229,7 @@ foreach(_name ${CINTINCDLLNAMES})
     add_custom_command(OUTPUT ${OutFileName} 
                        COMMAND cint_tmp -K -w1 -z${_name} -n${OutFileName} -D__MAKECINT__ -DG__MAKECINT ${_ExtraFlag} -c-2 -Z0 ${InFileName} ${AdditionalHeaderFiles} ${CMAKE_BINARY_DIR}/cint/cint/include/sys/types.h ${CMAKE_SOURCE_DIR}/cint/cint/lib/posix/posix.h
                        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-                       DEPENDS ${CMAKE_BINARY_DIR}/cint/cint/include/sys/types.h cint_tmp
+                       DEPENDS ${CMAKE_BINARY_DIR}/cint/cint/include/sys/types.h ${CINTDEP}
                       ) 
     set_source_files_properties(${OutFileName} 
                                 COMPILE_FLAGS "${CINT_C_DEFINITIONS}  -DG__HAVE_CONFIG -DG__NOMAKEINFO -I${CMAKE_SOURCE_DIR}/cint/cint/inc -I${CMAKE_SOURCE_DIR}/cint/cint/src -I${CMAKE_SOURCE_DIR}/cint/cint/src/dict -DG__SYSTYPES_H" 

cint/cint/CMakeLists.txt

@@ -79,7 +79,7 @@ else()
      COMMAND cint_tmp -I${CMAKE_CURRENT_SOURCE_DIR}/include 
        -I${CMAKE_CURRENT_SOURCE_DIR}/stl -I${CMAKE_CURRENT_SOURCE_DIR}/lib 
        -I${HEADER_OUTPUT_PATH} ${PROJECT_SOURCE_DIR}/cint/iosenum/iosenum.cxx
-     DEPENDS  cint_tmp
+     DEPENDS  ${CINTDEP}
   )
 endif()
 
@@ -138,6 +138,9 @@ ROOT_EXECUTABLE(cint.exe ${CMAKE_CURRENT_SOURCE_DIR}/main/cppmain.cxx LIBRARIES
 ROOT_EXECUTABLE(cint_tmp ${CMAKE_CURRENT_SOURCE_DIR}/main/cppmain.cxx 
                          ${CMAKE_CURRENT_BINARY_DIR}/loadfile_tmp.cxx LIBRARIES Cint_static ${CMAKE_THREAD_LIBS_INIT} ${CMAKE_DL_LIBS})
 
+#---Trick to avoid building all dictionaties when CINT is changed-------------------------------------------
+add_custom_target(CINTTARGET DEPENDS cint_tmp)
+
 #---Create the makecint executable--------------------------------------------------------------------------
 ROOT_EXECUTABLE(makecint ${CMAKE_SOURCE_DIR}/cint/tool/makecint.cxx LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
 

cmake/modules/RootNewMacros.cmake

@@ -63,6 +63,9 @@ else()
   endif()   
   set(rlibmap_cmd rlibmap)   
 endif()
+#---Dictionary dependencies to ${CMAKE_SOURCE_DIR}/cint/cint/inc/cintdictversion.h and rootcint executable 
+set(ROOTCINTDEP ${CMAKE_SOURCE_DIR}/cint/cint/inc/cintdictversion.h ROOTCINTTARGET)
+set(CINTDEP ${CMAKE_SOURCE_DIR}/cint/cint/inc/cintdictversion.h CINTTARGET)
 
 set(CMAKE_VERBOSE_MAKEFILES OFF)
 set(CMAKE_INCLUDE_CURRENT_DIR OFF)
@@ -210,7 +213,7 @@ function(ROOT_GENERATE_DICTIONARY dictionary)
   add_custom_command(OUTPUT ${dictionary}.cxx ${dictionary}.h
                      COMMAND ${rootcint_cmd} -cint -f  ${dictionary}.cxx 
                                           -c ${ARG_OPTIONS} ${definitions} ${includedirs} ${rheaderfiles} ${_linkdef} 
-                     DEPENDS ${headerfiles} ${_linkdef} rootcint)
+                     DEPENDS ${headerfiles} ${_linkdef} ${ROOTCINTDEP})
 endfunction()
 
 

core/utils/CMakeLists.txt

@@ -29,6 +29,9 @@ ROOT_EXECUTABLE(rootcint_tmp  rootcint_tmp.cxx RStl_tmp.cxx loadfile_tmp.cxx
                               LIBRARIES Cint_static ${CMAKE_DL_LIBS})
 add_dependencies(rootcint_tmp IOSENUM_H)
 
+#---Trick to avoid building all dictionaties when CINT is changed-------------
+add_custom_target(ROOTCINTTARGET DEPENDS rootcint rootcint_tmp)
+
 #---rlibmap executable--------------------------------------------------------
 ROOT_EXECUTABLE(rlibmap rlibmap.cxx LIBRARIES ${CMAKE_THREAD_LIBS_INIT})