[gsl] use proper CMake target and move builtin-build to subdir

.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt

@@ -5,6 +5,7 @@ builtin_freetype=ON
 builtin_ftgl=ON
 builtin_gif=ON
 builtin_gl2ps=ON
+builtin_gsl=ON
 builtin_jpeg=ON
 builtin_lz4=ON
 builtin_lzma=ON

builtins/gsl/CMakeLists.txt

@@ -0,0 +1,49 @@
+set(ROOT_GSL_VERSION 2.8)
+message(STATUS "Downloading and building GSL version ${ROOT_GSL_VERSION}")
+set(ROOT_GSL_PREFIX ${CMAKE_BINARY_DIR}/builtins/GSL-prefix)
+set(ROOT_GSL_LIBRARY ${ROOT_GSL_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gsl${CMAKE_STATIC_LIBRARY_SUFFIX})
+set(ROOT_GSL_CBLAS_LIBRARY ${ROOT_GSL_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gslcblas${CMAKE_STATIC_LIBRARY_SUFFIX})
+set(ROOT_GSL_LIBRARIES ${ROOT_GSL_LIBRARY} ${ROOT_GSL_CBLAS_LIBRARY})
+if(CMAKE_OSX_SYSROOT)
+  set(_gsl_cppflags "-isysroot ${CMAKE_OSX_SYSROOT}")
+  set(_gsl_ldflags  "-isysroot ${CMAKE_OSX_SYSROOT}")
+endif()
+ExternalProject_Add(
+  BUILTIN_GSL
+  PREFIX ${ROOT_GSL_PREFIX}
+  # http://mirror.switch.ch/ftp/mirror/gnu/gsl/gsl-${ROOT_GSL_VERSION}.tar.gz
+  URL ${lcgpackages}/gsl-${ROOT_GSL_VERSION}.tar.gz
+  URL_HASH SHA256=6a99eeed15632c6354895b1dd542ed5a855c0f15d9ad1326c6fe2b2c9e423190
+  SOURCE_DIR GSL-src # prevent "<gsl/...>" vs GSL/ macOS warning
+  INSTALL_DIR ${ROOT_GSL_PREFIX}
+  CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix <INSTALL_DIR>
+                    --libdir=<INSTALL_DIR>/lib
+                    --enable-shared=no --with-pic
+                    CC=${CMAKE_C_COMPILER}
+                    CFLAGS=${CMAKE_C_FLAGS}
+                    CPPFLAGS=${_gsl_cppflags}
+                    LDFLAGS=${_gsl_ldflags}
+  LOG_DOWNLOAD 1 LOG_CONFIGURE 1 LOG_BUILD 1 LOG_INSTALL 1 LOG_OUTPUT_ON_FAILURE 1
+  BUILD_BYPRODUCTS ${ROOT_GSL_LIBRARIES}
+  TIMEOUT 600
+)
+
+# FIXME: one need to find better way to extract path with GSL include files
+set(ROOT_GSL_INCLUDE_DIR ${ROOT_GSL_PREFIX}/src/BUILTIN_GSL-build)
+
+file(MAKE_DIRECTORY ${ROOT_GSL_INCLUDE_DIR})
+add_library(GSL::gsl IMPORTED STATIC GLOBAL)
+add_dependencies(GSL::gsl BUILTIN_GSL)
+set_target_properties(GSL::gsl PROPERTIES
+    IMPORTED_LOCATION ${ROOT_GSL_LIBRARY}
+    INTERFACE_INCLUDE_DIRECTORIES ${ROOT_GSL_INCLUDE_DIR})
+add_library(GSL::gslcblas IMPORTED STATIC GLOBAL)
+add_dependencies(GSL::gslcblas BUILTIN_GSL)
+set_target_properties(GSL::gslcblas PROPERTIES
+    IMPORTED_LOCATION ${ROOT_GSL_CBLAS_LIBRARY}
+    INTERFACE_INCLUDE_DIRECTORIES ${ROOT_GSL_INCLUDE_DIR})
+
+set(GSL_INCLUDE_DIRS ${ROOT_GSL_INCLUDE_DIR} PARENT_SCOPE)
+set(GSL_FOUND ON PARENT_SCOPE)
+set(GSL_VERSION ${ROOT_GSL_VERSION} PARENT_SCOPE)
+set(GSL_LIBRARIES ${ROOT_GSL_LIBRARIES} PARENT_SCOPE)

cmake/modules/SearchInstalledSoftware.cmake

@@ -1229,38 +1229,8 @@ if(mathmore OR builtin_gsl OR (tmva-cpu AND use_gsl_cblas))
       endif()
     endif()
   else()
-    set(gsl_version 2.8)
-    message(STATUS "Downloading and building GSL version ${gsl_version}")
-    foreach(l gsl gslcblas)
-      list(APPEND GSL_LIBRARIES ${CMAKE_BINARY_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}${l}${CMAKE_STATIC_LIBRARY_SUFFIX})
-    endforeach()
-    set(GSL_CBLAS_LIBRARY ${CMAKE_BINARY_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gslcblas${CMAKE_STATIC_LIBRARY_SUFFIX})
-    if(CMAKE_OSX_SYSROOT)
-      set(_gsl_cppflags "-isysroot ${CMAKE_OSX_SYSROOT}")
-      set(_gsl_ldflags  "-isysroot ${CMAKE_OSX_SYSROOT}")
-    endif()
-    ExternalProject_Add(
-      GSL
-      # http://mirror.switch.ch/ftp/mirror/gnu/gsl/gsl-${gsl_version}.tar.gz
-      URL ${lcgpackages}/gsl-${gsl_version}.tar.gz
-      URL_HASH SHA256=6a99eeed15632c6354895b1dd542ed5a855c0f15d9ad1326c6fe2b2c9e423190
-      SOURCE_DIR GSL-src # prevent "<gsl/...>" vs GSL/ macOS warning
-      INSTALL_DIR ${CMAKE_BINARY_DIR}
-      CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix <INSTALL_DIR>
-                        --libdir=<INSTALL_DIR>/lib
-                        --enable-shared=no --with-pic
-                        CC=${CMAKE_C_COMPILER}
-                        CFLAGS=${CMAKE_C_FLAGS}
-                        CPPFLAGS=${_gsl_cppflags}
-                        LDFLAGS=${_gsl_ldflags}
-      LOG_DOWNLOAD 1 LOG_CONFIGURE 1 LOG_BUILD 1 LOG_INSTALL 1 LOG_OUTPUT_ON_FAILURE 1
-      BUILD_BYPRODUCTS ${GSL_LIBRARIES}
-      TIMEOUT 600
-    )
-    set(GSL_TARGET GSL)
-    # FIXME: one need to find better way to extract path with GSL include files
-    set(GSL_INCLUDE_DIR ${CMAKE_BINARY_DIR}/GSL-prefix/src/GSL-build)
-    set(GSL_FOUND ON)
+    list(APPEND ROOT_BUILTINS BUILTIN_GSL)
+    add_subdirectory(builtins/gsl)
     set(mathmore ON CACHE BOOL "Enabled because builtin_gsl requested (${mathmore_description})" FORCE)
   endif()
 endif()
@@ -1272,16 +1242,14 @@ if(tmva-cpu)
   add_library(ROOT::BLAS ALIAS Blas)
   if (NOT use_gsl_cblas AND BLAS_FOUND)
     target_link_libraries(Blas INTERFACE BLAS::BLAS)
-  elseif(use_gsl_cblas AND builtin_gsl)
-    message(STATUS "Using builtin GSL CBLAS for optional parts of TMVA")
-    add_dependencies(Blas GSL)
-    target_include_directories(Blas INTERFACE ${GSL_INCLUDE_DIR})
-    target_link_libraries(Blas INTERFACE ${GSL_CBLAS_LIBRARY})
-    target_compile_definitions(Blas INTERFACE -DR__USE_CBLAS)
   elseif(use_gsl_cblas AND GSL_FOUND)
-    message(STATUS "Using GSL CBLAS for optional parts of TMVA")
-    target_link_libraries(Blas INTERFACE GSL::gslcblas)
+    if (builtin_gsl)
+      message(STATUS "Using builtin GSL CBLAS for optional parts of TMVA")
+    else()
+      message(STATUS "Using system GSL CBLAS for optional parts of TMVA")
+    endif()
     target_compile_definitions(Blas INTERFACE -DR__USE_CBLAS)
+    target_link_libraries(Blas INTERFACE GSL::gslcblas)
   else()
     if(fail-on-missing)
       message(SEND_ERROR "tmva-cpu can't be built because BLAS was not found!")

math/mathmore/CMakeLists.txt

@@ -79,11 +79,8 @@ SOURCES
     Math/LinkDef.h
   DEPENDENCIES
     MathCore
-  BUILTINS
-    GSL
 )
 
-target_include_directories(MathMore SYSTEM PRIVATE ${GSL_INCLUDE_DIR})
-target_link_libraries(MathMore PRIVATE ${GSL_LIBRARIES})
+target_link_libraries(MathMore PRIVATE GSL::gsl GSL::gslcblas)
 
 ROOT_ADD_TEST_SUBDIRECTORY(test)

math/mathmore/test/CMakeLists.txt

@@ -45,7 +45,7 @@ add_definitions(-DHAVE_ROOTLIBS)
 #---Build and add all the defined test in the list---------------
 foreach(file ${TestMathMoreSource})
   get_filename_component(testname ${file} NAME_WE)
-  ROOT_EXECUTABLE(${testname} ${file} LIBRARIES ${GSL_LIBRARIES} ${Libraries})
+  ROOT_EXECUTABLE(${testname} ${file} LIBRARIES GSL::gsl GSL::gslcblas ${Libraries})
   ROOT_ADD_TEST(mathmore-${testname} COMMAND ${testname} LABELS ${${testname}_LABELS})
 endforeach()
 

roofit/roofitmore/CMakeLists.txt

@@ -50,13 +50,10 @@ ROOT_STANDARD_LIBRARY_PACKAGE(RooFitMore
     RIO
     MathCore
     Foam
-  BUILTINS
-    GSL
   ${EXTRA_DICT_OPTS}
 )
 
-target_include_directories(RooFitMore SYSTEM PRIVATE ${GSL_INCLUDE_DIR})
-target_link_libraries(RooFitMore PRIVATE ${GSL_LIBRARIES})
+target_link_libraries(RooFitMore PRIVATE GSL::gsl GSL::gslcblas)
 
 # For recent clang, this can facilitate auto-vectorisation.
 # In RooFit, the errno side effect is not needed, anyway: