Cray: clean up CrayPrgEnv and CrayLinuxEnvironment modules

CrayPrgEnv:
  - add a new function __cmake_craype_linktype() that determines what
    link mode the Cray compiler wrapper will use in a more sophisticated
    way than just MATCHing for static/dynamic on the command line.

  - add a new function __cmake_craype_setupenv() that does a
    once-per-cmake-run setup that does the following:
       1. does a basic check of the wrapper's configuration.  Running
          cmake and then changing module and/or linktype configuration
          may cause build problems (since the data in the cmake cache
          may no longer be correct after the change).  We look for this
          and warn the user about it.
       2. uses the "module" provided PKG_CONFIG_PATH environment variable
          to add additional prefixes to the system prefix path.  This
          function used to be done by CrayLinuxEnvironment using the
          compiler implicit include/link paths but that is intended
          only for cross-compiling on Cray front-end nodes.  Since
          CrayPrgEnv runs on both front-end and compute nodes, we
          migrate this function here.

CrayLinuxEnvironment:
  - No need to set variables like CMAKE_SHARED_LIBRARY_PREFIX to values
    that have already been properly established by CMakeGenericSystem.cmake.
    Remove redundant sets of CMAKE_SHARED_LIBRARY_PREFIX,
    CMAKE_SHARED_LIBRARY_SUFFIX, CMAKE_STATIC_LIBRARY_PREFIX,
    CMAKE_STATIC_LIBRARY_SUFFIX, CMAKE_FIND_LIBRARY_PREFIXES, and
    CMAKE_DL_LIBS.

  - No need to add $ENV{SYSROOT_DIR}/usr/include to CMAKE_SYSTEM_INCLUDE_PATH
    when we already added $ENV{SYSROOT_DIR}/usr to CMAKE_SYSTEM_PREFIX_PATH.

  - Remove __cray_list_intersect(), __list_clean_dupes(), and buggy
    code that adds compiler implicit includes/libs to
    CMAKE_SYSTEM_INCLUDE_PATH and CMAKE_SYSTEM_LIBRARY_PATH.  This
    function has migrated to CrayPrgEnv.cmake, as noted above.

See discussion in issue #17413 for additional details.

2 files changed, 102 insertions, 81 deletions

diff --git a/Modules/Compiler/CrayPrgEnv.cmake b/Modules/Compiler/CrayPrgEnv.cmake
index 6c1c770..e55e587 100644
--- a/Modules/Compiler/CrayPrgEnv.cmake
+++ b/Modules/Compiler/CrayPrgEnv.cmake
@@ -1,8 +1,93 @@
 # Guard against multiple inclusions
-if(__craylinux_crayprgenv)
+if(__cmake_craype_crayprgenv)
   return()
 endif()
-set(__craylinux_crayprgenv 1)
+set(__cmake_craype_crayprgenv 1)
+
+# CrayPrgEnv: loaded when compiling through the Cray compiler wrapper.
+# The compiler wrapper can run on a front-end node or a compute node.
+
+cmake_policy(PUSH)
+cmake_policy(SET CMP0057 NEW)  # if IN_LIST
+
+# One-time setup of the craype environment.  First, check the wrapper config.
+# The wrapper's selection of a compiler (gcc, clang, intel, etc.) and
+# default include/library paths is selected using the "module" command.
+# The CRAYPE_LINK_TYPE environment variable partly controls if static
+# or dynamic binaries are generated (see __cmake_craype_linktype below).
+# Running cmake and then changing module and/or linktype configuration
+# may cause build problems (since the data in the cmake cache may no
+# longer be correct after the change).  We can look for this and warn
+# the user about it.  Second, use the "module" provided PKG_CONFIG_PATH-like
+# environment variable to add additional prefixes to the system prefix
+# path.
+function(__cmake_craype_setupenv)
+  if(NOT DEFINED __cmake_craype_setupenv_done)  # only done once per run
+    set(__cmake_craype_setupenv_done 1 PARENT_SCOPE)
+    unset(__cmake_check)
+    set(CMAKE_CRAYPE_LINKTYPE "$ENV{CRAYPE_LINK_TYPE}" CACHE STRING
+        "saved value of CRAYPE_LINK_TYPE environment variable")
+    set(CMAKE_CRAYPE_LOADEDMODULES "$ENV{LOADEDMODULES}" CACHE STRING
+        "saved value of LOADEDMODULES environment variable")
+    mark_as_advanced(CMAKE_CRAYPE_LINKTYPE CMAKE_CRAYPE_LOADEDMODULES)
+    if (NOT "${CMAKE_CRAYPE_LINKTYPE}" STREQUAL "$ENV{CRAYPE_LINK_TYPE}")
+      string(APPEND __cmake_check "CRAYPE_LINK_TYPE ")
+    endif()
+    if (NOT "${CMAKE_CRAYPE_LOADEDMODULES}" STREQUAL "$ENV{LOADEDMODULES}")
+      string(APPEND __cmake_check "LOADEDMODULES ")
+    endif()
+    if(DEFINED __cmake_check)
+      message(STATUS "NOTE: ${__cmake_check}changed since initial config!")
+      message(STATUS "NOTE: this may cause unexpected build errors.")
+    endif()
+    # loop over variables of interest
+    foreach(pkgcfgvar PKG_CONFIG_PATH PKG_CONFIG_PATH_DEFAULT
+            PE_PKG_CONFIG_PATH)
+      file(TO_CMAKE_PATH "$ENV{${pkgcfgvar}}" pkgcfg)
+      foreach(path ${pkgcfg})
+        string(REGEX REPLACE "(.*)/lib[^/]*/pkgconfig$" "\\1" path "${path}")
+        if(NOT "${path}" STREQUAL "" AND
+           NOT "${path}" IN_LIST CMAKE_SYSTEM_PREFIX_PATH)
+          list(APPEND CMAKE_SYSTEM_PREFIX_PATH "${path}")
+        endif()
+      endforeach()
+    endforeach()
+    # push it up out of this function into the parent scope
+    set(CMAKE_SYSTEM_PREFIX_PATH "${CMAKE_SYSTEM_PREFIX_PATH}" PARENT_SCOPE)
+  endif()
+endfunction()
+
+# The wrapper disables dynamic linking by default.  Dynamic linking is
+# enabled either by setting $ENV{CRAYPE_LINK_TYPE} to "dynamic" or by
+# specifying "-dynamic" to the wrapper when linking.  Specifying "-static"
+# to the wrapper when linking takes priority over $ENV{CRAYPE_LINK_TYPE}.
+# Furthermore, if you specify multiple "-dynamic" and "-static" flags to
+# the wrapper when linking, the last one will win.  In this case, the
+# wrapper will also print a warning like:
+#  Warning: -dynamic was already seen on command line, overriding with -static.
+#
+# note that cmake applies both CMAKE_${lang}_FLAGS and CMAKE_EXE_LINKER_FLAGS
+# (in that order) to the linking command, so -dynamic can appear in either
+# variable.
+function(__cmake_craype_linktype lang rv)
+  # start with ENV, but allow flags to override
+  if("$ENV{CRAYPE_LINK_TYPE}" STREQUAL "dynamic")
+    set(linktype dynamic)
+  else()
+    set(linktype static)
+  endif()
+  # combine flags and convert to a list so we can apply the flags in order
+  set(linkflags "${CMAKE_${lang}_FLAGS} ${CMAKE_EXE_LINKER_FLAGS}")
+  string(REPLACE " " ";" linkflags "${linkflags}")
+  foreach(flag IN LISTS linkflags)
+    if("${flag}" STREQUAL "-dynamic")
+      set(linktype dynamic)
+    elseif("${flag}" STREQUAL "-static")
+      set(linktype static)
+    endif()
+  endforeach()
+  set(${rv} ${linktype} PARENT_SCOPE)
+endfunction()
 
 macro(__CrayPrgEnv_setup lang)
   if(DEFINED ENV{CRAYPE_VERSION})
@@ -13,25 +98,25 @@ macro(__CrayPrgEnv_setup lang)
     message(STATUS "Cray Programming Environment (unknown version) ${lang}")
   endif()
 
+  # setup the craype environment
+  __cmake_craype_setupenv()
+
   # Flags for the Cray wrappers
   set(CMAKE_STATIC_LIBRARY_LINK_${lang}_FLAGS "-static")
   set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "-shared")
   set(CMAKE_SHARED_LIBRARY_LINK_${lang}_FLAGS "-dynamic")
 
-  # If the link type is not explicitly specified in the environment then
-  # the Cray wrappers assume that the code will be built statically so
-  # we check the following condition(s) are NOT met
-  #  Compiler flags are explicitly dynamic
-  #  Env var is dynamic and compiler flags are not explicitly static
-  if(NOT (((CMAKE_${lang}_FLAGS MATCHES "(^| )-dynamic($| )") OR
-         (CMAKE_EXE_LINKER_FLAGS MATCHES "(^| )-dynamic($| )"))
-         OR
-         (("$ENV{CRAYPE_LINK_TYPE}" STREQUAL "dynamic") AND
-          NOT ((CMAKE_${lang}_FLAGS MATCHES "(^| )-static($| )") OR
-               (CMAKE_EXE_LINKER_FLAGS MATCHES "(^| )-static($| )")))))
+  # determine linktype from environment and compiler flags
+  __cmake_craype_linktype(${lang} __cmake_craype_${lang}_linktype)
+
+  # switch off shared libs if we get a static linktype
+  if("${__cmake_craype_${lang}_linktype}" STREQUAL "static")
     set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS FALSE)
     set(BUILD_SHARED_LIBS FALSE CACHE BOOL "")
     set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
     set(CMAKE_LINK_SEARCH_START_STATIC TRUE)
   endif()
+
 endmacro()
+
+cmake_policy(POP)
diff --git a/Modules/Platform/CrayLinuxEnvironment.cmake b/Modules/Platform/CrayLinuxEnvironment.cmake
index a1a3d3f..f2aaf3f 100644
--- a/Modules/Platform/CrayLinuxEnvironment.cmake
+++ b/Modules/Platform/CrayLinuxEnvironment.cmake
@@ -1,6 +1,5 @@
-# Compute Node Linux doesn't quite work the same as native Linux so all of this
-# needs to be custom.  We use the variables defined through Cray's environment
-# modules to set up the right paths for things.
+# CrayLinuxEnvironment: loaded by users cross-compiling on a Cray front-end
+# node by specifying "-DCMAKE_SYSTEM_NAME=CrayLinuxEnvironment" to cmake
 
 set(UNIX 1)
 
@@ -30,13 +29,6 @@ endif()
 # Note: this may need to change in the future with 64-bit ARM
 set(CMAKE_SYSTEM_PROCESSOR "x86_64")
 
-set(CMAKE_SHARED_LIBRARY_PREFIX "lib")
-set(CMAKE_SHARED_LIBRARY_SUFFIX ".so")
-set(CMAKE_STATIC_LIBRARY_PREFIX "lib")
-set(CMAKE_STATIC_LIBRARY_SUFFIX ".a")
-
-set(CMAKE_FIND_LIBRARY_PREFIXES "lib")
-
 # Don't override shared lib support if it's already been set and possibly
 # overridden elsewhere by the CrayPrgEnv module
 if(NOT CMAKE_FIND_LIBRARY_SUFFIXES)
@@ -44,12 +36,9 @@ if(NOT CMAKE_FIND_LIBRARY_SUFFIXES)
   set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS TRUE)
 endif()
 
-set(CMAKE_DL_LIBS dl)
+# The rest of this file is based on UnixPaths.cmake, adjusted for Cray
 
-# Note: Much of this is pulled from UnixPaths.cmake but adjusted to the Cray
-# environment accordingly
-
-# Get the install directory of the running cmake to the search directories
+# add the install directory of the running cmake to the search directories
 # CMAKE_ROOT is CMAKE_INSTALL_PREFIX/share/cmake, so we need to go two levels up
 get_filename_component(__cmake_install_dir "${CMAKE_ROOT}" PATH)
 get_filename_component(__cmake_install_dir "${__cmake_install_dir}" PATH)
@@ -81,7 +70,6 @@ if (NOT CMAKE_FIND_NO_INSTALL_PREFIX)
 endif()
 
 list(APPEND CMAKE_SYSTEM_INCLUDE_PATH
-  $ENV{SYSROOT_DIR}/usr/include
   $ENV{SYSROOT_DIR}/usr/include/X11
 )
 list(APPEND CMAKE_SYSTEM_LIBRARY_PATH
@@ -95,57 +83,5 @@ list(APPEND CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES
   $ENV{SYSROOT_DIR}/lib64
 )
 
-# Compute the intersection of several lists
-function(__cray_list_intersect OUTPUT INPUT0)
-  if(ARGC EQUAL 2)
-    list(APPEND ${OUTPUT} ${${INPUT0}})
-  else()
-    foreach(I IN LISTS ${INPUT0})
-      set(__is_common 1)
-      foreach(L IN LISTS ARGN)
-        list(FIND ${L} "${I}" __idx)
-        if(__idx EQUAL -1)
-          set(__is_common 0)
-          break()
-        endif()
-      endforeach()
-      if(__is_common)
-        list(APPEND ${OUTPUT}  "${I}")
-      endif()
-    endforeach()
-  endif()
-  set(${OUTPUT} ${${OUTPUT}} PARENT_SCOPE)
-endfunction()
-
-macro(__list_clean_dupes var)
-  if(${var})
-    list(REMOVE_DUPLICATES ${var})
-  endif()
-endmacro()
-
-get_property(__langs GLOBAL PROPERTY ENABLED_LANGUAGES)
-set(__cray_inc_path_vars)
-set(__cray_lib_path_vars)
-foreach(__lang IN LISTS __langs)
-  list(APPEND __cray_inc_path_vars CMAKE_${__lang}_IMPLICIT_INCLUDE_DIRECTORIES)
-  list(APPEND __cray_lib_path_vars CMAKE_${__lang}_IMPLICIT_LINK_DIRECTORIES)
-endforeach()
-if(__cray_inc_path_vars)
-  __cray_list_intersect(__cray_implicit_include_dirs ${__cray_inc_path_vars})
-  if(__cray_implicit_include_dirs)
-    list(INSERT CMAKE_SYSTEM_INCLUDE_PATH 0 ${__cray_implicit_include_dirs})
-  endif()
-endif()
-if(__cray_lib_path_vars)
-  __cray_list_intersect(__cray_implicit_library_dirs ${__cray_lib_path_vars})
-  if(__cray_implicit_library_dirs)
-    list(INSERT CMAKE_SYSTEM_LIBRARY_PATH 0 ${__cray_implicit_library_dirs})
-  endif()
-endif()
-__list_clean_dupes(CMAKE_SYSTEM_PREFIX_PATH)
-__list_clean_dupes(CMAKE_SYSTEM_INCLUDE_PATH)
-__list_clean_dupes(CMAKE_SYSTEM_LIBRARY_PATH)
-__list_clean_dupes(CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES)
-
 # Enable use of lib64 search path variants by default.
 set_property(GLOBAL PROPERTY FIND_LIBRARY_USE_LIB64_PATHS TRUE)