[flang] Build intrinsic .mod files in include/flang

[tskeith]

Summary

The build was putting .mod files for intrinsic modules in
tools/flang/include/flang but the install puts them in include/flang,
as does the out-of-tree build. This confused things for the driver.
This change makes the build consistent with the install and simplifies
the flang script accordingly.

Also, clean up the cmake commands for building the .mod files.

[awarzynski]

Thank you, this simplifies a lot things!

flang/CMakeLists.txt

else()
   set(BACKEND_PACKAGE_STRING "${PACKAGE_STRING}")
   set(MLIR_MAIN_SRC_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --src-root
   set(MLIR_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --includedir
   set(MLIR_TABLEGEN_OUTPUT_DIR ${CMAKE_BINARY_DIR}/tools/mlir/include)
   set(MLIR_TABLEGEN_EXE $<TARGET_FILE:mlir-tblgen>)
   include_directories(SYSTEM ${MLIR_INCLUDE_DIR})
   include_directories(SYSTEM ${MLIR_TABLEGEN_OUTPUT_DIR})
 endif()
+set(FLANG_INTRINSIC_MODULES_DIR ${CMAKE_BINARY_DIR}/include/flang)
 
 if(FLANG_BUILD_NEW_DRIVER)
     # TODO: Remove when libclangDriver is lifted out of Clang
     if(FLANG_STANDALONE_BUILD)
       set(CLANG_INCLUDE_DIR ${CLANG_INCLUDE_DIRS} )
       # No need to specify TableGen output dir as that's embedded in CLANG_DIR
     else()
       set(CLANG_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/../clang/include )

flang/test/CMakeLists.txt

 # Test runner infrastructure for Flang. This configures the Flang test trees
 # for use by Lit, and delegates to LLVM's lit test handlers.
 
 llvm_canonicalize_cmake_booleans(
   FLANG_STANDALONE_BUILD
 )
 
-set(FLANG_INTRINSIC_MODULES_DIR ${FLANG_BINARY_DIR}/include/flang)
-
 set(FLANG_TOOLS_DIR ${FLANG_BINARY_DIR}/bin)
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
 )

flang/tools/f18/CMakeLists.txt

set(MODULES
   "ieee_features"
   "iso_c_binding"
   "iso_fortran_env"
   "omp_lib"
   "__fortran_builtins"
   "__fortran_type_info"
 )
 
-set(include ${FLANG_BINARY_DIR}/include/flang)
 target_include_directories(f18
   PRIVATE
   ${CMAKE_CURRENT_BINARY_DIR}
 )
 
 # Create module files directly from the top-level module source directory
 foreach(filename ${MODULES})
+  set(base ${FLANG_INTRINSIC_MODULES_DIR}/${filename})
   if(${filename} MATCHES "__fortran_type_info")
     set(depends "")
   elseif(${filename} MATCHES "__fortran_builtins")
-    set(depends ${include}/__fortran_type_info.mod)
+    set(depends ${FLANG_INTRINSIC_MODULES_DIR}/__fortran_type_info.mod)
   else()
-    set(depends ${include}/__fortran_builtins.mod)
+    set(depends ${FLANG_INTRINSIC_MODULES_DIR}/__fortran_builtins.mod)
   endif()
-  add_custom_command(OUTPUT ${include}/${filename}.mod
-    COMMAND f18 -fsyntax-only -I${include}
-      ${FLANG_SOURCE_DIR}/module/${filename}.f90
-    WORKING_DIRECTORY ${include}
+  add_custom_command(OUTPUT ${base}.mod
+    COMMAND f18 -fsyntax-only ${FLANG_SOURCE_DIR}/module/${filename}.f90
+    WORKING_DIRECTORY ${FLANG_INTRINSIC_MODULES_DIR}
     DEPENDS f18 ${FLANG_SOURCE_DIR}/module/${filename}.f90 ${depends}
   )
-  add_custom_command(OUTPUT ${include}/${filename}.f18.mod
-    DEPENDS ${include}/${filename}.mod
-    COMMAND ${CMAKE_COMMAND} -E
-      copy ${include}/${filename}.mod ${include}/${filename}.f18.mod)
-  list(APPEND MODULE_FILES ${include}/${filename}.mod)
-  list(APPEND MODULE_FILES ${include}/${filename}.f18.mod)
-  install(FILES ${include}/${filename}.mod DESTINATION include/flang)
-  install(FILES ${include}/${filename}.f18.mod DESTINATION include/flang)
+  add_custom_command(OUTPUT ${base}.f18.mod
+    DEPENDS ${base}.mod
+    COMMAND ${CMAKE_COMMAND} -E copy ${base}.mod ${base}.f18.mod)
+  list(APPEND MODULE_FILES ${base}.mod ${base}.f18.mod)
+  install(FILES ${base}.mod ${base}.f18.mod DESTINATION include/flang)
 endforeach()
 
 add_custom_target(module_files ALL DEPENDS ${MODULE_FILES})
 
 install(TARGETS f18 DESTINATION bin)
 
 # This flang shell script will only work in a POSIX shell.
 if (NOT WIN32)
   file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/flang
     DESTINATION ${CMAKE_BINARY_DIR}/bin
     FILE_PERMISSIONS OWNER_EXECUTE OWNER_READ OWNER_WRITE)
   install(PROGRAMS ${CMAKE_BINARY_DIR}/bin/flang DESTINATION bin)
 endif()

flang/tools/f18/flang

 #!/bin/bash
 #===-- tools/f18/flang.sh -----------------------------------------*- sh -*-===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #
 #===------------------------------------------------------------------------===#
 
 wd=$(cd $(dirname "$0")/.. && pwd)
-module_dir=$wd/include/flang
-if [[ ! -d $module_dir ]]; then
-  module_dir=$wd/tools/flang/include/flang
-fi
-opts="-module-suffix .f18.mod -intrinsic-module-directory $module_dir"
+opts="-module-suffix .f18.mod -intrinsic-module-directory $wd/include/flang"
 if ! $wd/bin/f18 $opts "$@"
 then status=$?
      echo flang: in $PWD, f18 failed with exit status $status: $wd/bin/f18 $opts "$@" >&2
      exit $status
 fi