Fix parallel build failures

This was because the static and shared libraries were both producing
.mod files at the same location and a parallel build was confusing
the compiler with the timestamps

Author: isuruf

CMakeLists.txt

@@ -25,7 +25,7 @@ SET(CMAKE_Fortran_ABI_COMPILED 0)
 SET(CMAKE_Fortran_COMPILER_SUPPORTS_F90 1)
 SET(CMAKE_Fortran_PREPROCESS_SOURCE
     "<CMAKE_Fortran_COMPILER> -cpp <DEFINES> <INCLUDES> <FLAGS> -E <SOURCE> -o <PREPROCESSED_SOURCE>")
-set(CMAKE_Fortran_MODDIR_FLAG "-module ")
+SET(CMAKE_Fortran_MODDIR_FLAG "-module ")
 
 # If we are not building as a part of LLVM, build Flang as an
 # standalone project, using LLVM as an external library:
@@ -361,7 +361,10 @@ include_directories(BEFORE
   )
 
 # Direct module files to build include directory
-set(CMAKE_Fortran_MODULE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include)
+set(FLANG_MODULE_DIRECTORY_SHARED ${CMAKE_CURRENT_BINARY_DIR}/include)
+# mod files in the following differs only by the timestamp. This is needed to
+# ensure that flang can be built parallelly. It is discarded after flang is built
+set(FLANG_MODULE_DIRECTORY_STATIC ${CMAKE_CURRENT_BINARY_DIR}/include-static)
 
 # Install Fortran module files
 install(DIRECTORY ${CMAKE_Fortran_MODULE_DIRECTORY}/

runtime/flang/CMakeLists.txt

@@ -206,7 +206,6 @@ SET(FTN_INTRINSICS
   mod.c
   mvbits3f.c
   nargs3f.c
-  omp_lib.F95
   outstr3f.c
   packtimeqq3f.c
   perror3f.c
@@ -273,7 +272,7 @@ SET(FTN_INTRINSICS
   wait3f.c
   )
 
-SET(FTN_SUPPORT
+SET(FTN_SUPPORT_COMMON
   bcopy.c
   bcopys.c
   buffer.c
@@ -338,13 +337,8 @@ SET(FTN_SUPPORT
   descIntrins.c
   descFioUtil.c
   descRW.c
-  ieee_arithmetic.F95
-  ieee_exceptions.F95
-  ieee_features.F95
   initpar.c
   inquire.c
-  iso_c_bind.F95
-  iso_fortran_env.f90
   ldread.c
   ldwrite.c
   linux_dummy.c
@@ -480,18 +474,46 @@ SET(FTN_SUPPORT
   xfer_rpm1.c
   )
 
-add_library(iso_c_bind OBJECT
-  iso_c_bind.F95
-)
+foreach(FTN_FILE ieee_arithmetic ieee_exceptions ieee_features iso_c_bind omp_lib)
+  configure_file(${FTN_FILE}.F95 ${FTN_FILE}_static.F95 COPYONLY)
+endforeach()
+configure_file(iso_fortran_env.f90 iso_fortran_env_static.f90 COPYONLY)
 
-add_library(ieee_arithmetic OBJECT
+SET(FTN_SUPPORT_SHARED
   ieee_arithmetic.F95
   ieee_exceptions.F95
+  iso_c_bind.F95
+  ieee_features.F95
+  iso_fortran_env.f90
+)
+
+SET(FTN_SUPPORT_STATIC
+  ieee_arithmetic_static.F95
+  ieee_exceptions_static.F95
+  iso_c_bind_static.F95
+  ieee_features_static.F95
+  iso_fortran_env_static.f90
+)
+
+SET(FTN_SUPPORT
+  ${FTN_SUPPORT_STATIC}
+  ${FTN_SUPPORT_SHARED}
+  ${FTN_SUPPORT_COMMON}
+)
+
+SET(FTN_INTRINSICS_STATIC
+  omp_lib_static.F95
+)
+
+SET(FTN_INTRINSICS_SHARED
+  omp_lib_static.F95
 )
 
 add_flang_library(flang_static
   ${FTN_INTRINSICS}
-  ${FTN_SUPPORT}
+  ${FTN_INTRINSICS_STATIC}
+  ${FTN_SUPPORT_COMMON}
+  ${FTN_SUPPORT_STATIC}
   ${SHARED_SOURCES}
   )
 
@@ -501,10 +523,30 @@ else()
   set_property(TARGET flang_static PROPERTY OUTPUT_NAME flang)
 endif()
 
+set_target_properties(flang_static PROPERTIES Fortran_MODULE_DIRECTORY ${FLANG_MODULE_DIRECTORY_STATIC})
+
+# State the module that the source is producing
+set_source_files_properties(
+  iso_c_bind_static.F95
+  PROPERTIES
+  OBJECT_OUTPUTS ${FLANG_MODULE_DIRECTORY_STATIC}/iso_c_binding.mod
+  )
+
+# State a dependency on the module
+set_source_files_properties(
+  ieee_arithmetic_static.F95
+  ieee_exceptions_static.F95
+  PROPERTIES
+  OBJECT_DEPENDS ${FLANG_MODULE_DIRECTORY_STATIC}/iso_c_binding.mod
+  )
+
 set(SHARED_LIBRARY TRUE)
+
 add_flang_library(flang_shared
   ${FTN_INTRINSICS}
-  ${FTN_SUPPORT}
+  ${FTN_INTRINSICS_SHARED}
+  ${FTN_SUPPORT_COMMON}
+  ${FTN_SUPPORT_SHARED}
   ${SHARED_SOURCES}
   )
 set_property(TARGET flang_shared PROPERTY OUTPUT_NAME flang)
@@ -515,6 +557,22 @@ if (NOT MSVC)
 else()
   set_target_properties(flang_shared PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS TRUE)
 endif()
+set_target_properties(flang_shared PROPERTIES Fortran_MODULE_DIRECTORY ${FLANG_MODULE_DIRECTORY_SHARED})
+
+# State the module that the source is producing
+set_source_files_properties(
+  iso_c_bind.F95
+  PROPERTIES
+  OBJECT_OUTPUTS ${FLANG_MODULE_DIRECTORY_SHARED}/iso_c_binding.mod
+  )
+
+# State a dependency on the module
+set_source_files_properties(
+  ieee_arithmetic.F95
+  ieee_exceptions.F95
+  PROPERTIES
+  OBJECT_DEPENDS ${FLANG_MODULE_DIRECTORY_SHARED}/iso_c_binding.mod
+  )
 
 set(SHARED_LIBRARY FALSE)
 
@@ -579,25 +637,14 @@ target_include_directories(flang_shared
 add_dependencies(flang_static 
   flang1
   flang2
-  ieee_arithmetic
   )
 
 # Make sure the compiler is built before we bootstrap
 add_dependencies(flang_shared 
   flang1
   flang2
-  ieee_arithmetic
   )
 
-add_dependencies(iso_c_bind
-  flang1
-  flang2
-)
-
-add_dependencies(ieee_arithmetic
-  iso_c_bind
-)
-
 if (NOT MSVC)
   target_compile_options(flang_static PRIVATE -fPIC)
   target_compile_options(flang_shared PRIVATE -fPIC)