[flang][NFC] Refactor MODULE definitions to not accidentally leak symbols (#80833)

This PR continues the work started with PR #79006, by setting visibility
in MODULES to PRIVATE by default and explicitly exporting only the
desired symbols. `omp_lib` needs more work, as it should maybe be
compiled from `omp_lib.f90` in
`openmp/runtime/src/incluce/omp_lib.f90.var` instead of simply using an
INCLUDE for `omp_lib.h`

Author: mjklemm

flang/module/__cuda_builtins.f90

@@ -16,4 +16,16 @@
     blockIdx => __builtin_blockIdx, &
     gridDim => __builtin_gridDim, &
     warpsize => __builtin_warpsize
+
+  implicit none
+
+  ! Set PRIVATE by default to explicitly only export what is meant
+  ! to be exported by this MODULE.
+  private
+
+  public :: threadIdx, &
+    blockDim, &
+    blockIdx, &
+    gridDim, &
+    warpsize
 end module

flang/module/__fortran_builtins.f90

@@ -11,52 +11,60 @@
 ! to USE the standard intrinsic modules in order to access the
 ! standard names of the procedures.
 module __fortran_builtins
+  implicit none
+
+  ! Set PRIVATE by default to explicitly only export what is meant
+  ! to be exported by this MODULE.
+  private
 
   intrinsic :: __builtin_c_loc
+
   intrinsic :: __builtin_c_f_pointer
+  public :: __builtin_c_f_pointer
+
   intrinsic :: sizeof ! extension
+  public :: sizeof
 
   intrinsic :: selected_int_kind
-  private :: selected_int_kind
-  integer, parameter, private :: int64 = selected_int_kind(18)
+  integer, parameter :: int64 = selected_int_kind(18)
 
-  type, bind(c) :: __builtin_c_ptr
+  type, bind(c), public :: __builtin_c_ptr
     integer(kind=int64), private :: __address
   end type
 
-  type, bind(c) :: __builtin_c_funptr
+  type, bind(c), public :: __builtin_c_funptr
     integer(kind=int64), private :: __address
   end type
 
-  type :: __builtin_event_type
+  type, public :: __builtin_event_type
     integer(kind=int64), private :: __count
   end type
 
-  type :: __builtin_notify_type
+  type, public :: __builtin_notify_type
     integer(kind=int64), private :: __count
   end type
 
-  type :: __builtin_lock_type
+  type, public :: __builtin_lock_type
     integer(kind=int64), private :: __count
   end type
 
-  type :: __builtin_team_type
+  type, public :: __builtin_team_type
     integer(kind=int64), private :: __id
   end type
 
-  integer, parameter :: __builtin_atomic_int_kind = selected_int_kind(18)
-  integer, parameter :: &
+  integer, parameter, public :: __builtin_atomic_int_kind = selected_int_kind(18)
+  integer, parameter, public :: &
     __builtin_atomic_logical_kind = __builtin_atomic_int_kind
 
-  procedure(type(__builtin_c_ptr)) :: __builtin_c_loc
+  procedure(type(__builtin_c_ptr)), public :: __builtin_c_loc
 
-  type :: __builtin_dim3
+  type, public :: __builtin_dim3
     integer :: x=1, y=1, z=1
   end type
-  type(__builtin_dim3) :: &
+  type(__builtin_dim3), public :: &
     __builtin_threadIdx, __builtin_blockDim, __builtin_blockIdx, &
     __builtin_gridDim
-  integer, parameter :: __builtin_warpsize = 32
+  integer, parameter, public :: __builtin_warpsize = 32
 
   intrinsic :: __builtin_fma
   intrinsic :: __builtin_ieee_is_nan, __builtin_ieee_is_negative, &
@@ -71,8 +79,21 @@
     __builtin_ieee_support_nan, __builtin_ieee_support_sqrt, &
     __builtin_ieee_support_standard, __builtin_ieee_support_subnormal, &
     __builtin_ieee_support_underflow_control
+  public :: __builtin_fma
+  public :: __builtin_ieee_is_nan, __builtin_ieee_is_negative, &
+    __builtin_ieee_is_normal
+  public :: __builtin_ieee_next_after, __builtin_ieee_next_down, &
+    __builtin_ieee_next_up
+  public :: scale ! for ieee_scalb
+  public :: __builtin_ieee_selected_real_kind
+  public :: __builtin_ieee_support_datatype, &
+    __builtin_ieee_support_denormal, __builtin_ieee_support_divide, &
+    __builtin_ieee_support_inf, __builtin_ieee_support_io, &
+    __builtin_ieee_support_nan, __builtin_ieee_support_sqrt, &
+    __builtin_ieee_support_standard, __builtin_ieee_support_subnormal, &
+    __builtin_ieee_support_underflow_control
 
-  type, private :: __force_derived_type_instantiations
+  type :: __force_derived_type_instantiations
     type(__builtin_c_ptr) :: c_ptr
     type(__builtin_c_funptr) :: c_funptr
     type(__builtin_event_type) :: event_type
@@ -81,25 +102,34 @@
   end type
 
   intrinsic :: __builtin_compiler_options, __builtin_compiler_version
+  public :: __builtin_compiler_options, __builtin_compiler_version
 
   interface operator(==)
     module procedure __builtin_c_ptr_eq
   end interface
+  public :: operator(==)
+
   interface operator(/=)
     module procedure __builtin_c_ptr_eq
   end interface
+  public :: operator(/=)
 
   interface __builtin_c_associated
     module procedure c_associated_c_ptr
     module procedure c_associated_c_funptr
   end interface
-  private :: c_associated_c_ptr, c_associated_c_funptr
+  public :: __builtin_c_associated
+!  private :: c_associated_c_ptr, c_associated_c_funptr
 
-  type(__builtin_c_ptr), parameter :: __builtin_c_null_ptr = __builtin_c_ptr(0)
-  type(__builtin_c_funptr), parameter :: &
+  type(__builtin_c_ptr), parameter, public :: __builtin_c_null_ptr = __builtin_c_ptr(0)
+  type(__builtin_c_funptr), parameter, public :: &
     __builtin_c_null_funptr = __builtin_c_funptr(0)
 
-contains
+  public :: __builtin_c_ptr_eq
+  public :: __builtin_c_ptr_ne
+  public :: __builtin_c_funloc
+
+  contains
 
   elemental logical function __builtin_c_ptr_eq(x, y)
     type(__builtin_c_ptr), intent(in) :: x, y

flang/module/__fortran_ieee_exceptions.f90

@@ -14,13 +14,18 @@
 include '../include/flang/Runtime/magic-numbers.h'
 
 module __fortran_ieee_exceptions
+  implicit none
 
-  type :: ieee_flag_type ! Fortran 2018, 17.2 & 17.3
+  ! Set PRIVATE by default to explicitly only export what is meant
+  ! to be exported by this MODULE.
+  private
+
+  type, public :: ieee_flag_type ! Fortran 2018, 17.2 & 17.3
     private
     integer(kind=1) :: flag = 0
   end type ieee_flag_type
 
-  type(ieee_flag_type), parameter :: &
+  type(ieee_flag_type), parameter, public :: &
     ieee_invalid = ieee_flag_type(_FORTRAN_RUNTIME_IEEE_INVALID), &
     ieee_overflow = ieee_flag_type(_FORTRAN_RUNTIME_IEEE_OVERFLOW), &
     ieee_divide_by_zero = &
@@ -29,16 +34,16 @@
     ieee_inexact = ieee_flag_type(_FORTRAN_RUNTIME_IEEE_INEXACT), &
     ieee_denorm = ieee_flag_type(_FORTRAN_RUNTIME_IEEE_DENORM) ! extension
 
-  type(ieee_flag_type), parameter :: &
+  type(ieee_flag_type), parameter, public :: &
     ieee_usual(*) = [ ieee_overflow, ieee_divide_by_zero, ieee_invalid ], &
     ieee_all(*) = [ ieee_usual, ieee_underflow, ieee_inexact ]
 
-  type :: ieee_modes_type ! Fortran 2018, 17.7
+  type, public :: ieee_modes_type ! Fortran 2018, 17.7
     private ! opaque fenv.h femode_t data
     integer(kind=4) :: __data(_FORTRAN_RUNTIME_IEEE_FEMODE_T_EXTENT)
   end type ieee_modes_type
 
-  type :: ieee_status_type ! Fortran 2018, 17.7
+  type, public :: ieee_status_type ! Fortran 2018, 17.7
     private ! opaque fenv.h fenv_t data
     integer(kind=4) :: __data(_FORTRAN_RUNTIME_IEEE_FENV_T_EXTENT)
   end type ieee_status_type
@@ -54,18 +59,6 @@
   G(2) G(3) G(4) G(8) G(16)
 #endif
 
-! Set PRIVATE accessibility for specifics with 1 LOGICAL or REAL argument for
-! generic G.
-#define PRIVATE_L(G) private :: \
-  G##_l1, G##_l2, G##_l4, G##_l8
-#if __x86_64__
-#define PRIVATE_R(G) private :: \
-  G##_a2, G##_a3, G##_a4, G##_a8, G##_a10, G##_a16
-#else
-#define PRIVATE_R(G) private :: \
-  G##_a2, G##_a3, G##_a4, G##_a8, G##_a16
-#endif
-
 #define IEEE_GET_FLAG_L(FVKIND) \
   elemental subroutine ieee_get_flag_l##FVKIND(flag, flag_value); \
     import ieee_flag_type; \
@@ -75,7 +68,7 @@ end subroutine ieee_get_flag_l##FVKIND;
   interface ieee_get_flag
     SPECIFICS_L(IEEE_GET_FLAG_L)
   end interface ieee_get_flag
-  PRIVATE_L(IEEE_GET_FLAG)
+  public :: ieee_get_flag
 #undef IEEE_GET_FLAG_L
 
 #define IEEE_GET_HALTING_MODE_L(HKIND) \
@@ -87,7 +80,7 @@ end subroutine ieee_get_halting_mode_l##HKIND;
   interface ieee_get_halting_mode
     SPECIFICS_L(IEEE_GET_HALTING_MODE_L)
   end interface ieee_get_halting_mode
-  PRIVATE_L(IEEE_GET_HALTING_MODE)
+  public :: ieee_get_halting_mode
 #undef IEEE_GET_HALTING_MODE_L
 
   interface ieee_get_modes
@@ -96,13 +89,15 @@ pure subroutine ieee_get_modes_0(modes)
       type(ieee_modes_type), intent(out) :: modes
     end subroutine ieee_get_modes_0
   end interface
+  public :: ieee_get_modes
 
   interface ieee_get_status
     pure subroutine ieee_get_status_0(status)
       import ieee_status_type
       type(ieee_status_type), intent(out) :: status
     end subroutine ieee_get_status_0
   end interface
+  public :: ieee_get_status
 
 #define IEEE_SET_FLAG_L(FVKIND) \
   elemental subroutine ieee_set_flag_l##FVKIND(flag, flag_value); \
@@ -113,7 +108,7 @@ end subroutine ieee_set_flag_l##FVKIND;
   interface ieee_set_flag
     SPECIFICS_L(IEEE_SET_FLAG_L)
   end interface ieee_set_flag
-  PRIVATE_L(IEEE_SET_FLAG)
+  public :: ieee_set_flag
 #undef IEEE_SET_FLAG_L
 
 #define IEEE_SET_HALTING_MODE_L(HKIND) \
@@ -125,7 +120,7 @@ end subroutine ieee_set_halting_mode_l##HKIND;
   interface ieee_set_halting_mode
     SPECIFICS_L(IEEE_SET_HALTING_MODE_L)
   end interface ieee_set_halting_mode
-  PRIVATE_L(IEEE_SET_HALTING_MODE)
+  public :: ieee_set_halting_mode
 #undef IEEE_SET_HALTING_MODE_L
 
   interface ieee_set_modes
@@ -134,13 +129,15 @@ subroutine ieee_set_modes_0(modes)
       type(ieee_modes_type), intent(in) :: modes
     end subroutine ieee_set_modes_0
   end interface
+  public :: ieee_set_modes
 
   interface ieee_set_status
     subroutine ieee_set_status_0(status)
       import ieee_status_type
       type(ieee_status_type), intent(in) :: status
     end subroutine ieee_set_status_0
   end interface
+  public :: ieee_set_status
 
 #define IEEE_SUPPORT_FLAG_R(XKIND) \
   pure logical function ieee_support_flag_a##XKIND(flag, x); \
@@ -155,7 +152,7 @@ pure logical function ieee_support_flag_0(flag)
     end function ieee_support_flag_0
     SPECIFICS_R(IEEE_SUPPORT_FLAG_R)
   end interface ieee_support_flag
-  PRIVATE_R(IEEE_SUPPORT_FLAG)
+  public :: ieee_support_flag
 #undef IEEE_SUPPORT_FLAG_R
 
   interface ieee_support_halting
@@ -164,5 +161,6 @@ pure logical function ieee_support_halting_0(flag)
       type(ieee_flag_type), intent(in) :: flag
     end function ieee_support_halting_0
   end interface
+  public :: ieee_support_halting
 
 end module __fortran_ieee_exceptions

flang/module/__fortran_type_info.f90

@@ -15,7 +15,10 @@
 
   use, intrinsic :: __fortran_builtins, &
     only: __builtin_c_ptr, __builtin_c_funptr
+  implicit none
 
+  ! Set PRIVATE by default to explicitly only export what is meant
+  ! to be exported by this MODULE.
   private
 
   integer, parameter :: int64 = selected_int_kind(18)

flang/module/__ppc_types.f90

@@ -7,7 +7,12 @@
 !===------------------------------------------------------------------------===!
 
 module __ppc_types
+  implicit none
+
+  ! Set PRIVATE by default to explicitly only export what is meant
+  ! to be exported by this MODULE.
   private
+
   ! Definition of derived-types that represent PowerPC vector types.
   type __builtin_ppc_intrinsic_vector(element_category, element_kind)
     integer, kind :: element_category, element_kind