Work around a GNU Fortran bug regarding unlimited polymorphic entities

.github/workflows/fortran_unit_tests.yml

@@ -37,13 +37,13 @@ jobs:
       - name: Build cam-sima
         run: |
           cmake \
-            -DCMAKE_PREFIX_PATH=/home/runner/work/CAM-SIMA/CAM-SIMA/pFUnit/build/installed \
+            -DCMAKE_PREFIX_PATH=$GITHUB_WORKSPACE/pFUnit/build/installed \
             -DCAM_SIMA_ENABLE_CODE_COVERAGE=ON \
             -B./build \
             -S./test/unit/fortran
           cd build
           make
-      
+
       - name: Run fortran unit tests
         run: |
           cd build && ctest -V --output-on-failure --output-junit test_results.xml
@@ -54,7 +54,7 @@ jobs:
           name: unit-test-results-${{ env.FC }}
           path: build/test_results.xml
 
-      - name: Setup GCov
+      - name: Setup Gcov
         run: |
           python3 -m venv venv
           source venv/bin/activate

src/core_utils/string_core_utils.F90

@@ -63,7 +63,7 @@ end function core_int_seconds_to_hhmmss
     !> If `value` contains more than one element, the elements will be stringified, delimited by `separator`, then concatenated.
     !> If `value` contains exactly one element, the element will be stringified without using `separator`.
     !> If `value` contains zero element or is of unsupported data types, an empty character string is produced.
-    !> If `separator` is not supplied, it defaults to `, ` (i.e., a comma and a space).
+    !> If `separator` is not supplied, it defaults to ", " (i.e., a comma and a space).
     !> (KCW, 2024-02-04)
     pure function core_stringify(value, separator)
         use, intrinsic :: iso_fortran_env, only: int32, int64, real32, real64
@@ -75,6 +75,7 @@ pure function core_stringify(value, separator)
         integer, parameter :: sizelimit = 1024
 
         character(:), allocatable :: buffer, delimiter, format
+        character(:), allocatable :: value_c(:)
         integer :: i, n, offset
 
         if (present(separator)) then
@@ -87,6 +88,7 @@ pure function core_stringify(value, separator)
 
         if (n == 0) then
             core_stringify = ''
+
             return
         end if
 
@@ -97,17 +99,26 @@ pure function core_stringify(value, separator)
                 buffer(:) = ''
                 offset = 0
 
+                ! Workaround for a bug in GNU Fortran >= 12. This is perhaps the manifestation of GCC Bugzilla Bug 100819.
+                ! When a character string array is passed as the actual argument to an unlimited polymorphic dummy argument,
+                ! its array index and length parameter are mishandled.
+                allocate(character(len(value)) :: value_c(size(value)))
+
+                value_c(:) = value(:)
+
                 do i = 1, n
                     if (len(delimiter) > 0 .and. i > 1) then
                         buffer(offset + 1:offset + len(delimiter)) = delimiter
                         offset = offset + len(delimiter)
                     end if
 
-                    if (len_trim(adjustl(value(i))) > 0) then
-                        buffer(offset + 1:offset + len_trim(adjustl(value(i)))) = trim(adjustl(value(i)))
-                        offset = offset + len_trim(adjustl(value(i)))
+                    if (len_trim(adjustl(value_c(i))) > 0) then
+                        buffer(offset + 1:offset + len_trim(adjustl(value_c(i)))) = trim(adjustl(value_c(i)))
+                        offset = offset + len_trim(adjustl(value_c(i)))
                     end if
                 end do
+
+                deallocate(value_c)
             type is (integer(int32))
                 allocate(character(11 * n + len(delimiter) * (n - 1)) :: buffer)
                 allocate(character(17 + len(delimiter) + floor(log10(real(n))) + 1) :: format)
@@ -151,12 +162,12 @@ pure function core_stringify(value, separator)
 
                 write(buffer, format) value
             class default
-            core_stringify = ''
+                core_stringify = ''
+
                 return
         end select
 
         core_stringify = trim(buffer)
-
     end function core_stringify
 
 end module string_core_utils

src/dynamics/mpas/driver/dyn_mpas_subdriver.F90

@@ -335,7 +335,7 @@ end subroutine dyn_mpas_debug_print
     !> If `value` contains more than one element, the elements will be stringified, delimited by `separator`, then concatenated.
     !> If `value` contains exactly one element, the element will be stringified without using `separator`.
     !> If `value` contains zero element or is of unsupported data types, an empty character string is produced.
-    !> If `separator` is not supplied, it defaults to `, ` (i.e., a comma and a space).
+    !> If `separator` is not supplied, it defaults to ", " (i.e., a comma and a space).
     !> (KCW, 2024-02-04)
     pure function stringify(value, separator)
         use, intrinsic :: iso_fortran_env, only: int32, int64, real32, real64
@@ -347,6 +347,7 @@ pure function stringify(value, separator)
         integer, parameter :: sizelimit = 1024
 
         character(:), allocatable :: buffer, delimiter, format
+        character(:), allocatable :: value_c(:)
         integer :: i, n, offset
 
         if (present(separator)) then
@@ -370,17 +371,26 @@ pure function stringify(value, separator)
                 buffer(:) = ''
                 offset = 0
 
+                ! Workaround for a bug in GNU Fortran >= 12. This is perhaps the manifestation of GCC Bugzilla Bug 100819.
+                ! When a character string array is passed as the actual argument to an unlimited polymorphic dummy argument,
+                ! its array index and length parameter are mishandled.
+                allocate(character(len(value)) :: value_c(size(value)))
+
+                value_c(:) = value(:)
+
                 do i = 1, n
                     if (len(delimiter) > 0 .and. i > 1) then
                         buffer(offset + 1:offset + len(delimiter)) = delimiter
                         offset = offset + len(delimiter)
                     end if
 
-                    if (len_trim(adjustl(value(i))) > 0) then
-                        buffer(offset + 1:offset + len_trim(adjustl(value(i)))) = trim(adjustl(value(i)))
-                        offset = offset + len_trim(adjustl(value(i)))
+                    if (len_trim(adjustl(value_c(i))) > 0) then
+                        buffer(offset + 1:offset + len_trim(adjustl(value_c(i)))) = trim(adjustl(value_c(i)))
+                        offset = offset + len_trim(adjustl(value_c(i)))
                     end if
                 end do
+
+                deallocate(value_c)
             type is (integer(int32))
                 allocate(character(11 * n + len(delimiter) * (n - 1)) :: buffer)
                 allocate(character(17 + len(delimiter) + floor(log10(real(n))) + 1) :: format)