Check for equality between Fortran and C logicals

CMakeLists.txt

@@ -59,6 +59,7 @@ endif()
 
 list(
   APPEND fyppFlags
+  "-DWITH_CBOOL=$<BOOL:${WITH_CBOOL}>"
   "-DWITH_QP=$<BOOL:${WITH_QP}>"
   "-DWITH_XDP=$<BOOL:${WITH_XDP}>"
   "-DPROJECT_VERSION_MAJOR=${PROJECT_VERSION_MAJOR}"

config/CMakeLists.txt

@@ -16,6 +16,13 @@ set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH}" PARENT_SCOPE)
 # Check for available features
 # Note: users can overwrite the automatic check by setting the value at configure time
 include(CheckFortranSourceRuns)
+if (NOT DEFINED WITH_CBOOL)
+  check_fortran_source_runs(
+    "use, intrinsic :: iso_c_binding, only: c_bool; integer, parameter :: lk = kind(.true.); if (c_bool == lk) stop 1; end"
+    WITH_CBOOL
+  )
+  set(WITH_CBOOL ${WITH_CBOOL} PARENT_SCOPE)
+endif()
 if (NOT DEFINED WITH_QP)
   check_fortran_source_runs(
     "if (selected_real_kind(33) == -1) stop 1; end"

config/template.cmake

@@ -1,5 +1,6 @@
 @PACKAGE_INIT@
 
+set("@PROJECT_NAME@_WITH_CBOOL" @WITH_CBOOL@)
 set("@PROJECT_NAME@_WITH_QP" @WITH_QP@)
 set("@PROJECT_NAME@_WITH_XDP" @WITH_XDP@)
 

src/common.fypp

@@ -3,6 +3,11 @@
 #! Project version number
 #:set PROJECT_VERSION = "{}.{}.{}".format(PROJECT_VERSION_MAJOR, PROJECT_VERSION_MINOR, PROJECT_VERSION_PATCH)
 
+#! Support for C_BOOL logical
+#:if not defined("WITH_CBOOL")
+#:set WITH_CBOOL = False
+#:endif
+
 #! Support for quadruple precision floating point numbers
 #:if not defined("WITH_QP")
 #:set WITH_QP = False
@@ -53,7 +58,10 @@
 #:set INT_KINDS_TYPES = list(zip(INT_KINDS, INT_TYPES))
 
 #! Logical kinds to be considered during templating
-#:set LOG_KINDS = ["lk", "c_bool"]
+#:set LOG_KINDS = ["lk"]
+#:if WITH_CBOOL
+#:set LOG_KINDS = LOG_KINDS + ["c_bool"]
+#:endif
 
 #! Logical types to be considered during templating
 #:set LOG_TYPES = ["logical({})".format(k) for k in LOG_KINDS]

test/ascii/test_ascii.f90

@@ -6,7 +6,7 @@ module test_ascii
         is_digit, is_octal_digit, is_hex_digit, is_white, is_blank, &
         is_control, is_punctuation, is_graphical, is_printable, is_ascii, &
         to_lower, to_upper, to_title, to_sentence, reverse, LF, TAB, NUL, DEL
-    use stdlib_kinds, only : int8, int16, int32, int64, lk, c_bool
+    use stdlib_kinds, only : int8, int16, int32, int64, lk
     implicit none
     private
 

test/string/CMakeLists.txt

@@ -1,3 +1,12 @@
+#### Pre-process: .fpp -> .f90 via Fypp
+
+# Create a list of the files to be preprocessed
+set(fppFiles
+    test_string_assignment.fypp
+)
+
+fypp_f90("${fyppFlags}" "${fppFiles}" outFiles)
+
 ADDTEST(string_assignment)
 ADDTEST(string_operator)
 ADDTEST(string_intrinsic)

test/string/test_string_assignment.f90 → test/string/test_string_assignment.fypp

@@ -79,9 +79,11 @@ subroutine test_constructor(error)
         call check(error, string_type(.false.) == trim(flc))
         if (allocated(error)) return
 
+#:if WITH_CBOOL
         write(flc, '(g0)') .false._c_bool
         call check(error, string_type(.false._c_bool) == trim(flc))
         if (allocated(error)) return
+#:endif
 
         write(flc, '(g0)') .true._lk
         call check(error, string_type(.true._lk) == trim(flc))