[flang-commits] [flang] [flang] Diagnose BIND(C) procedures in submodules without ancestor interfaces (PR #194571)

[Sairudra More via flang-commits]

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+! RUN: %python %S/test_errors.py %s %flang_fc1
+! Check for C1807: A procedure defined in a submodule shall not have a
+! binding label unless its interface is declared in the ancestor module.
+
+module m1
+  implicit none
+end module
+
+! Submodule with BIND(C) procedures that have no interface in the ancestor
+! module - these violate C1807.
+submodule(m1) sm1
+  implicit none
+contains
+  !ERROR: A procedure defined in a submodule shall not have a binding label unless its interface is declared in the ancestor module
+  subroutine sub1() bind(c)
+  end subroutine
+  !ERROR: A procedure defined in a submodule shall not have a binding label unless its interface is declared in the ancestor module
+  subroutine sub2() bind(c, name="my_sub2")
+  end subroutine
+  !ERROR: A procedure defined in a submodule shall not have a binding label unless its interface is declared in the ancestor module
+  function func1() bind(c)
+    use, intrinsic :: iso_c_binding, only: c_int
+    integer(c_int) :: func1
+    func1 = 0
+  end function
+end submodule
+
+! Valid: interfaces declared in ancestor module.
+module m2
+  implicit none
+  interface
+    module subroutine sub3() bind(c, name="sub3")
+    end subroutine
+    module function func2() bind(c) result(res)
+      use, intrinsic :: iso_c_binding, only: c_int
+      integer(c_int) :: res
+    end function
+  end interface
+end module
+
+submodule(m2) sm2
+  implicit none
+contains
+  module subroutine sub3() bind(c, name="sub3")
+  end subroutine
+  module function func2() bind(c) result(res)
+    use, intrinsic :: iso_c_binding, only: c_int
+    integer(c_int) :: res
+    res = 0
+  end function
+end submodule
+
+! Valid: BIND(C,NAME="") gives no binding label.
+module m3
+  implicit none
+end module
+
+submodule(m3) sm3
+  implicit none
+contains
+  subroutine sub4() bind(c, name="")
+  end subroutine
+end submodule
+
+! Valid: BIND(C,NAME=" ") gives no binding label (blanks are discarded).
+module m4
+  implicit none
+end module
+
+submodule(m4) sm4
+  implicit none
+contains
+  subroutine sub5() bind(c, name=" ")
+  end subroutine
+end submodule
+
+! Invalid: interface declared in a parent submodule, not the ancestor module.
+! C1807 requires the interface be in the ancestor module.
+module m5
+  implicit none
+end module
+
+submodule(m5) sm5parent
+  implicit none
+  interface
+    module subroutine sub6() bind(c, name="sub6")
+    end subroutine
+  end interface
+end submodule
+
+submodule(m5:sm5parent) sm5child
+  implicit none
+contains
+  !ERROR: A procedure defined in a submodule shall not have a binding label unless its interface is declared in the ancestor module
+  module subroutine sub6() bind(c, name="sub6")
+  end subroutine
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Saieiei wrote:

Done!

https://github.com/llvm/llvm-project/pull/194571