[PATCH] PR fortran/77960 -- inpute-item can't be function

[PATCH] PR fortran/77960 -- inpute-item can't be function

[Steve Kargl]

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The attached patch has been tested on x86_64-*-freebsd.
PR fortran/77960 uses a procedure pointer to expose the
bug, but it applied to any external subprogram.  So, the
patch checks for the external attribute.  OK to commit?

2019-01-19  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77960
	* io.c (match_io_element): input-item cannot be an external function.
 
2019-01-19  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77960
	* gfortran.dg/pr77960.f90: New test.

-- 
Steve

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Index: gcc/fortran/io.c
===================================================================
--- gcc/fortran/io.c	(revision 268095)
+++ gcc/fortran/io.c	(working copy)
@@ -3610,6 +3610,16 @@ match_io_element (io_kind k, gfc_code **cpp)
       m = gfc_match_variable (&expr, 0);
       if (m == MATCH_NO)
 	gfc_error ("Expected variable in READ statement at %C");
+
+      if (m == MATCH_YES
+	  && expr->expr_type == EXPR_VARIABLE
+	  && expr->symtree->n.sym->attr.external)
+	{
+	  gfc_error ("Expecting variable or io-implied-do at %L",
+		     &expr->where);
+	  m = MATCH_ERROR;
+	}
+
     }
   else
     {
Index: gcc/testsuite/gfortran.dg/pr77960.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr77960.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr77960.f90	(working copy)
@@ -0,0 +1,16 @@
+! { dg-do compile }
+! PR fortran/77960
+   procedure(g), pointer :: f
+   f => g
+   read(99) f                 ! { dg-error "Expecting variable" }
+contains
+   function g() result(z)
+      integer :: z(2)
+      z = 1
+   end
+end
+
+subroutine bar(x)
+   integer, external :: x
+   read(*,*) x                ! { dg-error "Expecting variable" }
+end subroutine

Re: [PATCH] PR fortran/77960 -- inpute-item can't be function

[Thomas Koenig]

Hi Steve,

> The attached patch has been tested on x86_64-*-freebsd.
> PR fortran/77960 uses a procedure pointer to expose the
> bug, but it applied to any external subprogram.  So, the
> patch checks for the external attribute.  OK to commit?

OK, and thanks.

Regards

	Thomas