re PR fortran/45776 (Full implementation of variable definition contexts (and related checks))

2010-09-25  Daniel Kraft  <d@domob.eu>

	PR fortran/45776
	* gfortran.h (struct gfc_dt): New member `dt_io_kind'.
	* io.c (resolve_tag): F2008 check for NEWUNIT and variable
	definition checks for NEWUNIT, IOSTAT, SIZE and IOMSG.
	(gfc_free_dt): Correctly handle freeing of `dt_io_kind' and
	`extra_comma' with changed semantics.
	(gfc_resolve_dt): Check variable definitions.
	(match_io_element): Remove INTENT and PURE checks here and
	initialize code->ext.dt member.
	(match_io): Set dt->dt_io_kind.
	(gfc_resolve_inquire): Check variable definition for all tags
	except UNIT, FILE and ID.
	* resolve.c (resolve_transfer): Variable definition check.

2010-09-25  Daniel Kraft  <d@domob.eu>

	PR fortran/45776
	* gfortran.dg/io_constraints_6.f03: New test.
	* gfortran.dg/io_constraints_7.f03: New test.
	* gfortran.dg/newunit_2.f90: New test.

From-SVN: r164619

gcc/fortran/ChangeLog

+2010-09-25  Daniel Kraft  <d@domob.eu>
+
+	PR fortran/45776
+	* gfortran.h (struct gfc_dt): New member `dt_io_kind'.
+	* io.c (resolve_tag): F2008 check for NEWUNIT and variable
+	definition checks for NEWUNIT, IOSTAT, SIZE and IOMSG.
+	(gfc_free_dt): Correctly handle freeing of `dt_io_kind' and
+	`extra_comma' with changed semantics.
+	(gfc_resolve_dt): Check variable definitions.
+	(match_io_element): Remove INTENT and PURE checks here and
+	initialize code->ext.dt member.
+	(match_io): Set dt->dt_io_kind.
+	(gfc_resolve_inquire): Check variable definition for all tags
+	except UNIT, FILE and ID.
+	* resolve.c (resolve_transfer): Variable definition check.
+
 2010-09-25  Tobias Burnus  <burnus@net-b.de>
 
 	* interface.c (gfc_match_end_interface): Constify char pointer

gcc/fortran/gfortran.h

@@ -2000,7 +2000,7 @@ typedef struct
 {
   gfc_expr *io_unit, *format_expr, *rec, *advance, *iostat, *size, *iomsg,
 	   *id, *pos, *asynchronous, *blank, *decimal, *delim, *pad, *round,
-	   *sign, *extra_comma;
+	   *sign, *extra_comma, *dt_io_kind;
 
   gfc_symbol *namelist;
   /* A format_label of `format_asterisk' indicates the "*" format */

gcc/fortran/resolve.c

@@ -7916,6 +7916,13 @@ resolve_transfer (gfc_code *code)
 		      && exp->expr_type != EXPR_FUNCTION))
     return;
 
+  /* If we are reading, the variable will be changed.  Note that
+     code->ext.dt may be NULL if the TRANSFER is related to
+     an INQUIRE statement -- but in this case, we are not reading, either.  */
+  if (code->ext.dt && code->ext.dt->dt_io_kind->value.iokind == M_READ
+      && gfc_check_vardef_context (exp, false, _("item in READ")) == FAILURE)
+    return;
+
   sym = exp->symtree->n.sym;
   ts = &sym->ts;
 

gcc/testsuite/ChangeLog

+2010-09-25  Daniel Kraft  <d@domob.eu>
+
+	PR fortran/45776
+	* gfortran.dg/io_constraints_6.f03: New test.
+	* gfortran.dg/io_constraints_7.f03: New test.
+	* gfortran.dg/newunit_2.f90: New test.
+
 2010-09-24  Steven G. Kargl  < kargl@gcc.gnu.org>
 
 	* testsuite/gfortran.dg/operator_c1202.f90: New test.

gcc/testsuite/gfortran.dg/io_constraints_6.f03

+! { dg-do compile }
+
+! PR fortran/45776
+! Variable definition context checks related to IO.
+
+! Contributed by Daniel Kraft, d@domob.eu.
+
+module m
+  implicit none
+
+  integer, protected :: a
+  character(len=128), protected :: str
+end module m
+
+program main
+  use :: m
+  integer, parameter :: b = 42
+  integer :: x
+  character(len=128) :: myStr
+
+  namelist /definable/ x, myStr
+  namelist /undefinable/ x, a
+
+  ! These are invalid.
+  read (myStr, *) a ! { dg-error "variable definition context" }
+  read (myStr, *) x, b ! { dg-error "variable definition context" }
+  write (str, *) 5 ! { dg-error "variable definition context" }
+  read (*, nml=undefinable) ! { dg-error "contains the symbol 'a' which may not" }
+
+  ! These are ok.
+  read (str, *) x
+  write (myStr, *) a
+  write (myStr, *) b
+  print *, a, b
+  write (*, nml=undefinable)
+  read (*, nml=definable)
+  write (*, nml=definable)
+end program main
+
+! { dg-final { cleanup-modules "m" } }

gcc/testsuite/gfortran.dg/io_constraints_7.f03

+! { dg-do compile }
+
+! PR fortran/45776
+! Variable definition context checks related to IO.
+
+! Contributed by Daniel Kraft, d@domob.eu.
+
+module m
+  implicit none
+  integer, protected :: a
+  character(len=128), protected :: msg
+end module m
+
+program main
+  use :: m
+  integer :: x
+  logical :: bool
+
+  write (*, iostat=a) 42 ! { dg-error "variable definition context" }
+  write (*, iomsg=msg) 42 ! { dg-error "variable definition context" }
+  read (*, '(I2)', advance='no', size=a) x ! { dg-error "variable definition context" }
+
+  ! These are ok.
+  inquire (unit=a)
+  inquire (file=msg, id=a, pending=bool)
+  inquire (file=msg)
+
+  ! These not, but list is not extensive.
+  inquire (unit=1, number=a) ! { dg-error "variable definition context" }
+  inquire (unit=1, encoding=msg) ! { dg-error "variable definition context" }
+  inquire (unit=1, formatted=msg) ! { dg-error "variable definition context" }
+
+  open (newunit=a, file="foo") ! { dg-error "variable definition context" }
+  close (unit=a)
+end program main
+
+! { dg-final { cleanup-modules "m" } }

gcc/testsuite/gfortran.dg/newunit_2.f90

+! { dg-do compile }
+! { dg-options "-std=f95" }
+
+! PR40008 F2008: Add NEWUNIT= for OPEN statement 
+! Check for rejection with pre-F2008 standard.
+
+! Contributed by Daniel Kraft, d@domob.eu.
+
+program main
+  character(len=25) :: str
+  integer(1) :: myunit
+
+  open (newunit=myunit, file="some_file") ! { dg-error "Fortran 2008" }
+  close (unit=myunit)
+end program main