Re: [PATCH] PR fortrsn/101564 - ICE in resolve_allocate_deallocate, at fortran/resolve.c:8169

[Harald Anlauf <anlauf@gmx.de>]

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Hi Tobias,

> > We should rather open a separate PR on auditing the related uses
> > of gfc_match.
> 
> I concur – I just wanted to quickly check how many %v are there –
> besides %v, there are also direct calls to gfc_match_variable.
> 
> Can you open a PR?

this is now https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101652

> The loops are clear – but the
>   '!stat->ref || (...ref->type != ARRAY || ref->type != COMPONENT))'
> is still not clear to me.

Ah, I was really missing the point and looking in the wrong place.
Actually, I also do not understand the reason for this version of
the check, and it also leads to a strange accepts-invalid for
certain non-integer STAT variables.  Removing the stat->ref part
fixes that without introducing any regression in the testsuite.
(There was an analogous part in the check for ERRMSG.)

> Can you add the (working) test:
>    allocate (A, stat=y%stat%kind)  ! { dg-error "cannot be a constant" }
>    deallocate (A, stat=y%stat%kind)  ! { dg-error "cannot be a constant" }
> to your testcase gcc/testsuite/gfortran.dg/allocate_stat_3.f90 ?

Done.

> And also the following one, which does not get diagnosed and, hence,
> later gives an ICE during gimplification.
> 
>    type tc
>      character (len=:), allocatable :: str
>    end type tc
> ...
>    type(tc) :: z
> ...
>    allocate(character(len=13) :: z%str)
>    allocate (A, stat=z%str%len)
>    deallocate (A, stat=z%str%len)
> 
> To fix it, I think the solution is to do the following:
> * In gfc_check_vardef_context, handle also REF_INQUIRY; in the
>      for (ref = e->ref; ref && check_intentin; ref = ref->next)
>    loop, I think there should be a
>      if (ref->type == REF_INQUIRY)
>        {
>          if (context)
>           gfc_error ("Type parameter inquiry for %qs in "
>                      "variable definition context (%s) at %L",
>                      name, context, &e->where);
>          return false;
>        }
> (untested)

This almost worked, needing only a restriction to %KIND and %LEN.
Note that %RE and %IM are usually definable.

> I assume (but have not tested it) that will give
> two error messages for:
>    allocate (A, errmsg=z%str%len)
>    deallocate (A, errmsg=z%str%len)
> one for the new type-param-inquiry check and one for
>    != BT_CHARACTER
> if you want to prevent the double error, consider to
> replace
>     gfc_check_vardef_context (...);
> by
>     if (!gfc_check_vardef_context (...))
>       goto done_errmsg;

Yes, that is reasonable.  Done.

> > Regtested on x86_64-pc-linux-gnu.  OK?
> LGTM - except for the two testcase additions proposed above
> and fixing the ICE. If you are happy with my changes and they
> work, feel free add them and commit without further review.
> In either case, I have the feeling we are nearly there. :-)

I have added the updated "final" version of the patch to give
everybody another 24h to have a look, and will commit if nobody
complains.

> Thanks for the patch and the review-modification-review-... patience!

Well, I believe this was really a worthwile review process,
with fixing a few issues on the way before Gerhard finds them...

Thanks,
Harald


Fortran: ICE in resolve_allocate_deallocate for invalid STAT argument

gcc/fortran/ChangeLog:

	PR fortran/101564
	* expr.c (gfc_check_vardef_context): Add check for KIND and LEN
	parameter inquiries.
	* match.c (gfc_match): Fix comment for %v code.
	(gfc_match_allocate, gfc_match_deallocate): Replace use of %v code
	by %e in gfc_match to allow for function references as STAT and
	ERRMSG arguments.
	* resolve.c (resolve_allocate_deallocate): Avoid NULL pointer
	dereferences and shortcut for bad STAT and ERRMSG argument to
	(DE)ALLOCATE.  Remove bogus parts of checks for STAT and ERRMSG.

gcc/testsuite/ChangeLog:

	PR fortran/101564
	* gfortran.dg/allocate_stat_3.f90: New test.
	* gfortran.dg/allocate_stat.f90: Adjust error messages.
	* gfortran.dg/implicit_11.f90: Likewise.
	* gfortran.dg/inquiry_type_ref_3.f90: Likewise.


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diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index b11ae7ce5c5..35563a78697 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -6199,6 +6199,16 @@ gfc_check_vardef_context (gfc_expr* e, bool pointer, bool alloc_obj,
 	  if (!pointer)
 	    check_intentin = false;
 	}
+      if (ref->type == REF_INQUIRY
+	  && (ref->u.i == INQUIRY_KIND || ref->u.i == INQUIRY_LEN))
+	{
+	  if (context)
+	    gfc_error ("%qs parameter inquiry for %qs in "
+		       "variable definition context (%s) at %L",
+		       ref->u.i == INQUIRY_KIND ? "KIND" : "LEN",
+		       sym->name, context, &e->where);
+	  return false;
+	}
     }

   if (check_intentin
diff --git a/gcc/fortran/match.c b/gcc/fortran/match.c
index d148de3e3b5..b1105481099 100644
--- a/gcc/fortran/match.c
+++ b/gcc/fortran/match.c
@@ -1109,7 +1109,8 @@ gfc_match_char (char c)
    %t  Matches end of statement.
    %o  Matches an intrinsic operator, returned as an INTRINSIC enum.
    %l  Matches a statement label
-   %v  Matches a variable expression (an lvalue)
+   %v  Matches a variable expression (an lvalue, except function references
+   having a data pointer result)
    %   Matches a required space (in free form) and optional spaces.  */

 match
@@ -4405,7 +4406,7 @@ gfc_match_allocate (void)

 alloc_opt_list:

-      m = gfc_match (" stat = %v", &tmp);
+      m = gfc_match (" stat = %e", &tmp);
       if (m == MATCH_ERROR)
 	goto cleanup;
       if (m == MATCH_YES)
@@ -4434,7 +4435,7 @@ alloc_opt_list:
 	    goto alloc_opt_list;
 	}

-      m = gfc_match (" errmsg = %v", &tmp);
+      m = gfc_match (" errmsg = %e", &tmp);
       if (m == MATCH_ERROR)
 	goto cleanup;
       if (m == MATCH_YES)
@@ -4777,7 +4778,7 @@ gfc_match_deallocate (void)

 dealloc_opt_list:

-      m = gfc_match (" stat = %v", &tmp);
+      m = gfc_match (" stat = %e", &tmp);
       if (m == MATCH_ERROR)
 	goto cleanup;
       if (m == MATCH_YES)
@@ -4799,7 +4800,7 @@ dealloc_opt_list:
 	    goto dealloc_opt_list;
 	}

-      m = gfc_match (" errmsg = %v", &tmp);
+      m = gfc_match (" errmsg = %e", &tmp);
       if (m == MATCH_ERROR)
 	goto cleanup;
       if (m == MATCH_YES)
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 45c3ad387ac..592364689f9 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -8155,16 +8155,21 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
   /* Check the stat variable.  */
   if (stat)
     {
-      gfc_check_vardef_context (stat, false, false, false,
-				_("STAT variable"));
+      if (!gfc_check_vardef_context (stat, false, false, false,
+				     _("STAT variable")))
+	  goto done_stat;

-      if ((stat->ts.type != BT_INTEGER
-	   && !(stat->ref && (stat->ref->type == REF_ARRAY
-			      || stat->ref->type == REF_COMPONENT)))
+      if (stat->ts.type != BT_INTEGER
 	  || stat->rank > 0)
 	gfc_error ("Stat-variable at %L must be a scalar INTEGER "
 		   "variable", &stat->where);

+      if (stat->expr_type == EXPR_CONSTANT || stat->symtree == NULL)
+	goto done_stat;
+
+      /* F2018:9.7.4: The stat-variable shall not be allocated or deallocated
+       * within the ALLOCATE or DEALLOCATE statement in which it appears ...
+       */
       for (p = code->ext.alloc.list; p; p = p->next)
 	if (p->expr->symtree->n.sym->name == stat->symtree->n.sym->name)
 	  {
@@ -8192,6 +8197,8 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	  }
     }

+done_stat:
+
   /* Check the errmsg variable.  */
   if (errmsg)
     {
@@ -8199,22 +8206,26 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	gfc_warning (0, "ERRMSG at %L is useless without a STAT tag",
 		     &errmsg->where);

-      gfc_check_vardef_context (errmsg, false, false, false,
-				_("ERRMSG variable"));
+      if (!gfc_check_vardef_context (errmsg, false, false, false,
+				     _("ERRMSG variable")))
+	  goto done_errmsg;

       /* F18:R928  alloc-opt             is ERRMSG = errmsg-variable
 	 F18:R930  errmsg-variable       is scalar-default-char-variable
 	 F18:R906  default-char-variable is variable
 	 F18:C906  default-char-variable shall be default character.  */
-      if ((errmsg->ts.type != BT_CHARACTER
-	   && !(errmsg->ref
-		&& (errmsg->ref->type == REF_ARRAY
-		    || errmsg->ref->type == REF_COMPONENT)))
+      if (errmsg->ts.type != BT_CHARACTER
 	  || errmsg->rank > 0
 	  || errmsg->ts.kind != gfc_default_character_kind)
 	gfc_error ("ERRMSG variable at %L shall be a scalar default CHARACTER "
 		   "variable", &errmsg->where);

+      if (errmsg->expr_type == EXPR_CONSTANT || errmsg->symtree == NULL)
+	goto done_errmsg;
+
+      /* F2018:9.7.5: The errmsg-variable shall not be allocated or deallocated
+       * within the ALLOCATE or DEALLOCATE statement in which it appears ...
+       */
       for (p = code->ext.alloc.list; p; p = p->next)
 	if (p->expr->symtree->n.sym->name == errmsg->symtree->n.sym->name)
 	  {
@@ -8242,6 +8253,8 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	  }
     }

+done_errmsg:
+
   /* Check that an allocate-object appears only once in the statement.  */

   for (p = code->ext.alloc.list; p; p = p->next)
diff --git a/gcc/testsuite/gfortran.dg/allocate_stat.f90 b/gcc/testsuite/gfortran.dg/allocate_stat.f90
index 7f9eaf58d6d..f8a12913c91 100644
--- a/gcc/testsuite/gfortran.dg/allocate_stat.f90
+++ b/gcc/testsuite/gfortran.dg/allocate_stat.f90
@@ -38,7 +38,7 @@ function func2() result(res)
   implicit none
   real, pointer :: gain
   integer :: res
-  allocate (gain,STAT=func2) ! { dg-error "is not a variable" }
+  allocate (gain,STAT=func2) ! { dg-error "requires an argument list" }
   deallocate(gain)
   res = 0
 end function func2
@@ -51,7 +51,7 @@ subroutine sub()
   end interface
   real, pointer :: gain
   integer, parameter :: res = 2
-  allocate (gain,STAT=func2) ! { dg-error "is not a variable" }
+  allocate (gain,STAT=func2) ! { dg-error "requires an argument list" }
   deallocate(gain)
 end subroutine sub

@@ -68,9 +68,9 @@ contains
  end function one
  subroutine sub()
    integer, pointer :: p
-   allocate(p, stat=one) ! { dg-error "is not a variable" }
+   allocate(p, stat=one) ! { dg-error "requires an argument list" }
    if(associated(p)) deallocate(p)
-   allocate(p, stat=two) ! { dg-error "is not a variable" }
+   allocate(p, stat=two) ! { dg-error "requires an argument list" }
    if(associated(p)) deallocate(p)
  end subroutine sub
 end module test
diff --git a/gcc/testsuite/gfortran.dg/allocate_stat_3.f90 b/gcc/testsuite/gfortran.dg/allocate_stat_3.f90
new file mode 100644
index 00000000000..1fa38925d6f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/allocate_stat_3.f90
@@ -0,0 +1,67 @@
+! { dg-do compile }
+! PR fortran/101564 - ICE in resolve_allocate_deallocate
+
+program p
+  implicit none
+  integer, allocatable :: x(:)
+  integer              :: stat
+  integer, pointer     :: A
+  integer, target      :: ptr
+  real,    target      :: r
+  character(4)         :: c
+  type t
+     integer :: stat
+     real    :: r
+     complex :: z
+  end type t
+  type(t), allocatable :: y
+  type tc
+     character(len=:), allocatable :: s
+  end type tc
+  type(tc) :: z
+  allocate (character(42) :: z%s, stat=stat)
+  allocate (A,   stat=stat, errmsg=z%s)
+  deallocate (A, stat=stat, errmsg=z%s)
+  allocate (x(2), stat=stat)
+  deallocate (x,  stat=stat)
+  allocate (A, stat=f())
+  deallocate (A, stat=f())
+  allocate (A, stat=y%stat)
+  deallocate (A, stat=y%stat)
+  allocate (A,    stat=y%r)  ! { dg-error "must be a scalar INTEGER variable" }
+  deallocate (A,  stat=y%r)  ! { dg-error "must be a scalar INTEGER variable" }
+  allocate (x(2), stat=stat%kind) ! { dg-error "STAT tag" }
+  deallocate (x,  stat=stat%kind) ! { dg-error "STAT variable" }
+  allocate (A,    stat=A%kind)    ! { dg-error "STAT tag" }
+  deallocate (A,  stat=A%kind)    ! { dg-error "STAT variable" }
+  allocate (A,    stat=c%len)     ! { dg-error "STAT tag" }
+  deallocate (A,  stat=c%len)     ! { dg-error "STAT variable" }
+  allocate (A,    stat=y%stat%kind) ! { dg-error "STAT tag" }
+  deallocate (A,  stat=y%stat%kind) ! { dg-error "STAT variable" }
+  allocate (y, stat=y%stat) ! { dg-error "within the same ALLOCATE statement" }
+  allocate (y, stat=r)      ! { dg-error "must be a scalar INTEGER variable" }
+  allocate (A, stat=y%z%re)   ! { dg-error "must be a scalar INTEGER variable" }
+  deallocate (A, stat=y%z%im) ! { dg-error "must be a scalar INTEGER variable" }
+  allocate (y, stat=g())    ! { dg-error "must be a scalar INTEGER variable" }
+  deallocate (y, stat=g())  ! { dg-error "must be a scalar INTEGER variable" }
+  allocate (A, stat=f)      ! { dg-error "requires an argument list" }
+  deallocate (A, stat=f)    ! { dg-error "requires an argument list" }
+  allocate (y, stat=g)      ! { dg-error "requires an argument list" }
+  deallocate (y, stat=g)    ! { dg-error "requires an argument list" }
+  allocate (A, stat=z%s%len)   ! { dg-error "parameter inquiry" }
+  deallocate (A, stat=z%s%len) ! { dg-error "parameter inquiry" }
+  allocate (A,   stat=f(), errmsg="") ! { dg-error "ERRMSG variable" }
+  deallocate (A, stat=f(), errmsg="") ! { dg-error "ERRMSG variable" }
+  allocate (A,   stat=stat, errmsg=z%s%len) ! { dg-error "ERRMSG variable" }
+  deallocate (A, stat=stat, errmsg=z%s%len) ! { dg-error "ERRMSG variable" }
+  deallocate (z%s, stat=stat, errmsg=z%s)   ! { dg-error "within the same DEALLOCATE statement" }
+contains
+  integer function f()
+    pointer :: f
+    f => ptr
+  end function f
+  real function g()
+    pointer :: g
+    g => r
+  end function g
+end
diff --git a/gcc/testsuite/gfortran.dg/implicit_11.f90 b/gcc/testsuite/gfortran.dg/implicit_11.f90
index 61091ec41a0..8f93704ac4c 100644
--- a/gcc/testsuite/gfortran.dg/implicit_11.f90
+++ b/gcc/testsuite/gfortran.dg/implicit_11.f90
@@ -31,6 +31,6 @@
      SUBROUTINE AD0001
        REAL RLA1(:)
        ALLOCATABLE RLA1
-       ALLOCATE (RLA1(NF10), STAT = ISTAT2) ! { dg-error "is not a variable" }
+       ALLOCATE (RLA1(NF10), STAT = ISTAT2) ! { dg-error "requires an argument list" }
      END SUBROUTINE
      END MODULE tests2
diff --git a/gcc/testsuite/gfortran.dg/inquiry_type_ref_3.f90 b/gcc/testsuite/gfortran.dg/inquiry_type_ref_3.f90
index 4e8d8a07b4e..7c1bf43785c 100644
--- a/gcc/testsuite/gfortran.dg/inquiry_type_ref_3.f90
+++ b/gcc/testsuite/gfortran.dg/inquiry_type_ref_3.f90
@@ -17,7 +17,7 @@ program main
    type(t) :: s
    b = "abcdefg"
    a%kind = 2        ! { dg-error "Assignment to a constant expression" }
-   b%len = 2         ! { dg-error "Assignment to a LEN or KIND part_ref" }
+   b%len = 2         ! { dg-error "parameter inquiry" }
    i = a%kind        ! OK
    i = b%len         ! OK
    print *, z%re     ! { dg-error "must be applied to a COMPLEX expression" }