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

[Harald Anlauf <anlauf@gmx.de>]

[-- Attachment #1: Type: text/plain, Size: 2853 bytes --]

Hi Tobias,

> > This works as expected with Intel and AOCC, but gives a
> > syntax error with every gfortran tested because of match.c:
> >
> > alloc_opt_list:
> >        m = gfc_match (" stat = %v", &tmp);
> 
> I think we can simply change that one to %e; the definable
> check should ensure that any non variable (in the Fortran sense)
> is rejected.
> 
> And we should update the comment for %v / match_variable to state
> that it does not include function references.

I've updated this for ALLOCATE/DEALLOCATE and STAT/ERRMSG, see
attached patch.  This required updating the error messages of
two existing files in the testsuite.

> Also affected: Some I/O items, a bunch of other stat=%v and
> errmsg=%v.

We should rather open a separate PR on auditing the related uses
of gfc_match.

> Talking about errmsg: In the same function, the same check is
> done for errmsg as for stat – hence, the patch should update
> also errmsg.

Done.

> >> Additionally, I have to admit that I do not understand the
> >> following existing condition, which you did not touch:
> >>
> >>         if ((stat->ts.type != BT_INTEGER
> >>              && !(stat->ref && (stat->ref->type == REF_ARRAY
> >>                                 || stat->ref->type == REF_COMPONENT)))
> >>             || stat->rank > 0)
> >>           gfc_error ("Stat-variable at %L must be a scalar INTEGER "
> >>                      "variable", &stat->where);
> >>
> >> I mean the ts.type != BT_INTEGER and stat->rank != 0 is clear,
> >> but what's the reason for the refs?
> > Well, that needs to be answered by Steve (see commit 3759634).
> 
> (https://gcc.gnu.org/g:3759634f3208cbc1226bec19d22cbff989a287c3 (svn
> r145331))
> 
> The reason for the ref checks is unclear and seem to be wrong. The added
> testcases also only use 'x' (real) and n or i (integer) as input, i.e.
> they do not exercise this. I did not look for the patch email for reasoning.

Well, there is some text in the standard that I added in front of
the for loops, and this code is now exercised in the new testcase.

Regtested on x86_64-pc-linux-gnu.  OK?

Thanks,
Harald

Fortran: ICE in resolve_allocate_deallocate for invalid STAT argument

gcc/fortran/ChangeLog:

	PR fortran/101564
	* 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.

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: Adjust error messages.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: pr101564-v2.patch --]
[-- Type: text/x-patch, Size: 7443 bytes --]

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..809a4ad86d1 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -8165,6 +8165,12 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	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 +8198,8 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	  }
     }

+done_stat:
+
   /* Check the errmsg variable.  */
   if (errmsg)
     {
@@ -8215,6 +8223,12 @@ resolve_allocate_deallocate (gfc_code *code, const char *fcn)
 	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 +8256,8 @@ 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..c5ba6b892da
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/allocate_stat_3.f90
@@ -0,0 +1,50 @@
+! { dg-do compile }
+! PR fortran/101564 - ICE in resolve_allocate_deallocate
+
+program p
+  integer, allocatable :: x(:)
+  integer              :: stat
+  integer, pointer     :: A
+  integer, target      :: ptr
+  real,    target      :: r
+  character(4)         :: c
+  type t
+     integer :: stat
+     real    :: r
+  end type t
+  type(t), allocatable :: y
+  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)
+  deallocate (A, stat=y%r)
+  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 (y, stat=y%stat) ! { dg-error "within the same ALLOCATE statement" }
+  allocate (y, stat=y%r)    ! { dg-error "within the same ALLOCATE statement" }
+  allocate (y, stat=r)      ! { 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=f(), errmsg="") ! { dg-error "ERRMSG variable" }
+  deallocate (A, stat=f(), errmsg="") ! { dg-error "ERRMSG variable" }
+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