Possible patch for fortran/57910

[Louis Krupp]

PR fortran/57910
* trans-expr.c (gfc_add_interface_mapping): Don't try to
dereference call-by-value scalar argument.

The patch seems to work without breaking other tests.

Louis Krupp 
 
-------------- next part --------------
Index: gcc/fortran/trans-array.c
===================================================================
--- gcc/fortran/trans-array.c	(revision 240723)
+++ gcc/fortran/trans-array.c	(working copy)
@@ -6963,6 +6963,7 @@ gfc_conv_expr_descriptor (gfc_se *se, gfc_expr *ex
       /* TODO: Optimize passing function return values.  */
       gfc_se lse;
       gfc_se rse;
+      bool deep_copy;
 
       /* Start the copying loops.  */
       gfc_mark_ss_chain_used (loop.temp_ss, 1);
@@ -6993,9 +6994,12 @@ gfc_conv_expr_descriptor (gfc_se *se, gfc_expr *ex
       gfc_add_block_to_block (&block, &lse.pre);
 
       lse.string_length = rse.string_length;
+
+      deep_copy = !se->data_not_needed
+		  && (expr->expr_type == EXPR_VARIABLE
+		      || expr->expr_type == EXPR_ARRAY);
       tmp = gfc_trans_scalar_assign (&lse, &rse, expr->ts,
-				     expr->expr_type == EXPR_VARIABLE
-				     || expr->expr_type == EXPR_ARRAY, false);
+				     deep_copy, false);
       gfc_add_expr_to_block (&block, tmp);
 
       /* Finish the copying loops.  */
Index: gcc/fortran/ChangeLog
===================================================================
--- gcc/fortran/ChangeLog	(revision 240723)
+++ gcc/fortran/ChangeLog	(working copy)
@@ -1,3 +1,9 @@
+2016-10-02  Louis Krupp  <louis.krupp@zoho.com>
+
+	PR fortran/69955
+	* trans-array.c (gfc_conv_expr_descriptor): Don't allocate
+	components if it's not necessary.
+
 2016-09-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR fortran/66643
Index: gcc/testsuite/ChangeLog
===================================================================
--- gcc/testsuite/ChangeLog	(revision 240723)
+++ gcc/testsuite/ChangeLog	(working copy)
@@ -1,3 +1,7 @@
+2016-10-02  Louis Krupp <louis.krupp@zoho.com>
+
+	* gfortran.dg/pr69955.f90: New test.
+
 2016-10-03  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
 
 	* gcc.target/avr/torture/builtins-error.c: Add -ffat-lto-objects
Index: gcc/testsuite/gfortran.dg/pr69955.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr69955.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr69955.f90	(working copy)
@@ -0,0 +1,78 @@
+! { dg-do run { target x86_64-*-linux* } }
+!
+! On Linux, this test reads /proc/<PID>/statm to retrieve the current
+! virtual memory size.  Other platforms might have something similar.
+
+program p
+  implicit none
+
+  type :: t1
+    integer, allocatable :: t(:)
+  end type t1
+
+  type :: t2
+    type(t1), allocatable :: x1(:)
+  end type t2
+
+  type(t2) :: var(10)
+
+  integer :: i
+  integer :: vm_after_short_run, vm_after_long_run
+
+  do i= 1, 10
+    allocate(var(i)%x1(100))
+    allocate(var(i)%x1(1)%t(100))
+  enddo
+
+  open(unit = 37, file = "/dev/null", status = "old")
+
+  call s(100)
+
+  vm_after_short_run = vm_usage()
+
+  call s(100000)
+
+  vm_after_long_run = vm_usage()
+
+  ! Has VM usage gone up significantly?  A test without the patch
+  ! showed an increase of a factor of 4.
+  if (vm_after_long_run > vm_after_short_run * 1.1) then
+    print '("vm after short run: ", i0, ", after long run: ", i0)', &
+            vm_after_short_run, vm_after_long_run
+    call abort
+  endif
+
+  close(unit = 37)
+
+  do i=1,10
+    deallocate(var(i)%x1)
+  enddo
+
+contains
+
+  subroutine s(counter)
+    implicit none
+    integer, intent(in) :: counter
+    integer :: i, j, n
+
+    do j=1, counter
+      n = size( [ ( var(i)%x1 , i = 1, size(var) ) ] )
+      write(unit = 37, fmt = '(i5)') n
+    enddo
+  end subroutine
+
+  function vm_usage()
+    implicit none
+    integer vm_usage
+    character(len=20) :: statm_name
+    integer, dimension(7) :: statm_info
+
+    write(statm_name, '("/proc/", i0, "/statm")') getpid()
+    open(unit = 21, file = statm_name, status = 'old')
+    read(21, *) statm_info(:)
+    close(unit = 21)
+
+    vm_usage = statm_info(1) ! VmSize
+  end function
+
+end program p