[Bug fortran/47767] New: SELECT TYPE fails to execute correct TYPE IS block

[Bug fortran/47767] New: SELECT TYPE fails to execute correct TYPE IS block

[abenson at caltech dot edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

           Summary: SELECT TYPE fails to execute correct TYPE IS block
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: abenson@caltech.edu


Created attachment 23363
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23363
Test case to reproduce the bug.

The attached code should execute the contents of the TYPE IS block and print
"correct", but fails to do so, falling through to the CLASS DEFAULT block and
printing "incorrect".

There are a number of ways to avoid the bug and get the output 'correct':

* removing the 'private' statement
* removing the 'public' statement
* removing the 'baseNode' component
* removing the unneeded module 'merger_tree_build'

Compiled using r170207 of gfortran 4.6.0

$ gfortran selectTypeFail.F90  -o selectTypeFail.exe -g -fbacktrace -v
Driving: gfortran selectTypeFail.F90 -o selectTypeFail.exe -g -fbacktrace -v -l
gfortran -l m -shared-libgcc
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/4.6.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ../gcc-4.6/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++,fortran --disable-multilib --with-gmp=/usr/local
--with-mpc=/usr/local --with-mpfr=/usr/local
Thread model: posix
gcc version 4.6.0 20110216 (experimental) (GCC) 
COLLECT_GCC_OPTIONS='-o' 'selectTypeFail.exe' '-g' '-fbacktrace' '-v'
'-shared-libgcc' '-mtune=generic' '-march=pentiumpro'
 /usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/4.6.0/f951
selectTypeFail.F90 -cpp=/tmp/ccro8Gvw.f90 -quiet -v selectTypeFail.F90 -quiet
-dumpbase selectTypeFail.F90 -mtune=generic -march=pentiumpro -auxbase
selectTypeFail -g -version -fbacktrace -fintrinsic-modules-path
/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/finclude -o
/tmp/ccguPzRS.s
GNU Fortran (GCC) version 4.6.0 20110216 (experimental) (i686-pc-linux-gnu)
        compiled by GNU C version 4.6.0 20110216 (experimental), GMP version
4.3.2, MPFR version 3.0.0, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
ignoring nonexistent directory
"/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/../../../../i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/finclude
 /usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/include
 /usr/local/include
 /usr/local/gcc-trunk/include
 /usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/include-fixed
 /usr/include
End of search list.
GNU Fortran (GCC) version 4.6.0 20110216 (experimental) (i686-pc-linux-gnu)
        compiled by GNU C version 4.6.0 20110216 (experimental), GMP version
4.3.2, MPFR version 3.0.0, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
COLLECT_GCC_OPTIONS='-o' 'selectTypeFail.exe' '-g' '-fbacktrace' '-v'
'-shared-libgcc' '-mtune=generic' '-march=pentiumpro'
 as --32 -o /tmp/ccZqndJg.o /tmp/ccguPzRS.s
Reading specs from
/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/../../../libgfortran.spec
rename spec lib to liborig
COLLECT_GCC_OPTIONS='-o' 'selectTypeFail.exe' '-g' '-fbacktrace' '-v'
'-shared-libgcc' '-mtune=generic' '-march=pentiumpro'
COMPILER_PATH=/usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/4.6.0/:/usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/4.6.0/:/usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/:/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/:/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/
LIBRARY_PATH=/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/:/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-o' 'selectTypeFail.exe' '-g' '-fbacktrace' '-v'
'-shared-libgcc' '-mtune=generic' '-march=pentiumpro'
 /usr/local/gcc-trunk/libexec/gcc/i686-pc-linux-gnu/4.6.0/collect2
--eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 -o
selectTypeFail.exe /usr/lib/crt1.o /usr/lib/crti.o
/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/crtbegin.o
-L/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0
-L/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/../../.. /tmp/ccZqndJg.o
-lgfortran -lm -lgcc_s -lgcc -lquadmath -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/local/gcc-trunk/lib/gcc/i686-pc-linux-gnu/4.6.0/crtend.o /usr/lib/crtn.o

$ selectTypeFail.exe 
 incorrect

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.02.16 17:32:32
                 CC|                            |janus at gcc dot gnu.org
            Summary|SELECT TYPE fails to        |[OOP] SELECT TYPE fails to
                   |execute correct TYPE IS     |execute correct TYPE IS
                   |block                       |block
     Ever Confirmed|0                           |1

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

--- Comment #1 from janus at gcc dot gnu.org 2011-02-16 18:31:06 UTC ---
Here is a variant: Apart from SELECT TYPE, this bug can also be exposed via the
SAME_TYPE_AS intrinsic.


module Tree_Nodes
  type treeNode
   contains
     procedure :: walk
  end type
contains
  subroutine walk (thisNode)
    class (treeNode) :: thisNode
    print *, SAME_TYPE_AS (thisNode, treeNode())
  end subroutine
end module

module Merger_Trees
  use Tree_Nodes
  private
  public :: mergerTree
  type mergerTree
     type(treeNode), pointer :: baseNode
  end type
end module

module Merger_Tree_Build
  use Merger_Trees
end module

program test
  use Merger_Tree_Build
  use Tree_Nodes
  type(treeNode) :: node
  call walk (node)
end program


This prints "F", but should print "T".


The underlying problem seems to be related to the vtable not being properly set
up. The vtab symbol for the type 'treeNode' apparently is present, but it is
not initialized properly: The '_hash' component is 0!

Looking at the mod files, the symbol '__vtab_tree_nodes_Treenode' seems to be
present in tree_nodes.mod and merger_tree_build.mod, but not in
merger_trees.mod!

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |janus at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #2 from janus at gcc dot gnu.org 2011-02-16 21:58:12 UTC ---
Ok, I think what we need to do is basically to make sure that vtab/vtype
symbols are always public and are not affected by PRIVATE statements. Here is a
first patch:


Index: gcc/fortran/module.c
===================================================================
--- gcc/fortran/module.c        (revision 170222)
+++ gcc/fortran/module.c        (working copy)
@@ -4874,7 +4874,8 @@ write_symbol0 (gfc_symtree *st)
       && !sym->attr.subroutine && !sym->attr.function)
     dont_write = true;

-  if (!gfc_check_access (sym->attr.access, sym->ns->default_access))
+  if (!sym->attr.vtab && !sym->attr.vtype
+      && !gfc_check_access (sym->attr.access, sym->ns->default_access))
     dont_write = true;

   if (!dont_write)
@@ -4982,7 +4983,8 @@ write_symtree (gfc_symtree *st)
        && sym->ns->proc_name->attr.if_source == IFSRC_IFBODY)
     return;

-  if (!gfc_check_access (sym->attr.access, sym->ns->default_access)
+  if ((!sym->attr.vtab && !sym->attr.vtype
+       && !gfc_check_access (sym->attr.access, sym->ns->default_access))
       || (sym->attr.flavor == FL_PROCEDURE && sym->attr.generic
          && !sym->attr.subroutine && !sym->attr.function))
     return;


This fixes the test case, but is not regtested yet.

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[abenson at caltech dot edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

--- Comment #3 from Andrew Benson <abenson at caltech dot edu> 2011-02-16 23:17:49 UTC ---
I can confirm that this patch resolves the problem in the application from
which my original test case was derived.

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

--- Comment #4 from janus at gcc dot gnu.org 2011-02-18 10:04:33 UTC ---
Author: janus
Date: Fri Feb 18 10:04:30 2011
New Revision: 170269

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170269
Log:
2011-02-18  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/47767
    * gfortran.h (gfc_check_access): Removed prototype.
    (gfc_check_symbol_access): Added prototype.
    * module.c (gfc_check_access): Renamed to 'check_access', made static.
    (gfc_check_symbol_access): New function, basically a shortcut for
    'check_access'.
    (write_dt_extensions,write_symbol0,write_generic,write_symtree): Use
    'gfc_check_symbol_access'.
    (write_operator,write_module): Renamed 'gfc_check_access'.
    * resolve.c (resolve_fl_procedure,resolve_fl_derived,
    resolve_fl_namelist,resolve_symbol,resolve_fntype): Use
    'gfc_check_symbol_access'.

2011-02-18  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/47767
    * gfortran.dg/class_40.f03: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/class_40.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/module.c
    trunk/gcc/fortran/resolve.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/47767] [OOP] SELECT TYPE fails to execute correct TYPE IS block

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47767

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #5 from janus at gcc dot gnu.org 2011-02-18 10:07:03 UTC ---
Fixed with r170269. Closing.

Thanks for the report, Andrew!