[Bug fortran/38907] New: ICE when contained function has same name as module function and used in expression

[Bug fortran/38907] New: ICE when contained function has same name as module function and used in expression

[dick dot hendrickson at gmail dot com]

The following program gives an internal compiler error.  If the line
RDA = -1 is commented out, there is a different ICE.  If the unary +
before the function reference in the assignment to RDA(1,2) is removed
the ICE goes away.

Dick Hendrickson


      module sa0054_stuff

! fails on Windows XP
! gcc version 4.4.0 20081219 (experimental) [trunk revision 142842] (GCC)

      contains

      PURE FUNCTION S_REAL_SUM_I (A,B)
      REAL  ::  S_REAL_SUM_I
      REAL, INTENT(IN), OPTIONAL  ::  A,B
      X = 0
      S_REAL_SUM_I = X

      END FUNCTION S_REAL_SUM_I

      SUBROUTINE SA0054(RDA, NF10,nf1,nf2,nf3,nf4)
      REAL RDA(NF10,NF10)

      RDA    = -1                  !changes ICE if commented out

          RDA(1,2) = + S_REAL_SUM_I(1.0,2.0)

!         RDA(1,2) =   S_REAL_SUM_I(1.0,2.0)     !This one works

      CONTAINS

      PURE FUNCTION S_REAL_SUM_I (A,B)
      REAL  ::  S_REAL_SUM_I
      REAL, INTENT(IN), OPTIONAL  ::  A,B
      S_REAL_SUM_I = 0
      END FUNCTION S_REAL_SUM_I

      END SUBROUTINE

      end module sa0054_stuff


With RDA = -1
C:\gfortran>gfortran try_sa0054.f
f951.exe: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


With RDA = -1 commented out
C:\gfortran>gfortran try_sa0054.f
f951.exe: internal compiler error: in check_host_association, at
fortran/resolve
.c:4369
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: ICE when contained function has same name as module
                    function and used in expression
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dick dot hendrickson at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] ICE when contained function has same name as module function and used in expression

[kargl at gcc dot gnu dot org]

------- Comment #1 from kargl at gcc dot gnu dot org  2009-01-18 21:44 -------
Confirmed for both ICEs.


-- 

kargl at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-01-18 21:44:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [regression 4.3/4.4] ICE when contained function has same name as module function and used in expression

[kargl at gcc dot gnu dot org]

------- Comment #2 from kargl at gcc dot gnu dot org  2009-01-18 21:47 -------
Both variations of the program work with 4.2.5, so this is
a regression.


-- 

kargl at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.3.3 4.4.0
      Known to work|                            |4.2.5
            Summary|ICE when contained function |[regression 4.3/4.4] ICE
                   |has same name as module     |when contained function has
                   |function and used in        |same name as module function
                   |expression                  |and used in expression


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [regression 4.3/4.4] ICE when contained function has same name as module function and used in expression

[kargl at gcc dot gnu dot org]

-- 

kargl at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sgk at troutmask dot apl dot
                   |                            |washington dot edu
           Priority|P3                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2009-01-18 22:27 -------
Confirm. Thanks for the report!

Valgrind shows:

==20941== Conditional jump or move depends on uninitialised value(s)
==20941==    at 0x46C602: gfc_resolve_expr (resolve.c:4353)
==20941==    by 0x46BC22: gfc_resolve_expr (resolve.c:3057)
==20941==    by 0x472944: resolve_code (resolve.c:6676)

==20941== Use of uninitialised value of size 8
==20941==    at 0x46C608: gfc_resolve_expr (resolve.c:4353)

==20941== Invalid read of size 8
==20941==    at 0x46C608: gfc_resolve_expr (resolve.c:4353)

That line is:

  4349            gfc_match_rvalue (&expr);
  4350            gfc_clear_error ();
  4351            gfc_buffer_error (0);
  4352
  4353            gcc_assert (expr && sym == expr->symtree->n.sym);

I added some debug printfs and valgrind shows invalid reads for:
  expr == NULL
and
  expr->symtree
where the latter results in a segfault.

I think the problem occurs if gfc_match_rvalue does not match. Then the
argument "&expr" will remain unmodified.

If one applies the following patch, the compilation will fail with the bogus
error

          RDA(1,2) = + S_REAL_SUM_I(1.0,2.0)
                                   1
Error: Unclassifiable statement at (1)


--- resolve.c   (Revision 143486)
+++ resolve.c
@@ -4348,3 +4348,4 @@ check_host_association (gfc_expr *e)
    only integers and vectors can be involved.  */
-         gfc_match_rvalue (&expr);
+         if (gfc_match_rvalue (&expr) == MATCH_YES)
+           {
          gfc_clear_error ();
@@ -4359,2 +4360,3 @@ check_host_association (gfc_expr *e)
          gfc_current_locus = temp_locus;
+           }
        }


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |32834
              nThis|                            |
           Keywords|                            |ice-on-valid-code
      Known to work|4.2.5                       |4.2.5 4.3.1
            Summary|[regression 4.3/4.4] ICE    |[4.3/4.4 Regression ] ICE
                   |when contained function has |when contained function has
                   |same name as module function|same name as module function
                   |and used in expression      |and used in expression
   Target Milestone|---                         |4.3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[mikael at gcc dot gnu dot org]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 683 bytes --]



------- Comment #4 from mikael at gcc dot gnu dot org  2009-01-19 22:33 -------
This removes the ICE:

Index: primary.c
===================================================================
--- primary.c   (révision 143501)
+++ primary.c   (copie de travail)
@@ -2370,6 +2370,8 @@
   bool implicit_char;
   gfc_ref *ref;

+  where = gfc_current_locus;
+
   m = gfc_match_name (name);
   if (m != MATCH_YES)
     return m;
@@ -2385,7 +2387,6 @@

   sym = symtree->n.sym;
   e = NULL;
-  where = gfc_current_locus;

   /* If this is an implicit do loop index and implicitly typed,
      it should not be host associated.  */


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[dominiq at lps dot ens dot fr]

------- Comment #5 from dominiq at lps dot ens dot fr  2009-01-19 22:39 -------
> This removes the ICE: ...

Do you understand why?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[pault at gcc dot gnu dot org]

------- Comment #6 from pault at gcc dot gnu dot org  2009-01-19 23:08 -------
Created an attachment (id=17148)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17148&action=view)
A patch for the PR

This regtests and bootstraps on FC9/x86_i64.  I'll do ChangeLogs and so on
tomorrow.

Thanks for the report, Dick!

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[mikael at gcc dot gnu dot org]

------- Comment #7 from mikael at gcc dot gnu dot org  2009-01-20 19:48 -------
(In reply to comment #5)
> > This removes the ICE: ...
> 
> Do you understand why?
> 
In the following:
          RDA(1,2) = + S_REAL_SUM_I(1.0,2.0)

gfc_match_rvalue sets where for the rhs to the marked position below:
          RDA(1,2) = + S_REAL_SUM_I(1.0,2.0)
                                   ^
check_host_association (before Paul's patch) calls gfc_match_rvalue again
starting at the e->where position (which is wrong). The match fails and there
is no code to handle it as it is unexpected. 

With my patch where is set at the beginning of the function name, permitting
proper match. This patch is needed I think, independently of Paul's one. For
4.5 if I don't forget about it. 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3/4.4 Regression ] ICE when contained function has same name as module function and used in expression

[pault at gcc dot gnu dot org]

------- Comment #8 from pault at gcc dot gnu dot org  2009-01-20 21:57 -------
Subject: Bug 38907

Author: pault
Date: Tue Jan 20 21:56:49 2009
New Revision: 143530

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143530
Log:
2009-01-20  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38907
        * resolve.c (check_host_association): Remove the matching to
        correct an incorrect host association and use manipulation of
        the expression instead.

2009-01-20  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38907
        * gfortran.dg/host_assoc_function_7.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/host_assoc_function_7.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/resolve.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3 Regression ] ICE when contained function has same name as module function and used in expression

[pault at gcc dot gnu dot org]

------- Comment #9 from pault at gcc dot gnu dot org  2009-01-20 21:59 -------
Fixed on trunk

Thanks for the report.

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3/4.4 Regression ] ICE   |[4.3 Regression ] ICE when
                   |when contained function has |contained function has same
                   |same name as module function|name as module function and
                   |and used in expression      |used in expression


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3 Regression ] ICE when contained function has same name as module function and used in expression

[pault at gcc dot gnu dot org]

------- Comment #10 from pault at gcc dot gnu dot org  2009-01-26 06:15 -------
Subject: Bug 38907

Author: pault
Date: Mon Jan 26 06:15:41 2009
New Revision: 143671

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143671
Log:
2009-01-26  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38907
        Backport from trunk
        * resolve.c (check_host_association): Remove the matching to
        correct an incorrect host association and use manipulation of
        the expression instead.

2009-01-26  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38907
        Backport from trunk
        * gfortran.dg/host_assoc_function_7.f90: New test.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/gfortran.dg/host_assoc_function_7.f90
Modified:
    branches/gcc-4_3-branch/gcc/fortran/ChangeLog
    branches/gcc-4_3-branch/gcc/fortran/resolve.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907

[Bug fortran/38907] [4.3 Regression ] ICE when contained function has same name as module function and used in expression

[pault at gcc dot gnu dot org]

------- Comment #11 from pault at gcc dot gnu dot org  2009-01-26 06:16 -------
Fixed on trunk and 4.3

Thanks for the report and thanks to Mikael for the fix.

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38907