LI76095: TYPO CAUSING INTERNAL COMPILER ERROR

April 2011 Update for XL Fortran for Linux, V13.1
July 2011 Update for XL Fortran for Linux, V13.1
October 2011 Update for XL Fortran for Linux, V13.1
June 2012 Update for XL Fortran for Linux, V13.1
October 2012 Update for XL Fortran for Linux, V13.1
XL Fortran for Linux Fix Pack 8 (June 2013 Update) for 13.1

APAR status

• Closed as program error.

Error description

• The typo on line 104 of test.f90 causes the Fortran compiler to
  abend.
  
  ===== COMPILE COMMAND:
  $ xlf95 -c test.f90
  
  ===== TESTCASE:
  $ cat test.f90
  Module Series
  
  Implicit None
  
  Integer, Parameter :: wp = Kind(1.0d0)   ! working, double
  
  Contains
  
  !------------------------------------------------------------
    Subroutine Jonc(z, s, res_J, est_abs_err, est_rel_err, &
         &               n, k, abs_err, rel_err, meth)
  
      Implicit none
  
      ! Subroutine arguments:
      Real(wp), intent(IN)  :: z
      Real(wp), intent(IN)  :: s
      Real(wp), intent(OUT) :: res_J
      Real(wp), intent(OUT) :: est_abs_err
      Real(wp), intent(OUT) :: est_rel_err
      Integer,  intent(IN), optional :: n
      Integer,  intent(IN), optional :: k
      Real(wp), intent(IN), optional :: abs_err
      Real(wp), intent(IN), optional :: rel_err
      Integer,  intent(IN), optional :: meth
  
      ! Local variables:
      Integer  :: i, j, j1, j2, nn, kk
      Real(wp) :: den, num, res
      Real(wp) :: uabs_err, r
      Integer  :: umeth
      Real(wp), allocatable :: C(:)
      Real(wp), allocatable :: A(:,:)
  
      If (present(n)) Then
         nn=n
      Else
         nn=50
      End If
      If (present(k)) Then
         kk=k
      Else
         kk=5
      End If
      If (present(abs_err)) Then
         uabs_err=abs_err
      Else
         uabs_err=1.0e-5
      End If
      If (present(meth)) Then
         umeth=meth
      Else
         umeth=1
      End If
  
      If ( (z <= 10.0_wp*tiny(1.0_wp)) .AND. (z >=
  10.0_wp*tiny(1.0_wp)) )  Then
         res_J = z
         est_abs_err = 0.00001_wp
  
      Else If ( (z <= 0.001_wp) .AND. ( z >= -0.001_wp) ) Then
         res_J = z + (z*z)/(2.0_wp**s)
         est_abs_err = 0.00001_wp
  
      Else If ( (z < 2.49_wp) ) Then
         allocate(C(1:nn))
         allocate(A(0:nn,1:kk))
         Forall (i=1:nn)
            C(i) = (z**i) *  ( 1.0_wp / (Real(i,wp))**s )
         End Forall
         A(0,1) = C(1)
         Forall (i=1: nn)
            A(i,1) = sum(C(1:i))
         End Forall
         If (umeth == 0) Then
            res = A(nn,1)
            est_abs_err = abs(res-A(nn-1,1))
            est_rel_err = abs(est_abs_err / res)
         End If
         deallocate(C)
         deallocate(A)
  
      End If
  
    End Subroutine Jonc
  End Module Series
  
  !===============================================================
  
  Program Jonc1
  
    Implicit none
  
    Integer, Parameter :: wp = Kind(1.0d0)   ! working, double
    Integer, Parameter :: kp = Kind(1.0e0)   ! komplot, single
  
    Integer, Parameter :: np=80, nirc = 12
    real(wp) :: psi, den, RI, RI_err
    Real(wp) :: bias, mo1, mo1_err, bias_err
    Real(wp) :: xar(1:np), yar(1:np), dyar(1:np), zar1(1:np),
  zar2(1:np)
    Real(wp) :: yintar(1:np), yintarc(1:np), dyintar(1:np)
    Real(wp) :: R(1:nirc), err_est(1:nirc)
    Integer  :: i
    ! syntax error -------------v
    Real(kp) :: xark(1:np), yark*1:np), dyark(1:np), zar1k(1:np),
  zar2k(1:np)
    ! syntax error -------------^
  
    Do i       = 1, np
       RI         = R(3) ; RI_err   = err_est(3)
       bias       = R(5) ; bias_err = err_est(5)
       Mo1        = R(9) ; Mo1_err  = err_est(9)
       yintarc(i) = yintar(i)/den
       dyintar(i) = RI/(xar(i)**2)
    End Do
  
    Forall (i=1:np)
      xark(i)     = Real(xar(i),kp)
      yark(i)     = max(min(Real(yar(i),kp), 1.0_kp), -1000.0_kp)
      dyark(i)    = max(min(Real(dyar(i),kp), 1000.0_kp),
  -1000.0_kp)
      zar1k(i)    = Real(zar1(i),kp)
      zar2k(i)    = Real(zar2(i),kp)
    End Forall
  
  End Program Jonc1
  
  !============================================================
  $
  
  
  
  ===== ACTUAL OUTPUT:
  $xlf95 -c test.f90
  ** series   === End of Compilation 1 ===
  /usr/bin/.orig/xlf95: 1501-230 (S) Internal compiler error;
  please contact your Service Representative. For more information
  visit:
  http://www.ibm.com/support/docview.wss?uid=swg21110810
  1501-511  Compilation failed for file test.f90.
  $
  
  ===== EXPECTED OUTPUT:
  $xlf95 -c test.f90
  ** series   === End of Compilation 1 ===
  "test.f90", line 104.12: 1515-019 (S) Syntax is incorrect.
  "test.f90", line 116.5: 1516-036 (S) Entity xark has undefined
  type.
  "test.f90", line 116.5: 1515-025 (S) Only a name of a variable,
  array element, or character substring is permitted on the left
  hand side of an assignment statement.
  "test.f90", line 117.5: 1516-036 (S) Entity yark has undefined
  type.
  "test.f90", line 117.5: 1515-025 (S) Only a name of a variable,
  array element, or character substring is permitted on the left
  hand side of an assignment statement.
  "test.f90", line 118.5: 1516-036 (S) Entity dyark has undefined
  type.
  "test.f90", line 118.5: 1515-025 (S) Only a name of a variable,
  array element, or character substring is permitted on the left
  hand side of an assignment statement.
  "test.f90", line 119.5: 1516-036 (S) Entity zar1k has undefined
  type.
  "test.f90", line 119.5: 1515-025 (S) Only a name of a variable,
  array element, or character substring is permitted on the left
  hand side of an assignment statement.
  "test.f90", line 120.5: 1516-036 (S) Entity zar2k has undefined
  type.
  "test.f90", line 120.5: 1515-025 (S) Only a name of a variable,
  array element, or character substring is permitted on the left
  hand side of an assignment statement.
  ** jonc1   === End of Compilation 2 ===
  

Local fix

• n/a
  

Problem summary

• USERS AFFECTED:
  Users of XL Fortran 13.1 on AIX and Linux are potentially
  affected by this issue.
  
  PROBLEM DESCRIPTION:
  When the declaration of a variable that is used in FORALL has a
  syntax error, the Fortran compiler can
  sometimes have an internal compiler error. The reason for this
  internal compiler error is because
  the compiler tries to recover from detecting the typo in the
  source code to continue finding other
  syntax errors during compile time. Due to the recovery process
  of the first syntax error, the compiler
  can sometimes miss interpret information leading to an abend.
  

Problem conclusion

• The problem has been fixed to detect and handle the scenario
  mentioned in the test case.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IZ87501

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL FORTRAN LINU

• Fixed component ID

  5724X1600

Applicable component levels

• RD10 PSN IZ87501

     UP06/09/13