Article ID: 105932
Article Last Modified on 10/2/2003
APPLIES TO
- Microsoft FORTRAN PowerStation 1.0 Standard Edition
- Microsoft Fortran PowerStation 1.0a for MS-DOS
This article was previously published under Q105932
SYMPTOMS
Character string concatenations that involve the automatic creation of temporary variables may cause the following memory related run-time problems:
- Very slow execution of the application
- F6700
- DX2010
RESOLUTION
This memory loss can be avoided by assigning the concatenated strings to a temporary character string variable.
STATUS
Microsoft has confirmed this to be a problem in FORTRAN PowerStation version 1.0. This problem has been resolved with FORTRAN PowerStation maintenance release version 1.0a for MS-DOS.
FORTRAN PowerStation version 1.0 can be differentiated from the maintenance release version 1.0a by invoking the linker. Typing "link32 | more" from \F32\BIN directory will show version 2.8 for FORTRAN PowerStation version 1.0, and it will show version 1.0f for the maintenance release version 1.0a.
MORE INFORMATION
The following two sample programs demonstrate a memory loss due to string concatenation in the argument list. In both of the following examples, using a temporary variable for the concatenated strings avoids the memory leak.
Sample Code 1
C Compile options needed: none character*40 c1,c2 c1 = 'abcd' c2 = 'efgh' k = 0 do i=1,500000 if(c1//c2 .eq. 'Never') k = k + 1 end do end
The code above will run very slowly, and eventually generate:
Sample Code 2
C Compile options needed: none character fmtout*20,label(1,3)*(9) double precision value data (label(1,j),j=1,3)/' Label',' Output',' Test'/ data value/3.14159/ fmtout='f10.3' write(6,'(3a,''='','//fmtout//')')(label(1,j),j=1,3),value end
The above code on execution will generate:
The code does run to completion because this type of DOS-extender error is not fatal.
Additional query words: 1.00 buglist1.00 fixlist1.00a
Keywords: kbbug kbfix KB105932