Memory Leak during WRITE in pgfortran

There appears to be a memory leak and double deallocation of formatting strings during I/O when a function is used to determine the logical unit number.

I know that i/o list items may not, themselves, be functions that also produce i/o, otherwise recursive i/o problems can occur. However I am not aware of any similar restriction on a function that returns an integer for the unit= specifier of a write statement.

In the code shown below, the PGI Fortran runtime seems to be doing the following:

  1. Allocate global pointer for “(A)” format
  2. Call Run_ErrUnit to determine the logical unit to use
  3. Allocate global pointer for “('===>…)” format
  4. Write file, line to output
  5. Deallocate global pointer
  6. Write error message
  7. Deallocate global pointer ! Ooops! not again

Other compilers tested (ifort, gfortran, nagfor) produce the following, correct output:

====> ERROR (macro.F90:26) <====
Error message.

====> ERROR (macro.F90:27) <====
Error message 127.

But pgfortran produces the following:

====> ERROR (macro.F90:26) <====

====> ERROR (
a.out(94046,0xa17941a8) malloc: *** error for object 0x1050400: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

A second “====> ERROR…” is appearing instead of the error message “Error message.”, indicating the main program write statement is using a stale format from the function call.

It seems the simple solution is for the compiler to reverse the order of #1 and #2 above.

The code used to test this is below (macro.F90):

module Run_Errors

	integer, save, private :: err_unit = 6
	integer, save, private :: warn_unit = 7
	integer, save, private :: err_count = 0

	integer function Run_ErrUnit(file,line)
		implicit none
		character(*), intent(in) :: file
		integer, intent(in)      :: line
		write(err_unit,"(/,'====> ERROR (',A,':',I0,') <====')") file,line
		if (err_unit /= warn_unit) write(warn_unit,"(/,'====> ERROR (',A,':',I0,') <====')") file,line
		Run_ErrUnit = err_unit
		err_count = err_count + 1
	end function

end module Run_Errors

#define RUN_ERROR(fmt) WRITE(Run_ErrUnit(__FILE__,__LINE__),fmt) 

program test

use Run_Errors

RUN_ERROR("(A)") "Error message."
RUN_ERROR("('Error: ',i0)") 127

end program

Thanks thfanning, I’ve sent this on to engineering for further investigation. The issue is being tracked as TPR#21313.

  • Mat

TPR 21313 - UF: Memory Leak during WRITE in pgfortran

is fixed in the current 15.3 release.