By default nag_fxref constructs tables 80 characters wide. If the -wide option is used nag_fxref uses 120 columns for constructing the tables.
If the -key option is specified, the output will contain a key of the cross referencer output as described below.
The nag_fxref output consists of two parts. The first is a cross reference table for each of the program units contained in each file. The second stage gives a global cross reference of all symbols appearing in each file.
The first section of the output is headed "Label Index for <Routine-Name>". Unnamed main programs are given the name "$MAIN" and unnamed block data subprograms are called "$BLOCK". This section of the output consists of three columns headed in turn by Label, Defined and Referenced. The first column contains a list of all the labels in the program unit. The second column contains the line number on which it appears and the third column a list of line numbers where the label is referenced by a statement, e.g. by a GOTO statement. This section is not displayed for a program unit which does not contain any labels or references to labels. If a label is found which is not referenced a warning is placed on standard error.
The second section contains a cross reference table for the symbols which appear in the program unit. The section is titled "Symbol Cross-Reference for <Routine-Name>". Two columns entitled "Symbol" and "Referenced" are then displayed. The first column contains the name of a symbol, for example "I", and the second contains a list of line numbers in which the symbol appears. The line numbers may be followed by certain characters which have interpretations as described below.
The third section entitled "Global Symbol Cross-Reference" contains a list of symbols in one column and a second column containing the names of program units in which they are referenced. The name of the routine will be followed by a single letter preceded by a star which indicate how the symbol is referenced.
The second table for each program unit (as described above), contains a list of line numbers for each symbol possibly suffixed by a character or characters.
The following characters may follow the line number:
These symbols can also be followed by number enclosed in brackets. If this is so, this indicates that the line number applies to an include file. The appropriate include file can be deduced by checking the key which appears under the local cross reference table.
nag_fxref recognises the ANSI standard Fortran 77 intrinsic functions, the US Military Standard intrinsic functions, and the double complex intrinsics defined in nag_Fortran77.
The output from nag_fxref will appear incorrectly alligned, but not unreadable, if more than 99 INCLUDE files are called from any one program unit.
Alignment may also suffer if a file contains more than 999999 lines of code.
Copyright, Numerical Algorithms Group, Oxford, 1991-2001