NAME

       error::pass4 - systemtap pass-4 errors

DESCRIPTION

       Errors that occur during pass 4 (compilation) have generally only a few causes:

       kernel or OS version changes
              The  systemtap  runtime and embedded-C fragments in the tapset library are designed
              to be portable across a wide range of OS versions.  However, incompatibilities  can
              occur  when  some  OS  changes  occur,  such  as  kernel  modifications that change
              functions, types, or macros referenced by systemtap.  Upstream builds of  systemtap
              are  often  quickly  updated to include relevant fixes, so try getting or making an
              updated build.  If  the  issue  persists,  report  the  problem  to  the  systemtap
              developers.

       buggy embedded-C code
              Embedded-C code in your own guru-mode script cannot be checked by systemtap, and is
              passed through verbatim to the compiler.  Errors in such snippets of  code  may  be
              found  during the pass-4 compiler invocation, though may be hard to identify by the
              compiler errors.

       incompatible embedded-C code
              The interface  standards  between  systemtap-generated  code  and  embedded-C  code
              occasionally  change.  For example, before version 1.8, arguments were passed using
              macros  THIS->foo  and  THIS->__retvalue  but  from  version  1.8   onward,   using
              STAP_ARG_foo  and STAP_RETVALUE.  Adjust your embedded-C code to current standards,
              or use the stap --compatible=VERSION option to make systemtap use a different one.

GATHERING MORE INFORMATION

       It may be necessary to run systemtap with -k or -p3  to  examine  the  generated  C  code.
       Increasing the verbosity of pass-4 with an option such as --vp 0001 can also help pinpoint
       the problem.

SEE ALSO

       stap(1), error::reporting(7stap)

                                                                              ERROR::PASS4(7stap)