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 (git://sourceware.org/git/systemtap.git) builds
of systemtap are often quickly updated to include relevant fixes, so try
getting or making an updated build. Reworded: build systemtap from git
for use with very young kernels.
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.
- compiler bugs and mysteries
-
Messages such as "internal compiler error" suggest compiler problems. These
should be reported to the compiler developers in the form of a preprocessed
.i
file, plus the compiler command line. To gather relevant information, run
-
stap -k --vp 0003 -p4 ....
Systemtap will report the saved temporary directory, and the compiler command line it attempted. Go to the directory to find he main generated file stap_NNNNN_src.c. Force the compiler to produce a preprocessed file with:
-
make -C /lib/modules/`uname -r`/build M=`pwd` stap_NNNNN_src.i
(note the .i suffix), and the compiler command line should be in the file .stap_NNNNN_src.i.cmd.
-