2005-01-12 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

2005-01-12 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	* configure.ac: Test for header file <ucontext.h> (for use in
	  signal processing).
	* sigevent.c: (trap_default_signals) Use the SA_SIGINFO flag to
	  pass additional siginfo_t and ucontext_t arguments to core_handler
	  and exit_handler.
	  (core_handler,exit_handler) Now invoked with 3 arguments (using
	  SA_SIGINFO).  Pass additional info to zlog_signal.
	  (program_counter) New function to find program counter in ucontext_t,
	  needs to be enhanced to support more platforms (currently works only
	  on Linux/x86).
	* log.h: Change the zlog_signal prototype to add new arguments
	  siginfo_t * and program_counter.
	* log.c: (zlog_signal) Add new arguments siginfo and program_counter.
	  Include si_addr and program counter (if non-NULL) in message.
	  And remove #ifdef HAVE_GLIBC_BACKTRACE around hex_append, since
	  that is now used to render the si_addr and PC pointers.