libunwind-eh_elf/doc/libunwind-dynamic.tex

unw\_dyn\_region\_info\_t:

        - insn_count can be negative to indicate that the region is
          at the end of the procedure; in such a case, the negated
          insn_count value specifies the length of the final region
          in number of instructions.  There must be at most one region
          with a negative insn_count and only the last region in a
          procedure's region list may be negative.  Furthermore, both
          di->start\_ip and di->end\_ip must be valid.
(Logical change 1.54) 2003-02-22 08:19:43 +00:00			`unw\_dyn\_region\_info\_t:`

			`- insn_count can be negative to indicate that the region is`
			`at the end of the procedure; in such a case, the negated`
			`insn_count value specifies the length of the final region`
			`in number of instructions. There must be at most one region`
			`with a negative insn_count and only the last region in a`
			`procedure's region list may be negative. Furthermore, both`
			`di->start\_ip and di->end\_ip must be valid.`