1\documentclass{article} 2\usepackage[fancyhdr,pdf]{latex2man} 3 4\input{common.tex} 5 6\begin{document} 7 8\begin{Name}{3}{unw\_get\_reg}{David Mosberger-Tang}{Programming Library}{unw\_get\_reg}unw\_get\_reg -- get register contents 9\end{Name} 10 11\section{Synopsis} 12 13\File{\#include $<$libunwind.h$>$}\\ 14 15\Type{int} \Func{unw\_get\_reg}(\Type{unw\_cursor\_t~*}\Var{cp}, \Type{unw\_regnum\_t} \Var{reg}, \Type{unw\_word\_t~*}\Var{valp});\\ 16 17\section{Description} 18 19The \Func{unw\_get\_reg}() routine reads the value of register 20\Var{reg} in the stack frame identified by cursor \Var{cp} and stores 21the value in the word pointed to by \Var{valp}. 22 23The register numbering is target-dependent and described in separate 24manual pages (e.g., libunwind-ia64(3) for the IA-64 target). 25Furthermore, the exact set of accessible registers may depend on the 26type of frame that \Var{cp} is referring to. For ordinary stack 27frames, it is normally possible to access only the preserved 28(``callee-saved'') registers and frame-related registers (such as the 29stack-pointer). However, for signal frames (see 30\Func{unw\_is\_signal\_frame}(3)), it is usually possible to access 31all registers. 32 33Note that \Func{unw\_get\_reg}() can only read the contents of 34registers whose values fit in a single word. See 35\Func{unw\_get\_fpreg}(3) for a way to read registers which do not fit 36this constraint. 37 38\section{Return Value} 39 40On successful completion, \Func{unw\_get\_reg}() returns 0. 41Otherwise the negative value of one of the error-codes below is 42returned. 43 44\section{Thread and Signal Safety} 45 46\Func{unw\_get\_reg}() is thread-safe as well as safe to use 47from a signal handler. 48 49\section{Errors} 50 51\begin{Description} 52\item[\Const{UNW\_EUNSPEC}] An unspecified error occurred. 53\item[\Const{UNW\_EBADREG}] An attempt was made to read a register 54 that is either invalid or not accessible in the current frame. 55\end{Description} 56In addition, \Func{unw\_get\_reg}() may return any error returned by 57the \Func{access\_mem}(), \Func{access\_reg}(), and 58\Func{access\_fpreg}() call-backs (see 59\Func{unw\_create\_addr\_space}(3)). 60 61\section{See Also} 62 63\SeeAlso{libunwind(3)}, 64\SeeAlso{libunwind-ia64(3)}, 65\SeeAlso{unw\_get\_fpreg(3)}, 66\SeeAlso{unw\_is\_signal\_frame(3)}, 67\SeeAlso{unw\_set\_reg(3)} 68 69\section{Author} 70 71\noindent 72David Mosberger-Tang\\ 73Email: \Email{dmosberger@gmail.com}\\ 74WWW: \URL{http://www.nongnu.org/libunwind/}. 75\LatexManEnd 76 77\end{document} 78