1d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\documentclass{article} 2d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\usepackage[fancyhdr,pdf]{latex2man} 3d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 4d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\input{common.tex} 5d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 6d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\begin{document} 7d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 8d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\begin{Name}{3}{unw\_set\_reg}{David Mosberger-Tang}{Programming Library}{unw\_set\_reg}unw\_set\_reg -- set register contents 9d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\end{Name} 10d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 11d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Synopsis} 12d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 13d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\File{\#include $<$libunwind.h$>$}\\ 14d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 15d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Type{int} \Func{unw\_set\_reg}(\Type{unw\_cursor\_t~*}\Var{cp}, \Type{unw\_regnum\_t} \Var{reg}, \Type{unw\_word\_t} \Var{val});\\ 16d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 17d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Description} 18d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 19d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmThe \Func{unw\_set\_reg}() routine sets the value of register 20d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Var{reg} in the stack frame identified by cursor \Var{cp} to the 21d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmvalue passed in \Var{val}. 22d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 23d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmThe register numbering is target-dependent and described in separate 24d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmmanual pages (e.g., libunwind-ia64(3) for the IA-64 target). 25d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmFurthermore, the exact set of accessible registers may depend on the 26d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmtype of frame that \Var{cp} is referring to. For ordinary stack 27d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmframes, it is normally possible to access only the preserved 28d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm(``callee-saved'') registers and frame-related registers (such as the 29d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmstack-pointer). However, for signal frames (see 30d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Func{unw\_is\_signal\_frame}(3)), it is usually possible to access 31d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmall registers. 32d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 33d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmNote that \Func{unw\_set\_reg}() can only write the contents of 34d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmregisters whose values fit in a single word. See 35d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Func{unw\_set\_fpreg}(3) for a way to write registers which do not 36d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmfit this constraint. 37d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 38d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Return Value} 39d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 40d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmOn successful completion, \Func{unw\_set\_reg}() returns 0. 41d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmOtherwise the negative value of one of the error-codes below is 42d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmreturned. 43d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 44d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Thread and Signal Safety} 45d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 46d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Func{unw\_set\_reg}() is thread-safe as well as safe to use 47d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmfrom a signal handler. 48d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 49d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Errors} 50d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 51d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\begin{Description} 52d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\item[\Const{UNW\_EUNSPEC}] An unspecified error occurred. 53d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\item[\Const{UNW\_EBADREG}] An attempt was made to write a register 54d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm that is either invalid or not accessible in the current frame. 55d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\item[\Const{UNW\_EREADONLY}] An attempt was made to write to a 56d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm read-only register. 57d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\end{Description} 58d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmIn addition, \Func{unw\_set\_reg}() may return any error returned by 59d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmthe \Func{access\_mem}(), \Func{access\_reg}(), and 60d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Func{access\_fpreg}() call-backs (see 61d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\Func{unw\_create\_addr\_space}(3)). 62d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 63d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{See Also} 64d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 65d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\SeeAlso{libunwind(3)}, 66d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\SeeAlso{libunwind-ia64(3)}, 67d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\SeeAlso{unw\_get\_reg(3)}, 68d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\SeeAlso{unw\_is\_signal\_frame(3)}, 69d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\SeeAlso{unw\_set\_fpreg(3)} 70d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 71d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\section{Author} 72d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 73d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\noindent 74d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidmDavid Mosberger-Tang\\ 7575f34ccb7dcdfd2b96e370824b3fd723b2f22b49David Mosberger-TangEmail: \Email{dmosberger@gmail.com}\\ 7675f34ccb7dcdfd2b96e370824b3fd723b2f22b49David Mosberger-TangWWW: \URL{http://www.nongnu.org/libunwind/}. 77d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\LatexManEnd 78d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm 79d0028f3b308078fe19b1ec7a29f1d8cf6ebf39efmostang.com!davidm\end{document} 80