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      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 
     19 The \Func{unw\_get\_reg}() routine reads the value of register
     20 \Var{reg} in the stack frame identified by cursor \Var{cp} and stores
     21 the value in the word pointed to by \Var{valp}.
     22 
     23 The register numbering is target-dependent and described in separate
     24 manual pages (e.g., libunwind-ia64(3) for the IA-64 target).
     25 Furthermore, the exact set of accessible registers may depend on the
     26 type of frame that \Var{cp} is referring to.  For ordinary stack
     27 frames, it is normally possible to access only the preserved
     28 (``callee-saved'') registers and frame-related registers (such as the
     29 stack-pointer).  However, for signal frames (see
     30 \Func{unw\_is\_signal\_frame}(3)), it is usually possible to access
     31 all registers.
     32 
     33 Note that \Func{unw\_get\_reg}() can only read the contents of
     34 registers whose values fit in a single word.  See
     35 \Func{unw\_get\_fpreg}(3) for a way to read registers which do not fit
     36 this constraint.
     37 
     38 \section{Return Value}
     39 
     40 On successful completion, \Func{unw\_get\_reg}() returns 0.
     41 Otherwise the negative value of one of the error-codes below is
     42 returned.
     43 
     44 \section{Thread and Signal Safety}
     45 
     46 \Func{unw\_get\_reg}() is thread-safe as well as safe to use
     47 from 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}
     56 In addition, \Func{unw\_get\_reg}() may return any error returned by
     57 the \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
     72 David Mosberger-Tang\\
     73 Email: \Email{dmosberger (a] gmail.com}\\
     74 WWW: \URL{http://www.nongnu.org/libunwind/}.
     75 \LatexManEnd
     76 
     77 \end{document}
     78