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Diffstat (limited to 'gas/doc/as.texinfo')
| -rw-r--r-- | gas/doc/as.texinfo | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo index dd78d68..720c054 100644 --- a/gas/doc/as.texinfo +++ b/gas/doc/as.texinfo @@ -3690,6 +3690,16 @@ Some machine configurations provide additional directives. * Balign:: @code{.balign @var{abs-expr} , @var{abs-expr}} * Byte:: @code{.byte @var{expressions}} * Comm:: @code{.comm @var{symbol} , @var{length} } + +* CFI directives:: @code{.cfi_startproc} + @code{.cfi_endproc} + @code{.cfi_def_cfa @var{register}, @var{offset}} + @code{.cfi_def_cfa_register @var{register}} + @code{.cfi_def_cfa_offset @var{offset}} + @code{.cfi_adjust_cfa_offset @var{offset}} + @code{.cfi_offset @var{register}, @var{offset}} + @code{.cfi_verbose [1|0]} + * Data:: @code{.data @var{subsection}} @ifset COFF * Def:: @code{.def @var{name}} @@ -3966,6 +3976,48 @@ undefined. @code{.byte} expects zero or more expressions, separated by commas. Each expression is assembled into the next byte. +@node CFI directives +@section @code{.cfi_startproc} +@cindex @code{cfi_startproc} directive +@code{.cfi_startproc} is used at the beginning of each function that +should have an entry in @code{.eh_frame}. It initializes some internal +data structures and emits architecture dependent initial CFI instructions. +Don't forget to close the function by +@code{.cfi_endproc}. + +@section @code{.cfi_endproc} +@cindex @code{cfi_endproc} directive +@code{.cfi_endproc} is used at the end of a function where it closes its +unwind entry previously opened by +@code{.cfi_startproc}. and emits it to @code{.eh_frame}. + +@section @code{.cfi_def_cfa @var{register}, @var{offset}} +@code{.cfi_def_cfa} defines a rule for computing CFA as: @i{take +address from @var{register} and add @var{offset} to it}. + +@section @code{.cfi_def_cfa_register @var{register}} +@code{.cfi_def_cfa_register} modifies a rule for computing CFA. From +now on @var{register} will be used instead of the old one. Offset +remains the same. + +@section @code{.cfi_def_cfa_offset @var{offset}} +@code{.cfi_def_cfa_offset} modifies a rule for computing CFA. Register +remains the same, but @var{offset} is new. Note that it is the +absolute offset that will be added to a defined register to compute +CFA address. + +@section @code{.cfi_adjust_cfa_offset @var{offset}} +Same as @code{.cfi_def_cfa_offset} but @var{offset} is a relative +value that is added/substracted from the previous offset. + +@section @code{.cfi_offset @var{register}, @var{offset}} +Previous value of @var{register} is saved at offset @var{offset} from +CFA. + +@section @code{.cfi_verbose [1|0]} +Switch on/off verbosity of the CFI machinery. @value{AS} will print +lots of useful messages to standard output if you use this directive. + @node Comm @section @code{.comm @var{symbol} , @var{length} } |