xref: /netbsd-src/external/bsd/elftoolchain/dist/libdwarf/dwarf_undef_macro.3 (revision 5ac3bc719ce6e70593039505b491894133237d12)

.\"	$NetBSD: dwarf_undef_macro.3,v 1.6 2024/03/03 17:37:32 christos Exp $
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.\" Copyright (c) 2011 Kai Wang
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.\" Id: dwarf_undef_macro.3 3963 2022-03-12 16:07:32Z jkoshy
.\"
.Dd November 9, 2011
.Dt DWARF_UNDEF_MACRO 3
.Os
.Sh NAME
.Nm dwarf_undef_macro
.Nd record the removal of a macro definition
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft "int"
.Fo dwarf_undef_macro
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_Unsigned lineno"
.Fa "char *name"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_undef_macro
records the removal of a macro definition in a DWARF producer
instance.
.Pp
Argument
.Fa dbg
should reference a DWARF producer instance allocated using
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Fa lineno
specifies the line number of the source line where the macro
definition was removed.
A value of zero indicates that the macro definition was removed before
any source files were read.
.Pp
Argument
.Fa name
should point to a NUL-terminated string containing the name
of the macro.
.Pp
If argument
.Fa err
is not
.Dv NULL ,
it will be used to store error information in case of an error.
.Sh RETURN VALUES
On success, function
.Fn dwarf_undef_macro
returns
.Dv DW_DLV_OK .
In case of an error, function
.Fn dwarf_undef_macro
returns
.Dv DW_DLV_ERROR
and sets the argument
.Fa err .
.Sh EXAMPLES
To record the fact that the macro named
.Dv _STDIO_H_
was removed at line 220 of the current macro file, use:
.Bd -literal -offset indent
Dwarf_P_Debug dbg;
Dwarf_Error de;

/* ... Assume 'dbg' refers to a DWARF producer instance... */
if (dwarf_undef_macro(dbg, 220, "_STDIO_H_", &de) != DW_DLV_OK)
	errx(EXIT_FAILURE, "dwarf_def_macro failed: %s",
	    dwarf_errmsg(-1));
.Ed
.Sh ERRORS
Function
.Fn dwarf_undef_macro
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
Either arguments
.Fa dbg
or
.Fa name
was
.Dv NULL .
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of the
function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_def_macro 3 ,
.Xr dwarf_end_macro_file 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3 ,
.Xr dwarf_start_macro_file 3 ,
.Xr dwarf_vendor_ext 3