ldlread.3x

<B>Digital的Unix操作系统VAX 4.2源码</B>

.TH ldlread 3x RISC
.SH Name
ldlread, ldlinit, ldlitem \- manipulate line number entries of a common object file function
.SH Syntax
.nf
.B #include <stdio.h>
.ie '\*p'' \{\
.B #include <filehdr.h>
.B #include <syms.h>
.B #include <ldfcn.h>
\}
.el \{\
.B #include "\s-1INCDIR\s+1\/filehdr.h"
.B #include "\s-1INCDIR\s+1\/syms.h"
.B #include "\s-1INCDIR\s+1\/ldfcn.h"
\}
.ft R
.PP
.BR "int ldlread (" "ldptr, fcnindx, linenum, linent" )
.BR "\s-1LDFILE\s+1 \(**" ldptr ;
.BR long " fcnindx" ;
.BR "unsigned short" " linenum" ;
.BR "\s-1LINER\s+1" " linent" ;
.PP
.BR "int ldlinit (" "ldptr, fcnindx" )
.BR "\s-1LDFILE\s+1 \(**" ldptr ;
.BR long " fcnindx" ;
.PP
.BR "int ldlitem (" "ldptr, linenum, linent" )
.BR "\s-1LDFILE\s+1 \(**" ldptr ;
.BR "unsigned short" " linenum" ;
.BR "\s-1LINER\s+1" " linent" ;
.fi
.DT
.SH Description
The 
.PN ldlread
function searches the line number entries of the common object file currently
associated with 
.IR ldptr .
The 
.PN ldlread
function begins its search with the line number entry for the beginning 
of a function and confines its search to the line numbers associated with 
a single function. The function is identified by
.IR fcnindx ,
which is the index of its local symbols entry in the object file symbol table.
The
.PN ldlread
function reads the entry with the smallest line number equal to or greater
than
.I linenum
into
.IR linent .
.PP
The
.PN dlinit
and 
.PN ldlitem
functions provide the same behavior as 
.PN ldlread .
After an initial call to
.PN ldlread
or
.PN ldlinit ,
.PN ldlitem
can be used to retrieve a series of line number entries associated with a
single function.
The 
.PN ldlinit
function 
simply finds the line number entries for the function identified by
.I fcnindx.
The 
.PN ldlitem
function finds and reads the entry with the smallest line number equal to 
or greater than
.I linenum
into
.IR linent .
.PP
The functions
.PN ldlread ,
.PN ldlinit ,
and
.PN ldlitem
each return either success or failure.  The
.PN ldlread 
function fails if one of the following occurs:
.IP \(bu 5
If line number entries do not exist in the object file.
.IP \(bu 5
If \fIfcnindx\fR does not index a function entry in the symbol table.
.IP \(bu 5
If it does not find a line number equal to or greater than \fIlinenum\fR.
.PP
The 
.PN ldlitem
fails if it does not find a line number equal to or greater than
\fIlinenum\fR.
.SH See Also
ldclose(3x),
ldopen(3x),
ldtbindex(3x),
ldfcn(5)