DWARF_GET_LOCLIST_ENTRY(3) | Library Functions Manual | DWARF_GET_LOCLIST_ENTRY(3)

# NAME

`dwarf_get_loclist_entry` —
retrieve DWARF location list entry

# LIBRARY

DWARF Access Library (libdwarf, -ldwarf)

# SYNOPSIS

`#include <libdwarf.h>`

int
`dwarf_get_loclist_entry`(Dwarf_Debug dbg, Dwarf_Unsigned offset, Dwarf_Addr *hipc, Dwarf_Addr *lopc, Dwarf_Ptr *data, Dwarf_Unsigned *entry_len, Dwarf_Unsigned *next_entry, Dwarf_Error *err);

# DESCRIPTION

Function `dwarf_get_loclist_entry`() retrieves a location list entry from the DWARF section “.debug_loc”.

Argument dbg should reference a DWARF debug context allocated using dwarf_init(3).

Argument offset is an offset, relative to the “.debug_loc” section, to the start of the desired location list entry.

Argument hipc should point to a location which will hold the offset, relative to the base address of the location list entry, of the highest program counter value for the entry.

Argument lowpc should point to a location which will hold the offset, relative to the base address of the location list entry, of the lowest program counter value for the entry.

Argument data should point to a location which will be set to a pointer to the location list data.

Argument entry_len should point to a location which will hold the length in bytes of the location list data returned in argument data.

Argument next_entry should point to a location which will hold the offset of the next location list entry.

If argument err is not NULL, it will be used to store error information in case of an error.

# RETURN VALUES

Function `dwarf_get_loclist_entry`() returns `DW_DLV_OK` when it succeeds. It returns `DW_DLV_NO_ENTRY` if there is no location list at the specified offset offset. In case of an error, it returns `DW_DLV_ERROR` and sets the argument err.

# ERRORS

Function `dwarf_get_loclist_entry`() can fail with:

[`DW_DLE_ARGUMENT`]
  One of the arguments dbg, hipc, lopc, data, entry_len or next_entry was NULL.
[`DW_DLE_NO_ENTRY`]
  There is no location list at the specified offset offset.

# EXAMPLE

To iterate through all the location list entries in the “.debug_loc” section, use:

    Dwarf_Debug dbg;
    Dwarf_Unsigned off, len, next;
    Dwarf_Addr hipc, lopc;
    Dwarf_Ptr data;
    Dwarf_Error de;
    int ret;

    off = 0;
    while ((ret = dwarf_get_loclist_entry(dbg, off, &hipc, &lopc, &data,
        &len, &next, &de)) == DW_DLV_OK) {
    	/* ... use loclist entry ... */
    	off = next;
    }
    if (ret == DW_DLV_ERROR)
    	warnx("dwarf_get_loclist_entry failed: %s", dwarf_errmsg(de));

# SEE ALSO

dwarf(3), dwarf_loclist(3), dwarf_loclist_n(3), dwarf_loclist_from_expr(3), dwarf_loclist_from_expr_a(3)

July 6, 2011 | NetBSD 9.3