Ranges: code addresses in DWARF3-4

Functions
int	dwarf_get_ranges_b (Dwarf_Debug dw_dbg, Dwarf_Off dw_rangesoffset, Dwarf_Die dw_die, Dwarf_Off *dw_return_realoffset, Dwarf_Ranges **dw_rangesbuf, Dwarf_Signed *dw_rangecount, Dwarf_Unsigned *dw_bytecount, Dwarf_Error *dw_error)
	Access to code ranges from a CU or just reading through the raw .debug_ranges section. More...
void	dwarf_dealloc_ranges (Dwarf_Debug dw_dbg, Dwarf_Ranges *dw_rangesbuf, Dwarf_Signed dw_rangecount)
	Dealloc the array dw_rangesbuf. More...
int	dwarf_get_ranges_baseaddress (Dwarf_Debug dw_dbg, Dwarf_Die dw_die, Dwarf_Bool *dw_known_base, Dwarf_Unsigned *dw_baseaddress, Dwarf_Bool *dw_at_ranges_offset_present, Dwarf_Unsigned *dw_at_ranges_offset, Dwarf_Error *dw_error)
	Find ranges base address. More...

Detailed Description

In DWARF3 and DWARF4 the DW_AT_ranges attribute provides an offset into the .debug_ranges section, which contains code address ranges.

See also

Dwarf_Ranges

DWARF3 and DWARF4. DW_AT_ranges with an unsigned constant FORM (DWARF3) or DW_FORM_sec_offset(DWARF4).

Function Documentation

dwarf_get_ranges_b()

int dwarf_get_ranges_b	(	Dwarf_Debug	dw_dbg,
		Dwarf_Off	dw_rangesoffset,
		Dwarf_Die	dw_die,
		Dwarf_Off *	dw_return_realoffset,
		Dwarf_Ranges **	dw_rangesbuf,
		Dwarf_Signed *	dw_rangecount,
		Dwarf_Unsigned *	dw_bytecount,
		Dwarf_Error *	dw_error
	)

Adds return of the dw_realoffset to accommodate DWARF4 GNU split-dwarf, where the ranges could be in the tieddbg (meaning the real executable, a.out, not in a dwp). DWARF4 split-dwarf is an extension, not standard DWARF4.

If printing all entries in the section pass in an initial dw_rangesoffset of zero and dw_die of NULL. Then increment dw_rangesoffset by dw_bytecount and call again to get the next batch of ranges. With a specific option dwarfdump can do this. This not a normal thing to do!

See also

Example getting .debug_ranges data

Parameters

dw_dbg	The Dwarf_Debug of interest
dw_rangesoffset	The offset to read from in the section.
dw_die	Pass in the DIE whose DW_AT_ranges brought us to ranges.
dw_return_realoffset	The actual offset in the section actually read. In a tieddbg dwp DWARF4 extension object the base offset is added to dw_rangesoffset and returned here.
dw_rangesbuf	A pointer to an array of structs is returned here. The struct contents are the raw values in the section.
dw_rangecount	The count of structs in the array is returned here.
dw_bytecount	The number of bytes in the .debug_ranges section applying to the returned array. This makes possible just marching through the section by offset.
dw_error	The usual error detail return pointer.

Returns

Returns DW_DLV_OK etc.

dwarf_dealloc_ranges()

void dwarf_dealloc_ranges	(	Dwarf_Debug	dw_dbg,
		Dwarf_Ranges *	dw_rangesbuf,
		Dwarf_Signed	dw_rangecount
	)

Parameters

dw_dbg	The Dwarf_Debug of interest.
dw_rangesbuf	The dw_rangesbuf pointer returned by dwarf_get_ranges_b
dw_rangecount	The dw_rangecount returned by dwarf_get_ranges_b

dwarf_get_ranges_baseaddress()

int dwarf_get_ranges_baseaddress	(	Dwarf_Debug	dw_dbg,
		Dwarf_Die	dw_die,
		Dwarf_Bool *	dw_known_base,
		Dwarf_Unsigned *	dw_baseaddress,
		Dwarf_Bool *	dw_at_ranges_offset_present,
		Dwarf_Unsigned *	dw_at_ranges_offset,
		Dwarf_Error *	dw_error
	)

The function allows callers to calculate actual address from .debug_ranges data in a simple and efficient way.

Parameters

dw_dbg	The Dwarf_Debug of interest.
dw_die	Pass in any non-null valid Dwarf_Die to find the applicable .debug_ranges base address. The dw_die need not be a CU-DIE. A null dw_die is allowed.
dw_known_base	if dw_die is non-null and there is a known base address for the CU DIE that (a DW_at_low_pc in the CU DIE) dw_known_base will be set TRUE, Otherwise the value FALSE will be returned through dw_known_base.
dw_baseaddress	if dw_known_base is retured as TRUE then dw_baseaddress will be set with the correct pc value. Otherwise zero will be set through dw_baseaddress.
dw_at_ranges_offset_present	Set to 1 (TRUE) if the dw_die has the attribute DW_AT_ranges, otherwise set to zero (FALSE).
dw_at_ranges_offset	Set to the value of dw_die DW_AT_ranges attribute of dw_die if and only iff dw_at_ranges_offset_present was set to 1.
dw_error	The usual error detail return pointer.

Returns

Returns DW_DLV_OK or DW_DLV_ERROR. Never returns DW_DLV_NO_ENTRY.