error.h isn't standard and so isn't part of the musl C library.
To easy future porting, consolidate the inclusion of error.h into system.h.

https://sourceware.org/bugzilla/show_bug.cgi?id=21008

Signed-off-by: Ross Burton <ross.burton@intel.com>

This is only useful for bad DWARF where an expression block might have
an expression that refers to a DIE that contains the expression block
itself. But that might happen with bad DWARF generated by a fuzzer.

Signed-off-by: Mark Wielaard <mark@klomp.org>

If the target of a DW_OP_GNU_parameter_ref isn't a DW_TAG_formal_parameter
that is bad data (which varlocs should error on). But it isn't an internal
consistency check (for which varlocs should assert).

Signed-off-by: Mark Wielaard <mark@klomp.org>

It is only a consistency issue if we actually have an cfi_debug and the
cfi_debug_bias is not zero (because they come from the same file as the
other debug data).

Signed-off-by: Mark Wielaard <mark@klomp.org>

When using the varlocs test with a fuzzer using assert for internal
sanity checks is great to find issues. But when encountering bad data
using an assert is wrong. Just use error to show we handle the data
correctly (by reporting it is bad, instead of crashing).

Signed-off-by: Mark Wielaard <mark@klomp.org>

Handle all new DW_LLE opcodes in .debug_loclists in dwarf_getlocation.
__libdw_read_begin_end_pair_inc now also handles a default location
(which is simply the range [0,-1]). Since expression blocks can now
also come from the .debug_loclists section add a new fake_loclists_cu
necessary for checking bounds while parsing expression blocks.

Adapt varlocs test to handle debug-only files.
Test testfileranges5.debug and testfilesplitranges5.debug with it.

Signed-off-by: Mark Wielaard <mark@klomp.org>

DW_OP_addrx/constx and GNU DebugFission DW_OP_GNU_addr/const_index take
as argument an index into the .debug_addr section for the associated CU.
This index gets resolved through dwarf_getlocation_attr. A new fake addr
CU is created per Dwarf for use with this new attribute. For split DWARF
files, the IDX_debug_addr gets replaced with the skeleton section and the
addr base is resolved immediately when constructing the split DWARF CU.
Move __libdw_cu_addr_base to libdwP.h to share with eu-readelf. Also
make it possible to resolve addrx[1234]/GNU_addr_index also as constant
indexes to (also) show when displaying these attributes in eu-readelf.

A new varlocs tests is added to test the resolving for both the DWARF4
and DWARF5 DW_OP variants. And now that addrx forms are resolved in
split DWARF files add the new DIEs with "single ranges" (those DIEs that
have a lowpc/highpc attribute pair) to run-all-dwarf-ranges.sh.

Signed-off-by: Mark Wielaard <mark@klomp.org>

DW_OP_implicit_pointer, DW_OP_entry_value, DW_OP_const_type,
DW_OP_regval_type, DW_OP_deref_type, DW_OP_xderef_type,
DW_OP_convert and OP_reinterpret are implemented like their
pre-DWARF5 GNU variants.

DW_OP_xderef_type is implemented as a (non-CU relative) variant of
DW_OP_deref_type.

DW_OP_addrx and DW_OP_constx are recognized but not interpreted yet.

Signed-off-by: Mark Wielaard <mark@klomp.org>

We want to check whether the bias is zero, not whether we have dwarf
debug_frame cfi.

This triggered on a ppc64/ppc64le self-check since it has both
debug_frame and eh_frame cfi (other arches often only have eh_frame).

Signed-off-by: Mark Wielaard <mark@klomp.org>

Make sure the testcases (library functions they use) don't crash,
triggers self-check/asserts or leaks memory under valgrind. This
also helps making sure newer DWARF constructs are handled (when
building with -gdwarf-5).

Signed-off-by: Mark Wielaard <mark@klomp.org>