ctfconvert: Handle DW_AT_data_bit_offset

This attribute is new in DWARF 4 and supersedes DW_AT_bit_offset.

PR: 276059
Reported by: rscheff
Tested by: rscheff
MFC after: 1 week

ctfconvert: Integer encoding types are unsigned

Before this change, encodings in the user-defined range were being
sign-extended.

MFC after: 1 week
Sponsored by: Innovate UK

ctfconvert: Actually use the asprintf() helper

Fixes: 1165fc9a5266 ("ctfconvert: Give bitfield types names distinct from the base type")

ctfconvert: Give bitfield types names distinct from the base type

CTF integers have an explicit width and so can be used to represent
bitfields. Bitfield types emitted by ctfconvert(1) share the name of
the base integer type, so a struct field with type "unsigned int : 15"
will have a type named "unsigned int".

To avoid ambiguity when looking up types by name, add a suffix to names
of bitfield types to distinguish them from the base type. Then, if
ctfmerge happens to order bitfield types before the corresponding base
type in a CTF file, a name lookup will return the base type, which is
always going to be the desired behaviour.

PR: 265403
Reported by: cy
MFC after: 1 week
Sponsored by: The FreeBSD Foundation

ctfconvert: Handle arrays of empty structs

Members with such a type will legitimately have a size of zero, so don't
emit a warning.

PR: 260818
Reviewed by: bz
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33700

Increase ctfconvert buffer size

Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D19353

Process CUs with a language attribute of DW_LANG_Mips_Assembler.

At the moment ctfconvert(1) does not do much with such CUs, but
that may not be true in the future, and we run ctfconvert on several
assembly files during the build.

X-MFC with: r334883

Don't process DWARF generated from non-C/C++ code.

ctfconvert(1) is not designed to handle DWARF generated from such code,
and will generally fail in non-obvious ways. Use an explicit check to
help catch such potential failures.

Reported by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 2 weeks

ctf dwarf: don't report "no dwarf entry" as if it were an error

ctfconvert/ctfmerge: Fix a memory leak enumerating DWARF files

Reported by: Coverity
Sponsored by: Dell EMC Isilon

Revert r253678, r253661:
Fix a segfault in ctfmerge(1) due to a bug in GCC.

The change was correct and the bug real, but upstream didn't adopt it
and we want to remain in sync. When/if upstream does something about it
we can bring their version.

The bug in question was fixed in GCC 4.9 which is now the default in
FreeBSD's ports. Our native gcc-4.2, which is still in use in some Tier-2
platforms also has a workaround so no end-user should be harmed by the
revert.

Fix handling of forward enum declarations in the CTF tools.

Reported by: mmacy
MFC after: 2 weeks

DWARF emitted by clang 3.7 encodes array sizes using the DW_AT_count
attribute rather than DW_AT_upper_bound. Teach ctfconvert about this so that
array type sizes are encoded correctly.

PR: 203772
MFC after: 1 week

Mechanically convert cddl sun #ifdef's to illumos

Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.

Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.

MFC after: 1 month
Sponsored by: Multiplay

Fix a couple of bugs around the handling of structs and unions of size zero.
These would cause ctfconvert(1) to return an error when attempting to
resolve valid C types.

Reviewed by: Robert Mustacchi <rm@joyent.com>
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division

Only declare `bysz' variable under little endian archs.

Simplify DWARF version check.

Submitted by: emaste

Let ctfconvert accept DWARF version 3 and 4.

Clang 3.4 will sometimes emit DIE for struct/union member before
emitting the DIE for the type of that member. ctfconvert can not
handle this properly and will calculate a wrong member bit offset.
Same struct/union type from different .o file will be treated as
different types when their member bit offsets are different, and
gets added/merged multiple times. This will in turn cause many other
structs/pointers/typedefs that refer to the duplicated struct/union
gets added/merged multiple times and eventually causes numerous
duplicated CTF types in the kernel.debug file.

The simple workaround here is to make use of DW_AT_byte_size attribute
of the member DIE to calculate the bits occupied by the member's type,
without actually resolving the type.

* Make die_mem_offset() be able to handle DW_AT_data_member_location
attributes generated by Clang 3.4.
* Document how different compilers generate DW_AT_data_member_location
attributes differently.
* Document the quirks about DW_FORM_data[48].

We should not set the unnamed DIE's name to "__anon__" since that will
bring back a known issue with DTrace regarding type name
comparison. Instead, we can set the name to an empty string.

Pointed out by: avg

If function die_name() finds a DIE without a name, set its name to
"__anon__". This hack is used to workaround a issue that compilers
like GCC could generate DW_TAG_base_type DIE without a name.

Note that we didn't need this before because the old libdwarf
internally set all the unnamed DIE's name to "__anon__".

Convert ctfconvert to use the new libdwarf API.

Merge various CTF fixes from illumos

2942 CTF tools need to handle files which legitimately lack data
2978 ctfconvert still needs to ignore legitimately dataless files on SPARC

Illumos Revisions: 13745:6b3106b4250f
13754:7231b684c18b

Reference:

https://www.illumos.org/issues/2942
https://www.illumos.org/issues/2978

MFC after: 3 weeks

Fix a segfault in ctfmerge due to a bug in gcc.

GCC can generate bogus dwarf attributes with DW_AT_byte_size
set to 0xFFFFFFFF.
The issue was originaly detected in NetBSD but it has been
adapted for portability and to avoid compiler warnings.

Reference:
https://www.illumos.org/issues/3776

Obtained from: NetBSD
MFC after: 1 month

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Use FreeBSD's libdwarf which is BSD licensed instead of the GPL'd one that
is used in Solaris.