2021-02-15:
  dwarfdump given -ku now prints brief lists counting
  the uses of every TAG, ATtribute, and FORM,
  a concise summary of the basic building blocks of DWARF.
2021-01-23:
  dwarfdump now reports and checks-for-sensible-values
  the expression block offsets that DW_OP_bra and 
  DW_OP_skip use.  If an expression does not use either of
  those operators dwarfdump does not report the individual DW_OP
  expression offsets.
2020-12-23:
  dwarfdump --print-macinfo now follows DW_MACRO_imports
  and does several additional checks on .debug_macro section
  data. --check-macros skips printing most entries but does
  all that and reports even more about that section. Since
  .debug_macro does not reproduce all macro operations in
  the original source the MACRONOTEs printed are indications
  of things to consider, not errors.

2020-11-21:
  dwarfdump now prints DWARF expression operators each on
  its own line.  This makes viewing DWARF expressions much
  nicer given the increased use of much longer expressions.
  Those expression operators that reference DIES are now
  followed, verified, and the target DW_TAG and DW_AT_name
  are printed.  A new dwarfdump.conf command 'option:' lets
  one specify option: --format-expr-ops-joined in case you
  want the old style DWARF expression operators-on-one-line.
  Where the DWARF DIE children nest > nine-deep dwarfdump
  switches from indentation by spaces to a nest-level number.

2020-09-08:
  libdwarf/dwarfdump work well with DWARF4 and DWARF5,
  including DWP files.

2020-07-08:
  libdwarf now reads .debug_gnu_pubtypes & pubnames
  (non-standard but gcc creates them in DWARF5) via a small
  number of new functions and dwarfdump  --print-debug-gnu
  prints both sections.  Verifying the .debug_info offsets
  is not yet done.

2020-06-29:
  Dwarfdump now dumps DWARF5 .debug_rnglists and
  .debug_loclists.  To handle DWARF5 there are a small
  number of new functions. All existing functions are
  still supported, but to read DWARF5 some small changes
  are required.  In libdwarf see libdwarf2.1.pdf and also
  see libdwarf/ChangeLog for details.

2020-05-23:
  dwarfdump now takes much less malloc() to work, as
  measured by valgrind --tool=massif  and massif-visualizer.
  A dwarfdump run that did 2.2Gib of malloc/free before the
  changes now does 1.4GiB.

2020-05-19:
  libdwarf and dwarfdump now support DWARF5 .debug_rnglists.
  The new interfaces are documented in libdwarf/libdwarf2.1.pdf.
  The new option to dwarfdump is "--print-raw-rnglists".
2019-11-04:
  The code (dwarfdump/libdwarf), regressiontests,
  and readelfobj directories and all their tests
  are known to work on Linux(Ubuntu on x86_64 and i686), 
  FreeBSD, MacOS Catalina (with Apple Command Line Tools),
  and IBM s390 (Big Endian!) running Ubuntu Linux.
  On Windows-MinGW the full regression tests
  have not been tested, but 'make check' works
  for dwarfdump/libdwarf (the current dwarfdump 
  make check actually does run dwarfdump and 
  checks that dwarfdump basically works).
2019-04-16:
  Now a --disable-libelf configure/build of libdwarf/dwarfdump
  can read elf, mach-o DSYM, and PE executable/dll object files.
  Such a build will not need or use libelf or elf.h .
  The dwarfdump options that display Elf section headers
  or relocation record data are not available in a 
  --disable-libelf build. 
  Nor is dwarfdump's support of reading archive files
  available in a --disable-libelf build. 
  This libdwarf detects corrupt Elf object files much sooner
  than before, but does not explain what the corruption
  really is. Use GNU readelf (or readelfobj, a project
  on sourceforge) to get more detail about the problems found.  
  See https://www.prevanders.net/dwarf.html for the git clone
  command for readelfobj.
  With --disable-libelf the --enable-dwarfgen option
  does not work: the dwarfgen build will fail.
2019-02-18:
  For building on machines without a usable elf.h or libelf
  but possibly with a libelf.h visible, --disable-libelf
  ensures the build won't use libelf or elf.h anywhere. 
  -lz will be done if zlib.h is visible, independent of
  libelf, libelf.h, and elf.h
2019-02-08:
  If one has a standard Bourne shell (sh) available
  (such as sh on MacOS and sh in MinGW on Windows)
  one may be able to build libdwarf and dwarfdump natively
  and they can read Mach-o dSYM and PE object files
  to access DWARF information. 
  This has NOT been tested under MacOS, so will likely
  fail on MacOS.
  No elf.h, libelf.h or zlib.h should be present. 
  For example, the following
  is known to work under MinGW and this general plan
  applies to all builds including all builds with elf.h
  and libelf:
    mkdir test
    cd test
    #(copy the source tree into test, if from git
    #the name of the top level will likely be 'code')
    cd code
    sh -x scripts/FIX-CONFIGURE-TIMES
    cd ..
    mkdir bld
    cd bld
    ../code/configure (choose your preferred options here)
    make
  
2019-01-15:
  The pre-build dwarf_names.[hc] and the tag related
  files are now part of the standard build so there is
  no longer any two-stage aspect of the build. 
  The build simply compiles files in the distribution.
  If you use git to access the source be sure to
  sh scripts/FIX-CONFIGURE-TIMES
  to adjust the file timestamps as having timestamps
  in the right relationships is vital and git
  does not maintain timestamps.
  The script is always safe to run. It takes about 30 seconds.
2018-12-22:
  The complicated process of building certain .c and .h
  files has been relegated to the few people updating
  files libdwarf/libdwarf.h.in, libdwarf/dwarf_errmsg_list.h,
  dwarfdump/tag_attr_ext.list,dwarfdump/tag_attr.list,
  dwarfdump/tag_tree_ext.list, and dwarfdump/tag_tree.list.
  For everyone else the build is simply compiling
  the .c and .h files in the distribution. Simpler.
    sh scripts/buildstandardsource.sh
  creates these files.
2018-10-22:
  dwarfdump can now dump mach-o (MacOS) dSYM dwarf.
  All the usual libdwarf interfaces work.
  A new libdwarf initialization call dwarf_init_path()
  may be convenient for you to use.
2018-08-05:
  dwarfdump.conf is now installed by make install
  in <install prefix>/shared/libdwarf/dwarfdump  .
  Any  dwarfdump.conf or .dwarfdump.conf in your
  $HOME directory will be found before the
  one in shared.  The file is only opened when
  one wants a more accurate register naming in frame
  reports (the default is just to name things r54 
  etc, choosing the right abi with -x abi=<something>
  can be helpful at times).
2018-06-24:
  The configure has been completely rewritten to follow
  current standards and practices. For simple builds
  the standard
    ./configure
    make
  works as always, but the generated libdwarf.a appears
  in libdwarf/.libs/libdwarf.a , as does the shared object
  if "./configure --enable-shared" is used.
  
  To build dwarfgen one adds the configure option --enable-dwarfgen
    instead of using 'make all'.
  To build the example code one adds the configure option 
    --enable-dwarfexample  instead of using 'make all'.

  "mkdir /tmp/bld ; cd /tmp/bld ; <sourcebase>/configure"
  continues to work, as does configure --host=<name>  .
2018-06-14:
  A small simplification of build options simplifies building
  across different environments.  If your environment needs
  to use the non-standard elf_open() call instead of unix/linux open()
  then do <path>/configure --enable-elf-open which sets
  HAVE_ELF_OPEN in config.h.
2018-03-27:
  All the DWARF5 FORMs appear to be dealt with.
  It's now possible to cross-compile libdwarf and dwarfdump.
  See the README.
2016-11-30:
  An alternative build mechanism using cmake is now in the source tree.
  The builds for product testing continue to be done using configure && make.
2016-09-20:
  --enable-sanitize option added to configure. This builds
  with -fsanitize=address to check for out of bounds
  memory access. 
2016-09-05:
  dwarfexample/simpleexample.c now has a simple option letting one
  extract all .debug_info, .debug_types strings into a file by
  themselves in case one wanted to examine string frequencies,
  for example.
2016-06-01:  Now we use DW_VERSION_DATE_STR for
  dates everywhere instead of __DATE__ __TIME__
  so a repeated build gets identical object output.
  DW_VERSION_DATE_STR is updated by UPDATEDWARFDUMPVERSION.sh
  wherever that string is needed.
  
2015-11-26:  If DWARF section data you intend to read
  with libdwarf is compressed by zlib (a section name
  like  .zdebug_info indicates such compression) libdwarf etc
  will need zlib's headers and archive or shared-library
  at build and link time. If you  do not have zlib
  everything will compile fine and will work
  on ordinary DWARF sections but libdwarf will not be
  able to read .zdebug_ compressed sections.
  zlib.h is the main zlib header and libz.a is the
  most likely zlib library you will encounter.

2015-11-15:  It is now possible to build
  outside of the source tree. See README.
  So configure.in changed a little.
2015-01-13:  Removed dwarfdump2 and references to it.
  dwarfdump has the (tsearch) features needed so the C++
  version no longer a benefit.
