On 10/26/2016 10:47 AM, Mark Wielaard wrote:
On Wed, Oct 26, 2016 at 09:36:31AM -0700, Josh Stone wrote:
> On 10/26/2016 03:24 AM, Mark Wielaard wrote:
>> The name used in the standard and other DWARF implementations for
>> Programming Language One, PL/I, is DW_LANG_PLI (not DW_LANG_PL1).
>> [...]
>> +Version 0.168
>> +
>> +libdw: dwarf.h corrected the DW_LANG_PLI constant name (was DW_LANG_PL1).
>> + Any existing sources using the old name will have to be updated.
>> +
>
> That typo has been there since the dawn of elfutils.git, 2005-07-26
> commit b08d5a8fb42f. It seems callous to break API here, even if it was
> wrong. Why not include a #define to preserve compatibility?
Since it doesn't break ABI we have historically just fixed such wrong
constant names, see e.g. the removal in 0.160 of the non-existing
DW_TAG_mutable_type in 0.160. Given that others (libdwarf, binutils)
do define the correct name in their headers.
It doesn't matter what other headers do -- if someone was already using
the bad constant in elfutils' headers, that's an API break. But sure,
you might still decide that's acceptable.
Also I would be somewhat afraid that might break the generation
of known-dwarf.h (although I didn't try).
It might be ok for known-dwarf.h to know both PL1 and PLI.
Is there actually any source out there that uses this (wrong)
constant name?
https://github.com/search?q=dw_lang_pl1&type=Code
Lots of hits, but in the first few pages they're all just clones of
dwarf_aggregate_size.c.
via Google I found at least one real hit from an elfutils user:
https://lists.gforge.inria.fr/pipermail/simgrid-commits/2015-September/02...
and it seems some version of eclipse cdt had the same typo:
https://www.cct.lsu.edu/~rguidry/eclipse-doc36/src-html/org/eclipse/cdt/u...
and also found the typo in a dwarfstd issue:
http://www.dwarfstd.org/ShowIssue.php?issue=130819.1
>> - DW_LANG_PL1 = 0x000f, /* ISO PL/1:1976 */
>> + DW_LANG_PLI = 0x000f, /* ISO PL/1:1976 */
>
> You should correct the comment too, "PL/I".
The '1' in the comment really is correct, because that
is the actual name of the standard. That is probably where
the confusion came from.
Figure 8 in the DWARF 3 and 4 standards both call it "ANSI PL/I:1976"
(not "ISO"), as does Table 3.1 in the DWARF 5 draft I've got.
Wikipedia also uses "PL/I", and even has a redirect from "PL/1".
This "I" is pronounced "one" though, surely as a roman numeral.