https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92386
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-11-06
CC| |edlinger at gcc dot gnu.org,
| |jason at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org,
| |tromey at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed. The issue is that those free-flow variables are "live" at the
start of the containing DW_TAG_lexical_block which spans its natural
PC range.
I believe this is a defect in DWARF not being able to represent C99/C++ here.
The only chance GCC has here is to add "fake" lexical blocks starting at
every free-flow variable declaration and ending at the end of the containing
lexical block. Once we generate debug info all the original information
is already lost. I fear that doing this blows up memory use and debuginfo
size.
It's also bad style to shadow a variable in a way so that two are live
at different points in the same lexical scope - this probably deserves
a warning and should be considered bad style?
