On Fri, 13 May 2022 08:43:35 GMT, Christian Hagedorn <chaged...@openjdk.org> wrote:
>> I'm googling around for some information about -gdwarf-4 but is mostly >> coming up empty handed. :( I found >> [this](https://www.phoronix.com/scan.php?page=news_item&px=GCC-11-DWARF-5-Possible-Default) >> saying that dwarf-5 became default in gcc11. It also claims dwarf-4 is >> about 10 years old. My guess is that all our supported gcc versions do >> support -gdwarf-4, but this needs to be verified. >> >> In practice, we only use gcc on linux so I'm not convinced we need to have >> an addition check for that. If we ever are going to support gcc on other >> OSes I think we'll have many more, much harder problems, than to remove the >> -gdwarf-4 flag. > > I'm back to work again. I also had a look but could not find something on > Google, either. I then skimmed through the old GCC manuals. I found the first > occurrence of `-gdwarf-4` in the manual for GCC 4.5.4 > [here](https://gcc.gnu.org/onlinedocs/gcc-4.5.4/gcc.pdf): > > > - gdwarf-version > Produce debugging information in DWARF format (if that is supported). This > is the format used by DBX on IRIX 6. The value of version may be either > 2, 3 > or 4; the default version is 2. > > While the manual for GCC 4.4.7 only mentions `-gdwarf-2`: > > -gdwarf-2 > Produce debugging information in DWARF version 2 format (if that is > supported). This is the format used by DBX on > IRIX 6. With this option, GCC > uses features of DWARF version 3 when they are useful; version 3 is upward > compatible with version 2, but may still cause problems for older > debuggers. > > > The minimum accepted GCC version is currently 5.0 according to: > https://github.com/openjdk/jdk/blob/d5ae3833b1b71eb84fadb69c0c92851400f8921c/doc/building.md?plain=1#L341-L344 > > This suggests that all our supported GCC versions should accept `-gdwarf-4`. @chhagedorn Thanks for the research. You provide more than necessary reason to accept `-gdwarf-4` without any further checks. ------------- PR: https://git.openjdk.java.net/jdk/pull/7126
