GDB for Windows does not work correctly in Eclipse plugin

[kolerov]

On Windows 10 hosts Eclipse plugin for ARC cannot connect to any GDB server correctly. To reproduce it you can create a simple debug configuration for nSIM and try to debug an application. The problem is that Eclipse plugin sends to GDB this string:

arget remote ...

instead of this:

target remote ...

I've created a pull request with temporary fix (foss-for-synopsys-dwc-arc-processors/binutils-gdb#66). This pull request reverts commit d08cbc5d3203118da5583296e49273cf82378042 which introduced that bug. This revert is temporary since it's not clear what exactly leads to this error.

Note, on Linux hosts that problem is not happening.

[kolerov]

Seems like the problem is in GDB itself. Compare gdb/even-top.c in our repository and in upstream:

https://github.com/foss-for-synopsys-dwc-arc-processors/binutils-gdb/blob/arc64/gdb/event-top.c
https://github.com/bminor/binutils-gdb/commits/master/gdb/event-top.c

You will see that after bminor/binutils-gdb@d08cbc5 commit there is a series of other commits which related to input/output and buffering. I tried to cherry-pick some of them, build GDB and try to use it with Eclipse on Windows. Then everything worked fine. There is a list of commits which I got:

$ git log --oneline -n 10 gdb/event-top.c
3e6f0b82f9d (HEAD -> ykolerov-fix-win-rebase) gdb: remove static buffer in command_line_input
48df998111d [gdb] Handle pending ^C after rl_callback_read_char
974c80a52be gdb: move setbuf calls out of gdb_readline_no_editing_callback
1b991eb9d81 gdb: handle bracketed-paste-mode and EOF correctly
4a52ae68069 gdb: improved EOF handling when using readline 7
fa121beb516 gdb: work around prompt corruption caused by bracketed-paste-mode
d08cbc5d320 gdb: unbuffer all input streams when not using readline

Picking some of these commits to our current source tree leads to conflict thus it's necessary to do it carefully.

[shahab-vahedi]

Thank you Yuriy for the inputs. I will make sure that the next cut out release of GDB will either have these commits naturally or cherry-picked.

[kolerov]

I confirm that all those commits are presented in our binutils-gdb repository now. The latest arc-2023.03-rc1 release is built without this issue.