[PATCH 00/30] Stop throwing exceptions from signal handlers

Pedro Alves
2016-03-18T19:18:50Z

Aka, get rid of immediate_quit.

Throwing exceptions from signal handlers is undefined C++. So for C++
conversion we need to replace the immediate_quit mechanism by
something else.

This series:

- Replaces all immediate_quit uses with something else.

- Removes a few custom SIGINT handlers, centralizing more on the
"quit" flag and GDB's default SIGINT handler.

- Fixes several classical signal handler / mainline code races, using
the self-pipe trick.

- Introduces a "struct serial_event" abstraction to hide the self-pipe
trick -- on Windows we don't use pipes at all, and on Linux, we
could use eventfd (but I didn't do that, at least yet).

- Stumbles on a few bogus clear_quit_flag uses, and thus completely
eliminates it, for good measure.

- Decouples target_interrupt from all-stop/non-stop modes

- Fixes a few cases of indefinitely-delayed Ctrl-C handling.

- Fixes/incorrect handling of EINTR in ser-*.c backends

- Goes through the tree fixing all target_terminal_ours calls that
should be target_terminal_ours_for_output instead. We only end up
with a few target_terminal_ours calls, at places were we need to
handle input.

- Plugs a few leaks along the way.

- Fixes a bug where you can't answer y/n to an internal error if the
target has the terminal.

- Introduces the concept of quit handlers.

- Does a few clean ups along the way.

Tested on x86-64 Fedora 23, native and gdbserver.

A slightly older version manually test on mingw64/Windows 7, to make
sure Ctrl-C still works as expected there.

This applies on top of the "target mips" elimination patch:
https://sourceware.org/ml/gdb-patches/2016-03/msg00313.html

I've pushed the whole series to users/palves/immediate_quit.

Pedro Alves (30):
Don't rely on immediate_quit in command_line_input
Inline command_loop in read_command_line
TUI: check whether in secondary prompt instead of immediate_quit
Don't set immediate_quit in prompt_for_continue
Stop remote-fileio.c from throwing from SIGINT handler
Remove unused struct serial::name field
Introduce a serial interface for select'able events
Fix signal handler/event-loop races
Introduce interruptible_select
Make Python use a struct serial event
Don't call clear_quit_flag after check_quit_flag
Don't call clear_quit_flag in command_handler
Don't call clear_quit_flag in prepare_to_throw_exception
Don't call clear_quit_flag in captured_main
Eliminate clear_quit_flag
Decouple target_interrupt from all-stop/non-stop modes
Pass Ctrl-C to the target in target_terminal_inferior
Fix inconsistent handling of EINTR in ser-*.c backends
ada-lang.c: Introduce type_as_string and use it
Use target_terminal_ours_for_output in cp-support.c
Use target_terminal_ours_for_output in exceptions.c
Use target_terminal_ours_for_output in infcmd.c
Use target_terminal_ours_for_output in warning/internal_error
Add missing cleanups to defaulted_query and prompt_for_continue
Do target_terminal_ours in query & friends instead of in all callers
Use target_terminal_ours_for_output in MI
TUI: GC tui_target_has_run
target remote: Don't rely on immediate_quit (introduce quit handlers)
Eliminate immediate_quit
Eliminate target_check_pending_interrupt

gdb/Makefile.in | 6 +-
gdb/ada-lang.c | 74 ++++++-----
gdb/cp-support.c | 4 +-
gdb/defs.h | 58 +++++++--
gdb/event-loop.c | 41 ++++--
gdb/event-loop.h | 26 +---
gdb/event-top.c | 165 ++++++++++++++++++++++---
gdb/exceptions.c | 17 ++-
gdb/extension-priv.h | 5 +-
gdb/extension.c | 34 +++--
gdb/gdb_select.h | 15 +++
gdb/gnu-nat.c | 12 +-
gdb/guile/guile.c | 1 -
gdb/guile/scm-ports.c | 4 +-
gdb/i386-tdep.c | 49 ++------
gdb/infcmd.c | 10 +-
gdb/linux-nat.c | 10 --
gdb/linux-record.c | 54 +++-----
gdb/main.c | 1 -
gdb/mi/mi-interp.c | 125 ++++++++++++++++---
gdb/mi/mi-main.c | 7 +-
gdb/mingw-hdep.c | 52 +-------
gdb/nto-procfs.c | 4 -
gdb/posix-hdep.c | 13 --
gdb/python/python.c | 44 +++----
gdb/record-full.c | 22 ++--
gdb/remote-fileio.c | 34 +----
gdb/remote-sim.c | 5 +-
gdb/remote.c | 329 +++++++++++++++++++++----------------------------
gdb/ser-base.c | 30 ++++-
gdb/ser-event.c | 220 +++++++++++++++++++++++++++++++++
gdb/ser-event.h | 51 ++++++++
gdb/ser-go32.c | 4 +
gdb/ser-unix.c | 108 ++--------------
gdb/serial.c | 66 ++++++----
gdb/serial.h | 8 +-
gdb/target-delegates.c | 25 ++--
gdb/target.c | 17 ++-
gdb/target.h | 19 +--
gdb/top.c | 67 +++++-----
gdb/tui/tui-hooks.c | 24 ----
gdb/tui/tui-io.c | 2 +-
gdb/tui/tui.c | 4 +-
gdb/ui-file.c | 8 +-
gdb/utils.c | 66 ++++++----
45 files changed, 1115 insertions(+), 825 deletions(-)
create mode 100644 gdb/ser-event.c
create mode 100644 gdb/ser-event.h

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2.5.0