From 6b25d11b012055936bb07179e246e04763cac27e Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 9 May 2024 12:32:53 +0100 Subject: Windows gdb+gdbserver: Check whether DBG_REPLY_LATER is available Per , DBG_REPLY_LATER is "Supported in Windows 10, version 1507 or above, ..." Since we support versions of Windows older than 10, we need to know whether DBG_REPLY_LATER is available. And we need to know this before starting any inferior. This adds a function that probes for support (and caches the result), by trying to call ContinueDebugEvent on pid=0,tid=0 with DBG_REPLY_LATER, and inspecting the resulting error. Suggested-by: Hannes Domani Suggested-by: Eli Zaretskii Change-Id: Ia27b981aeecaeef430ec90cebc5b3abdce00449d --- gdb/nat/windows-nat.c | 20 ++++++++++++++++++++ gdb/nat/windows-nat.h | 9 +++++++++ 2 files changed, 29 insertions(+) diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c index 4fd717e..0fdfcba 100644 --- a/gdb/nat/windows-nat.c +++ b/gdb/nat/windows-nat.c @@ -942,6 +942,26 @@ disable_randomization_available () /* See windows-nat.h. */ bool +dbg_reply_later_available () +{ + static int available = -1; + if (available == -1) + { + /* DBG_REPLY_LATER is supported since Windows 10, Version 1507. + If supported, this fails with ERROR_INVALID_HANDLE (tested on + Win10 and Win11). If not supported, it fails with + ERROR_INVALID_PARAMETER (tested on Win7). */ + if (ContinueDebugEvent (0, 0, DBG_REPLY_LATER)) + internal_error (_("ContinueDebugEvent call should not " + "have succeeded")); + available = (GetLastError () != ERROR_INVALID_PARAMETER); + } + return available; +} + +/* See windows-nat.h. */ + +bool initialize_loadable () { bool result = true; diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h index 2efb54e..96835b3 100644 --- a/gdb/nat/windows-nat.h +++ b/gdb/nat/windows-nat.h @@ -415,6 +415,15 @@ extern DeleteProcThreadAttributeList_ftype *DeleteProcThreadAttributeList; extern bool disable_randomization_available (); +/* This is available starting with Windows 10. */ +#ifndef DBG_REPLY_LATER +# define DBG_REPLY_LATER 0x40010001L +#endif + +/* Return true if it's possible to use DBG_REPLY_LATER with + ContinueDebugEvent on this host. */ +extern bool dbg_reply_later_available (); + /* Load any functions which may not be available in ancient versions of Windows. */ -- cgit v1.1