[PATCH 3/3] Windows gdb: Document "info threads" Windows specifics

[Pedro Alves <pedro@palves.net>]

Document "info threads" Windows specifics in the Windows debugging
features section.

Change-Id: I2123899bb8482381657ffbb4f0cc99f196526623
commit-id:856225ce
---
 gdb/doc/gdb.texinfo | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 29d959e68f7..318299fdd3d 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -25905,6 +25905,23 @@ supports @kbd{C-@key{BREAK}} as an alternative interrupt key
 sequence, which can be used to interrupt the debuggee even if it
 ignores @kbd{C-c}.
 
+The @code{info threads} command displays whether a thread stopped due
+to an exception or whether it stopped while running a system call.
+For example:
+
+@smallexample
+(@value{GDBP}) info threads
+  Id   Target Id                            Frame
+  1    Thread 15648.0x4338                  main () at example.c:5
+  2    Thread 15648.0x3d58 (in syscall)     0x00007ffde37057b4 in ntdll!ZwWaitForWorkViaWorkerFactory () from C:/WINDOWS/SYSTEM32/ntdll.dll
+* 3    Thread 15648.0x12d4 (in exception)   0x00007ffde00aa464 in KERNELBASE!CtrlRoutine () from C:/WINDOWS/System32/KERNELBASE.dll
+@end smallexample
+
+Above we see that thread 2 is blocked inside a system call, thread 3
+stopped for an exception, and thread 1 simply stopped while running
+user space code.  Debug events such as breakpoint traps, single-steps,
+and @samp{Ctrl-C} interruptions are considered exceptions.
+
 There are various additional Windows-specific commands, described in
 this section.  Working with DLLs that have no debugging symbols is
 described in @ref{Non-debug DLL Symbols}.
-- 
2.53.0