[PATCH v3 16/29] Share some Windows-related globals

Tom Tromey
2020-03-13T19:09:02Z

This moves some Windows-related globals into nat/windows-nat.c,
sharing them between gdb and gdbserver.

gdb/ChangeLog
2020-03-13 Tom Tromey <tromey@adacore.com>

* windows-nat.c (current_process_handle, current_process_id)
(main_thread_id, last_sig, current_event, last_wait_event)
(current_windows_thread, desired_stop_thread_id, pending_stops)
(struct pending_stop, siginfo_er): Move to nat/windows-nat.c.
(display_selectors, fake_create_process)
(get_windows_debug_event): Update.
* nat/windows-nat.h (current_process_handle, current_process_id)
(main_thread_id, last_sig, current_event, last_wait_event)
(current_windows_thread, desired_stop_thread_id, pending_stops)
(struct pending_stop, siginfo_er): Move from windows-nat.c.
* nat/windows-nat.c (current_process_handle, current_process_id)
(main_thread_id, last_sig, current_event, last_wait_event)
(current_windows_thread, desired_stop_thread_id, pending_stops)
(siginfo_er): New globals. Move from windows-nat.c.

gdbserver/ChangeLog
2020-03-13 Tom Tromey <tromey@adacore.com>

* win32-low.c (current_process_handle, current_process_id)
(main_thread_id, last_sig, current_event, siginfo_er): Move to
nat/windows-nat.c.
---
gdb/ChangeLog | 17 ++++++
gdb/nat/windows-nat.c | 13 ++++-
gdb/nat/windows-nat.h | 57 +++++++++++++++++++
gdb/windows-nat.c | 125 +++++++++++++----------------------------
gdbserver/ChangeLog | 6 ++
gdbserver/win32-low.cc | 8 ---
6 files changed, 130 insertions(+), 96 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index 8217a985320..80a1583b884 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -1,5 +1,5 @@
/* Internal interfaces for the Windows code
- Copyright (C) 1995-2019 Free Software Foundation, Inc.
+ Copyright (C) 1995-2020 Free Software Foundation, Inc.

This file is part of GDB.

@@ -22,6 +22,17 @@
namespace windows_nat
{

+HANDLE current_process_handle;
+DWORD current_process_id;
+DWORD main_thread_id;
+enum gdb_signal last_sig = GDB_SIGNAL_0;
+DEBUG_EVENT current_event;
+DEBUG_EVENT last_wait_event;
+windows_thread_info *current_windows_thread;
+DWORD desired_stop_thread_id = -1;
+std::vector<pending_stop> pending_stops;
+EXCEPTION_RECORD siginfo_er;
+
windows_thread_info::~windows_thread_info ()
{
CloseHandle (h);
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 4176ed7f660..501147b2c90 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -20,6 +20,9 @@
#define NAT_WINDOWS_NAT_H

#include <windows.h>
+#include <vector>
+
+#include "target/waitstatus.h"

namespace windows_nat
{
@@ -111,6 +114,60 @@ enum thread_disposition_type
extern windows_thread_info *thread_rec (ptid_t ptid,
thread_disposition_type disposition);

+/* Currently executing process */
+extern HANDLE current_process_handle;
+extern DWORD current_process_id;
+extern DWORD main_thread_id;
+extern enum gdb_signal last_sig;
+
+/* The current debug event from WaitForDebugEvent or from a pending
+ stop. */
+extern DEBUG_EVENT current_event;
+
+/* The most recent event from WaitForDebugEvent. Unlike
+ current_event, this is guaranteed never to come from a pending
+ stop. This is important because only data from the most recent
+ event from WaitForDebugEvent can be used when calling
+ ContinueDebugEvent. */
+extern DEBUG_EVENT last_wait_event;
+
+/* Info on currently selected thread */
+extern windows_thread_info *current_windows_thread;
+
+/* The ID of the thread for which we anticipate a stop event.
+ Normally this is -1, meaning we'll accept an event in any
+ thread. */
+extern DWORD desired_stop_thread_id;
+
+/* A single pending stop. See "pending_stops" for more
+ information. */
+struct pending_stop
+{
+ /* The thread id. */
+ DWORD thread_id;
+
+ /* The target waitstatus we computed. */
+ target_waitstatus status;
+
+ /* The event. A few fields of this can be referenced after a stop,
+ and it seemed simplest to store the entire event. */
+ DEBUG_EVENT event;
+};
+
+/* A vector of pending stops. Sometimes, Windows will report a stop
+ on a thread that has been ostensibly suspended. We believe what
+ happens here is that two threads hit a breakpoint simultaneously,
+ and the Windows kernel queues the stop events. However, this can
+ result in the strange effect of trying to single step thread A --
+ leaving all other threads suspended -- and then seeing a stop in
+ thread B. To handle this scenario, we queue all such "pending"
+ stops here, and then process them once the step has completed. See
+ PR gdb/22992. */
+extern std::vector<pending_stop> pending_stops;
+
+/* Contents of $_siginfo */
+extern EXCEPTION_RECORD siginfo_er;
+
/* Return the name of the DLL referenced by H at ADDRESS. UNICODE
determines what sort of string is read from the inferior. Returns
the name of the DLL, or NULL on error. If a name is returned, it
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index c0b1b8521db..74b852ca603 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -244,28 +244,8 @@ static CORE_ADDR cygwin_get_dr (int i);
static unsigned long cygwin_get_dr6 (void);
static unsigned long cygwin_get_dr7 (void);

-static enum gdb_signal last_sig = GDB_SIGNAL_0;
-/* Set if a signal was received from the debugged process. */
-
static std::vector<windows_thread_info *> thread_list;

-/* The process and thread handles for the above context. */
-
-/* The current debug event from WaitForDebugEvent or from a pending
- stop. */
-static DEBUG_EVENT current_event;
-
-/* The most recent event from WaitForDebugEvent. Unlike
- current_event, this is guaranteed never to come from a pending
- stop. This is important because only data from the most recent
- event from WaitForDebugEvent can be used when calling
- ContinueDebugEvent. */
-static DEBUG_EVENT last_wait_event;
-
-static HANDLE current_process_handle; /* Currently executing process */
-static windows_thread_info *current_thread; /* Info on currently selected thread */
-static EXCEPTION_RECORD siginfo_er; /* Contents of $_siginfo */
-
/* Counts of things. */
static int exception_count = 0;
static int event_count = 0;
@@ -336,37 +316,6 @@ static const struct xlate_exception xlate[] =

#endif /* 0 */

-/* The ID of the thread for which we anticipate a stop event.
- Normally this is -1, meaning we'll accept an event in any
- thread. */
-static DWORD desired_stop_thread_id = -1;
-
-/* A single pending stop. See "pending_stops" for more
- information. */
-struct pending_stop
-{
- /* The thread id. */
- DWORD thread_id;
-
- /* The target waitstatus we computed. */
- target_waitstatus status;
-
- /* The event. A few fields of this can be referenced after a stop,
- and it seemed simplest to store the entire event. */
- DEBUG_EVENT event;
-};
-
-/* A vector of pending stops. Sometimes, Windows will report a stop
- on a thread that has been ostensibly suspended. We believe what
- happens here is that two threads hit a breakpoint simultaneously,
- and the Windows kernel queues the stop events. However, this can
- result in the strange effect of trying to single step thread A --
- leaving all other threads suspended -- and then seeing a stop in
- thread B. To handle this scenario, we queue all such "pending"
- stops here, and then process them once the step has completed. See
- PR gdb/22992. */
-static std::vector<pending_stop> pending_stops;
-
struct windows_nat_target final : public x86_nat_target<inf_child_target>
{
void close () override;
@@ -387,7 +336,7 @@ struct windows_nat_target final : public x86_nat_target<inf_child_target>

bool stopped_by_sw_breakpoint () override
{
- return current_thread->stopped_at_software_breakpoint;
+ return current_windows_thread->stopped_at_software_breakpoint;
}

bool supports_stopped_by_sw_breakpoint () override
@@ -1207,7 +1156,7 @@ display_selector (HANDLE thread, DWORD sel)
static void
display_selectors (const char * args, int from_tty)
{
- if (!current_thread)
+ if (!current_windows_thread)
{
puts_filtered ("Impossible to display selectors now.\n");
return;
@@ -1218,45 +1167,45 @@ display_selectors (const char * args, int from_tty)
if (wow64_process)
{
puts_filtered ("Selector $cs\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegCs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegCs);
puts_filtered ("Selector $ds\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegDs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegDs);
puts_filtered ("Selector $es\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegEs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegEs);
puts_filtered ("Selector $ss\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegSs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegSs);
puts_filtered ("Selector $fs\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegFs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegFs);
puts_filtered ("Selector $gs\n");
- display_selector (current_thread->h,
- current_thread->wow64_context.SegGs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->wow64_context.SegGs);
}
else
#endif
{
puts_filtered ("Selector $cs\n");
- display_selector (current_thread->h,
- current_thread->context.SegCs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegCs);
puts_filtered ("Selector $ds\n");
- display_selector (current_thread->h,
- current_thread->context.SegDs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegDs);
puts_filtered ("Selector $es\n");
- display_selector (current_thread->h,
- current_thread->context.SegEs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegEs);
puts_filtered ("Selector $ss\n");
- display_selector (current_thread->h,
- current_thread->context.SegSs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegSs);
puts_filtered ("Selector $fs\n");
- display_selector (current_thread->h,
- current_thread->context.SegFs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegFs);
puts_filtered ("Selector $gs\n");
- display_selector (current_thread->h,
- current_thread->context.SegGs);
+ display_selector (current_windows_thread->h,
+ current_windows_thread->context.SegGs);
}
}
else
@@ -1264,7 +1213,7 @@ display_selectors (const char * args, int from_tty)
int sel;
sel = parse_and_eval_long (args);
printf_filtered ("Selector \"%s\"\n",args);
- display_selector (current_thread->h, sel);
+ display_selector (current_windows_thread->h, sel);
}
}

@@ -1587,7 +1536,7 @@ fake_create_process (void)
(unsigned) GetLastError ());
/* We can not debug anything in that case. */
}
- current_thread
+ current_windows_thread
= windows_add_thread (ptid_t (current_event.dwProcessId,
current_event.dwThreadId, 0),
current_event.u.CreateThread.hThread,
@@ -1782,8 +1731,9 @@ windows_nat_target::get_windows_debug_event (int pid,
current_event = iter->event;

inferior_ptid = ptid_t (current_event.dwProcessId, thread_id, 0);
- current_thread = thread_rec (inferior_ptid, INVALIDATE_CONTEXT);
- current_thread->reload_context = 1;
+ current_windows_thread = thread_rec (inferior_ptid,
+ INVALIDATE_CONTEXT);
+ current_windows_thread->reload_context = 1;

DEBUG_EVENTS (("get_windows_debug_event - "
"pending stop found in 0x%x (desired=0x%x)\n",
@@ -2006,9 +1956,10 @@ windows_nat_target::get_windows_debug_event (int pid,
else
{
inferior_ptid = ptid_t (current_event.dwProcessId, thread_id, 0);
- current_thread = th;
- if (!current_thread)
- current_thread = thread_rec (inferior_ptid, INVALIDATE_CONTEXT);
+ current_windows_thread = th;
+ if (!current_windows_thread)
+ current_windows_thread = thread_rec (inferior_ptid,
+ INVALIDATE_CONTEXT);
}

out:
@@ -2066,14 +2017,14 @@ windows_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
{
ptid_t result = ptid_t (current_event.dwProcessId, retval, 0);

- if (current_thread != nullptr)
+ if (current_windows_thread != nullptr)
{
- current_thread->stopped_at_software_breakpoint = false;
+ current_windows_thread->stopped_at_software_breakpoint = false;
if (current_event.dwDebugEventCode == EXCEPTION_DEBUG_EVENT
&& (current_event.u.Exception.ExceptionRecord.ExceptionCode
== EXCEPTION_BREAKPOINT)
&& windows_initialization_done)
- current_thread->stopped_at_software_breakpoint = true;
+ current_windows_thread->stopped_at_software_breakpoint = true;
}

return result;
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 810896e87ca..7060b6d1527 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -74,14 +74,6 @@ int using_threads = 1;

/* Globals. */
static int attaching = 0;
-static HANDLE current_process_handle = NULL;
-static DWORD current_process_id = 0;
-static DWORD main_thread_id = 0;
-static EXCEPTION_RECORD siginfo_er; /* Contents of $_siginfo */
-static enum gdb_signal last_sig = GDB_SIGNAL_0;
-
-/* The current debug event from WaitForDebugEvent. */
-static DEBUG_EVENT current_event;

/* A status that hasn't been reported to the core yet, and so
win32_wait should return it next, instead of fetching the next
--
2.21.1