From: Pedro Alves <pedro@palves.net>
Date: Thu, 1 Jun 2023 15:19:03 +0000 (+0100)
Subject: gdb testsuite: Introduce allow_fork_tests and use it throughout
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f74bd9bcabce02de70169ea441d0ab6b8a2e2451;p=thirdparty%2Fbinutils-gdb.git

gdb testsuite: Introduce allow_fork_tests and use it throughout

Cygwin debugging does not support follow fork.  There is currently no
interface between the debugger and the Cygwin runtime to be able to
intercept forks and execs.  Consequently, testcases that try to
exercise fork/exec all FAIL, and several hit long cascading timeouts.

Add a new allow_fork_tests procedure, meant to be used with require,
and sprinkle it throughout testcases that exercise fork.

Note that some tests currently are skipped on targets other than
Linux, with something like:

 # Until "set follow-fork-mode" and "catch vfork" are implemented on
 # other targets...
 #
 if {![istarget "*-linux*"]} {
     continue
 }

However, some BSD ports also support fork debugging nowadays, and the
testcases were never adjusted...  That is why the new allow_fork_tests
procedure doesn't look for linux.

With this patch, on Cygwin, I get this:

 $ make check TESTS="*/*fork*.exp"

 ...
		 === gdb Summary ===

 # of expected passes            6
 # of untested testcases         1
 # of unsupported tests          31

Reviewed-By: Keith Seitz <keiths@redhat.com>
Change-Id: I0c5e8c574d1f61b28d370c22a0b0b6bc3efaf978
---

diff --git a/gdb/testsuite/gdb.base/catch-fork-kill.exp b/gdb/testsuite/gdb.base/catch-fork-kill.exp
index 0fd853b9085..224a8dfec89 100644
--- a/gdb/testsuite/gdb.base/catch-fork-kill.exp
+++ b/gdb/testsuite/gdb.base/catch-fork-kill.exp
@@ -32,6 +32,8 @@
 
 standard_testfile
 
+require allow_fork_tests
+
 # Build two programs -- one for fork, and another for vfork.
 set testfile_fork "${testfile}-fork"
 set testfile_vfork "${testfile}-vfork"
diff --git a/gdb/testsuite/gdb.base/catch-fork-static.exp b/gdb/testsuite/gdb.base/catch-fork-static.exp
index b171a6dbdd2..9d50d5dc428 100644
--- a/gdb/testsuite/gdb.base/catch-fork-static.exp
+++ b/gdb/testsuite/gdb.base/catch-fork-static.exp
@@ -21,9 +21,7 @@
 # ld.so probes before reaching main, and ptrace flags were set then.  But a
 # static executable would just keep running and never catch the fork.
 
-# Until "catch fork" is implemented on other targets...
-#
-require {is_any_target "*-*-linux*" "*-*-openbsd*"}
+require allow_fork_tests
 
 # Reusing foll-fork.c since it's a simple forking program.
 standard_testfile foll-fork.c
diff --git a/gdb/testsuite/gdb.base/catch-signal-fork.exp b/gdb/testsuite/gdb.base/catch-signal-fork.exp
index dea0cc48f75..2a33ee19f60 100644
--- a/gdb/testsuite/gdb.base/catch-signal-fork.exp
+++ b/gdb/testsuite/gdb.base/catch-signal-fork.exp
@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 require {!target_info exists gdb,nosignals}
+require allow_fork_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.base/foll-fork-syscall.exp b/gdb/testsuite/gdb.base/foll-fork-syscall.exp
index 4aee683c8d1..21ef3347dc1 100644
--- a/gdb/testsuite/gdb.base/foll-fork-syscall.exp
+++ b/gdb/testsuite/gdb.base/foll-fork-syscall.exp
@@ -20,6 +20,7 @@
 # enabled because it will be redirected to the log.
 require !gdb_debug_enabled
 require {is_any_target "i?86-*-*" "x86_64-*-*"}
+require allow_fork_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.base/foll-fork.exp b/gdb/testsuite/gdb.base/foll-fork.exp
index 94755c61186..12db516d58a 100644
--- a/gdb/testsuite/gdb.base/foll-fork.exp
+++ b/gdb/testsuite/gdb.base/foll-fork.exp
@@ -17,6 +17,8 @@
 # enabled as it will be redirected to the log.
 require !gdb_debug_enabled
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
diff --git a/gdb/testsuite/gdb.base/foll-vfork.exp b/gdb/testsuite/gdb.base/foll-vfork.exp
index 266df46a188..6ca7711fe81 100644
--- a/gdb/testsuite/gdb.base/foll-vfork.exp
+++ b/gdb/testsuite/gdb.base/foll-vfork.exp
@@ -18,12 +18,7 @@
 # either execs or exits --- since those events take somewhat different
 # code paths in GDB, both variants are exercised.
 
-# Until "set follow-fork-mode" and "catch vfork" are implemented on
-# other targets...
-#
-if {![istarget "*-linux*"]} {
-    continue
-}
+require allow_fork_tests
 
 standard_testfile .c -exit.c vforked-prog.c
 
diff --git a/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp b/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp
index 311d7ba62de..2d47d5d2c20 100644
--- a/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp
+++ b/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp
@@ -23,6 +23,7 @@
 # in the source of the shlib, and "list" should display the source where
 # the program stopped.
 
+require allow_fork_tests
 require allow_shlib_tests
 
 standard_testfile .c -shlib.c
diff --git a/gdb/testsuite/gdb.base/fork-print-inferior-events.exp b/gdb/testsuite/gdb.base/fork-print-inferior-events.exp
index 26ed2f9765d..19ace001b08 100644
--- a/gdb/testsuite/gdb.base/fork-print-inferior-events.exp
+++ b/gdb/testsuite/gdb.base/fork-print-inferior-events.exp
@@ -19,6 +19,8 @@
 # inferior-events [on,off]', 'set follow-fork-mode [child,parent]' and
 # 'set detach-on-fork [on,off]' are the correct ones.
 
+require allow_fork_tests
+
 # This test relies on "run", so it cannot run on target remote stubs.
 require !use_gdb_stub
 
diff --git a/gdb/testsuite/gdb.base/fork-running-state.exp b/gdb/testsuite/gdb.base/fork-running-state.exp
index 4b810a65648..c446800b885 100644
--- a/gdb/testsuite/gdb.base/fork-running-state.exp
+++ b/gdb/testsuite/gdb.base/fork-running-state.exp
@@ -17,6 +17,8 @@
 # in non-stop).  GDB used to miss updating the parent/child running
 # states after a fork.
 
+require allow_fork_tests
+
 standard_testfile
 
 # The test proper.
diff --git a/gdb/testsuite/gdb.base/inferior-died.exp b/gdb/testsuite/gdb.base/inferior-died.exp
index 3992561d64e..764a88da8c2 100644
--- a/gdb/testsuite/gdb.base/inferior-died.exp
+++ b/gdb/testsuite/gdb.base/inferior-died.exp
@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Until "set follow-fork-mode" and "catch fork" are implemented on
-# other targets...
-#
-require {istarget "*-*-linux*"}
+require allow_fork_tests
 
 require support_displaced_stepping
 
diff --git a/gdb/testsuite/gdb.base/interrupt-daemon.exp b/gdb/testsuite/gdb.base/interrupt-daemon.exp
index 161f854ed36..8b8c61d6fc9 100644
--- a/gdb/testsuite/gdb.base/interrupt-daemon.exp
+++ b/gdb/testsuite/gdb.base/interrupt-daemon.exp
@@ -16,6 +16,8 @@
 # Make sure that we can interrupt an inferior that forks and moves to
 # its own session.
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to build" $testfile $srcfile {debug}]} {
diff --git a/gdb/testsuite/gdb.base/jit-elf-fork.exp b/gdb/testsuite/gdb.base/jit-elf-fork.exp
index 81d33502449..c1fa4283362 100644
--- a/gdb/testsuite/gdb.base/jit-elf-fork.exp
+++ b/gdb/testsuite/gdb.base/jit-elf-fork.exp
@@ -15,6 +15,7 @@
 
 # Test fork handling of an inferior that has JIT-ed objfiles.
 
+require allow_fork_tests
 require allow_shlib_tests
 
 load_lib jit-elf-helpers.exp
diff --git a/gdb/testsuite/gdb.base/multi-forks.exp b/gdb/testsuite/gdb.base/multi-forks.exp
index 61a240f6cc0..3facccb6315 100644
--- a/gdb/testsuite/gdb.base/multi-forks.exp
+++ b/gdb/testsuite/gdb.base/multi-forks.exp
@@ -13,11 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Until "set follow-fork-mode" and "catch fork" are implemented on
-# other targets...
-#
-require {istarget "*-*-linux*"}
-
+require allow_fork_tests
 
 standard_testfile .c
 
diff --git a/gdb/testsuite/gdb.base/pie-fork.exp b/gdb/testsuite/gdb.base/pie-fork.exp
index 48c01d9885e..86407b4adad 100644
--- a/gdb/testsuite/gdb.base/pie-fork.exp
+++ b/gdb/testsuite/gdb.base/pie-fork.exp
@@ -16,6 +16,8 @@
 # Test that we can follow forks properly when the executable is
 # position-independent.
 
+require allow_fork_tests
+
 standard_testfile
 
 set opts [list debug pie]
diff --git a/gdb/testsuite/gdb.base/step-over-exit.exp b/gdb/testsuite/gdb.base/step-over-exit.exp
index 2370f973622..6dfa7bbb219 100644
--- a/gdb/testsuite/gdb.base/step-over-exit.exp
+++ b/gdb/testsuite/gdb.base/step-over-exit.exp
@@ -13,11 +13,14 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-standard_testfile
-
 # Test a thread is doing step-over a syscall instruction which is exit,
 # and GDBserver should cleanup its state of step-over properly.
 
+# The testcase relies on follow-fork-mode child.
+require allow_fork_tests
+
+standard_testfile
+
 set syscall_insn ""
 
 # Define the syscall instruction for each target.
diff --git a/gdb/testsuite/gdb.base/vfork-follow-parent.exp b/gdb/testsuite/gdb.base/vfork-follow-parent.exp
index fca2993bf08..8cb785d6c82 100644
--- a/gdb/testsuite/gdb.base/vfork-follow-parent.exp
+++ b/gdb/testsuite/gdb.base/vfork-follow-parent.exp
@@ -19,6 +19,8 @@
 # schedule-multiple on" or "set detach-on-fork on".  Test these two resolution
 # methods.
 
+require allow_fork_tests
+
 standard_testfile .c vforked-prog.c
 
 set binfile ${testfile}-exit
diff --git a/gdb/testsuite/gdb.base/watch-before-fork.exp b/gdb/testsuite/gdb.base/watch-before-fork.exp
index 074cfbd4366..509561ea7f4 100644
--- a/gdb/testsuite/gdb.base/watch-before-fork.exp
+++ b/gdb/testsuite/gdb.base/watch-before-fork.exp
@@ -20,6 +20,8 @@
 # This test uses "awatch".
 require allow_hw_watchpoint_access_tests
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
diff --git a/gdb/testsuite/gdb.base/watch-vfork.exp b/gdb/testsuite/gdb.base/watch-vfork.exp
index 1bc61bcd197..503727dbbae 100644
--- a/gdb/testsuite/gdb.base/watch-vfork.exp
+++ b/gdb/testsuite/gdb.base/watch-vfork.exp
@@ -17,6 +17,8 @@
 
 standard_testfile .c
 
+require allow_fork_tests
+
 if { [build_executable ${testfile}.exp ${testfile} $srcfile {debug}] } {
     untested "failed to compile"
     return -1
diff --git a/gdb/testsuite/gdb.multi/watchpoint-multi-exit.exp b/gdb/testsuite/gdb.multi/watchpoint-multi-exit.exp
index 70c3da93d4a..3446296e3fb 100644
--- a/gdb/testsuite/gdb.multi/watchpoint-multi-exit.exp
+++ b/gdb/testsuite/gdb.multi/watchpoint-multi-exit.exp
@@ -17,6 +17,8 @@
 # watchpoints don't end up with stale locations, preventing resumption
 # of other inferiors.
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to build" $testfile $srcfile {debug}]} {
diff --git a/gdb/testsuite/gdb.rocm/fork-exec-gpu-to-non-gpu.exp b/gdb/testsuite/gdb.rocm/fork-exec-gpu-to-non-gpu.exp
index 7588525081c..22d4b75caa0 100644
--- a/gdb/testsuite/gdb.rocm/fork-exec-gpu-to-non-gpu.exp
+++ b/gdb/testsuite/gdb.rocm/fork-exec-gpu-to-non-gpu.exp
@@ -21,6 +21,7 @@
 load_lib rocm.exp
 
 require allow_hipcc_tests
+require allow_fork_tests
 
 standard_testfile -execer.cpp -execee.cpp
 
diff --git a/gdb/testsuite/gdb.rocm/fork-exec-non-gpu-to-gpu.exp b/gdb/testsuite/gdb.rocm/fork-exec-non-gpu-to-gpu.exp
index a6bcf69aa3e..13860993bde 100644
--- a/gdb/testsuite/gdb.rocm/fork-exec-non-gpu-to-gpu.exp
+++ b/gdb/testsuite/gdb.rocm/fork-exec-non-gpu-to-gpu.exp
@@ -20,6 +20,7 @@
 load_lib rocm.exp
 
 require allow_hipcc_tests
+require allow_fork_tests
 
 standard_testfile -execer.cpp -execee.cpp
 
diff --git a/gdb/testsuite/gdb.rocm/precise-memory-fork.exp b/gdb/testsuite/gdb.rocm/precise-memory-fork.exp
index d326c2ec55b..23c1ebe6249 100644
--- a/gdb/testsuite/gdb.rocm/precise-memory-fork.exp
+++ b/gdb/testsuite/gdb.rocm/precise-memory-fork.exp
@@ -21,6 +21,7 @@
 load_lib rocm.exp
 
 require allow_hipcc_tests
+require allow_fork_tests
 
 standard_testfile .c
 
diff --git a/gdb/testsuite/gdb.threads/foll-fork-other-thread.exp b/gdb/testsuite/gdb.threads/foll-fork-other-thread.exp
index 52459886a7a..8ab540c98c4 100644
--- a/gdb/testsuite/gdb.threads/foll-fork-other-thread.exp
+++ b/gdb/testsuite/gdb.threads/foll-fork-other-thread.exp
@@ -17,6 +17,8 @@
 # another thread, in different combinations of "set follow-fork
 # parent/child", and other execution modes.
 
+require allow_fork_tests
+
 standard_testfile
 
 # Line where to stop the main thread.
diff --git a/gdb/testsuite/gdb.threads/fork-child-threads.exp b/gdb/testsuite/gdb.threads/fork-child-threads.exp
index abe9769b2de..ba9dfc241f6 100644
--- a/gdb/testsuite/gdb.threads/fork-child-threads.exp
+++ b/gdb/testsuite/gdb.threads/fork-child-threads.exp
@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Only GNU/Linux is known to support `set follow-fork-mode child'.
-if { ! [istarget "*-*-linux*"] } {
-    return 0
-}
+require allow_fork_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.threads/fork-plus-threads.exp b/gdb/testsuite/gdb.threads/fork-plus-threads.exp
index 3a5e66adada..4ce88d33293 100644
--- a/gdb/testsuite/gdb.threads/fork-plus-threads.exp
+++ b/gdb/testsuite/gdb.threads/fork-plus-threads.exp
@@ -20,6 +20,8 @@
 #
 # See https://sourceware.org/bugzilla/show_bug.cgi?id=18600
 
+require allow_fork_tests
+
 # In remote mode, we cannot continue debugging after all
 # inferiors have terminated, and this test requires that.
 if { [target_info exists gdb_protocol]
diff --git a/gdb/testsuite/gdb.threads/fork-thread-pending.exp b/gdb/testsuite/gdb.threads/fork-thread-pending.exp
index d0a1ca182a3..538e1ca6f3f 100644
--- a/gdb/testsuite/gdb.threads/fork-thread-pending.exp
+++ b/gdb/testsuite/gdb.threads/fork-thread-pending.exp
@@ -13,11 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Only GNU/Linux is known to support `set follow-fork-mode child'.
-#
-if { ! [istarget "*-*-linux*"] } {
-    return 0
-}
+require allow_fork_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp b/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp
index 1f768983a45..c668a655522 100644
--- a/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp
+++ b/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp
@@ -16,6 +16,8 @@
 # This test verifies that several threads forking while another thread
 # is constantly stepping over a breakpoint is properly handled.
 
+require allow_fork_tests
+
 standard_testfile
 
 set linenum [gdb_get_line_number "set break here"]
diff --git a/gdb/testsuite/gdb.threads/next-fork-exec-other-thread.exp b/gdb/testsuite/gdb.threads/next-fork-exec-other-thread.exp
index bd814382626..3a971274784 100644
--- a/gdb/testsuite/gdb.threads/next-fork-exec-other-thread.exp
+++ b/gdb/testsuite/gdb.threads/next-fork-exec-other-thread.exp
@@ -25,6 +25,8 @@
 # 20.04.5 LTS with 32-bit kernel + 32-bit userland.  It was NOT reproducible
 # using a circa 2023 Raspberry Pi OS w/ 64-bit kernel and 32-bit userland.
 
+require allow_fork_tests
+
 standard_testfile
 
 # Line where to stop the main thread.
diff --git a/gdb/testsuite/gdb.threads/next-fork-other-thread.exp b/gdb/testsuite/gdb.threads/next-fork-other-thread.exp
index 183fda6dd6e..1cd6685215c 100644
--- a/gdb/testsuite/gdb.threads/next-fork-other-thread.exp
+++ b/gdb/testsuite/gdb.threads/next-fork-other-thread.exp
@@ -16,6 +16,8 @@
 # Test doing a "next" on a thread during which forks or vforks happen in other
 # threads.
 
+require allow_fork_tests
+
 standard_testfile
 
 # Line where to stop the main thread.
diff --git a/gdb/testsuite/gdb.threads/pending-fork-event-detach-ns.exp b/gdb/testsuite/gdb.threads/pending-fork-event-detach-ns.exp
index e6e311eee00..29a011e1a7d 100644
--- a/gdb/testsuite/gdb.threads/pending-fork-event-detach-ns.exp
+++ b/gdb/testsuite/gdb.threads/pending-fork-event-detach-ns.exp
@@ -29,6 +29,8 @@
 #     parent thread from waitpid'ing it, preventing the main thread from joining
 #     it, prevent it from writing the flag file, failing the test.
 
+require allow_fork_tests
+
 standard_testfile
 
 if { [is_remote target] } {
diff --git a/gdb/testsuite/gdb.threads/pending-fork-event-detach.exp b/gdb/testsuite/gdb.threads/pending-fork-event-detach.exp
index 8e77ab0ca7c..e627241caed 100644
--- a/gdb/testsuite/gdb.threads/pending-fork-event-detach.exp
+++ b/gdb/testsuite/gdb.threads/pending-fork-event-detach.exp
@@ -34,6 +34,8 @@
 # event, and erroneously create a new inferior for it.  Once fixed, the child
 # process' thread is hidden by whoever holds the pending fork event.
 
+require allow_fork_tests
+
 standard_testfile .c -touch-file.c
 
 set touch_file_bin $binfile-touch-file
diff --git a/gdb/testsuite/gdb.threads/vfork-follow-child-exec.exp b/gdb/testsuite/gdb.threads/vfork-follow-child-exec.exp
index e23db0a616b..0b95a75c132 100644
--- a/gdb/testsuite/gdb.threads/vfork-follow-child-exec.exp
+++ b/gdb/testsuite/gdb.threads/vfork-follow-child-exec.exp
@@ -16,6 +16,8 @@
 # Test following a vfork child that execs, when the vfork parent is a
 # threaded program, and it's a non-main thread that vforks.
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to prepare" $testfile $srcfile {debug pthreads}]} {
diff --git a/gdb/testsuite/gdb.threads/vfork-follow-child-exit.exp b/gdb/testsuite/gdb.threads/vfork-follow-child-exit.exp
index a6b7f496276..ced52dfa964 100644
--- a/gdb/testsuite/gdb.threads/vfork-follow-child-exit.exp
+++ b/gdb/testsuite/gdb.threads/vfork-follow-child-exit.exp
@@ -16,6 +16,8 @@
 # Test following a vfork child that exits, when the vfork parent is a
 # threaded program, and it's a non-main thread that vforks.
 
+require allow_fork_tests
+
 standard_testfile
 
 if {[build_executable "failed to prepare" $testfile $srcfile {debug pthreads}]} {
diff --git a/gdb/testsuite/gdb.threads/vfork-multi-inferior.exp b/gdb/testsuite/gdb.threads/vfork-multi-inferior.exp
index fd081b3764e..d552039a400 100644
--- a/gdb/testsuite/gdb.threads/vfork-multi-inferior.exp
+++ b/gdb/testsuite/gdb.threads/vfork-multi-inferior.exp
@@ -25,6 +25,8 @@
 # To catch the bug, this test verifies that we can hit a breakpoint after a
 # vfork call, while a second inferior runs in the background.
 
+require allow_fork_tests
+
 require !use_gdb_stub
 
 standard_testfile .c -sleep.c
diff --git a/gdb/testsuite/gdb.threads/vfork-multi-thread.exp b/gdb/testsuite/gdb.threads/vfork-multi-thread.exp
index 2b9294d894f..61811aed725 100644
--- a/gdb/testsuite/gdb.threads/vfork-multi-thread.exp
+++ b/gdb/testsuite/gdb.threads/vfork-multi-thread.exp
@@ -30,6 +30,8 @@
 # breakpoints are removed, so the main thread would miss the breakpoint and run
 # until exit.
 
+require allow_fork_tests
+
 standard_testfile
 
 if { [build_executable "failed to prepare" ${testfile} ${srcfile} {debug pthreads}] } {
diff --git a/gdb/testsuite/gdb.threads/watchpoint-fork.exp b/gdb/testsuite/gdb.threads/watchpoint-fork.exp
index 376ca2ab54b..8e9b1c33c9b 100644
--- a/gdb/testsuite/gdb.threads/watchpoint-fork.exp
+++ b/gdb/testsuite/gdb.threads/watchpoint-fork.exp
@@ -21,6 +21,8 @@
 # must be done before starting the test so as to not disrupt the execution
 # of the actual test.
 
+require allow_fork_tests
+
 set allow_hw_watchpoint_tests_p [allow_hw_watchpoint_tests]
 
 set testfile watchpoint-fork
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 5cc7e11287b..669068536e9 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -5095,6 +5095,22 @@ proc skip_inline_var_tests {} {
     return 0
 }
 
+# Return whether we allow running fork-related testcases.  Targets
+# that don't even have any concept of fork will just fail to compile
+# the testcases and skip the tests that way if this returns true for
+# them.  Unix targets that do have a fork system call, but don't
+# support intercepting forks will want to return false here, otherwise
+# the testcases that exercise fork may hit a number of long cascading
+# time out sequences.
+
+proc allow_fork_tests {} {
+    if {[istarget "*-*-cygwin*"] || [istarget "*-*-mingw*"]} {
+	return 0
+    }
+
+    return 1
+}
+
 # Return a 1 if we should run tests that require hardware breakpoints
 
 proc allow_hw_breakpoint_tests {} {