gdb testsuite: Introduce allow_multi_inferior_tests and use it throughout

The Windows port does not support multi-process debugging.  Testcases
that want to exercise multi-process currently FAIL and some hit
cascading timeouts.  Add a new allow_multi_inferior_tests procedure,
meant to be used with require, and sprinkle it throughout testcases as
needed.

Approved-by: Kevin Buettner <kevinb@redhat.com>
Change-Id: I4a10d8f04f9fa10f4b751f140ad0a6d31fbd9dfb

gdb/testsuite/gdb.base/kill-detach-inferiors-cmd.exp

@@ -19,6 +19,7 @@
 # commands.
 
 require can_spawn_for_attach
+require allow_multi_inferior_tests
 
 standard_testfile
 set executable $testfile

gdb/testsuite/gdb.base/run-control-while-bg-execution.exp

@@ -49,6 +49,11 @@ if {[build_executable "failed to prepare" $testfile $srcfile]} {
 #  - run: use the run command
 #  - attach: start a process outside of GDB and attach it
 proc do_test { action1 action2 } {
+
+    if {$action1 == "add" && ![allow_multi_inferior_tests]} {
+	return
+    }
+
     save_vars { ::GDBFLAGS } {
 	append ::GDBFLAGS " -ex \"maintenance set target-non-stop on\""
 	clean_restart $::binfile

gdb/testsuite/gdb.btrace/multi-inferior.exp

@@ -24,6 +24,8 @@
 
 require allow_btrace_tests
 
+require allow_multi_inferior_tests
+
 require !use_gdb_stub
 
 standard_testfile

gdb/testsuite/gdb.mi/interrupt-thread-group.exp

@@ -54,7 +54,7 @@ mi_send_resuming_command "exec-continue --thread-group i1" \
 
 # We can't run a second inferior on stub targets.  We can still test with one
 # inferior and ensure that the command has the desired effect.
-set use_second_inferior [expr {![use_gdb_stub]}]
+set use_second_inferior [expr {![use_gdb_stub] && [allow_multi_inferior_tests]}]
 
 if { $use_second_inferior } {
     mi_gdb_test "-add-inferior" \

gdb/testsuite/gdb.mi/user-selected-context-sync.exp

@@ -40,6 +40,8 @@ standard_testfile
 # gdbserver modes are supported.
 require !use_gdb_stub
 
+require allow_multi_inferior_tests
+
 set compile_options "debug pthreads"
 if {[build_executable $testfile.exp $testfile ${srcfile} ${compile_options}] == -1} {
     untested "failed to compile"

gdb/testsuite/gdb.multi/attach-while-running.exp

@@ -37,6 +37,7 @@
 standard_testfile
 
 require can_spawn_for_attach
+require allow_multi_inferior_tests
 
 if { [build_executable "failed to prepare" ${testfile} ${srcfile}] } {
     return

gdb/testsuite/gdb.multi/bp-thread-specific.exp

@@ -19,6 +19,8 @@
 # Also check that the correct thread-ids are used in the saved
 # breakpoints file.
 
+require allow_multi_inferior_tests
+
 # The plain remote target can't do multiple inferiors.
 require !use_gdb_stub
 

gdb/testsuite/gdb.multi/dummy-frame-restore.exp

@@ -19,6 +19,8 @@ set executable ${testfile}
 # The plain remote target can't do multiple inferiors.
 require !use_gdb_stub
 
+require allow_multi_inferior_tests
+
 if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {
     return -1
 }

gdb/testsuite/gdb.multi/multi-arch.exp

@@ -18,6 +18,8 @@
 
 set testfile "multi-arch"
 
+require allow_multi_inferior_tests
+
 # The plain remote target can't do multiple inferiors.
 require !use_gdb_stub
 

gdb/testsuite/gdb.multi/multi-attach.exp

@@ -17,6 +17,8 @@
 
 # Test attaching to multiple threaded programs.
 
+require allow_multi_inferior_tests
+
 standard_testfile
 
 require can_spawn_for_attach

gdb/testsuite/gdb.multi/multi-exit.exp

@@ -24,6 +24,8 @@
 
 standard_testfile
 
+require allow_multi_inferior_tests
+
 require !use_gdb_stub
 
 if {[build_executable "failed to prepare" $testfile $srcfile]} {

gdb/testsuite/gdb.multi/multi-kill.exp

@@ -24,6 +24,8 @@
 
 standard_testfile
 
+require allow_multi_inferior_tests
+
 require !use_gdb_stub
 
 if {[build_executable "failed to prepare" $testfile $srcfile {debug}]} {

gdb/testsuite/gdb.multi/multi-re-run.exp

@@ -20,6 +20,8 @@
 # misbehave, including failing to load libthread_db.so.  See PR
 # gdb/25410.
 
+require allow_multi_inferior_tests
+
 # Build two executables, with different symbols.
 
 set exec1 "multi-re-run-1"

gdb/testsuite/gdb.multi/multi-target.exp.tcl

@@ -175,6 +175,10 @@ proc multi_target_prepare {} {
 	return 0
     }
 
+    if {![allow_multi_inferior_tests]} {
+	return 0
+    }
+
     # The plain remote target can't do multiple inferiors.
     if {[target_info gdb_protocol] != ""} {
 	return 0

gdb/testsuite/gdb.multi/multi-term-settings.exp

@@ -25,6 +25,8 @@
 
 standard_testfile
 
+require allow_multi_inferior_tests
+
 require can_spawn_for_attach
 
 if [build_executable "failed to prepare" $testfile $srcfile {debug}] {

gdb/testsuite/gdb.multi/start-inferior-specific.exp

@@ -25,6 +25,8 @@
 
 standard_testfile .c -other.c
 
+require allow_multi_inferior_tests
+
 require !use_gdb_stub
 
 set srcfile_other ${srcfile2}

gdb/testsuite/gdb.multi/stop-all-on-exit.exp

@@ -18,6 +18,8 @@
 # Test that in all-stop mode with multiple inferiors, GDB stops all
 # threads upon receiving an exit event from one of the inferiors.
 
+require allow_multi_inferior_tests
+
 # This is a test specific for a native target, where we use the
 # "-exec" argument to "add-inferior" and we explicitly don't do
 # "maint set target-non-stop on".

gdb/testsuite/gdb.multi/tids-gid-reset.exp

@@ -54,6 +54,8 @@ with_test_prefix "single-inferior" {
 # non-extended gdbserver is not supported.
 require !use_gdb_stub
 
+require allow_multi_inferior_tests
+
 # Test with multiple inferiors.  This time, since we restart inferior
 # 1 while inferior 2 still has threads, then the new thread 1.1 should
 # end up with GID == 3, since we won't be able to reset the global

gdb/testsuite/gdb.multi/tids.exp

@@ -124,6 +124,9 @@ with_test_prefix "single inferior" {
     gdb_test "print \$_inferior_thread_count" " = 1"
 }
 
+# The rest of the tests require running multiple inferiors.
+require allow_multi_inferior_tests
+
 # "info threads" while there are multiple inferiors should show
 # qualified thread IDs.
 with_test_prefix "two inferiors" {

gdb/testsuite/gdb.multi/watchpoint-multi.exp

@@ -16,6 +16,8 @@
 standard_testfile
 set executable ${testfile}
 
+require allow_multi_inferior_tests
+
 # Multiple inferiors are needed, therefore both native and extended gdbserver
 # modes are supported.  Only non-extended gdbserver is not supported.
 require !use_gdb_stub

gdb/testsuite/gdb.threads/access-mem-running-thread-exit.exp

@@ -74,42 +74,45 @@ proc test { non_stop } {
     delete_breakpoints
 
     # Start the second inferior.
-    with_test_prefix "second inferior" {
-	# With stub targets that do reload on run, if we let the new
-	# inferior share inferior 1's connection, runto would
-	# fail because GDB is already connected to something, like
-	# e.g. with --target_board=native-gdbserver:
-	#
-	#  (gdb) kill
-	#  ...
-	#  (gdb) target remote localhost:2348
-	#  Already connected to a remote target.  Disconnect? (y or n)
-	#
-	# Instead, start the inferior with no connection, and let
-	# gdb_load/runto spawn a new remote connection/gdbserver.
-	#
-	# OTOH, with extended-remote, we must let the new inferior
-	# reuse the current connection, so that runto below can
-	# issue the "run" command, and have the inferior run on the
-	# remote target.  If we forced no connection, then "run" would
-	# either fail if "set auto-connect-native-target" is on, like
-	# the native-extended-gdbserver board enforces, or it would
-	# run the inferior on the native target, which isn't what is
-	# being tested.
-	#
-	# Since it's reload_on_run targets that need special care, we
-	# default to reusing the connection on most targets.
-	if [target_info exists gdb,do_reload_on_run] {
-	    gdb_test "add-inferior -no-connection" "New inferior 2.*"
-	} else {
-	    gdb_test "add-inferior" "New inferior 2.*"
-	}
-	gdb_test "inferior 2" "Switching to inferior 2 .*"
+    if {[allow_multi_inferior_tests]} {
+	with_test_prefix "second inferior" {
+	    # With stub targets that do reload on run, if we let the
+	    # new inferior share inferior 1's connection, runto would
+	    # fail because GDB is already connected to something, like
+	    # e.g. with --target_board=native-gdbserver:
+	    #
+	    #  (gdb) kill
+	    #  ...
+	    #  (gdb) target remote localhost:2348
+	    #  Already connected to a remote target.  Disconnect? (y or n)
+	    #
+	    # Instead, start the inferior with no connection, and let
+	    # gdb_load/runto spawn a new remote connection/gdbserver.
+	    #
+	    # OTOH, with extended-remote, we must let the new inferior
+	    # reuse the current connection, so that runto below can
+	    # issue the "run" command, and have the inferior run on
+	    # the remote target.  If we forced no connection, then
+	    # "run" would either fail if "set
+	    # auto-connect-native-target" is on, like the
+	    # native-extended-gdbserver board enforces, or it would
+	    # run the inferior on the native target, which isn't what
+	    # is being tested.
+	    #
+	    # Since it's reload_on_run targets that need special care,
+	    # we default to reusing the connection on most targets.
+	    if [target_info exists gdb,do_reload_on_run] {
+		gdb_test "add-inferior -no-connection" "New inferior 2.*"
+	    } else {
+		gdb_test "add-inferior" "New inferior 2.*"
+	    }
+	    gdb_test "inferior 2" "Switching to inferior 2 .*"
 
-	gdb_load $binfile
+	    gdb_load $binfile
 
-	if ![runto setup_done] {
-	    return -1
+	    if ![runto setup_done] {
+		return -1
+	    }
 	}
     }
 
@@ -158,13 +161,15 @@ proc test { non_stop } {
 	verbose -log "xxxxx: iteration $iter"
 	gdb_test -nopass "info threads"
 
-	if {$inf == 1} {
-	    set inf 2
-	} else {
-	    set inf 1
-	}
+	if {[allow_multi_inferior_tests]} {
+	    if {$inf == 1} {
+		set inf 2
+	    } else {
+		set inf 1
+	    }
 
-	my_gdb_test "inferior $inf" ".*" "inferior $inf"
+	    my_gdb_test "inferior $inf" ".*" "inferior $inf"
+	}
 
 	my_gdb_test "print global_var = 555" " = 555" \
 	    "write to global_var"

gdb/testsuite/gdb.threads/detach-step-over.exp

@@ -50,6 +50,8 @@
 
 require can_spawn_for_attach
 
+require allow_multi_inferior_tests
+
 standard_testfile
 
 set bp_lineno [gdb_get_line_number "Set breakpoint here"]

gdb/testsuite/gdb.threads/threadapply.exp

@@ -224,6 +224,8 @@ proc kill_and_remove_inferior {thread_set} {
 
 # Test both "all" and a thread list, because those are implemented as
 # different commands in GDB.
-foreach_with_prefix thread_set {"all" "1.1"} {
-    kill_and_remove_inferior $thread_set
+if {[allow_multi_inferior_tests]} {
+    foreach_with_prefix thread_set {"all" "1.1"} {
+	kill_and_remove_inferior $thread_set
+    }
 }

gdb/testsuite/gdb.threads/vfork-multi-inferior.exp

@@ -27,6 +27,8 @@
 
 require allow_fork_tests
 
+require allow_multi_inferior_tests
+
 require !use_gdb_stub
 
 standard_testfile .c -sleep.c

gdb/testsuite/lib/gdb.exp

@@ -5111,6 +5111,24 @@ proc allow_fork_tests {} {
     return 1
 }
 
+# Return whether we allow running testcases that want to debug
+# multiple inferiors with the same target.  Not all targets support
+# this.  Note that some tests add a second inferior but never start
+# it.  Those tests should not be skipped due to this proc returning
+# false.
+
+proc allow_multi_inferior_tests {} {
+    if {[istarget "*-*-cygwin*"] || [istarget "*-*-mingw*"]} {
+	return 0
+    }
+
+    if {[use_gdb_stub]} {
+	return 0
+    }
+
+    return 1
+}
+
 # Return a 1 if we should run tests that require hardware breakpoints
 
 proc allow_hw_breakpoint_tests {} {