1# Copyright 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2007
2# Free Software Foundation, Inc.
3
4# This program is free software; you can redistribute it and/or modify
5# it under the terms of the GNU General Public License as published by
6# the Free Software Foundation; either version 3 of the License, or
7# (at your option) any later version.
8#
9# This program is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12# GNU General Public License for more details.
13#
14# You should have received a copy of the GNU General Public License
15# along with this program.  If not, see <http://www.gnu.org/licenses/>.
16
17# Please email any bugs, comments, and/or additions to this file to:
18# bug-gdb@prep.ai.mit.edu
19
20# This file was written by Jeff Law. (law@cs.utah.edu)
21
22if $tracelevel then {
23    strace $tracelevel
24}
25
26set prms_id 0
27set bug_id 0
28
29set testfile "recurse"
30set srcfile ${testfile}.c
31set binfile ${objdir}/${subdir}/${testfile}
32if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
33     untested recurse.exp
34     return -1
35}
36
37# Start with a fresh gdb.
38
39gdb_exit
40gdb_start
41gdb_reinitialize_dir $srcdir/$subdir
42gdb_load ${binfile}
43
44proc recurse_tests {} {
45
46    # Disable hardware watchpoints if necessary.
47    if [target_info exists gdb,no_hardware_watchpoints] {
48	gdb_test "set can-use-hw-watchpoints 0" "" ""
49    }
50
51    if [runto recurse] then {
52	# First we need to step over the assignment of b, so it has a known
53	# value.
54	gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance"
55	gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
56	    "set first instance watchpoint"
57
58	# Continue until initial set of b.
59	if [gdb_test "continue" \
60	    "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \
61	    "continue to first instance watchpoint, first time"] then {
62	    gdb_suppress_tests;
63	}
64
65	# Continue inward for a few iterations
66	gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \
67	    "continue to recurse (a = 9)"
68	gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \
69	    "continue to recurse (a = 8)"
70	gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \
71	    "continue to recurse (a = 7)"
72	gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \
73	    "continue to recurse (a = 6)"
74	gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \
75	    "continue to recurse (a = 5)"
76
77	# Put a watchpoint on another instance of b
78	# First we need to step over the assignment of b, so it has a known
79	# value.
80	gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance"
81	gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
82	    "set second instance watchpoint"
83
84	# Continue until initial set of b (second instance).
85	if [gdb_test "continue" \
86	    "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\
87	    "continue to second instance watchpoint, first time"] then {
88	gdb_suppress_tests;
89	}
90
91	# Continue inward for a few iterations
92	gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \
93	    "continue to recurse (a = 4)"
94	gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \
95	    "continue to recurse (a = 3)"
96	gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \
97	    "continue to recurse (a = 2)"
98	gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \
99	    "continue to recurse (a = 1)"
100
101	# Continue until second set of b (second instance).
102	if [gdb_test "continue" \
103	    "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \
104	    "continue to second instance watchpoint, second time"] then {
105	    gdb_suppress_tests;
106	}
107
108	# Continue again.  We should have a watchpoint go out of scope now
109	if [gdb_test "continue" \
110	    "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \
111	    "second instance watchpoint deleted when leaving scope"] then {
112	    gdb_suppress_tests;
113	}
114
115	# Continue until second set of b (first instance).
116	# 24320 is allowed as the final value for b as that's the value
117	# b would have on systems with 16bit integers.
118	#
119	# We could fix the test program to deal with this too.
120	if [gdb_test "continue" \
121	    "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \
122	    "continue to first instance watchpoint, second time"] then {
123	    gdb_suppress_tests
124	}
125
126	# Continue again.  We should have a watchpoint go out of scope now.
127	#
128	# The former version expected the test to return to main().
129	# Now it expects the test to return to main or to stop in the
130	# function's epilogue.
131	#
132	# The problem is that gdb needs to (but doesn't) understand
133	# function epilogues in the same way as for prologues.
134	#
135	# If there is no hardware watchpoint (such as a x86 debug register),
136	# then watchpoints are done "the hard way" by single-stepping the
137	# target until the value of the watched variable changes.  If you
138	# are single-stepping, you will eventually step into an epilogue.
139	# When you do that, the "top" stack frame may become partially
140	# deconstructed (as when you pop the frame pointer, for instance),
141	# and from that point on, GDB can no longer make sense of the stack.
142	#
143	# A test which stops in the epilogue is trying to determine when GDB
144	# leaves the stack frame in which the watchpoint was created.  It does
145	# this basically by watching for the frame pointer to change.  When
146	# the frame pointer changes, the test expects to be back in main, but
147	# instead it is still in the epilogue of the callee.
148	if [gdb_test "continue" \
149	    "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
150	    "first instance watchpoint deleted when leaving scope"] then {
151	    gdb_suppress_tests;
152	}
153    }
154    gdb_stop_suppressing_tests;
155}
156
157# Preserve the old timeout, and set a new one that should be
158# sufficient to avoid timing out during this test.
159set oldtimeout $timeout
160set timeout [expr "$timeout + 60"]
161verbose "Timeout is now $timeout seconds" 2
162
163recurse_tests
164
165# Restore the preserved old timeout value.
166set timeout $oldtimeout
167verbose "Timeout is now $timeout seconds" 2
168
169