testsuite/gdb.reverse/finish-reverse-next.exp

# Copyright 2008-2024 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

# This file is part of the GDB testsuite.  It tests reverse stepping.
# Lots of code borrowed from "step-test.exp".

# The reverse finish command should return from a function and stop on
# the first instruction of the source line where the function call is made.
# Specifically, the behavior should match doing a reverse next from the
# first instruction in the function.  GDB should only take one reverse step
# or next statement to reach the previous source code line.

# This testcase verifies the reverse-finish command stops at the first
# instruction in the source code line where the function was called.  There
# are two scenarios that must be checked:
#   1) gdb is at the entry point instruction for the function
#   2) gdb is in the body of the function.

# This test verifies the fix for gdb bugzilla:
#   https://sourceware.org/bugzilla/show_bug.cgi?id=29927

# PowerPC supports two entry points to a function.  The normal entry point
# is called the local entry point (LEP).  The alternate entry point is called
# the global entry point (GEP).  A function call via a function pointer
# will entry via the GEP.  A normal function call will enter via the LEP.
#
# This test has been expanded to include tests to verify the reverse-finish
# command works properly if the function is called via the GEP.  The original
# test only verified the reverse-finish command for a normal call that used
# the LEP.

if ![supports_reverse] {
    return
}

standard_testfile

if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
    return -1
}

runto_main

if [supports_process_record] {
    # Activate process record/replay.
    gdb_test_no_output "record" "turn on process record for test1"
}


### TEST 1: reverse finish from the entry point instruction (LEP) in
### function1 when called using the normal entry point (LEP).

# Set breakpoint at call to function1 in main.
set bp_LEP_test [gdb_get_line_number "CALL VIA LEP" $srcfile]
gdb_breakpoint $srcfile:$bp_LEP_test temporary

# Continue to break point at function1 call in main.
gdb_continue_to_breakpoint \
    "stopped at function1 entry point instruction to stepi into function" \
    ".*$srcfile:$bp_LEP_test\r\n.*"

# stepi until we see "{" indicating we entered function1
repeat_cmd_until "stepi" "CALL VIA LEP" "{" "stepi into function1 call" "100"

# The reverse-finish command should stop on the function call instruction
# which is the last instruction in the source code line.  Another reverse-next
# instruction stops at the previous source code line.
gdb_test "reverse-finish" ".*function1 \\(a, b\\);   // CALL VIA LEP.*" \
    "reverse-finish function1 LEP call from LEP "
gdb_test "reverse-next" ".*b = 5;.*" "reverse next 2, at b = 5, call from LEP"


gdb_test "reverse-continue" ".*" "setup for test 2"

# Turn off record to clear logs and turn on again
gdb_test "record stop"  "Process record is stopped.*" \
    "turn off process record for test1"
gdb_test_no_output "record" "turn on process record for test2"


### TEST 2: reverse finish from the body of function1.

# Set breakpoint at call to function1 in main.
gdb_breakpoint $srcfile:$bp_LEP_test temporary

# Continue to break point at function1 call in main.
gdb_continue_to_breakpoint \
    "at function1 entry point instruction to step to body of function" \
    ".*$srcfile:$bp_LEP_test\r\n.*"

# do a step instruction to get to the body of the function
gdb_test "step" ".*int ret = 0;.*" "step test 1"

# The reverse-finish command should stop on the function call instruction
# which is the last instruction in the source code line.  Another reverse-next
# instruction stops at the previous source code line.
gdb_test "reverse-finish" ".*function1 \\(a, b\\);   // CALL VIA LEP.*" \
    "reverse-finish function1 LEP call from function body"
gdb_test "reverse-next" ".*b = 5;.*" \
    "reverse next 2 at b = 5, from function body"

gdb_test "reverse-continue" ".*" "setup for test 3"

# Turn off record to clear logs and turn on again
gdb_test "record stop"  "Process record is stopped.*" \
    "turn off process record for test2"
gdb_test_no_output "record" "turn on process record for test3"


### TEST 3: reverse finish from the alternate entry point instruction (GEP) in
### function1 when called using the alternate entry point (GEP).

# Set breakpoint at call to funp in main.
set bp_GEP_test  [gdb_get_line_number "CALL VIA GEP" $srcfile]
gdb_breakpoint $srcfile:$bp_GEP_test temporary

# Continue to break point at funp call in main.
gdb_continue_to_breakpoint \
    "stopped at function1 entry point instruction to stepi into funp" \
    ".*$srcfile:$bp_GEP_test\r\n.*"

# stepi until we see "{" indicating we entered function.
repeat_cmd_until "stepi" "CALL VIA GEP" "{" "stepi into funp call"

# The reverse-finish command should stop on the function call instruction
# which is the last instruction in the source code line.  Another reverse-next
# instruction stops at the previous source code line.
gdb_test "reverse-finish" ".*funp \\(a, b\\);.*" \
    "function1 GEP call call from GEP"
gdb_test "reverse-next" ".*b = 50;.*" "reverse next 2 at b = 50, call from GEP"

gdb_test "reverse-continue" ".*" "setup for test 4"

# Turn off record to clear logs and turn on again
gdb_test "record stop"  "Process record is stopped.*" \
    "turn off process record for test3"
gdb_test_no_output "record" "turn on process record for test4"

### TEST 4: reverse finish from between the GEP and LEP in
### function1 when called using the alternate entry point (GEP).

# Set breakpoint at call to funp in main.
set bp_GEP_test  [gdb_get_line_number "CALL VIA GEP" $srcfile]
gdb_breakpoint $srcfile:$bp_GEP_test temporary

# Continue to break point at funp call in main.
gdb_continue_to_breakpoint \
    "stopped at function1 entry point instruction to stepi into funp again" \
    ".*$srcfile:$bp_GEP_test\r\n.*"

# stepi until we see "{" indicating we entered function.
repeat_cmd_until "stepi" "CALL VIA GEP" "{" "stepi into funp call again"

# do one more stepi so we are between the GEP and LEP.
gdb_test "stepi" "{" "stepi to between GEP and LEP"

# The reverse-finish command should stop on the function call instruction
# which is the last instruction in the source code line.  Another reverse-next
# instruction stops at the previous source code line.
gdb_test "reverse-finish" ".*funp \\(a, b\\);.*" \
    "function1 GEP call call from GEP again"
gdb_test "reverse-next" ".*b = 50;.*" \
    "reverse next 2 at b = 50, call from GEP again"

gdb_test "reverse-continue" ".*" "setup for test 5"

# Turn off record to clear logs and turn on again
gdb_test "record stop"  "Process record is stopped.*" \
    "turn off process record for test4"
gdb_test_no_output "record" "turn on process record for test5"


### TEST 5: reverse finish from the body of function 1 when calling using the
### alternate entrypoint (GEP).
gdb_breakpoint $srcfile:$bp_GEP_test temporary

# Continue to break point at funp call.
gdb_continue_to_breakpoint \
    "at function1 entry point instruction to step to body of funp call" \
    ".*$srcfile:$bp_GEP_test\r\n.*"

# Step into body of funp, called via GEP.
gdb_test "step" ".*int ret = 0;.*" "step test 2"

# The reverse-finish command should stop on the function call instruction
# which is the last instruction in the source code line.  Another reverse-next
# instruction stops at the previous source code line.
gdb_test "reverse-finish" ".*funp \\(a, b\\);.*" \
    "reverse-finish function1 GEP call, from function body  "
gdb_test "reverse-next" ".*b = 50;.*" \
    "reverse next 2 at b = 50 from function body"