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# Copyright 2015-2023 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 testsuite is to test examining memory backward by specifying a negative
# number in the 'x' command.
standard_testfile
if { [prepare_for_testing "failed to prepare for examine-backward" \
${testfile} ${srcfile}] } {
return -1
}
if ![runto_main] {
return -1
}
proc get_first_mapped_address {} {
global gdb_prompt
set addr "0"
gdb_test_multiple "info proc mappings" "info proc mappings" {
-re "objfile\[\r\n\t \]+(0x\[0-9a-fA-F\]+).*\[\r\n\]*$gdb_prompt $" {
set addr $expect_out(1,string)
}
-re "$gdb_prompt $" {
unsupported "current target does not support 'info proc mappings'"
}
}
return ${addr}
}
with_test_prefix "invalid format" {
gdb_test "x/- 10xb main" "Invalid number \"10xb\"\." \
"a whitespace after a leading hyphen"
gdb_test "x/--10xb main" "Invalid number \"10xb\"\." \
"double hyphen"
gdb_test "x/-a10xb main" "Invalid number \"10xb\"\." \
"an alphabet after a leading hyphen"
gdb_test_no_output "x/-0i main" "zero with backward disassemble"
gdb_test_no_output "x/-0sh main" "zero with backward examine string"
}
with_test_prefix "memory page boundary" {
set boundary [get_first_mapped_address]
if {![is_address_zero_readable] && $boundary != 0} {
gdb_test_no_output "set print elements 0"
gdb_test_sequence "x/3s ${boundary}" "take 3 strings forward" {
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/-4s" "take 4 strings backward" {
"Cannot access memory at address 0x"
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/3s ${boundary}" "take 3 strings forward again" {
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/-3s" "take 3 strings backward" {
"Cannot access memory at address 0x"
"0x"
"0x"
"0x"
}
}
}
with_test_prefix "address zero boundary" {
global gdb_prompt
set address_zero "0x0"
set byte "\t0x\[0-9a-f\]+"
set test "examine 3 bytes forward from ${address_zero}"
gdb_test_multiple "x/3xb ${address_zero}" "$test" {
-re "0x\[0-9a-f\]*0.*:${byte}${byte}${byte}\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]*0.*:\tCannot access memory at address 0x\[0-9a-f\]*0\[\r\n\]*$gdb_prompt $" {
# If we failed to read address 0 then this is fine, so
# long as we're not expecting to be able to read from
# address 0.
if {![is_address_zero_readable]} {
# The next test assumes that the last address examined
# would be 0x2. As we just failed to read address 0x0
# things are going to go wrong unless we now tell GDB
# to examine address 0x2. We assume here that if we
# can't read 0x0 we can't read 0x2 either.
gdb_test "x/3xb 0x2" "Cannot access memory at address 0x\[0-9a-f\]*2" \
"set last examined address to 0x2"
pass $test
} else {
fail $test
}
}
}
set test "examine 6 bytes backward"
gdb_test_multiple "x/-6x" "$test" {
-re "0x\[0-9a-f\]+fd.*:${byte}${byte}${byte}${byte}${byte}${byte}.*\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]+fd.*:\tCannot access memory at address 0x\[0-9a-f\]+fd.*\[\r\n\]*$gdb_prompt $" {
# We may, or may not have managed to read from address 0x0
# in the previous test, however, being able to read 0x0 is
# no guarantee that we can read from the other end of the
# address space. If we get an error about trying to read
# from the expected address then we count that as a pass,
# GDB did try to read the correct location, and this test
# is (mostly) about does GDB calculate the correct address
# when wrapping around.
pass $test
}
}
set test "examine 3 bytes backward from ${address_zero}"
gdb_test_multiple "x/-3x ${address_zero}" "$test" {
-re "0x\[0-9a-f\]+fd.*:${byte}${byte}${byte}.*\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]+fd.*:\tCannot access memory at address 0x\[0-9a-f\]+fd.*\[\r\n\]*$gdb_prompt $" {
# See previous test for why this is a pass.
pass $test
}
}
}
gdb_test_no_output "set charset ASCII"
with_test_prefix "char-width=1, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6s &TestStrings" "take 6 strings forward" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xb" "0x39" "take 1 char backward"
gdb_test_sequence "x/-6s" "take 6 strings backward" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6s &TestStrings" "take 6 strings forward again" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xb" "0x39" "take 1 char backward again"
gdb_test "x/-s" "\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-s" "\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-s" "\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-s" "\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-s" "\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-s" "\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=2, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xh" "0x0039" "take 1 char backward"
gdb_test_sequence "x/-6sh" "take 6 strings backward" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward again" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xh" "0x0039" "take 1 char backward again"
gdb_test "x/-sh" "u\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-sh" "u\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sh" "u\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sh" "u\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=4, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6sw &TestStringsW" "take 6 strings forward" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xw" "0x00000039" "take 1 char backward"
gdb_test_sequence "x/-6sw" "take 6 strings backward" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6sw &TestStringsW" "take 6 strings forward again" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xw" "0x00000039" "take 1 char backward again"
gdb_test "x/-sw" "U\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-sw" "U\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sw" "U\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sw" "U\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sw" "U\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sw" "U\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=2, print-max=0" {
gdb_test_no_output "set print elements 0"
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"\\\\x307b\\\\x3052\\\\x307b\\\\x3052\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test "x/-4xh" "0x0021\[\t \]+0x0021\[\t \]+0x0021\[\t \]+0x0000" \
"take 4 characters backward"
gdb_test_sequence "x/-6sh" "take 6 strings backward" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward again" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"\\\\x307b\\\\x3052\\\\x307b\\\\x3052\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test "x/-xh" "0x0000" "take 1 char backward"
gdb_test "x/-sh" "u\"!!!!!!\"" \
"take 1 string backward (1/6)"
gdb_test "x/-sh" "u\"012345678901234567890123456789\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sh" "u\".+\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sh" "u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=1, print-max=4" {
gdb_test_no_output "set print elements 4"
gdb_test_sequence "x/9s &TestStrings" "take 9 strings forward" {
"\"ABCD\"\.\.\."
"\"EFGH\"\.\.\."
"\"IJKL\"\.\.\."
"\"MNOP\"\.\.\."
"\"QRST\"\.\.\."
"\"UVWX\"\.\.\."
"\"YZ\""
"\"\""
"\"\""
}
gdb_test "x/-xb" "0x00" "take 1 byte backward"
gdb_test_sequence "x/-4s" "take 4 strings backward (1/2)" {
"\"TUVW\"\.\.\."
"\"XYZ\""
"\"\""
"\"\""
}
gdb_test_sequence "x/-4s" "take 4 strings backward (2/2)" {
"\"CDEF\"\.\.\."
"\"GHIJ\"\.\.\."
"\"KLMN\"\.\.\."
"\"OPQR\"\.\.\."
}
}
with_test_prefix "backward disassemble general" {
set length_to_examine {1 2 3 4 10}
set disassmbly {}
gdb_test_no_output "set print asm-demangle on"
set main_re "main(\\(\\))?"
gdb_test "x/i main" "0x\[0-9a-fA-F\]+ <$main_re>:\t.*" \
"move the current position to main (x/i)"
gdb_test "x/-i" "0x\[0-9a-fA-F\]+ <$main_re>:\t.*" \
"move the current position to main (x/-i)"
for {set i 0} {$i < [llength $length_to_examine]} {incr i} {
set len [lindex $length_to_examine $i]
set instructions [capture_command_output "x/${len}i" ""]
lappend disassmbly $instructions
}
for {set i 0} {$i < [llength $length_to_examine]} {incr i} {
set idx [expr [llength $length_to_examine] - $i - 1]
set len [lindex $length_to_examine $idx]
set actual [capture_command_output "x/-${len}i" ""]
set expected [lindex $disassmbly $idx]
if {$actual == $expected} {
pass "inst:$idx"
} else {
fail "inst:$idx"
}
}
}
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