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      1 # Copyright 2018-2024 Free Software Foundation, Inc.
      2 
      3 # This program is free software; you can redistribute it and/or modify
      4 # it under the terms of the GNU General Public License as published by
      5 # the Free Software Foundation; either version 3 of the License, or
      6 # (at your option) any later version.
      7 #
      8 # This program is distributed in the hope that it will be useful,
      9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
     10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     11 # GNU General Public License for more details.
     12 #
     13 # You should have received a copy of the GNU General Public License
     14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
     15 
     16 # This testcase is a regression test for a regression in the in-line
     17 # step-over machinery.  If a resumption that starts a step-over
     18 # failed, a following resumption would make GDB hang forever:
     19 #
     20 #  (gdb) b *0
     21 #  Breakpoint 2 at 0x0
     22 #  continue
     23 #  Continuing.
     24 #  Warning:
     25 #  Cannot insert breakpoint 2.
     26 #  Cannot access memory at address 0x0
     27 #
     28 #  Command aborted.
     29 #  delete breakpoints
     30 #  Delete all breakpoints, watchpoints, tracepoints, and catchpoints? (y or n) y
     31 #  (gdb) b function
     32 #  Breakpoint 3 at 0x40048b: file test.c, line 33.
     33 #  continue
     34 #  Continuing.
     35 #  *GDB hangs forever*
     36 
     37 standard_testfile
     38 
     39 if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
     40     return -1
     41 }
     42 
     43 # DISPLACED indicates whether to use displaced-stepping.
     44 proc do_test {displaced breakpoint_always_inserted} {
     45     global gdb_prompt decimal
     46     global srcfile binfile
     47 
     48     clean_restart $binfile
     49 
     50     gdb_test_no_output "set displaced-stepping $displaced"
     51     gdb_test_no_output "set breakpoint always-inserted $breakpoint_always_inserted"
     52 
     53     if ![runto_main] {
     54 	return -1
     55     }
     56 
     57     # We rely on not being able to set a breakpoint at 0, as proxy for
     58     # any kind of breakpoint insertion failure.  If we can examine
     59     # what's at memory address 0, it is possible that we could also
     60     # execute it.
     61     if [is_address_zero_readable] {
     62 	untested "memory at address 0 is possibly executable"
     63 	return
     64     }
     65 
     66     # Set a breakpoint that fails to insert.
     67     if { $breakpoint_always_inserted == "on" } {
     68 	gdb_test "b *0" "Breakpoint $decimal at 0x0.*"
     69     } else {
     70 	gdb_test "b *0" "Breakpoint $decimal at 0x0"
     71     }
     72 
     73     gdb_test "continue" \
     74 	"Command aborted\\." \
     75 	"continue aborts"
     76 
     77     # Delete the "bad" breakpoint and try continuing again.
     78     delete_breakpoints
     79     gdb_test "b function" "Breakpoint $decimal .*$srcfile.*"
     80 
     81     gdb_test "continue" \
     82 	"Breakpoint $decimal, function \\(\\) at .*$srcfile:.*" \
     83 	"continue to function"
     84 }
     85 
     86 # This testcase exercises a regression with the in-line step-over
     87 # machinery.  So make sure this runs with displaced stepping disabled,
     88 # and for good measure, also try with displaced stepping enabled.
     89 foreach_with_prefix displaced-stepping {"off" "on"} {
     90     foreach_with_prefix breakpoint-always-inserted {"off" "on"} {
     91 	do_test ${displaced-stepping} ${breakpoint-always-inserted}
     92     }
     93 }
     94