Home | History | Annotate | Line # | Download | only in gdb.opt 
      1 # Copyright 2021-2024 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 # Set a breakpoint on libc's _exit, and verify that it triggers.  The function
     17 # tends to do a syscall immediately after the prologue, and if the breakpoint is
     18 # set past the syscall due to faulty prologue skipping, the breakpoint will not
     19 # trigger.
     20 #
     21 # In particular, we're trying to exercise the instruction analysis
     22 # functionality of prologue skipping.  If the non-minimal symbols are
     23 # read for libc, then that functionality might not be used because f.i.
     24 # line-info is used instead.  Also, if the minimal symbols are not read
     25 # for libc, then the breakpoint is set on the exec-local _exit@plt instead,
     26 # and that functionality will also not be used.
     27 #
     28 # We may get the required setup in case of a libc with misssing separate
     29 # debuginfo, but we want the same effect if that debuginfo is installed.
     30 #
     31 # So, we use -readnever to read minimal symbols, but not non-miminal symbols.
     32 #
     33 # Because the code at _exit may be and usually is optimized, the test is in
     34 # the gdb.opt directory.
     35 
     36 standard_testfile
     37 
     38 # See if we have target board readnow.exp or similar.
     39 if {[readnow]} {
     40     untested "--readnever not allowed in combination with --readnow"
     41     return -1
     42 }
     43 
     44 save_vars { GDBFLAGS } {
     45     append GDBFLAGS " -readnever"
     46 
     47     if {[prepare_for_testing "failed to prepare" $testfile $srcfile nodebug]} {
     48 	return -1
     49     }
     50 }
     51 
     52 if {![runto_main]} {
     53     return 0
     54 }
     55 
     56 gdb_breakpoint "_exit"
     57 
     58 # Give some background information about the breakpoint(s) and corresponding
     59 # the shared lib(s).
     60 gdb_test "info breakpoints"
     61 gdb_test "info shared"
     62 
     63 # If the skip_prologue analysis of _exit is too eager, we may not hit the
     64 # breakpoint.
     65 gdb_continue_to_breakpoint "_exit" "_exit \\(\\) .*"
     66