binutils-gdb/gdb/testsuite/gdb.base/break-main-file-remove-fail...

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# Copyright 2014-2017 Free Software Foundation, Inc.
"$ gdb PROGRAM" vs "(gdb) file PROGRAM" difference; warn on failure to remove breakpoint. Turns out there's a difference between loading the program with "gdb PROGRAM", vs loading it with "(gdb) file PROGRAM". The latter results in the objfile ending up with OBJF_USERLOADED set, while not with the former. (That difference seems bogus, but still that's not the point of this patch. We can revisit that afterwards.) The new code that suppresses breakpoint removal errors for add-symbol-file objects ends up being too greedy: /* In some cases, we might not be able to remove a breakpoint in a shared library that has already been removed, but we have not yet processed the shlib unload event. Similarly for an unloaded add-symbol-file object - the user might not yet have had the chance to remove-symbol-file it. shlib_disabled will be set if the library/object has already been removed, but the breakpoint hasn't been uninserted yet, e.g., after "nosharedlibrary" or "remove-symbol-file" with breakpoints always-inserted mode. */ if (val && (bl->loc_type == bp_loc_software_breakpoint && (bl->shlib_disabled || solib_name_from_address (bl->pspace, bl->address) || userloaded_objfile_contains_address_p (bl->pspace, bl->address)))) val = 0; as it turns out that OBJF_USERLOADED can be set for objfiles loaded by some other means not add-symbol-file. In this case, symbol-file (or "file", which is really just "exec-file"+"symbol-file"). Recall that add-symbol-file is documented as: (gdb) help add-symbol-file Load symbols from FILE, assuming FILE has been dynamically loaded. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ And it's the "dynamically loaded" aspect that the breakpoint.c code cares about. So make add-symbol-file set OBJF_SHARED on its objfiles too, and tweak the breakpoint.c code to look for OBJF_SHARED instead of OBJF_USERLOADED. This restores back the missing breakpoint removal warning when we let sss-bp-on-user-bp-2.exp run on native GNU/Linux (https://sourceware.org/ml/gdb-patches/2014-06/msg00335.html): (gdb) PASS: gdb.base/sss-bp-on-user-bp-2.exp: define stepi_del_break stepi_del_break warning: Error removing breakpoint 3 (gdb) FAIL: gdb.base/sss-bp-on-user-bp-2.exp: stepi_del_break I say "restores" because this was GDB's behavior in 7.7 and earlier. And, likewise, "file" with no arguments only started turning breakpoints set in the main executable to "<pending>" with the remote-symbol-file patch (63644780). The old behavior is now restored, and we break-unload-file.exp test now exercizes both "gdb; file PROGRAM" and "gdb PROGRAM". gdb/ 2014-06-16 Pedro Alves <palves@redhat.com> * breakpoint.c (insert_bp_location, remove_breakpoint_1): Adjust. (disable_breakpoints_in_freed_objfile): Skip objfiles that don't have OBJF_SHARED set. * objfiles.c (userloaded_objfile_contains_address_p): Rename to... (shared_objfile_contains_address_p): ... this. Check OBJF_SHARED instead of OBJF_USERLOADED. * objfiles.h (OBJF_SHARED): Update comment. (userloaded_objfile_contains_address_p): Rename to ... (shared_objfile_contains_address_p): ... this, and update comments. * symfile.c (add_symbol_file_command): Also set OBJF_SHARED in the new objfile. (remove_symbol_file_command): Skip objfiles that don't have OBJF_SHARED set. gdb/testsuite/ 2014-06-16 Pedro Alves <palves@redhat.com> * gdb.base/break-main-file-remove-fail.c: New file. * gdb.base/break-main-file-remove-fail.exp: New file. * gdb.base/break-unload-file.exp: Use build_executable instead of prepare_for_testing. (test_break): New parameter "initial_load". Handle it. (top level): Add initial_load cmdline/file axis.
2014-06-16 16:38:13 +02:00
# 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/>. */
# Test that GDB isn't silent if it fails to remove a breakpoint from
# the main program, independently of whether the program was loaded
# with "file PROGRAM" or directly from the command line with "gdb
# PROGRAM".
standard_testfile
if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
return -1
}
# Run the test proper. INITIAL_LOAD determines whether the program is
# initially loaded by the "file" command or by passing it to GDB on
# the command line.
proc test_remove_bp { initial_load } {
with_test_prefix "$initial_load" {
global srcdir subdir binfile
global gdb_prompt hex
global GDBFLAGS
gdb_exit
set saved_gdbflags $GDBFLAGS
# See "used to behave differently" further below.
if { $initial_load == "file" } {
gdb_start
gdb_file_cmd $binfile
} else {
global last_loaded_file
# gdb_file_cmd sets this. This is what gdb_reload
# implementations use as binary.
set last_loaded_file $binfile
set GDBFLAGS "$GDBFLAGS $binfile"
gdb_start
}
gdb_reinitialize_dir $srcdir/$subdir
gdb_reload
set GDBFLAGS $saved_gdbflags
if ![runto start] {
Fix test names starting with uppercase output by basic functions The following patch is based on the previous patch i sent and handles cases of test names that start with an uppercase letter. Test names should start with lowercase unless it starts with the name of a technology, architecture, ISA etc. This first patch addresses cases of test names output explicitly via xfail, kfail, kpass, fail, pass, unsupported, untested and also names set with the pattern "set test" and "set testname". gdb/testsuite/ChangeLog: 2016-12-01 Luis Machado <lgustavo@codesourcery.com> Fix test names starting with uppercase throughout all the files below. * gdb.ada/array_return.exp * gdb.ada/catch_ex.exp * gdb.ada/info_exc.exp * gdb.ada/mi_catch_ex.exp * gdb.ada/mi_dyn_arr.exp * gdb.ada/mi_ex_cond.exp * gdb.ada/mi_exc_info.exp * gdb.ada/mi_interface.exp * gdb.ada/mi_task_arg.exp * gdb.ada/mi_task_info.exp * gdb.ada/mi_var_array.exp * gdb.arch/alpha-step.exp * gdb.arch/amd64-disp-step.exp * gdb.arch/arm-disp-step.exp * gdb.arch/disp-step-insn-reloc.exp * gdb.arch/e500-prologue.exp * gdb.arch/ftrace-insn-reloc.exp * gdb.arch/gdb1558.exp * gdb.arch/i386-bp_permanent.exp * gdb.arch/i386-disp-step.exp * gdb.arch/i386-float.exp * gdb.arch/i386-gnu-cfi.exp * gdb.arch/ia64-breakpoint-shadow.exp * gdb.arch/mips16-thunks.exp * gdb.arch/pa-nullify.exp * gdb.arch/powerpc-aix-prologue.exp * gdb.arch/powerpc-power.exp * gdb.arch/ppc-dfp.exp * gdb.arch/s390-tdbregs.exp * gdb.arch/spu-info.exp * gdb.arch/spu-ls.exp * gdb.arch/thumb-bx-pc.exp * gdb.base/advance.exp * gdb.base/annota-input-while-running.exp * gdb.base/arrayidx.exp * gdb.base/asmlabel.exp * gdb.base/async.exp * gdb.base/attach-wait-input.exp * gdb.base/auto-connect-native-target.exp * gdb.base/batch-preserve-term-settings.exp * gdb.base/bfp-test.exp * gdb.base/bigcore.exp * gdb.base/bp-permanent.exp * gdb.base/break-always.exp * gdb.base/break-fun-addr.exp * gdb.base/break-idempotent.exp * gdb.base/break-main-file-remove-fail.exp * gdb.base/break-probes.exp * gdb.base/break-unload-file.exp * gdb.base/break.exp * gdb.base/call-ar-st.exp * gdb.base/call-rt-st.exp * gdb.base/call-sc.exp * gdb.base/call-signal-resume.exp * gdb.base/call-strs.exp * gdb.base/callexit.exp * gdb.base/callfuncs.exp * gdb.base/catch-gdb-caused-signals.exp * gdb.base/catch-signal-siginfo-cond.exp * gdb.base/catch-syscall.exp * gdb.base/compare-sections.exp * gdb.base/cond-eval-mode.exp * gdb.base/condbreak-call-false.exp * gdb.base/consecutive-step-over.exp * gdb.base/cursal.exp * gdb.base/disabled-location.exp * gdb.base/disasm-end-cu.exp * gdb.base/display.exp * gdb.base/double-prompt-target-event-error.exp * gdb.base/dprintf-bp-same-addr.exp * gdb.base/dprintf-detach.exp * gdb.base/dprintf-next.exp * gdb.base/dprintf-non-stop.exp * gdb.base/dprintf-pending.exp * gdb.base/dso2dso.exp * gdb.base/ending-run.exp * gdb.base/enum_cond.exp * gdb.base/examine-backward.exp * gdb.base/exe-lock.exp * gdb.base/exec-invalid-sysroot.exp * gdb.base/execl-update-breakpoints.exp * gdb.base/execution-termios.exp * gdb.base/fileio.exp * gdb.base/fixsection.exp * gdb.base/foll-exec-mode.exp * gdb.base/foll-exec.exp * gdb.base/fork-running-state.exp * gdb.base/frame-args.exp * gdb.base/fullpath-expand.exp * gdb.base/func-ptr.exp * gdb.base/gcore-relro-pie.exp * gdb.base/gdb1090.exp * gdb.base/gdb1555.exp * gdb.base/global-var-nested-by-dso.exp * gdb.base/gnu-ifunc.exp * gdb.base/hbreak-in-shr-unsupported.exp * gdb.base/hbreak-unmapped.exp * gdb.base/hook-stop.exp * gdb.base/infcall-input.exp * gdb.base/info-fun.exp * gdb.base/info-shared.exp * gdb.base/interrupt-noterm.exp * gdb.base/jit-so.exp * gdb.base/jit.exp * gdb.base/line-symtabs.exp * gdb.base/list.exp * gdb.base/longjmp.exp * gdb.base/macscp.exp * gdb.base/max-value-size.exp * gdb.base/nodebug.exp * gdb.base/nofield.exp * gdb.base/overlays.exp * gdb.base/paginate-after-ctrl-c-running.exp * gdb.base/paginate-bg-execution.exp * gdb.base/paginate-inferior-exit.exp * gdb.base/pending.exp * gdb.base/pr11022.exp * gdb.base/printcmds.exp * gdb.base/ptr-typedef.exp * gdb.base/ptype.exp * gdb.base/randomize.exp * gdb.base/range-stepping.exp * gdb.base/realname-expand.exp * gdb.base/relativedebug.exp * gdb.base/remote.exp * gdb.base/savedregs.exp * gdb.base/sepdebug.exp * gdb.base/set-noassign.exp * gdb.base/shlib-call.exp * gdb.base/shreloc.exp * gdb.base/sigaltstack.exp * gdb.base/sigbpt.exp * gdb.base/siginfo-addr.exp * gdb.base/siginfo-obj.exp * gdb.base/siginfo-thread.exp * gdb.base/signest.exp * gdb.base/signull.exp * gdb.base/sigrepeat.exp * gdb.base/skip.exp * gdb.base/so-impl-ld.exp * gdb.base/solib-corrupted.exp * gdb.base/solib-disc.exp * gdb.base/solib-display.exp * gdb.base/solib-overlap.exp * gdb.base/solib-search.exp * gdb.base/solib-symbol.exp * gdb.base/source-execution.exp * gdb.base/sss-bp-on-user-bp-2.exp * gdb.base/sss-bp-on-user-bp.exp * gdb.base/stack-checking.exp * gdb.base/stale-infcall.exp * gdb.base/step-break.exp * gdb.base/step-line.exp * gdb.base/step-over-exit.exp * gdb.base/step-test.exp * gdb.base/structs.exp * gdb.base/sym-file.exp * gdb.base/symtab-search-order.exp * gdb.base/term.exp * gdb.base/type-opaque.exp * gdb.base/unload.exp * gdb.base/until-nodebug.exp * gdb.base/until.exp * gdb.base/unwindonsignal.exp * gdb.base/watch-cond.exp * gdb.base/watch-non-mem.exp * gdb.base/watch_thread_num.exp * gdb.base/watchpoint-reuse-slot.exp * gdb.base/watchpoint-solib.exp * gdb.base/watchpoint.exp * gdb.btrace/dlopen.exp * gdb.cell/arch.exp * gdb.cell/break.exp * gdb.cell/bt.exp * gdb.cell/core.exp * gdb.cell/data.exp * gdb.cell/dwarfaddr.exp * gdb.cell/ea-cache.exp * gdb.cell/ea-standalone.exp * gdb.cell/ea-test.exp * gdb.cell/f-regs.exp * gdb.cell/fork.exp * gdb.cell/gcore.exp * gdb.cell/mem-access.exp * gdb.cell/ptype.exp * gdb.cell/registers.exp * gdb.cell/sizeof.exp * gdb.cell/solib-symbol.exp * gdb.cell/solib.exp * gdb.compile/compile-tls.exp * gdb.cp/exception.exp * gdb.cp/gdb2495.exp * gdb.cp/local.exp * gdb.cp/mb-inline.exp * gdb.cp/mb-templates.exp * gdb.cp/pr10687.exp * gdb.cp/pr9167.exp * gdb.cp/scope-err.exp * gdb.cp/templates.exp * gdb.cp/virtfunc.exp * gdb.dwarf2/dw2-dir-file-name.exp * gdb.dwarf2/dw2-single-line-discriminators.exp * gdb.fortran/complex.exp * gdb.fortran/library-module.exp * gdb.guile/guile.exp * gdb.guile/scm-cmd.exp * gdb.guile/scm-frame-inline.exp * gdb.guile/scm-objfile.exp * gdb.guile/scm-pretty-print.exp * gdb.guile/scm-symbol.exp * gdb.guile/scm-type.exp * gdb.guile/scm-value.exp * gdb.linespec/keywords.exp * gdb.linespec/ls-errs.exp * gdb.linespec/macro-relative.exp * gdb.linespec/thread.exp * gdb.mi/mi-breakpoint-changed.exp * gdb.mi/mi-dprintf-pending.exp * gdb.mi/mi-fullname-deleted.exp * gdb.mi/mi-logging.exp * gdb.mi/mi-pending.exp * gdb.mi/mi-solib.exp * gdb.mi/new-ui-mi-sync.exp * gdb.mi/user-selected-context-sync.exp * gdb.multi/dummy-frame-restore.exp * gdb.multi/multi-arch-exec.exp * gdb.multi/remove-inferiors.exp * gdb.multi/watchpoint-multi-exit.exp * gdb.opt/solib-intra-step.exp * gdb.perf/backtrace.exp * gdb.perf/single-step.exp * gdb.perf/skip-command.exp * gdb.perf/skip-prologue.exp * gdb.perf/solib.exp * gdb.python/lib-types.exp * gdb.python/py-as-string.exp * gdb.python/py-bad-printers.exp * gdb.python/py-block.exp * gdb.python/py-breakpoint.exp * gdb.python/py-cmd.exp * gdb.python/py-events.exp * gdb.python/py-evthreads.exp * gdb.python/py-finish-breakpoint.exp * gdb.python/py-finish-breakpoint2.exp * gdb.python/py-frame-inline.exp * gdb.python/py-frame.exp * gdb.python/py-inferior.exp * gdb.python/py-infthread.exp * gdb.python/py-mi.exp * gdb.python/py-objfile.exp * gdb.python/py-pp-maint.exp * gdb.python/py-pp-registration.exp * gdb.python/py-prettyprint.exp * gdb.python/py-recurse-unwind.exp * gdb.python/py-shared.exp * gdb.python/py-symbol.exp * gdb.python/py-symtab.exp * gdb.python/py-template.exp * gdb.python/py-type.exp * gdb.python/py-unwind-maint.exp * gdb.python/py-unwind.exp * gdb.python/py-value.exp * gdb.python/python.exp * gdb.reverse/finish-reverse-bkpt.exp * gdb.reverse/insn-reverse.exp * gdb.reverse/next-reverse-bkpt-over-sr.exp * gdb.reverse/solib-precsave.exp * gdb.reverse/solib-reverse.exp * gdb.stabs/gdb11479.exp * gdb.stabs/weird.exp * gdb.threads/fork-child-threads.exp * gdb.threads/fork-plus-threads.exp * gdb.threads/fork-thread-pending.exp * gdb.threads/forking-threads-plus-breakpoint.exp * gdb.threads/hand-call-in-threads.exp * gdb.threads/interrupted-hand-call.exp * gdb.threads/linux-dp.exp * gdb.threads/local-watch-wrong-thread.exp * gdb.threads/next-while-other-thread-longjmps.exp * gdb.threads/non-ldr-exit.exp * gdb.threads/pending-step.exp * gdb.threads/print-threads.exp * gdb.threads/process-dies-while-detaching.exp * gdb.threads/process-dies-while-handling-bp.exp * gdb.threads/pthreads.exp * gdb.threads/queue-signal.exp * gdb.threads/reconnect-signal.exp * gdb.threads/signal-command-handle-nopass.exp * gdb.threads/signal-command-multiple-signals-pending.exp * gdb.threads/signal-delivered-right-thread.exp * gdb.threads/signal-sigtrap.exp * gdb.threads/sigthread.exp * gdb.threads/staticthreads.exp * gdb.threads/stepi-random-signal.exp * gdb.threads/thread-unwindonsignal.exp * gdb.threads/thread_check.exp * gdb.threads/thread_events.exp * gdb.threads/tid-reuse.exp * gdb.threads/tls-nodebug.exp * gdb.threads/tls-shared.exp * gdb.threads/tls-so_extern.exp * gdb.threads/tls.exp * gdb.threads/wp-replication.exp * gdb.trace/actions-changed.exp * gdb.trace/actions.exp * gdb.trace/backtrace.exp * gdb.trace/change-loc.exp * gdb.trace/collection.exp * gdb.trace/deltrace.exp * gdb.trace/disconnected-tracing.exp * gdb.trace/entry-values.exp * gdb.trace/ftrace-lock.exp * gdb.trace/ftrace.exp * gdb.trace/infotrace.exp * gdb.trace/mi-trace-frame-collected.exp * gdb.trace/mi-trace-unavailable.exp * gdb.trace/mi-traceframe-changed.exp * gdb.trace/mi-tracepoint-changed.exp * gdb.trace/mi-tsv-changed.exp * gdb.trace/no-attach-trace.exp * gdb.trace/packetlen.exp * gdb.trace/passc-dyn.exp * gdb.trace/passcount.exp * gdb.trace/pending.exp * gdb.trace/pr16508.exp * gdb.trace/qtro.exp * gdb.trace/range-stepping.exp * gdb.trace/read-memory.exp * gdb.trace/report.exp * gdb.trace/save-trace.exp * gdb.trace/signal.exp * gdb.trace/stap-trace.exp * gdb.trace/status-stop.exp * gdb.trace/strace.exp * gdb.trace/tfile.exp * gdb.trace/tfind.exp * gdb.trace/trace-break.exp * gdb.trace/trace-condition.exp * gdb.trace/trace-enable-disable.exp * gdb.trace/trace-mt.exp * gdb.trace/tracecmd.exp * gdb.trace/tracefile-pseudo-reg.exp * gdb.trace/tspeed.exp * gdb.trace/tstatus.exp * gdb.trace/tsv.exp * gdb.trace/unavailable.exp * gdb.trace/while-dyn.exp * gdb.trace/while-stepping.exp * lib/gdb-guile.exp * lib/gdb.exp * lib/mi-support.exp * lib/pascal.exp * lib/perftest.exp * lib/prelink-support.exp * lib/selftest-support.exp
2016-12-01 21:40:05 +01:00
fail "can't run to start"
"$ gdb PROGRAM" vs "(gdb) file PROGRAM" difference; warn on failure to remove breakpoint. Turns out there's a difference between loading the program with "gdb PROGRAM", vs loading it with "(gdb) file PROGRAM". The latter results in the objfile ending up with OBJF_USERLOADED set, while not with the former. (That difference seems bogus, but still that's not the point of this patch. We can revisit that afterwards.) The new code that suppresses breakpoint removal errors for add-symbol-file objects ends up being too greedy: /* In some cases, we might not be able to remove a breakpoint in a shared library that has already been removed, but we have not yet processed the shlib unload event. Similarly for an unloaded add-symbol-file object - the user might not yet have had the chance to remove-symbol-file it. shlib_disabled will be set if the library/object has already been removed, but the breakpoint hasn't been uninserted yet, e.g., after "nosharedlibrary" or "remove-symbol-file" with breakpoints always-inserted mode. */ if (val && (bl->loc_type == bp_loc_software_breakpoint && (bl->shlib_disabled || solib_name_from_address (bl->pspace, bl->address) || userloaded_objfile_contains_address_p (bl->pspace, bl->address)))) val = 0; as it turns out that OBJF_USERLOADED can be set for objfiles loaded by some other means not add-symbol-file. In this case, symbol-file (or "file", which is really just "exec-file"+"symbol-file"). Recall that add-symbol-file is documented as: (gdb) help add-symbol-file Load symbols from FILE, assuming FILE has been dynamically loaded. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ And it's the "dynamically loaded" aspect that the breakpoint.c code cares about. So make add-symbol-file set OBJF_SHARED on its objfiles too, and tweak the breakpoint.c code to look for OBJF_SHARED instead of OBJF_USERLOADED. This restores back the missing breakpoint removal warning when we let sss-bp-on-user-bp-2.exp run on native GNU/Linux (https://sourceware.org/ml/gdb-patches/2014-06/msg00335.html): (gdb) PASS: gdb.base/sss-bp-on-user-bp-2.exp: define stepi_del_break stepi_del_break warning: Error removing breakpoint 3 (gdb) FAIL: gdb.base/sss-bp-on-user-bp-2.exp: stepi_del_break I say "restores" because this was GDB's behavior in 7.7 and earlier. And, likewise, "file" with no arguments only started turning breakpoints set in the main executable to "<pending>" with the remote-symbol-file patch (63644780). The old behavior is now restored, and we break-unload-file.exp test now exercizes both "gdb; file PROGRAM" and "gdb PROGRAM". gdb/ 2014-06-16 Pedro Alves <palves@redhat.com> * breakpoint.c (insert_bp_location, remove_breakpoint_1): Adjust. (disable_breakpoints_in_freed_objfile): Skip objfiles that don't have OBJF_SHARED set. * objfiles.c (userloaded_objfile_contains_address_p): Rename to... (shared_objfile_contains_address_p): ... this. Check OBJF_SHARED instead of OBJF_USERLOADED. * objfiles.h (OBJF_SHARED): Update comment. (userloaded_objfile_contains_address_p): Rename to ... (shared_objfile_contains_address_p): ... this, and update comments. * symfile.c (add_symbol_file_command): Also set OBJF_SHARED in the new objfile. (remove_symbol_file_command): Skip objfiles that don't have OBJF_SHARED set. gdb/testsuite/ 2014-06-16 Pedro Alves <palves@redhat.com> * gdb.base/break-main-file-remove-fail.c: New file. * gdb.base/break-main-file-remove-fail.exp: New file. * gdb.base/break-unload-file.exp: Use build_executable instead of prepare_for_testing. (test_break): New parameter "initial_load". Handle it. (top level): Add initial_load cmdline/file axis.
2014-06-16 16:38:13 +02:00
return
}
delete_breakpoints
# So we can easily control when are breakpoints removed.
gdb_test_no_output "set breakpoint always-inserted on"
set bp_addr ""
set test "break foo"
gdb_test_multiple $test $test {
-re "Breakpoint .* at ($hex).*$gdb_prompt $" {
set bp_addr $expect_out(1,string)
pass $test
}
}
if {$bp_addr == ""} {
unsupported "can't extract foo's address"
return
}
gdb_test "info break" "y.*$hex.*in foo at.*" \
"breakpoint is set"
# Now unmap the page where the breakpoint is set. Trying to
# remove the memory breakpoint afterwards should fail, and GDB
# should warn the user about it.
set pagesize [get_integer_valueof "pg_size" 0]
set align_addr [expr $bp_addr - $bp_addr % $pagesize]
Stop assuming no-debug-info functions return int The fact that GDB defaults to assuming that functions return int, when it has no debug info for the function has been a recurring source of user confusion. Recently this came up on the errno pretty printer discussions. Shortly after, it came up again on IRC, with someone wondering why does getenv() in GDB return a negative int: (gdb) p getenv("PATH") $1 = -6185 This question (with s/getenv/random-other-C-runtime-function) is a FAQ on IRC. The reason for the above is: (gdb) p getenv $2 = {<text variable, no debug info>} 0x7ffff7751d80 <getenv> (gdb) ptype getenv type = int () ... which means that GDB truncated the 64-bit pointer that is actually returned from getent to 32-bit, and then sign-extended it: (gdb) p /x -6185 $6 = 0xffffe7d7 The workaround is to cast the function to the right type, like: (gdb) p ((char *(*) (const char *)) getenv) ("PATH") $3 = 0x7fffffffe7d7 "/usr/local/bin:/"... IMO, we should do better than this. I see the "assume-int" issue the same way I see printing bogus values for optimized-out variables instead of "<optimized out>" -- I'd much rather that the debugger tells me "I don't know" and tells me how to fix it than showing me bogus misleading results, making me go around tilting at windmills. If GDB prints a signed integer when you're expecting a pointer or aggregate, you at least have some sense that something is off, but consider the case of the function actually returning a 64-bit integer. For example, compile this without debug info: unsigned long long function () { return 0x7fffffffffffffff; } Currently, with pristine GDB, you get: (gdb) p function () $1 = -1 # incorrect (gdb) p /x function () $2 = 0xffffffff # incorrect maybe after spending a few hours debugging you suspect something is wrong with that -1, and do: (gdb) ptype function type = int () and maybe, just maybe, you realize that the function actually returns unsigned long long. And you try to fix it with: (gdb) p /x (unsigned long long) function () $3 = 0xffffffffffffffff # incorrect ... which still produces the wrong result, because GDB simply applied int to unsigned long long conversion. Meaning, it sign-extended the integer that it extracted from the return of the function, to 64-bits. and then maybe, after asking around on IRC, you realize you have to cast the function to a pointer of the right type, and call that. It won't be easy, but after a few missteps, you'll get to it: ..... (gdb) p /x ((unsigned long long(*) ()) function) () $666 = 0x7fffffffffffffff # finally! :-) So to improve on the user experience, this patch does the following (interrelated) things: - makes no-debug-info functions no longer default to "int" as return type. Instead, they're left with NULL/"<unknown return type>" return type. (gdb) ptype getenv type = <unknown return type> () - makes calling a function with unknown return type an error. (gdb) p getenv ("PATH") 'getenv' has unknown return type; cast the call to its declared return type - and then to make it easier to call the function, makes it possible to _only_ cast the return of the function to the right type, instead of having to cast the function to a function pointer: (gdb) p (char *) getenv ("PATH") # now Just Works $3 = 0x7fffffffe7d7 "/usr/local/bin:/"... (gdb) p ((char *(*) (const char *)) getenv) ("PATH") # continues working $4 = 0x7fffffffe7d7 "/usr/local/bin:/"... I.e., it makes GDB default the function's return type to the type of the cast, and the function's parameters to the type of the arguments passed down. After this patch, here's what you'll get for the "unsigned long long" example above: (gdb) p function () 'function' has unknown return type; cast the call to its declared return type (gdb) p /x (unsigned long long) function () $4 = 0x7fffffffffffffff # correct! Note that while with "print" GDB shows the name of the function that has the problem: (gdb) p getenv ("PATH") 'getenv' has unknown return type; cast the call to its declared return type which can by handy in more complicated expressions, "ptype" does not: (gdb) ptype getenv ("PATH") function has unknown return type; cast the call to its declared return type This will be fixed in the next patch. gdb/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * ada-lang.c (ada_evaluate_subexp) <TYPE_CODE_FUNC>: Don't handle TYPE_GNU_IFUNC specially here. Throw error if return type is unknown. * ada-typeprint.c (print_func_type): Handle functions with unknown return type. * c-typeprint.c (c_type_print_base): Handle functions and methods with unknown return type. * compile/compile-c-symbols.c (convert_symbol_bmsym) <mst_text_gnu_ifunc>: Use nodebug_text_gnu_ifunc_symbol. * compile/compile-c-types.c: Include "objfiles.h". (convert_func): For functions with unknown return type, warn and default to int. * compile/compile-object-run.c (compile_object_run): Adjust call to call_function_by_hand_dummy. * elfread.c (elf_gnu_ifunc_resolve_addr): Adjust call to call_function_by_hand. * eval.c (evaluate_subexp_standard): Adjust calls to call_function_by_hand. Handle functions and methods with unknown return type. Pass expect_type to call_function_by_hand. * f-typeprint.c (f_type_print_base): Handle functions with unknown return type. * gcore.c (call_target_sbrk): Adjust call to call_function_by_hand. * gdbtypes.c (objfile_type): Leave nodebug text symbol with NULL return type instead of int. Make nodebug_text_gnu_ifunc_symbol be an integer address type instead of nodebug. * guile/scm-value.c (gdbscm_value_call): Adjust call to call_function_by_hand. * infcall.c (error_call_unknown_return_type): New function. (call_function_by_hand): New "default_return_type" parameter. Pass it down. (call_function_by_hand_dummy): New "default_return_type" parameter. Use it instead of defaulting to int. If there's no default and the return type is unknown, throw an error. If there's a default return type, and the called function has no debug info, then assume the function is prototyped. * infcall.h (call_function_by_hand, call_function_by_hand_dummy): New "default_return_type" parameter. (error_call_unknown_return_type): New declaration. * linux-fork.c (call_lseek): Cast return type of lseek. (inferior_call_waitpid, checkpoint_command): Adjust calls to call_function_by_hand. * linux-tdep.c (linux_infcall_mmap, linux_infcall_munmap): Adjust calls to call_function_by_hand. * m2-typeprint.c (m2_procedure): Handle functions with unknown return type. * objc-lang.c (lookup_objc_class, lookup_child_selector) (value_nsstring, print_object_command): Adjust calls to call_function_by_hand. * p-typeprint.c (pascal_type_print_varspec_prefix): Handle functions with unknown return type. (pascal_type_print_func_varspec_suffix): New function. (pascal_type_print_varspec_suffix) <TYPE_CODE_FUNC, TYPE_CODE_METHOD>: Use it. * python/py-value.c (valpy_call): Adjust call to call_function_by_hand. * rust-lang.c (rust_evaluate_funcall): Adjust call to call_function_by_hand. * valarith.c (value_x_binop, value_x_unop): Adjust calls to call_function_by_hand. * valops.c (value_allocate_space_in_inferior): Adjust call to call_function_by_hand. * typeprint.c (type_print_unknown_return_type): New function. * typeprint.h (type_print_unknown_return_type): New declaration. gdb/testsuite/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * gdb.base/break-main-file-remove-fail.exp (test_remove_bp): Cast return type of munmap in infcall. * gdb.base/break-probes.exp: Cast return type of foo in infcall. * gdb.base/checkpoint.exp: Simplify using for loop. Cast return type of ftell in infcall. * gdb.base/dprintf-detach.exp (dprintf_detach_test): Cast return type of getpid in infcall. * gdb.base/infcall-exec.exp: Cast return type of execlp in infcall. * gdb.base/info-os.exp: Cast return type of getpid in infcall. Bail on failure to extract the pid. * gdb.base/nodebug.c: #include <stdint.h>. (multf, multf_noproto, mult, mult_noproto, add8, add8_noproto): New functions. * gdb.base/nodebug.exp (test_call_promotion): New procedure. Change expected output of print/whatis/ptype with functions with no debug info. Test all supported languages. Call test_call_promotion. * gdb.compile/compile.exp: Adjust expected output to expect warning. * gdb.threads/siginfo-threads.exp: Likewise.
2017-09-04 21:21:13 +02:00
set munmap [get_integer_valueof "(int) munmap ($align_addr, $pagesize)" -1]
"$ gdb PROGRAM" vs "(gdb) file PROGRAM" difference; warn on failure to remove breakpoint. Turns out there's a difference between loading the program with "gdb PROGRAM", vs loading it with "(gdb) file PROGRAM". The latter results in the objfile ending up with OBJF_USERLOADED set, while not with the former. (That difference seems bogus, but still that's not the point of this patch. We can revisit that afterwards.) The new code that suppresses breakpoint removal errors for add-symbol-file objects ends up being too greedy: /* In some cases, we might not be able to remove a breakpoint in a shared library that has already been removed, but we have not yet processed the shlib unload event. Similarly for an unloaded add-symbol-file object - the user might not yet have had the chance to remove-symbol-file it. shlib_disabled will be set if the library/object has already been removed, but the breakpoint hasn't been uninserted yet, e.g., after "nosharedlibrary" or "remove-symbol-file" with breakpoints always-inserted mode. */ if (val && (bl->loc_type == bp_loc_software_breakpoint && (bl->shlib_disabled || solib_name_from_address (bl->pspace, bl->address) || userloaded_objfile_contains_address_p (bl->pspace, bl->address)))) val = 0; as it turns out that OBJF_USERLOADED can be set for objfiles loaded by some other means not add-symbol-file. In this case, symbol-file (or "file", which is really just "exec-file"+"symbol-file"). Recall that add-symbol-file is documented as: (gdb) help add-symbol-file Load symbols from FILE, assuming FILE has been dynamically loaded. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ And it's the "dynamically loaded" aspect that the breakpoint.c code cares about. So make add-symbol-file set OBJF_SHARED on its objfiles too, and tweak the breakpoint.c code to look for OBJF_SHARED instead of OBJF_USERLOADED. This restores back the missing breakpoint removal warning when we let sss-bp-on-user-bp-2.exp run on native GNU/Linux (https://sourceware.org/ml/gdb-patches/2014-06/msg00335.html): (gdb) PASS: gdb.base/sss-bp-on-user-bp-2.exp: define stepi_del_break stepi_del_break warning: Error removing breakpoint 3 (gdb) FAIL: gdb.base/sss-bp-on-user-bp-2.exp: stepi_del_break I say "restores" because this was GDB's behavior in 7.7 and earlier. And, likewise, "file" with no arguments only started turning breakpoints set in the main executable to "<pending>" with the remote-symbol-file patch (63644780). The old behavior is now restored, and we break-unload-file.exp test now exercizes both "gdb; file PROGRAM" and "gdb PROGRAM". gdb/ 2014-06-16 Pedro Alves <palves@redhat.com> * breakpoint.c (insert_bp_location, remove_breakpoint_1): Adjust. (disable_breakpoints_in_freed_objfile): Skip objfiles that don't have OBJF_SHARED set. * objfiles.c (userloaded_objfile_contains_address_p): Rename to... (shared_objfile_contains_address_p): ... this. Check OBJF_SHARED instead of OBJF_USERLOADED. * objfiles.h (OBJF_SHARED): Update comment. (userloaded_objfile_contains_address_p): Rename to ... (shared_objfile_contains_address_p): ... this, and update comments. * symfile.c (add_symbol_file_command): Also set OBJF_SHARED in the new objfile. (remove_symbol_file_command): Skip objfiles that don't have OBJF_SHARED set. gdb/testsuite/ 2014-06-16 Pedro Alves <palves@redhat.com> * gdb.base/break-main-file-remove-fail.c: New file. * gdb.base/break-main-file-remove-fail.exp: New file. * gdb.base/break-unload-file.exp: Use build_executable instead of prepare_for_testing. (test_break): New parameter "initial_load". Handle it. (top level): Add initial_load cmdline/file axis.
2014-06-16 16:38:13 +02:00
if {$munmap != 0} {
unsupported "can't munmap foo's page"
return
}
gdb_test "delete \$bpnum" \
"warning: Error removing breakpoint .*" \
"failure to remove breakpoint warns"
}
}
foreach initial_load { "cmdline" "file" } {
test_remove_bp $initial_load
}