Doing "info frame" in the outermost frame, when that was indicated by
the next frame saying the unwound PC is undefined/not saved, results
in error and incomplete output:
(gdb) bt
#0 thread_function0 (arg=0x0) at threads.c:63
#1 0x00000034cf407d14 in start_thread (arg=0x7ffff7fcb700) at pthread_create.c:309
#2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115
(gdb) frame 2
#2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115
115 call *%rax
(gdb) info frame
Stack level 2, frame at 0x0:
rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip Register 16 was not saved
(gdb)
Not saved register values are treated as optimized out values
internally throughout. stack.c:frame_info is handing unvailable
values, but not optimized out ones. The patch deletes the
frame_unwind_caller_pc_if_available wrapper function and instead lets
errors propagate to frame_info (it's only user).
As frame_unwind_pc now needs to be able to handle and cache two
different error scenarios, the prev_pc.p variable is replaced with an
enumeration.
(FWIW, I looked into making gdbarch_unwind_pc or a variant return
struct value's instead, but it results in lots of boxing and unboxing
for no real gain -- e.g., the mips and arm implementations need to do
computation on the unboxed PC value. Might as well throw an error on
first attempt to get at invalid contents.)
After the patch, we get:
(gdb) info frame
Stack level 2, frame at 0x0:
rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip = <not saved>
Outermost frame: outermost
caller of frame at 0x7ffff7fcafc0
source language asm.
Arglist at 0x7ffff7fcafb8, args:
Locals at 0x7ffff7fcafb8, Previous frame's sp is 0x7ffff7fcafc8
(gdb)
A new test is added. It's based off dw2-reg-undefined.exp, and tweaked to
mark the return address (rip) of "stop_frame" as undefined.
Tested on x86_64 Fedora 17.
gdb/
2013-12-06 Pedro Alves <palves@redhat.com>
* frame.c (enum cached_copy_status): New enum.
(struct frame_info) <prev_pc.p>: Change type to enum
cached_copy_status.
(fprint_frame): Handle not saved and unavailable prev_pc values.
(frame_unwind_pc_if_available): Delete and merge contents into ...
(frame_unwind_pc): ... here. Handle OPTIMIZED_OUT_ERROR. Adjust
to use enum cached_copy_status.
(frame_unwind_caller_pc_if_available): Delete.
(create_new_frame): Adjust.
* frame.h (frame_unwind_caller_pc_if_available): Delete
declaration.
* stack.c (frame_info): Use frame_unwind_caller_pc instead of
frame_unwind_caller_pc_if_available, and handle
NOT_AVAILABLE_ERROR and OPTIMIZED_OUT_ERROR errors.
* valprint.c (val_print_optimized_out): Use val_print_not_saved.
(val_print_not_saved): New function.
* valprint.h (val_print_not_saved): Declare.
gdb/testsuite/
2013-12-06 Pedro Alves <palves@redhat.com>
* gdb.dwarf2/dw2-undefined-ret-addr.S: New file.
* gdb.dwarf2/dw2-undefined-ret-addr.c: New file.
* gdb.dwarf2/dw2-undefined-ret-addr.exp: New file.
In order to catch <optimized out> errors like we catch <unavailable>
errors, this adds a new OPTIMIZED_OUT_ERROR error code, and throws it
in various places.
gdb/ChangeLog
2013-12-06 Andrew Burgess <aburgess@broadcom.com>
Pedro Alves <palves@redhat.com>
* exceptions.h (errors): Add OPTIMIZED_OUT_ERROR.
* dwarf2loc.c (write_pieced_value): Throw OPTIMIZED_OUT_ERROR.
* frame.c (frame_unwind_register): Throw OPTIMIZED_OUT_ERROR.
* spu-tdep.c (spu_software_single_step): Throw
OPTIMIZED_OUT_ERROR.
* valops.c (value_assign): Throw OPTIMIZED_OUT_ERROR.
The introductory comment to free_objfile is obsolete.
This patch fixes it by removing all the obsolete bits.
2013-12-06 Tom Tromey <tromey@redhat.com>
* objfiles.c (free_objfile): Update comment.
I happened to notice that nothing uses objfile_to_front.
This patch removes it.
2013-12-06 Tom Tromey <tromey@redhat.com>
* objfiles.h (objfile_to_front): Remove.
* objfiles.c (objfile_to_front): Remove.
This removes an unnecessary declaration from minsyms.c.
2013-12-06 Tom Tromey <tromey@redhat.com>
* minsyms.c (get_symbol_leading_char): Remove unnecessary
declaration.
This improves the packing of struct partial_symtab. I noticed with
pahole that were were a couple of holes. This consolidates the holes
without, I think, affecting readability -- it just moves the "user"
field a bit earlier in the struct. This change saves a small amount
of memory.
2013-12-06 Tom Tromey <tromey@redhat.com>
* psympriv.h (struct partial_symtab) <user>: Move earlier.
This fixes a couple of old "32x64" FIXME comments by using paddress
with current_gdbarch rather than hex_string and a cast to long.
2013-12-06 Tom Tromey <tromey@redhat.com>
* cli/cli-cmds.c (edit_command): Use paddress, not hex_string.
(list_command): Likewise.
This puts the psymtab filename in the filename bcache.
This saves a small amount of memory.
2013-12-06 Tom Tromey <tromey@redhat.com>
* psymtab.c (allocate_psymtab): Put the filename in the filename
bcache.
This makes symtab::dirname const and updates one spot to avoid an
intermediate constless result.
2013-12-06 Tom Tromey <tromey@redhat.com>
* buildsym.c (end_symtab_from_static_block): Use obstack_copy0.
* symtab.h (struct symtab) <dirname>: Now const.
This makes symtab::filename const and removes a newly unnecessary
cast.
2013-12-06 Tom Tromey <tromey@redhat.com>
* symfile.c (allocate_symtab): Remove cast.
* symtab.h (struct symtab) <filename>: Now const.
While looking into the probe API, it seemed to me that there were a
number of methods in sym_probe_fns that were not needed. This patch
removes them.
Specifically, it seems to me that sym_probe_fns ought to be concerned
with the API for constructing the probes. Any method relating to some
aspect of an individual probe can be handled via the probe's own
vtable. That is, the double indirection here doesn't seem useful --
it certainly isn't in fact used, but also I couldn't think of a
potential use.
2013-12-06 Tom Tromey <tromey@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Use
get_probe_argument_count and evaluate_probe_argument.
* elfread.c (elf_get_probe_argument_count)
(elf_can_evaluate_probe_arguments, elf_evaluate_probe_argument)
(elf_compile_to_ax): Remove.
(elf_probe_fns): Update.
* probe.c (get_probe_argument_count, can_evaluate_probe_arguments)
(evaluate_probe_argument): Call method on probe, not via sym
functions.
* stap-probe.c (compute_probe_arg): Use get_probe_argument_count,
evaluate_probe_argument.
(compile_probe_arg): Use get_probe_argument_count. Call method on
probe, not via sym functions.
* symfile-debug.c (debug_sym_get_probe_argument_count)
(debug_can_evaluate_probe_arguments)
(debug_sym_evaluate_probe_argument, debug_sym_compile_to_ax):
Remove.
(debug_sym_probe_fns): Remove.
* symfile.h (struct sym_probe_fns) <sym_get_probe_argument_count,
can_evaluate_probe_arguments, sym_evaluate_probe_argument,
sym_compile_to_ax>: Remove fields.
In some languages, e.g. fortran, arrays start with index 1
instead 0. This patch changes the MI library to support testing
varobj children of fortran arrays.
2013-11-21 Keven Boell <keven.boell@intel.com>
testsuite/
* lib/mi-support.exp (mi_list_varobj_children_range): Add
call to mi_list_array_varobj_children_with_index.
(mi_list_array_varobj_children_with_index): New function.
Add parameter to specify array start.
* p-exp.y (exp : field_exp name): Do not call mark_struct_expression.
(exp : field_exp name COMPLETE): New rule.
(exp : SIZEOF): Set correct current_type.
(last_was_structop): Remove static variable.
(yylex): Remove saw_structop local variable.
Adapt code to removal of variables above.
With a simple Ada program where I have 3 functions, one just calling
the next, the backtrace is currently broken when GDB is compiled
at -O2:
#0 hello.first () at hello.adb:5
#1 0x0000000100001475 in hello.second () at hello.adb:10
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
It turns out that a recent patch deleted the assignment of variable
this_id, making it an unitialized variable:
* frame-unwind.c (default_frame_unwind_stop_reason): Return
UNWIND_OUTERMOST if the frame's ID is outer_frame_id.
* frame.c (get_prev_frame_1): Remove outer_frame_id check.
The hunk in question starts with:
- /* Check that this frame is not the outermost. If it is, don't try
- to unwind to the prev frame. */
- this_id = get_frame_id (this_frame);
- if (frame_id_eq (this_id, outer_frame_id))
(the code was removed as redundant - but removing the assignment
was in fact not intentional).
There is no other code in this function that sets the variable.
Instead of re-adding the statement in the lone section where it is
actually used, I inlined it, and then got rid of the variable
altogether. This way, and until we start needing this frame ID
in another location within that function, we dont' have to worry
about the variable's validity/lifetime.
gdb/ChangeLog:
* frame.c (get_prev_frame_1): Delete variable "this_id".
Replace its use by a call to get_frame_id.
We've observed in Windows 2012 that ntdll.dll contains some unwind
records with the version field set to 2. This patch adjusts the
decoder to accept records flagged with this version as well.
Version 2 appears to still be largely undocumented at this stage.
However, apart from a mysterious opcode 6, everything else still
seems to remain the same. So this patch also changes the decoder
to ignore those opcodes; before this change, the debugger would
silently stop the decoding, and let the frame unwinder make do
with what it the decoder managed to decode up to that point.
It's unclear at this point what we're losing by not being able to
decode that opcode. But the information does not appear to be critical,
at least as far as call unwinding is concerned.
gdb/ChangeLog:
(from Tristan Gingold <gingold@adacore.com>)
(from Joel Brobecker <brobecker@adacore.com>)
* amd64-windows-tdep.c (amd64_windows_frame_decode_insns):
Accept version 2. Ignore operations using opcode 6.
I wanted to find the docs for "catch load" the other day, and I found
out that this isn't in the index. It seems to me that each command
ought to be in the index for quick reference like this, so this patch
adds an @kindex (chosen because it seems to be what the rest of the
manual does) for each "catch" subcommand.
2013-12-03 Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Set Catchpoints): Add @kindex for each command
documented here.
I happened to notice that the gdbserver program doesn't appear in the
top-level "dir" file. This adds an entry for it to the gdb manual.
2013-12-03 Tom Tromey <tromey@redhat.com>
* gdb.texinfo (@direntry): Add menu item for gdbserver.
an entry in a .rsrc section.
(pe_print_resource_directory): New function: Displays a directory
in a .rsrc section.
(pe_print_rsrc): New function: Displays the contents of .rsrc
section.
(_bfd_XX_print_private_bfd_data_common): Call pe_print_rsrc.
* binutils-all/windres/windres.exp: Run for x86_64-pc-cygwin.
Add test of "objump -p" output.
2013-10-03 Jose E. Marchesi <jose.marchesi@oracle.com>
* gdb.base/sigall.exp (test_one_sig): gdb identifies SIGLOST as a
SIGPWR in sparc64.
* gdb.base/sigall.c (main): In some targets SIGLOST and SIGPWR
have the same signal number. Handle this situation.
Consider the following code:
type Ptr is access all Integer;
IP : Ptr := new Integer'(123);
IP is the Ada exception of a pointer to an integer. To dereference
the pointer and get its value, the user uses the reserved word "all"
as follow:
(gdb) p ip.all
$1 = 123
Ada being a case-insensitive language, the casing should not matter.
Unfortunately, for the reserved word "all", things don't work. For
instance:
(gdb) p ip.ALL
Type integer is not a structure or union type
This patch fixes the problem.
gdb/ChangeLog:
* ada-lex.l (find_dot_all): Use strncasecmp instead of strncmp.
gdb/testsuite/ChangeLog:
* gdb.ada/dot_all: New testcase.
With a program raising an exception, trying to debug that program
in GDB/MI mode can yield a crash:
% gdb -i=mi foo
(gdb)
-catch-exception -e "Program_Error"
^done,bkptno="2",bkpt={number="2",type="breakpoint",[...]
(gdb)
-exec-continue
^running
*running,thread-id="all"
(gdb)
=library-loaded,id=[...]
&"warning: failed to reevaluate internal exception condition for catchpoint 2: Error in expression, near `'.\n"
zsh: 22956 bus error (core dumped) gdb -q -i=mi foo
The problem is triggered by a problem in the compiler which causes
EXP in the following TRY_CATCH block to change unexpectedly when
parse_exp_1 throws an error :
| TRY_CATCH (e, RETURN_MASK_ERROR)
| {
| exp = parse_exp_1 (&s, bl->address,
| block_for_pc (bl->address), 0);
| }
In ada-lang.c:create_excep_cond_exprs, EXP is initialized to NULL,
and is expected to remain NULL if parse_exp_1 throws. Instead,
its value gets changed to something invalid. This later crashes
the debugger, when trying to evaluate the bogus expression.
This patch works around the issue by simply forcing EXP back to NULL
when an exception was thrown. A comment explaining why, and the sort
of timeline we're looking at for a fix, is also added.
gdb/ChangeLog:
* ada-lang.c (create_excep_cond_exprs): Force EXP to NULL
when parse_exp_1 threw an error. Add comment.
This patch extends a bit the news entry we added which documents
general support of the --language option, to add a small reference
to the associated entry which was also added to the "-list-features"
command output.
gdb/ChangeLog:
* NEWS: Mention "-list-features" in the entry documenting
the support for the "--language" option.
I don't know what I was thinking here to omit the save of r2.
Possibly I was looking at -msave-toc-indirect code at the time, where
r2 is saved in the function prologue.
* elf64-ppc.c (ppc_build_one_stub <ppc_stub_plt_branch_r2off>):
Don't omit saving of r2 for ELFv2. Don't addi 2,2,0.
(ppc_size_one_stub <ppc_stub_plt_branch_r2off>): Adjust to suit.
Now that the -info-gdb-mi-command is available, there is no need for
this entry. The entry and associated new commands were added recently
enough that no front-end out there should be depending on it yet.
gdb/ChangeLog:
* mi/mi-main.c (mi_cmd_list_features): Remove "ada-exceptions".
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Miscellaneous Commands): Remove the
documentation of the "ada-exceptions" entry.
With -mcmodel=medium we can't assume that a -R object doesn't use
toc-relative addressing if there's no toc. Lots of things are
accessed via r2, not just the toc/got section. Also, testing for
.opd is plain wrong for ELFv2.
* elf64-ppc.c (ppc64_elf_link_just_syms): Remove .got check.
Handle ELFv2.
... when trying to execute an undefined GDB/MI command. When trying
to execute a GDB/MI command which does not exist, the current error
result record looks like this:
-unsupported
^error,msg="Undefined MI command: unsupported"
The only indication that the command does not exist is the error
message. It would be a little fragile for a consumer to rely solely
on the contents of the error message in order to determine whether
a command exists or not.
This patch improves the situation by adding concept of error
code, starting with one well-defined error code ("undefined-command")
identifying errors due to a non-existant command. Here is the new
output:
-unsupported
^error,msg="Undefined MI command: unsupported",code="undefined-command"
This error code is only displayed when the corresponding error
condition is met. Otherwise, the error record remains unchanged.
For instance:
-symbol-list-lines foo.adb
^error,msg="-symbol-list-lines: Unknown source file name."
For frontends to be able to know whether they can rely on this
variable, a new entry "undefined-command-error-code" has been
added to the "-list-features" command. Another option would be
to always generate an error="..." variable (for the default case,
we could decide for instance that the error code is the empty string).
But it seems more efficient to provide that info in "-list-features"
and then only add the error code when meaningful.
gdb/ChangeLog:
(from Pedro Alves <palves@redhat.com>)
(from Joel Brobecker <brobecker@adacore.com>)
* exceptions.h (enum_errors) <UNDEFINED_COMMAND_ERROR>: New enum.
* mi/mi-parse.c (mi_parse): Throw UNDEFINED_COMMAND_ERROR instead
of a regular error when the GDB/MI command does not exist.
* mi/mi-main.c (mi_cmd_list_features): Add
"undefined-command-error-code".
(mi_print_exception): Print an "undefined-command"
error code if EXCEPTION.ERROR is UNDEFINED_COMMAND_ERROR.
* NEWS: Add entry documenting the new "code" variable in
"^error" result records.
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Result Records): Fix the syntax of the
"^error" result record concerning the error message. Document
the error code that may also be part of that result record.
(GDB/MI Miscellaneous Commands): Document the
"undefined-command-error-code" element in the output of
the "-list-features" GDB/MI command.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-undefined-cmd.exp: New testcase.
This patch adds a new GDB/MI command meant for graphical frontends
trying to determine whether a given GDB/MI command exists or not.
Examples:
-info-gdb-mi-command unsupported-command
^done,command={exists="false"}
(gdb)
-info-gdb-mi-command symbol-list-lines
^done,command={exists="true"}
(gdb)
At the moment, this is the only piece of information that this
command returns.
Eventually, and if needed, we can extend it to provide
command-specific pieces of information, such as updates to
the command's syntax since inception. This could become,
for instance:
-info-gdb-mi-command symbol-list-lines
^done,command={exists="true",features=[]}
(gdb)
-info-gdb-mi-command catch-assert
^done,command={exists="true",features=["conditions"]}
In the first case, it would mean that no extra features,
while in the second, it announces that the -catch-assert
command in this version of the debugger supports a feature
called "condition" - exact semantics to be documented with
combined with the rest of the queried command's documentation.
But for now, we start small, and only worry about existance.
And to bootstrap the process, I have added an entry in the
output of the -list-features command as well ("info-gdb-mi-command"),
allowing the graphical frontends to go through the following process:
1. Send -list-features, collect info from there as before;
2. Check if the output contains "info-gdb-mi-command".
If it does, then support for various commands can be
queried though -info-gdb-mi-command. Newer commands
will be expected to always be checked via this new
-info-gdb-mi-command.
gdb/ChangeLog:
* mi/mi-cmds.h (mi_cmd_info_gdb_mi_command): Declare.
* mi/mi-cmd-info.c (mi_cmd_info_gdb_mi_command): New function.
* mi/mi-cmds.c (mi_cmds): Add -info-gdb-mi-command command.
* mi/mi-main.c (mi_cmd_list_features): Add "info-gdb-mi-command"
field to output of "-list-features".
* NEWS: Add entry for new -info-gdb-mi-command.
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Miscellaneous Commands): Document
the new -info-gdb-mi-command GDB/MI command. Document
the meaning of "-info-gdb-mi-command" in the output of
-list-features.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-i-cmd.exp: New file.
gdb/
2013-12-02 Doug Evans <dje@google.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* objfiles.c (allocate_objfile): Save original_name as an absolute
path.
* objfiles.h (struct objfile): Expand comment on original_name.
* source.c (openp): Call gdb_abspath.
* utils.c (gdb_abspath): New function.
* utils.h (gdb_abspath): Declare.
gdb/testsuite/
2013-12-02 Doug Evans <dje@google.com>
* gdb.dwarf/dwp-symlink.c: Fake out gdb to not load debug info
at start.
* gdb.dwarf/dwp-symlink.exp: Test trying to load dwp when the binary
has been specified with a relative path and we have chdir'd before
accessing the debug info.
