At <https://sourceware.org/ml/gdb-patches/2017-12/msg00298.html>, Joel
wrote:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Consider the following code which first declares a tagged type (the
equivalent of a class in Ada), and then a procedure which takes a
pointer (access) to this type's 'Class.
package Pck is
type Top_T is tagged record
N : Integer := 1;
end record;
procedure Inspect (Obj: access Top_T'Class);
end Pck;
Putting a breakpoint in that procedure and then running to it triggers
an internal error:
(gdb) break inspect
(gdb) continue
Breakpoint 1, pck.inspect (obj=0x63e010
/[...]/gdb/stack.c:621: internal-error: void print_frame_args(symbol*, frame_info*, int, ui_file*): Assertion `nsym != NULL' failed.
What's special about this subprogram is that it takes an access to
what we call a 'Class type, and for implementation reasons, the
compiler adds an extra argument named "objL". If you are curious why,
it allows the compiler for perform dynamic accessibility checks that
are mandated by the language.
If we look at the location where we get the internal error (in
stack.c), we find that we are looping over the symbol of each
parameter, and for each parameter, we do:
/* We have to look up the symbol because arguments can have
two entries (one a parameter, one a local) and the one we
want is the local, which lookup_symbol will find for us.
[...]
nsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym),
b, VAR_DOMAIN, NULL).symbol;
gdb_assert (nsym != NULL);
The lookup_symbol goes through the lookup structure, which means the
symbol's linkage name ("objL") gets transformed into a
lookup_name_info object (in block_lookup_symbol), before it gets fed
to the block symbol dictionary iterators. This, in turn, triggers the
symbol matching by comparing the "lookup" name which, for Ada, means
among other things, lowercasing the given name to "objl". It is this
transformation that causes the lookup find no matches, and therefore
trip this assertion.
Going back to the "offending" call to lookup_symbol in stack.c, what
we are trying to do, here, is do a lookup by linkage name. So, I
think what we mean to be doing is a completely literal symbol lookup,
so maybe not even strcmp_iw, but actually just plain strcmp???
In the past, in practice, you could get that effect by doing a lookup
using the C language. But that doesn't work, because we still end up
somehow using Ada's lookup_name routine which transforms "objL".
So, ideally, as I hinted before, I think what we need is a way to
perform a literal lookup so that searches by linkage names like the
above can be performed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This commit fixes the problem by implementing something similar to
Joel's literal idea, but with some important differences.
I considered adding a symbol_name_match_type::LINKAGE and supporting
searching by linkage name for any language, but the problem with that
is that the dictionaries only work with SYMBOL_SEARCH_NAME, because
that's what is used for hashing. We'd need separate dictionaries for
hashed linkage names.
So with the current symbol tables infrastructure, it's not literal
linkage names that we want to pass down, but instead literal _search_
names (SYMBOL_SEARCH_NAME, etc.).
However, psymbols have no overload/function parameter info in C++, so
a straight strcmp doesn't work properly for C++ name matching.
So what we do is be a little less aggressive then and add a new
symbol_name_match_type::SEARCH_SYMBOL instead that takes as input a
non-user-input search symbol, and then we skip any decoding/demangling
steps and make:
- Ada treat that as a verbatim match,
- other languages treat it as symbol_name_match_type::FULL.
This also fixes the new '"maint check-psymtabs" for Ada' testcase for
me (gdb.ada/maint_with_ada.exp). I've not removed the kfail yet
because Joel still sees that testcase failing with this patch.
That'll be fixed in follow up patches.
gdb/ChangeLog:
2018-01-05 Pedro Alves <palves@redhat.com>
PR gdb/22670
* ada-lang.c (literal_symbol_name_matcher): New function.
(ada_get_symbol_name_matcher): Use it for
symbol_name_match_type::SEARCH_NAME.
* block.c (block_lookup_symbol): New parameter 'match_type'. Pass
it down instead of assuming symbol_name_match_type::FULL.
* block.h (block_lookup_symbol): New parameter 'match_type'.
* c-valprint.c (print_unpacked_pointer): Use
lookup_symbol_search_name instead of lookup_symbol.
* compile/compile-object-load.c (get_out_value_type): Pass down
symbol_name_match_type::SEARCH_NAME.
* cp-namespace.c (cp_basic_lookup_symbol): Pass down
symbol_name_match_type::FULL.
* cp-support.c (cp_get_symbol_name_matcher): Handle
symbol_name_match_type::SEARCH_NAME.
* infrun.c (insert_exception_resume_breakpoint): Use
lookup_symbol_search_name.
* p-valprint.c (pascal_val_print): Use lookup_symbol_search_name.
* psymtab.c (maintenance_check_psymtabs): Use
symbol_name_match_type::SEARCH_NAME and SYMBOL_SEARCH_NAME.
* stack.c (print_frame_args): Use lookup_symbol_search_name and
SYMBOL_SEARCH_NAME.
* symtab.c (lookup_local_symbol): Don't demangle the lookup name
if symbol_name_match_type::SEARCH_NAME.
(lookup_symbol_in_language): Pass down
symbol_name_match_type::FULL.
(lookup_symbol_search_name): New.
(lookup_language_this): Pass down
symbol_name_match_type::SEARCH_NAME.
(lookup_symbol_aux, lookup_local_symbol): New parameter
'match_type'. Pass it down.
* symtab.h (symbol_name_match_type::SEARCH_NAME): New enumerator.
(lookup_symbol_search_name): New declaration.
(lookup_symbol_in_block): New 'match_type' parameter.
gdb/testsuite/ChangeLog:
2018-01-05 Joel Brobecker <brobecker@adacore.com>
PR gdb/22670
* gdb.ada/access_tagged_param.exp: New file.
* gdb.ada/access_tagged_param/foo.adb: New file.
This removes a cleanup from link_callbacks_einfo by using std::string.
gdb/ChangeLog
2017-11-04 Tom Tromey <tom@tromey.com>
* compile/compile-object-load.c (link_callbacks_einfo): Use
std::string.
This patch changes most sites calling tilde_expand to use
gdb::unique_xmalloc_ptr, rather than a cleanup. It also changes
scan_expression_with_cleanup to return a unique pointer, because the
patch was already touching code in that area.
Regression tested on the buildbot.
ChangeLog
2017-08-05 Tom Tromey <tom@tromey.com>
* compile/compile-object-load.c (compile_object_load): Use
gdb::unique_xmalloc_ptr.
* cli/cli-dump.c (scan_filename): Rename from
scan_filename_with_cleanup. Change return type.
(scan_expression): Rename from scan_expression_with_cleanup.
Change return type.
(dump_memory_to_file, dump_value_to_file, restore_command):
Use gdb::unique_xmalloc_ptr. Update.
* cli/cli-cmds.c (find_and_open_script): Use
gdb::unique_xmalloc_ptr.
* tracefile-tfile.c (tfile_open): Use gdb::unique_xmalloc_ptr.
* symmisc.c (maintenance_print_symbols)
(maintenance_print_msymbols): Use gdb::unique_xmalloc_ptr.
* symfile.c (symfile_bfd_open, generic_load)
(add_symbol_file_command, remove_symbol_file_command): Use
gdb::unique_xmalloc_ptr.
* source.c (openp): Use gdb::unique_xmalloc_ptr.
* psymtab.c (maintenance_print_psymbols): Use
gdb::unique_xmalloc_ptr.
* corelow.c (core_open): Use gdb::unique_xmalloc_ptr.
* breakpoint.c (save_breakpoints): Use gdb::unique_xmalloc_ptr.
* solib.c (solib_map_sections): Use gdb::unique_xmalloc_ptr.
(reload_shared_libraries_1): Likewise.
This introduces a new specialization of gdb::ref_ptr that can be used
to manage BFD reference counts. Then it changes most places in gdb to
use this new class, rather than explicit reference-counting or
cleanups. This patch removes make_cleanup_bfd_unref.
If you look you will see a couple of spots using "release" where a use
of gdb_bfd_ref_ptr would be cleaner. These will be fixed in the next
patch.
I think this patch fixes some latent bugs. For example, it seems to
me that previously objfpy_add_separate_debug_file leaked a BFD.
I'm not 100% certain that the macho_symfile_read_all_oso change is
correct. The existing code here is hard for me to follow. One goal
of this sort of automated reference counting, though, is to make it
more difficult to make logic errors; so hopefully the code is clear
now.
2017-01-10 Tom Tromey <tom@tromey.com>
* windows-tdep.c (windows_xfer_shared_library): Update.
* windows-nat.c (windows_make_so): Update.
* utils.h (make_cleanup_bfd_unref): Remove.
* utils.c (do_bfd_close_cleanup, make_cleanup_bfd_unref): Remove.
* symfile.h (symfile_bfd_open)
(find_separate_debug_file_in_section): Return gdb_bfd_ref_ptr.
* symfile.c (read_symbols, symbol_file_add)
(separate_debug_file_exists): Update.
(symfile_bfd_open): Return gdb_bfd_ref_ptr.
(generic_load, reread_symbols): Update.
* symfile-mem.c (symbol_file_add_from_memory): Update.
* spu-linux-nat.c (spu_bfd_open): Return gdb_bfd_ref_ptr.
(spu_symbol_file_add_from_memory): Update.
* solist.h (struct target_so_ops) <bfd_open>: Return
gdb_bfd_ref_ptr.
(solib_bfd_fopen, solib_bfd_open): Return gdb_bfd_ref_ptr.
* solib.c (solib_bfd_fopen, solib_bfd_open): Return
gdb_bfd_ref_ptr.
(solib_map_sections, reload_shared_libraries_1): Update.
* solib-svr4.c (enable_break): Update.
* solib-spu.c (spu_bfd_fopen): Return gdb_bfd_ref_ptr.
* solib-frv.c (enable_break2): Update.
* solib-dsbt.c (enable_break): Update.
* solib-darwin.c (gdb_bfd_mach_o_fat_extract): Return
gdb_bfd_ref_ptr.
(darwin_solib_get_all_image_info_addr_at_init): Update.
(darwin_bfd_open): Return gdb_bfd_ref_ptr.
* solib-aix.c (solib_aix_bfd_open): Return gdb_bfd_ref_ptr.
* record-full.c (record_full_save): Update.
* python/py-objfile.c (objfpy_add_separate_debug_file): Update.
* procfs.c (insert_dbx_link_bpt_in_file): Update.
* minidebug.c (find_separate_debug_file_in_section): Return
gdb_bfd_ref_ptr.
* machoread.c (macho_add_oso_symfile): Change abfd to
gdb_bfd_ref_ptr.
(macho_symfile_read_all_oso): Update.
(macho_check_dsym): Return gdb_bfd_ref_ptr.
(macho_symfile_read): Update.
* jit.c (bfd_open_from_target_memory): Return gdb_bfd_ref_ptr.
(jit_bfd_try_read_symtab): Update.
* gdb_bfd.h (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
(gdb_bfd_openw, gdb_bfd_openr_iovec)
(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
gdb_bfd_ref_ptr.
(gdb_bfd_ref_policy): New struct.
(gdb_bfd_ref_ptr): New typedef.
* gdb_bfd.c (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
(gdb_bfd_openw, gdb_bfd_openr_iovec)
(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
gdb_bfd_ref_ptr.
* gcore.h (create_gcore_bfd): Return gdb_bfd_ref_ptr.
* gcore.c (create_gcore_bfd): Return gdb_bfd_ref_ptr.
(gcore_command): Update.
* exec.c (exec_file_attach): Update.
* elfread.c (elf_symfile_read): Update.
* dwarf2read.c (dwarf2_get_dwz_file): Update.
(try_open_dwop_file, open_dwo_file): Return gdb_bfd_ref_ptr.
(open_and_init_dwo_file): Update.
(open_dwp_file): Return gdb_bfd_ref_ptr.
(open_and_init_dwp_file): Update.
* corelow.c (core_open): Update.
* compile/compile-object-load.c (compile_object_load): Update.
* common/gdb_ref_ptr.h (ref_ptr::operator->): New operator.
* coffread.c (coff_symfile_read): Update.
* cli/cli-dump.c (bfd_openr_or_error, bfd_openw_or_error): Return
gdb_bfd_ref_ptr. Rename.
(dump_bfd_file, restore_command): Update.
* build-id.h (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
* build-id.c (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
(find_separate_debug_file_by_buildid): Update.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
Using ui_file_as_string would imply changing a few prototypes to pass
around source and object file names as std::string. Instead of that,
wrap those two in a new class. This ends up eliminating a small
wrinkle: get_new_file_names and compile_object_load have swapped
parameters. The former takes "source, objfile", while the latter
takes "objfile, source".
gdb/ChangeLog:
2016-11-08 Pedro Alves <palves@redhat.com>
* c-lang.h (c_compute_program): Now returns std::string.
* compile/compile-internal.h (class compile_file_names): New
class.
* compile/compile-object-load.c (compile_object_load): Replace
object_file and source_file parameters with a compile_file_names
parameter. Adjust.
* compile-object-load.h: Include "compile-internal.h".
(compile_object_load): Replace object_file and source_file
parameters with a compile_file_names parameter.
* compile/compile-c-support.c (c_compute_program): Now returns a
std::string. Use ui_file_as_string.
* compile/compile.c (get_new_file_names): Remove parameters and
return a compile_file_names instead.
(compile_to_object): Now returns a compile_file_names. Use
ui_file_as_string.
(eval_compile_command): Use compile_file_names.
* language.h (struct language_defn) <la_compute_program>: Now
returns std::string.
As Pedro suggested on gdb-patches@ (see
https://sourceware.org/ml/gdb-patches/2015-05/msg00714.html), this
change makes symbol lookup functions return a structure that includes
both the symbol found and the block in which it was found. This makes
it possible to get rid of the block_found global variable and thus makes
block hunting explicit.
gdb/
* ada-exp.y (write_object_renaming): Replace struct
ada_symbol_info with struct block_symbol. Update field
references accordingly.
(block_lookup, select_possible_type_sym): Likewise.
(find_primitive_type): Likewise. Also update call to
ada_lookup_symbol to extract the symbol itself.
(write_var_or_type, write_name_assoc): Likewise.
* ada-lang.h (struct ada_symbol_info): Remove.
(ada_lookup_symbol_list): Replace struct ada_symbol_info with
struct block_symbol.
(ada_lookup_encoded_symbol, user_select_syms): Likewise.
(ada_lookup_symbol): Return struct block_symbol instead of a
mere symbol.
* ada-lang.c (defns_collected): Replace struct ada_symbol_info
with struct block_symbol.
(resolve_subexp, ada_resolve_function, sort_choices,
user_select_syms, is_nonfunction, add_defn_to_vec,
num_defns_collected, defns_collected,
symbols_are_identical_enums, remove_extra_symbols,
remove_irrelevant_renamings, add_lookup_symbol_list_worker,
ada_lookup_symbol_list, ada_iterate_over_symbols,
ada_lookup_encoded_symbol, get_var_value): Likewise.
(ada_lookup_symbol): Return a block_symbol instead of a mere
symbol. Replace struct ada_symbol_info with struct
block_symbol.
(ada_lookup_symbol_nonlocal): Likewise.
(standard_lookup): Make block passing explicit through
lookup_symbol_in_language.
* ada-tasks.c (get_tcb_types_info): Update the calls to
lookup_symbol_in_language to extract the mere symbol out of the
returned value.
(ada_tasks_inferior_data_sniffer): Likewise.
* ax-gdb.c (gen_static_field): Likewise for the call to
lookup_symbol.
(gen_maybe_namespace_elt): Deal with struct symbol_in_block from
lookup functions.
(gen_expr): Likewise.
* c-exp.y: Likewise. Remove uses of block_found.
(lex_one_token, classify_inner_name, c_print_token): Likewise.
(classify_name): Likewise. Rename the "sym" local variable to
"bsym".
* c-valprint.c (print_unpacked_pointer): Likewise.
* compile/compile-c-symbols.c (convert_symbol_sym): Promote the
"sym" parameter from struct symbol * to struct block_symbol.
Use it to remove uses of block_found. Deal with struct
symbol_in_block from lookup functions.
(gcc_convert_symbol): Likewise. Update the call to
convert_symbol_sym.
* compile/compile-object-load.c (compile_object_load): Deal with
struct symbol_in_block from lookup functions.
* cp-namespace.c (cp_lookup_nested_symbol_1,
cp_lookup_nested_symbol, cp_lookup_bare_symbol,
cp_search_static_and_baseclasses,
cp_lookup_symbol_in_namespace, cp_lookup_symbol_via_imports,
cp_lookup_symbol_imports_or_template,
cp_lookup_symbol_via_all_imports, cp_lookup_symbol_namespace,
lookup_namespace_scope, cp_lookup_nonlocal,
find_symbol_in_baseclass): Return struct symbol_in_block instead
of mere symbols and deal with struct symbol_in_block from lookup
functions.
* cp-support.c (inspect_type, replace_typedefs,
cp_lookup_rtti_type): Deal with struct symbol_in_block from
lookup functions.
* cp-support.h (cp_lookup_symbol_nonlocal,
cp_lookup_symbol_from_namespace,
cp_lookup_symbol_imports_or_template, cp_lookup_nested_symbol):
Return struct symbol_in_block instead of mere symbols.
* d-exp.y (d_type_from_name, d_module_from_name, push_variable,
push_module_name):
Deal with struct symbol_in_block from lookup functions. Remove
uses of block_found.
* eval.c (evaluate_subexp_standard): Update call to
cp_lookup_symbol_namespace.
* f-exp.y: Deal with struct symbol_in_block from lookup
functions. Remove uses of block_found.
(yylex): Likewise.
* gdbtypes.c (lookup_typename, lookup_struct, lookup_union,
lookup_enum, lookup_template_type, check_typedef): Deal with
struct symbol_in_block from lookup functions.
* guile/scm-frame.c (gdbscm_frame_read_var): Likewise.
* guile/scm-symbol.c (gdbscm_lookup_symbol): Likewise.
(gdbscm_lookup_global_symbol): Likewise.
* gnu-v3-abi.c (gnuv3_get_typeid_type): Likewise.
* go-exp.y: Likewise. Remove uses of block_found.
(package_name_p, classify_packaged_name, classify_name):
Likewise.
* infrun.c (insert_exception_resume_breakpoint): Likewise.
* jv-exp.y (push_variable): Likewise.
* jv-lang.c (java_lookup_class, get_java_object_type): Likewise.
* language.c (language_bool_type): Likewise.
* language.h (struct language_defn): Update
la_lookup_symbol_nonlocal to return a struct symbol_in_block
rather than a mere symbol.
* linespec.c (find_label_symbols): Deal with struct
symbol_in_block from lookup functions.
* m2-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* mi/mi-cmd-stack.c (list_args_or_locals): Likewise.
* objc-lang.c (lookup_struct_typedef, find_imps): Likewise.
* p-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* p-valprint.c (pascal_val_print): Likewise.
* parse.c (write_dollar_variable): Likewise. Remove uses of
block_found.
* parser-defs.h (struct symtoken): Turn the SYM field into a
struct symbol_in_block.
* printcmd.c (address_info): Deal with struct symbol_in_block
from lookup functions.
* python/py-frame.c (frapy_read_var): Likewise.
* python/py-symbol.c (gdbpy_lookup_symbol,
gdbpy_lookup_global_symbol): Likewise.
* skip.c (skip_function_command): Likewise.
* solib-darwin.c (darwin_lookup_lib_symbol): Return a struct
symbol_in_block instead of a mere symbol.
* solib-spu.c (spu_lookup_lib_symbol): Likewise.
* solib-svr4.c (elf_lookup_lib_symbol): Likewise.
* solib.c (solib_global_lookup): Likewise.
* solist.h (solib_global_lookup): Likewise.
(struct target_so_ops): Update lookup_lib_global_symbol to
return a struct symbol_in_block rather than a mere symbol.
* source.c (select_source_symtab): Deal with struct
symbol_in_block from lookup functions.
* stack.c (print_frame_args, iterate_over_block_arg_vars):
Likewise.
* symfile.c (set_initial_language): Likewise.
* symtab.c (SYMBOL_LOOKUP_FAILED): Turn into a struct
symbol_in_block.
(SYMBOL_LOOKUP_FAILED_P): New predicate as a macro.
(struct symbol_cache_slot): Turn the FOUND field into a struct
symbol_in_block.
(block_found): Remove.
(eq_symbol_entry): Update to deal with struct symbol_in_block in
cache slots.
(symbol_cache_lookup): Return a struct symbol_in_block rather
than a mere symbol.
(symbol_cache_mark_found): Add a BLOCK parameter to fill
appropriately the cache slots. Update callers.
(symbol_cache_dump): Update cache slots handling to the type
change.
(lookup_symbol_in_language, lookup_symbol, lookup_language_this,
lookup_symbol_aux, lookup_local_symbol,
lookup_symbol_in_objfile, lookup_global_symbol_from_objfile,
lookup_symbol_in_objfile_symtabs,
lookup_symbol_in_objfile_from_linkage_name,
lookup_symbol_via_quick_fns, basic_lookup_symbol_nonlocal,
lookup_symbol_in_static_block, lookup_static_symbol,
lookup_global_symbol):
Return a struct symbol_in_block rather than a mere symbol. Deal
with struct symbol_in_block from other lookup functions. Remove
uses of block_found.
(lookup_symbol_in_block): Remove uses of block_found.
(struct global_sym_lookup_data): Turn the RESULT field into a
struct symbol_in_block.
(lookup_symbol_global_iterator_cb): Update references to the
RESULT field.
(search_symbols): Deal with struct symbol_in_block from lookup
functions.
* symtab.h (struct symbol_in_block): New structure.
(block_found): Remove.
(lookup_symbol_in_language, lookup_symbol,
basic_lookup_symbol_nonlocal, lookup_symbol_in_static_block,
looku_static_symbol, lookup_global_symbol,
lookup_symbol_in_block, lookup_language_this,
lookup_global_symbol_from_objfile): Return a struct
symbol_in_block rather than just a mere symbol. Update comments
to remove mentions of block_found.
* valops.c (find_function_in_inferior,
value_struct_elt_for_reference, value_maybe_namespace_elt,
value_of_this): Deal with struct symbol_in_block from lookup
functions.
* value.c (value_static_field, value_fn_field): Likewise.
It was found that from
(gdb) set debug compile 1
(gdb) compile code 1
[...]
allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
lookup undefined ELF symbol "_GLOBAL_OFFSET_TABLE_"
allocated 0x10 bytes at 0x7ffff7ff7000 for registers
(gdb) _
the message 'lookup undefined ELF symbol' looks as an error to people,
including to myself once.
Change it to:
allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
ELF symbol "_GLOBAL_OFFSET_TABLE_" relocated to zero
allocated 0x10 bytes at 0x7ffff7ff7000 for registers
(gdb) _
gdb/ChangeLog
2015-07-02 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (compile_object_load): Replace debug
message "lookup undefined ELF symbol" by 3 more specific messages.
Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed. This was
intentional so that one can do for example:
inferior:
char *str = "foo";
GDB:
(gdb) compile code str = "bar";
I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
compile: objfiles lifetime UI
https://sourceware.org/ml/gdb/2015-04/msg00051.html
Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
https://sourceware.org/ml/gdb/2015-05/msg00007.html
As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
(gdb) compile code str = strdup ("bar");
I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
compile code int ff = 5; p = &ff;
In this example, @code{p} would point to @code{ff} when the
@code{compile} command is executing the source code provided to it.
However, as variables in the (example) program persist with their
assigned values, the variable @code{p} would point to an invalid
location when the command exists.
gdb/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_munmap): New.
* arch-utils.h (default_infcall_munmap): New declaration.
* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
(munmap_list_free, munmap_listp_free_cleanup): New.
(struct setup_sections_data): Add field munmap_list_headp.
(setup_sections): Call munmap_list_add.
(compile_object_load): New variable munmap_list_head, initialize
setup_sections_data.munmap_list_headp, return munmap_list_head.
* compile/compile-object-load.h (struct munmap_list): New declaration.
(struct compile_module): Add field munmap_list_head.
(munmap_list_free): New declaration.
* compile/compile-object-run.c (struct do_module_cleanup): Add field
munmap_list_head.
(do_module_cleanup): Call munmap_list_free.
(compile_object_run): Pass munmap_list_head to do_module_cleanup.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (infcall_munmap): New.
* linux-tdep.c (linux_infcall_munmap): New.
(linux_init_abi): Install it.
gdb/testsuite/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (keep jit in memory): Rename to ...
(do not keep jit in memory): ... this.
(expect 5): Change it to ...
(expect no 5): ... this.
Please send debug output to gdb_stdlog.
OK but gdb/compile/ is using now only gdb_stdout; the error above is due to
a copy-paste. So I will send a follow-up patch to change all the other
gdb/compile/ gdb_stdout strings to gdb_stdlog.
gdb/ChangeLog
2015-05-19 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-c-symbols.c (convert_symbol_sym, gcc_convert_symbol)
(gcc_symbol_address): Change gdb_stdout to gdb_stdlog.
* compile/compile-object-load.c (setup_sections, compile_object_load):
Likewise.
* compile/compile.c (compile_to_object): Likewise.
It is planned the existing GDB command 'print' will be able to evaluate its
expressions using the compiler. There will be some option to choose between
the existing GDB evaluation and the compiler evaluation. But as an
intermediate step this patch provides the expression printing feature as a new
command.
I can imagine it could be also called 'maintenance compile print' as in the
future one should be able to use its functionality by the normal 'print'
command.
There was a discussion with Eli about the command name:
https://sourceware.org/ml/gdb-patches/2015-03/msg00880.html
As there were no other comments yet I haven't renamed it yet, before there is
some confirmation about settlement on the final name.
Support for the GDB '@' operator to create arrays has been submitted for GCC:
[gcc patch] libcc1: '@' GDB array operator
https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01451.html
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
Phil Muldoon <pmuldoon@redhat.com>
* NEWS (Changes since GDB 7.9): Add compile print.
* compile/compile-c-support.c (add_code_header, add_code_footer)
(c_compute_program): Add COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
* compile/compile-internal.h (COMPILE_I_PRINT_OUT_ARG_TYPE)
(COMPILE_I_PRINT_OUT_ARG, COMPILE_I_EXPR_VAL, COMPILE_I_EXPR_PTR_TYPE):
New.
* compile/compile-object-load.c: Include block.h.
(get_out_value_type): New function.
(compile_object_load): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE. Set compile_module's OUT_VALUE_ADDR and
OUT_VALUE_TYPE.
* compile/compile-object-load.h (struct compile_module): Add fields
out_value_addr and out_value_type.
* compile/compile-object-run.c: Include valprint.h and compile.h.
(struct do_module_cleanup): Add fields out_value_addr and
out_value_type.
(do_module_cleanup): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
(compile_object_run): Propagate out_value_addr and out_value_type.
Pass OUT_VALUE_ADDR.
* compile/compile.c: Include valprint.h.
(compile_print_value, compile_print_command): New functions.
(eval_compile_command): Handle failed COMPILE_I_PRINT_ADDRESS_SCOPE.
(_initialize_compile): Update compile code help text. Install
compile_print_command.
* compile/compile.h (compile_print_value): New prototype.
* defs.h (enum compile_i_scope_types): Add
COMPILE_I_PRINT_ADDRESS_SCOPE and COMPILE_I_PRINT_VALUE_SCOPE.
gdb/doc/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Compiling and Injecting Code): Add compile print.
gdb/testsuite/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile-print.c: New file.
* gdb.compile/compile-print.exp: New file.
Currently the code fetches _gdb_expr address/types at multiple places, guessing
its parameters at multiple places etc.
Fetch it once, verify it has expected type and then rely on it.
While the patch tries to clean up the code it is still horrible due to the
missing C++ sub-classing.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (get_regs_type): Add parameter func_sym.
Rely on its parameter count.
(compile_object_load): Replace lookup_minimal_symbol_text by
lookup_global_symbol_from_objfile. Verify FUNC_SYM. Set it in the
return value.
* compile/compile-object-load.h (struct compile_module): Replace
func_addr by func_sym.
* compile/compile-object-run.c: Include block.h.
(compile_object_run): Reset module variable after it is freed. Use
FUNC_SYM instead of FUNC_ADDR. Rely on it.
Provide a way to access current 'scope' during the do_module_cleanup stage and
associate more data with it.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* cli/cli-script.c (execute_control_command): Update
eval_compile_command caller.
* compile/compile-object-load.c (compile_object_load): Add parameters
scope and scope_data. Set them.
* compile/compile-object-load.h (struct compile_module): Add fields
scope and scope_data.
(compile_object_load): Add parameters scope and scope_data.
* compile/compile-object-run.c (struct do_module_cleanup): Add fields
scope and scope_data.
(compile_object_run): Propagate the fields scope and scope_data.
* compile/compile.c (compile_file_command, compile_code_command):
Update eval_compile_command callers.
(eval_compile_command): Add parameter scope_data. Pass it plus scope.
* compile/compile.h (eval_compile_command): Add parameter scope_data.
* defs.h (struct command_line): Add field scope_data.
Calling memcpy() could fail as memcpy() from libc is GNU-IFUNC.
gdb/ChangeLog
2015-05-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (compile_object_load): Support
mst_text_gnu_ifunc.
Fixes building gdb on x86_64-apple-darwin14 with clang, which produces
a number of warnings from -Wformat-nonliteral.
Ref: https://sourceware.org/ml/gdb/2015-02/msg00047.html
gdb/ChangeLog:
2015-02-26 Pedro Alves <palves@redhat.com>
* auto-load.h (file_is_auto_load_safe): Add ATTRIBUTE_PRINTF.
* complaints.c (vcomplaint): Pass argument FMT directly to
printf-like functions instead of complaint->fmt.
* ctf.c (ctf_save_write_metadata): Add ATTRIBUTE_PRINTF.
* darwin-nat.c (inferior_debug): Add ATTRIBUTE_PRINTF.
* compile/compile-loc2c.c (pushf, unary, binary): Add
ATTRIBUTE_PRINTF.
(do_compile_dwarf_expr_to_c): Pass string literal as format string
to pushf.
(BINARY): Pass string literal as format string to 'binary'.
* compile/compile-object-load.c (link_callbacks_einfo): Add
ATTRIBUTE_PRINTF.
* guile/guile-internal.h (gdbscm_printf): Add ATTRIBUTE_PRINTF.
gdb/ChangeLog:
* compile/compile-object-load.c (link_callbacks_multiple_definition)
(link_callbacks_warning, link_callbacks_einfo): Remove trailing
newline at end of warning message.
Tested on x86_64-linux.
This final patch adds the new "compile" command and subcommands, and
all the machinery needed to make it work.
A shared library supplied by gcc is used for all communications with
gcc. Types and most aspects of symbols are provided directly by gdb
to the compiler using this library.
gdb provides some information about the user's code using plain text.
Macros are emitted this way, and DWARF location expressions (and
bounds for VLA) are compiled to C code.
This hybrid approach was taken because, on the one hand, it is better
to provide global declarations and such on demand; but on the other
hand, for local variables, translating DWARF location expressions to C
was much simpler than exporting a full compiler API to gdb -- the same
result, only easier to implement, understand, and debug.
In the ordinary mode, the user's expression is wrapped in a dummy
function. After compilation, gdb inserts the resulting object code
into the inferior, then calls this function.
Access to local variables is provided by noting which registers are
used by location expressions, and passing a structure of register
values into the function. Writes to registers are supported by
copying out these values after the function returns.
This approach was taken so that we could eventually implement other
more interesting features based on this same infrastructure; for
example, we're planning to investigate inferior-side breakpoint
conditions.
gdb/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Update.
* symtab.h (struct symbol_computed_ops) <generate_c_location>: New
field.
* p-lang.c (pascal_language_defn): Update.
* opencl-lang.c (opencl_language_defn): Update.
* objc-lang.c (objc_language_defn): Update.
* m2-lang.c (m2_language_defn): Update.
* language.h (struct language_defn) <la_get_compile_instance,
la_compute_program>: New fields.
* language.c (unknown_language_defn, auto_language_defn)
(local_language_defn): Update.
* jv-lang.c (java_language_defn): Update.
* go-lang.c (go_language_defn): Update.
* f-lang.c (f_language_defn): Update.
* dwarf2loc.h (dwarf2_compile_property_to_c): Declare.
* dwarf2loc.c (dwarf2_compile_property_to_c)
(locexpr_generate_c_location, loclist_generate_c_location): New
functions.
(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
* defs.h (enum compile_i_scope_types): New.
(enum command_control_type) <compile_control>: New constant.
(struct command_line) <control_u>: New field.
* d-lang.c (d_language_defn): Update.
* compile/compile.c: New file.
* compile/compile-c-support.c: New file.
* compile/compile-c-symbols.c: New file.
* compile/compile-c-types.c: New file.
* compile/compile.h: New file.
* compile/compile-internal.h: New file.
* compile/compile-loc2c.c: New file.
* compile/compile-object-load.c: New file.
* compile/compile-object-load.h: New file.
* compile/compile-object-run.c: New file.
* compile/compile-object-run.h: New file.
* cli/cli-script.c (multi_line_command_p, print_command_lines)
(execute_control_command, process_next_line)
(recurse_read_control_structure): Handle compile_control.
* c-lang.h (c_get_compile_context, c_compute_program): Declare.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Update.
* ada-lang.c (ada_language_defn): Update.
* Makefile.in (SUBDIR_GCC_COMPILE_OBS, SUBDIR_GCC_COMPILE_SRCS):
New variables.
(SFILES): Add SUBDIR_GCC_COMPILE_SRCS.
(HFILES_NO_SRCDIR): Add compile.h.
(COMMON_OBS): Add SUBDIR_GCC_COMPILE_OBS.
(INIT_FILES): Add SUBDIR_GCC_COMPILE_SRCS.
(compile.o, compile-c-types.o, compile-c-symbols.o)
(compile-object-load.o, compile-object-run.o, compile-loc2c.o)
(compile-c-support.o): New targets.
gdb/doc/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Altering): Update.
(Compiling and Injecting Code): New node.
gdb/testsuite/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* configure.ac: Add gdb.compile/.
* configure: Regenerate.
* gdb.compile/Makefile.in: New file.
* gdb.compile/compile-ops.exp: New file.
* gdb.compile/compile-ops.c: New file.
* gdb.compile/compile-tls.c: New file.
* gdb.compile/compile-tls.exp: New file.
* gdb.compile/compile-constvar.S: New file.
* gdb.compile/compile-constvar.c: New file.
* gdb.compile/compile-mod.c: New file.
* gdb.compile/compile-nodebug.c: New file.
* gdb.compile/compile-setjmp-mod.c: New file.
* gdb.compile/compile-setjmp.c: New file.
* gdb.compile/compile-setjmp.exp: New file.
* gdb.compile/compile-shlib.c: New file.
* gdb.compile/compile.c: New file.
* gdb.compile/compile.exp: New file.
* lib/gdb.exp (skip_compile_feature_tests): New proc.
Pedro Alves
Joel Brobecker
Simon Marchi
Tom Tromey
Alan Modra
Pierre-Marie de Rodat
Jan Kratochvil
Tom Tromey