Just some code cleanup. This change has a few benefits:
- Shorter argument list in the functions
- If the caller needs to calculate the string, they no longer
need to explicitly call strlen
- It is easy to pass std::string to this (done in one place
currently)
This also updates a couple of places that were passing 0/1 to
a bool parameter.
gdb/ChangeLog:
2019-10-29 Christian Biesinger <cbiesinger@google.com>
* coffread.c (record_minimal_symbol): Update.
(process_coff_symbol): Update.
* dbxread.c (read_dbx_symtab): Update.
* dwarf2read.c (add_partial_symbol): Update.
(fixup_go_packaging): Update.
(load_partial_dies): Update.
(new_symbol): Update.
* elfread.c (record_minimal_symbol): Change signature to use
gdb::string_view instead of name+len.
(elf_symtab_read): Update.
(elf_rel_plt_read): Update.
* mdebugread.c (parse_partial_symbols): Update.
(handle_psymbol_enumerators): Update.
(new_symbol): Update.
* minsyms.c (minimal_symbol_reader::record_full): Change signature
to use gdb::string_view instead of name+len.
* minsyms.h (class minimal_symbol_reader) <record_full>: Likewise.
* psympriv.h (add_psymbol_to_list): Likewise.
* psymtab.c (add_psymbol_to_bcache): Likewise.
(add_psymbol_to_list): Likewise.
* stabsread.c (define_symbol): Update.
* symtab.c (symbol_set_names): Change signature to use gdb::string_view.
* symtab.h (SYMBOL_SET_NAMES): Likewise.
(symbol_set_names): Likewise.
* xcoffread.c (scan_xcoff_symtab): Update.
Change-Id: I2675c6865e0368f9c755a1081088a53aa54dda4c
In ELF, if a data symbol is defined in a shared library and used by
the main program, it will be subject to a "copy relocation". In this
scenario, the main program has a copy of the symbol in question, and a
relocation that tells ld.so to copy the data from the shared library.
Then the symbol in the main program is used to satisfy all references.
This patch changes gdb to handle this scenario. Data symbols coming
from ELF shared libraries get a special flag that indicates that the
symbol's address may be subject to copy relocation.
I looked briefly into handling copy relocations by looking at the
actual relocations in the main program, but this seemed difficult to
do with BFD.
Note that no caching is done here. Perhaps this could be changed if
need be; I wanted to avoid possible problems with either objfile
lifetimes and changes, or conflicts with the long-term (vapor-ware)
objfile splitting project.
gdb/ChangeLog
2019-10-02 Tom Tromey <tromey@adacore.com>
* symmisc.c (dump_msymbols): Don't use MSYMBOL_VALUE_ADDRESS.
* ada-lang.c (lesseq_defined_than): Handle
LOC_STATIC.
* dwarf2read.c (dwarf2_per_objfile): Add can_copy
parameter.
(dwarf2_has_info): Likewise.
(new_symbol): Set maybe_copied on symbol when
appropriate.
* dwarf2read.h (dwarf2_per_objfile): Add can_copy
parameter.
<can_copy>: New member.
* elfread.c (record_minimal_symbol): Set maybe_copied
on symbol when appropriate.
(elf_symfile_read): Update call to dwarf2_has_info.
* minsyms.c (lookup_minimal_symbol_linkage): New
function.
* minsyms.h (lookup_minimal_symbol_linkage): Declare.
* symtab.c (get_symbol_address, get_msymbol_address):
New functions.
* symtab.h (get_symbol_address, get_msymbol_address):
Declare.
(SYMBOL_VALUE_ADDRESS, MSYMBOL_VALUE_ADDRESS): Handle
maybe_copied.
(struct symbol, struct minimal_symbol) <maybe_copied>:
New member.
This just clarifies some comments about the hashtables involved
in msymbols.
gdb/ChangeLog:
2019-09-29 Christian Biesinger <cbiesinger@google.com>
* minsyms.h (msymbol_hash): Document that this is a case-insensitive
hash and why.
* objfiles.h (struct objfile_per_bfd_storage) <demangled_names_hash,
msymbol_hash, msymbol_demangled_hash>: Improve comments.
lookup_minimal_symbol_solib_trampoline is unused, so this patch
removes it. The last use was apparently removed in
commit 61a12cfa ("Remove HPUX").
gdb/ChangeLog
2019-06-26 Tom Tromey <tromey@adacore.com>
* minsyms.c (lookup_minimal_symbol_solib_trampoline): Remove.
* minsyms.h (lookup_minimal_symbol_solib_trampoline): Don't
declare.
I was curious what used the terminating "null" minimal symbol; and
after looking I could not find anything. This patch removes
terminate_minimal_symbol_table and the extra minimal symbol that is
allocated for it.
gdb/ChangeLog
2019-03-15 Tom Tromey <tom@tromey.com>
* symfile.c (reread_symbols): Update.
* objfiles.c (objfile::objfile): Update.
* minsyms.h (terminate_minimal_symbol_table): Don't declare.
* minsyms.c (lookup_minimal_symbol_by_pc_section): Update
comment.
(minimal_symbol_reader::install): Update.
(terminate_minimal_symbol_table): Remove.
* jit.c (jit_object_close_impl): Update.
Only one caller of minimal_symbol_reader::record_with_info was using
the return value, so this patch simplifies this code by having it
return void and changing that caller to use record_full instead.
gdb/ChangeLog
2019-03-15 Tom Tromey <tom@tromey.com>
* minsyms.h (class minimal_symbol_reader) <record_with_info>:
Don't return the symbol.
* coffread.c (record_minimal_symbol): Use record_full.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This changes minimal_symbol_reader to use DISABLE_COPY_AND_ASSIGN,
rather than the manual approach it currently uses.
Tested by rebuilding.
gdb/ChangeLog
2018-12-27 Tom Tromey <tom@tromey.com>
* minsyms.h (class minimal_symbol_reader): Use
DISABLE_COPY_AND_ASSIGN.
Function lookup_minimal_symbol_and_objfile iterates on all objfiles and
calls lookup_minimal_symbol for each of them, effectively searching in all
objfiles. lookup_bound_minimal_symbol calls lookup_minimal_symbol with NULL,
which also effectively searches all objfiles. AFAIK, they do exactly the same
thing, so we can get rid of one (and lookup_minimal_symbol_and_objfile happens
to be the most inefficient because it ends up n^2 on the number of objfiles).
Tested in both aarch64-linux-gnu and amd64-linux-gnu. No regressions.
When we're stepping (with "step"), we want to skip trampoline-like
functions automatically, including GNU ifunc resolvers. That is done
by infrun.c calling into:
in_solib_dynsym_resolve_code
-> svr4_in_dynsym_resolve_code
-> in_gnu_ifunc_stub
A problem here is that if there's a regular text symbol at the same
address as the ifunc symbol, the minimal symbol lookup in
in_gnu_ifunc_stub may miss the GNU ifunc symbol:
(...)
41: 000000000000071a 53 FUNC GLOBAL DEFAULT 11 gnu_ifunc_resolver
(...)
50: 000000000000071a 53 IFUNC GLOBAL DEFAULT 11 gnu_ifunc
(...)
This causes this FAIL in the tests added later in the series:
(gdb) PASS: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=0: final_debug=0: resolver received HWCAP
set step-mode on
(gdb) PASS: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=0: final_debug=0: set step-mode on
step
0x00007ffff7bd371a in gnu_ifunc_resolver () from build/gdb/testsuite/outputs/gdb.base/gnu-ifunc/gnu-ifunc-lib-1-0-0.so
(gdb) FAIL: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=0: final_debug=0: step
Above, GDB simply thought that it stepped into a regular function, so
it stopped stepping, while it should have continued stepping past the
resolver.
The fix is to teach minimal symbol lookup to prefer GNU ifunc symbols
if desired.
gdb/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* minsyms.c (lookup_minimal_symbol_by_pc_section_1): Rename to ...
(lookup_minimal_symbol_by_pc_section): ... this. Replace
'want_trampoline' parameter by a lookup_msym_prefer parameter.
Handle it.
(lookup_minimal_symbol_by_pc_section): Delete old implementation.
(lookup_minimal_symbol_by_pc): Adjust.
(in_gnu_ifunc_stub): Prefer GNU ifunc symbols.
(lookup_solib_trampoline_symbol_by_pc): Adjust.
* minsyms.h (lookup_msym_prefer): New enum.
(lookup_minimal_symbol_by_pc_section): Replace 'want_trampoline'
parameter by a lookup_msym_prefer parameter.
If the GNU ifunc resolver has the same name as the user visible
symbol, and the resolver has debug info, then the DWARF info for the
resolver masks the ifunc minsym. In that scenario, if you try calling
the ifunc from GDB, you call the resolver instead. With the
gnu-ifunc.exp testcase added in a following patch, you'd see:
(gdb) p gnu_ifunc (3)
$1 = (int (*)(int)) 0x400753 <final>
(gdb) FAIL: gdb.base/gnu-ifunc.exp: resolver_attr=0: resolver_debug=1: resolved_debug=0: p gnu_ifunc (3)
^^^^^^^^^^^^^^^^
That is, we called the ifunc resolver manually, which returned a
pointer to the ifunc target function ("final"). The "final" symbol is
the function that GDB should have called automatically,
~~~~~~~~~~~~
int
final (int arg)
{
return arg + 1;
}
~~~~~~~~~
which is what happens if you don't have debug info for the resolver:
(gdb) p gnu_ifunc (3)
$1 = 4
(gdb) PASS: gdb.base/gnu-ifunc.exp: resolver_attr=0: resolver_debug=0: resolved_debug=1: p gnu_ifunc (3)
^^^^^^^^^^^^^^^^
or if the resolver's symbol has a different name from the ifunc (as is
the case with modern uses of ifunc via __attribute__ ifunc, such as
glibc uses):
(gdb) p gnu_ifunc (3)
$1 = 4
(gdb) PASS: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=1: resolved_debug=0: p gnu_ifunc (3)
^^^^^^^^^^^^^^^
in which case after this patch, you can still call the resolver
directly if you want:
(gdb) p gnu_ifunc_resolver (3)
$1 = (int (*)(int)) 0x400753 <final>
gdb/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* c-exp.y (variable production): Prefer ifunc minsyms over
regular function symbols.
* symtab.c (find_gnu_ifunc): New function.
* minsyms.h (lookup_msym_prefer): New enum.
(lookup_minimal_symbol_by_pc_section): Replace 'want_trampoline'
parameter by a lookup_msym_prefer parameter.
* symtab.h (find_gnu_ifunc): New declaration.
This changes struct collect_minsyms to use a std::vector, which
enables the removal of a cleanup from search_minsyms_for_name. This
also changes iterate_over_minimal_symbols to take a
gdb::function_view, which makes a function in linespec.c more
type-safe.
ChangeLog
2018-04-05 Tom Tromey <tom@tromey.com>
* minsyms.h (iterate_over_minimal_symbols): Update.
* minsyms.c (iterate_over_minimal_symbols): Take a
gdb::function_view.
* linespec.c (struct collect_minsyms): Remove.
(compare_msyms): Now a std::sort comparator.
(add_minsym): Add parameters.
(search_minsyms_for_name): Update. Use std::vector.
TLS variables can't be resolved on aarch64-linux-gnu
Running the test case with upstream gdb shows two failures:
(1) Receiving different error messages when printing TLS variable before
program runs - because the ARM compiler does not emit dwarf attribute
DW_AT_location for TLS, the result is expected and the baseline may
need to be changed for aarch64.
(2) Using "info address" command on C++ static TLS object resulted in
"symbol unresolved" error - below is a snippet from the test case:
class K {
public:
static __thread int another_thread_local;
};
__thread int K::another_thread_local;
(gdb) info address K::another_thread_local
Symbol "K::another_thread_local" is unresolved.
This patch contains fix for (2).
Function info_address_command() handles the "info address" command and
calls lookup_minimal_symbol_and_objfile() to find sym's symbol entry in
mininal symbol table if SYMBOL_COMPUTED_OPS (sym) is false. Problem is
that function lookup_minimal_symbol_and_objfile() only looked up an
objfile's minsym ordinary hash table, not its demangled hash table, which
was the reason why the C++ name was not found.
The fix is to call lookup_minimal_symbol(), which already looks up entries
in both minsym's hash tables, to find names when traversing the object file
list in lookup_minimal_symbol_and_objfile().
Tested in both aarch64-linux-gnu and amd64-linux-gnu. No regressions.
The recent-ish commit e5f25bc5d6 ('Fix "list ambiguous_variable"')
caused a serious regression on PPC64. See
<https://sourceware.org/ml/gdb-patches/2017-11/msg00666.html>.
Basically, after that patch, GDB sets breakpoints in function
descriptors instead of where the descriptors point to, which is
incorrect.
The problem is that GDB now only runs a minsym's address through
gdbarch_convert_from_func_ptr_addr if msymbol_is_text returns true.
However, if the symbol points to a function descriptor,
msymbol_is_text is false since function descriptors are in fact
outside the text section.
The fix is to also run a non-text address through
gdbarch_convert_from_func_ptr_addr, and if that detects that it was
indeed a function descriptor, treat the resulting address as a
function.
While implementing that directly in linespec.c:minsym_found (where the
bad msymbol_is_text check is) fixes the issue, I noticed that
linespec.c:add_minsym has some code that also basically needs to do
the same checks, however it's implemented differently. Also,
add_minsym is calling find_pc_sect_line on non-function symbols, which
also doesn't look right.
So I introduced msymbol_is_function, so that we have a simple place to
consider minsyms and function descriptors.
And then, the only other use of msymbol_is_text is in
find_function_alias_target, which turns out to also be incorrect.
Changing that one to use msymbol_is_function, i.e., to consider
function descriptors too fixes (on PPC64):
-FAIL: gdb.base/symbol-alias.exp: p func_alias
-FAIL: gdb.base/symbol-alias.exp: p *func_alias()
+PASS: gdb.base/symbol-alias.exp: p func_alias
+PASS: gdb.base/symbol-alias.exp: p *func_alias()
And then after that, msymbol_is_text is no longer used anywhere, so it
can be removed.
Tested on x86_64 GNU/Linux, no regressions. Tested on PPC64 GNU/Linux
and results compared to a testrun of e5f25bc5d6db^ (before the
offending commit), also no regressions. (there's a couple new FAILs
and some new symbol name matching unit tests are crashing, but that
looks unrelated).
gdb/ChangeLog:
2017-11-29 Pedro Alves <palves@redhat.com>
* linespec.c (minsym_found, add_minsym): Use msymbol_is_function.
* minsyms.c (msymbol_is_text): Delete.
(msymbol_is_function): New function.
* minsyms.h (msymbol_is_text): Delete.
(msymbol_is_function): New declaration.
* symtab.c (find_function_alias_target): Use msymbol_is_function.
The support for setting breakpoint in functions with ABI tags patch
will add a use of SYMBOL_HASH_NEXT in cp-support.c, which fails to
compile with:
src/gdb/cp-support.c:38:0:
src/gdb/cp-support.c: In function ‘unsigned int cp_search_name_hash(const char*)’:
src/gdb/../include/safe-ctype.h:148:20: error: ‘do_not_use_tolower_with_safe_ctype’ was not declared in this scope
#define tolower(c) do_not_use_tolower_with_safe_ctype
^
src/gdb/minsyms.h:174:18: note: in expansion of macro ‘tolower’
((hash) * 67 + tolower ((unsigned char) (c)) - 113)
^
src/gdb/cp-support.c:1677:14: note: in expansion of macro ‘SYMBOL_HASH_NEXT’
hash = SYMBOL_HASH_NEXT (hash, *string);
^
This fixes the problem before it happens.
I was somewhat worried about whether this might have an impact with
languages that are case insensitive, but I convinced myself that it
doesn't. As bonus, this improves GDB's minsym interning performance a
bit (3%-10%). See
<https://sourceware.org/ml/gdb/2017-11/msg00021.html>.
gdb/ChangeLog:
2017-11-25 Pedro Alves <palves@redhat.com>
* dictionary.c: Include "safe-ctype.h".
* minsyms.c: Include "safe-ctype.h".
* minsyms.c (SYMBOL_HASH_NEXT): Use TOLOWER instead of tolower.
Summary:
- This is preparation for supporting wild name matching on C++ too.
- This is also preparation for TAB-completion fixes.
- Makes symbol name matching (think strcmp_iw) be based on a per-language method.
- Merges completion and non-completion name comparison (think
language_ops::la_get_symbol_name_cmp generalized).
- Avoid re-hashing lookup name multiple times
- Centralizes preparing a name for lookup (Ada name encoding / C++ Demangling),
both completion and non-completion.
- Fixes Ada latent bug with verbatim name matches in expressions
- Makes ada-lang.c use common|symtab.c completion code a bit more.
Ada's wild matching basically means that
"(gdb) break foo"
will find all methods named "foo" in all packages. Translating to
C++, it's roughly the same as saying that "break klass::method" sets
breakpoints on all "klass::method" methods of all classes, no matter
the namespace. A following patch will teach GDB about fullname vs
wild matching for C++ too. This patch is preparatory work to get
there.
Another idea here is to do symbol name matching based on the symbol
language's algorithm. I.e., avoid dependency on current language set.
This allows for example doing
(gdb) b foo::bar< int > (<tab>
and having gdb name match the C++ symbols correctly even if the
current language is C or Assembly (or Rust, or Ada, or ...), which can
easily happen if you step into an Assembly/C runtime library frame.
By encapsulating all the information related to a lookup name in a
class, we can also cache hash computation for a given language in the
lookup name object, to avoid recomputing it over and over.
Similarly, because we don't really know upfront which languages the
lookup name will be matched against, for each language we store the
lookup name transformed into a search name. E.g., for C++, that means
demangling the name. But for Ada, it means encoding the name. This
actually forces us to centralize all the different lookup name
encoding in a central place, resulting in clearer code, IMO. See
e.g., the new ada_lookup_name_info class.
The lookup name -> symbol search name computation is also done only
once per language.
The old language->la_get_symbol_name_cmp / symbol_name_cmp_ftype are
generalized to work with both completion, and normal symbol look up.
At some point early on, I had separate completion vs non-completion
language vector entry points, but a single method ends up being better
IMO for simplifying things -- the more we merge the completion /
non-completion name lookup code paths, the less changes for bugs
causing completion vs normal lookup finding different symbols.
The ada-lex.l change is necessary because when doing
(gdb) p <UpperCase>
then the name that is passed to write_ write_var_or_type ->
ada_lookup_symbol_list misses the "<>", i.e., it's just "UpperCase",
and we end up doing a wild match against "UpperCase" lowercased by
ada_lookup_name_info's constructor. I.e., "uppercase" wouldn't ever
match "UpperCase", and the symbol lookup fails.
This wouldn't cause any regression in the testsuite, but I added a new
test that would pass before the patch and fail after, if it weren't
for that fix.
This is latent bug that happens to go unnoticed because that
particular path was inconsistent with the rest of Ada symbol lookup by
not lowercasing the lookup name.
Ada's symbol_completion_add is deleted, replaced by using common
code's completion_list_add_name. To make the latter work for Ada, we
needed to add a new output parameter, because Ada wants to return back
a custom completion candidates that are not the symbol name.
With this patch, minimal symbol demangled name hashing is made
consistent with regular symbol hashing. I.e., it now goes via the
language vector's search_name_hash method too, as I had suggested in a
previous patch.
dw2_expand_symtabs_matching / .gdb_index symbol names were a
challenge. The problem is that we have no way to telling what is the
language of each symbol name found in the index, until we expand the
corresponding full symbol, which is off course what we're trying to
avoid. Language information is simply not considered in the index
format... Since the symbol name hashing and comparison routines are
per-language, we now have a problem. The patch sorts this out by
matching each name against all languages. This is inneficient, and
indeed slows down completion several times. E.g., with:
$ cat script.cmd
set pagination off
set $count = 0
while $count < 400
complete b string_prin
printf "count = %d\n", $count
set $count = $count + 1
end
$ time gdb --batch -q ./gdb-with-index -ex "source script-string_printf.cmd"
I get, before patch (-O2, x86-64):
real 0m1.773s
user 0m1.737s
sys 0m0.040s
While after patch (-O2, x86-64):
real 0m9.843s
user 0m9.482s
sys 0m0.034s
However, the following patch will optimize this, and will actually
make this use case faster compared to the "before patch" above:
real 0m1.321s
user 0m1.285s
sys 0m0.039s
gdb/ChangeLog:
2017-11-08 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_encode): Rename to ..
(ada_encode_1): ... this. Add throw_errors parameter and handle
it.
(ada_encode): Reimplement.
(match_name): Delete, folded into full_name.
(resolve_subexp): No longer pass the encoded name to
ada_lookup_symbol_list.
(should_use_wild_match): Delete.
(name_match_type_from_name): New.
(ada_lookup_simple_minsym): Use lookup_name_info and the
language's symbol_name_matcher_ftype.
(add_symbols_from_enclosing_procs, ada_add_local_symbols)
(ada_add_block_renamings): Adjust to use lookup_name_info.
(ada_lookup_name): New.
(add_nonlocal_symbols, ada_add_all_symbols)
(ada_lookup_symbol_list_worker, ada_lookup_symbol_list)
(ada_iterate_over_symbols): Adjust to use lookup_name_info.
(ada_name_for_lookup): Delete.
(ada_lookup_encoded_symbol): Construct a verbatim name.
(wild_match): Reverse sense of return type. Use bool.
(full_match): Reverse sense of return type. Inline bits of old
match_name here.
(ada_add_block_symbols): Adjust to use lookup_name_info.
(symbol_completion_match): Delete, folded into...
(ada_lookup_name_info::matches): ... .this new method.
(symbol_completion_add): Delete.
(ada_collect_symbol_completion_matches): Add name_match_type
parameter. Adjust to use lookup_name_info and
completion_list_add_name.
(get_var_value, ada_add_global_exceptions): Adjust to use
lookup_name_info.
(ada_get_symbol_name_cmp): Delete.
(do_wild_match, do_full_match): New functions.
(ada_lookup_name_info::ada_lookup_name_info): New method.
(ada_symbol_name_matches, ada_get_symbol_name_matcher): New
functions.
(ada_language_defn): Install ada_get_symbol_name_matcher.
* ada-lex.l (processId): If name starts with '<', copy it
verbatim.
* block.c (block_iter_match_step, block_iter_match_first)
(block_iter_match_next, block_lookup_symbol)
(block_lookup_symbol_primary, block_find_symbol): Adjust to use
lookup_name_info.
* block.h (block_iter_match_first, block_iter_match_next)
(ALL_BLOCK_SYMBOLS_WITH_NAME): Adjust to use lookup_name_info.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Adjust comments to
refer to la_get_symbol_name_matcher.
* completer.c (complete_files_symbols)
(collect_explicit_location_matches, symbol_completer): Pass a
symbol_name_match_type down.
* completer.h (class completion_match, completion_match_result):
New classes.
(completion_tracker::reset_completion_match_result): New method.
(completion_tracker::m_completion_match_result): New field.
* cp-support.c (make_symbol_overload_list_block): Adjust to use
lookup_name_info.
(cp_fq_symbol_name_matches, cp_get_symbol_name_matcher): New
functions.
* cp-support.h (cp_get_symbol_name_matcher): New declaration.
* d-lang.c: Adjust comments to refer to
la_get_symbol_name_matcher.
* dictionary.c (dict_vector) <iter_match_first, iter_match_next>:
Adjust to use lookup_name_info.
(dict_iter_match_first, dict_iter_match_next)
(iter_match_first_hashed, iter_match_next_hashed)
(iter_match_first_linear, iter_match_next_linear): Adjust to work
with a lookup_name_info.
* dictionary.h (dict_iter_match_first, dict_iter_match_next):
Likewise.
* dwarf2read.c (dw2_lookup_symbol): Adjust to use lookup_name_info.
(dw2_map_matching_symbols): Adjust to use symbol_name_match_type.
(gdb_index_symbol_name_matcher): New class.
(dw2_expand_symtabs_matching) Adjust to use lookup_name_info and
gdb_index_symbol_name_matcher. Accept a NULL symbol_matcher.
* f-lang.c (f_collect_symbol_completion_matches): Adjust to work
with a symbol_name_match_type.
(f_language_defn): Adjust comments to refer to
la_get_symbol_name_matcher.
* go-lang.c (go_language_defn): Adjust comments to refer to
la_get_symbol_name_matcher.
* language.c (default_symbol_name_matcher)
(language_get_symbol_name_matcher): New functions.
(unknown_language_defn, auto_language_defn): Adjust comments to
refer to la_get_symbol_name_matcher.
* language.h (symbol_name_cmp_ftype): Delete.
(language_defn) <la_collect_symbol_completion_matches>: Add match
type parameter.
<la_get_symbol_name_cmp>: Delete field.
<la_get_symbol_name_matcher>: New field.
<la_iterate_over_symbols>: Adjust to use lookup_name_info.
(default_symbol_name_matcher, language_get_symbol_name_matcher):
Declare.
* linespec.c (iterate_over_all_matching_symtabs)
(iterate_over_file_blocks): Adjust to use lookup_name_info.
(find_methods): Add language parameter, and use lookup_name_info
and the language's symbol_name_matcher_ftype.
(linespec_complete_function): Adjust.
(lookup_prefix_sym): Use lookup_name_info.
(add_all_symbol_names_from_pspace): Adjust.
(find_superclass_methods): Add language parameter and pass it
down.
(find_method): Pass symbol language down.
(find_linespec_symbols): Don't demangle or Ada encode here.
(search_minsyms_for_name): Add lookup_name_info parameter.
(add_matching_symbols_to_info): Add name_match_type parameter.
Use lookup_name_info.
* m2-lang.c (m2_language_defn): Adjust comments to refer to
la_get_symbol_name_matcher.
* minsyms.c: Include <algorithm>.
(add_minsym_to_demangled_hash_table): Remove table parameter and
add objfile parameter. Use search_name_hash, and add language to
demangled languages vector.
(struct found_minimal_symbols): New struct.
(lookup_minimal_symbol_mangled, lookup_minimal_symbol_demangled):
New functions.
(lookup_minimal_symbol): Adjust to use them. Don't canonicalize
input names here. Use lookup_name_info instead. Lookup up
demangled names once for each language in the demangled names
vector.
(iterate_over_minimal_symbols): Use lookup_name_info. Lookup up
demangled names once for each language in the demangled names
vector.
(build_minimal_symbol_hash_tables): Adjust.
* minsyms.h (iterate_over_minimal_symbols): Adjust to pass down a
lookup_name_info.
* objc-lang.c (objc_language_defn): Adjust comment to refer to
la_get_symbol_name_matcher.
* objfiles.h: Include <vector>.
(objfile_per_bfd_storage) <demangled_hash_languages>: New field.
* opencl-lang.c (opencl_language_defn): Adjust comment to refer to
la_get_symbol_name_matcher.
* p-lang.c (pascal_language_defn): Adjust comment to refer to
la_get_symbol_name_matcher.
* psymtab.c (psym_lookup_symbol): Use lookup_name_info.
(match_partial_symbol): Use symbol_name_match_type,
lookup_name_info and psymbol_name_matches.
(lookup_partial_symbol): Use lookup_name_info.
(map_block): Use symbol_name_match_type and lookup_name_info.
(psym_map_matching_symbols): Use symbol_name_match_type.
(psymbol_name_matches): New.
(recursively_search_psymtabs): Use lookup_name_info and
psymbol_name_matches. Rename 'kind' parameter to 'domain'.
(psym_expand_symtabs_matching): Use lookup_name_info. Rename
'kind' parameter to 'domain'.
* rust-lang.c (rust_language_defn): Adjust comment to refer to
la_get_symbol_name_matcher.
* symfile-debug.c (debug_qf_map_matching_symbols)
(debug_qf_map_matching_symbols): Use symbol_name_match_type.
(debug_qf_expand_symtabs_matching): Use lookup_name_info.
* symfile.c (expand_symtabs_matching): Use lookup_name_info.
* symfile.h (quick_symbol_functions) <map_matching_symbols>:
Adjust to use symbol_name_match_type.
<expand_symtabs_matching>: Adjust to use lookup_name_info.
(expand_symtabs_matching): Adjust to use lookup_name_info.
* symmisc.c (maintenance_expand_symtabs): Use
lookup_name_info::match_any ().
* symtab.c (symbol_matches_search_name): New.
(eq_symbol_entry): Adjust to use lookup_name_info and the
language's matcher.
(demangle_for_lookup_info::demangle_for_lookup_info): New.
(lookup_name_info::match_any): New.
(iterate_over_symbols, search_symbols): Use lookup_name_info.
(compare_symbol_name): Add language, lookup_name_info and
completion_match_result parameters, and use them.
(completion_list_add_name): Make extern. Add language and
lookup_name_info parameters. Use them.
(completion_list_add_symbol, completion_list_add_msymbol)
(completion_list_objc_symbol): Add lookup_name_info parameters and
adjust. Pass down language.
(completion_list_add_fields): Add lookup_name_info parameters and
adjust. Pass down language.
(add_symtab_completions): Add lookup_name_info parameters and
adjust.
(default_collect_symbol_completion_matches_break_on): Add
name_match_type parameter, and use it. Use lookup_name_info.
(default_collect_symbol_completion_matches)
(collect_symbol_completion_matches): Add name_match_type
parameter, and pass it down.
(collect_symbol_completion_matches_type): Adjust.
(collect_file_symbol_completion_matches): Add name_match_type
parameter, and use lookup_name_info.
* symtab.h: Include <string> and "common/gdb_optional.h".
(enum class symbol_name_match_type): New.
(class ada_lookup_name_info): New.
(struct demangle_for_lookup_info): New.
(class lookup_name_info): New.
(symbol_name_matcher_ftype): New.
(SYMBOL_MATCHES_SEARCH_NAME): Use symbol_matches_search_name.
(symbol_matches_search_name): Declare.
(MSYMBOL_MATCHES_SEARCH_NAME): Delete.
(default_collect_symbol_completion_matches)
(collect_symbol_completion_matches)
(collect_file_symbol_completion_matches): Add name_match_type
parameter.
(iterate_over_symbols): Use lookup_name_info.
(completion_list_add_name): Declare.
* utils.c (enum class strncmp_iw_mode): Moved to utils.h.
(strncmp_iw_with_mode): Now extern.
* utils.h (enum class strncmp_iw_mode): Moved from utils.c.
(strncmp_iw_with_mode): Declare.
gdb/testsuite/ChangeLog:
2017-11-08 Pedro Alves <palves@redhat.com>
* gdb.ada/complete.exp (p <Exported_Capitalized>): New test.
(p Exported_Capitalized): New test.
(p exported_capitalized): New test.
The previous patch left GDB with an inconsistency. While with normal
expression evaluation the "unknown return type" error shows the name
of the function that misses debug info:
(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 commit is a step toward fixing it.
The problem is that while evaluating the expression above, we have no
reference to the minimal symbol where we could extract the name from.
This is because the resulting expression tree has no reference to the
minsym at all. During parsing, the type and address of the minsym are
extracted and an UNOP_MEMVAL / UNOP_MEMVAL_TLS operator is generated
(see write_exp_elt_msym). With "set debug expression", here's what
you see:
0 OP_FUNCALL Number of args: 0
3 UNOP_MEMVAL Type @0x565334a51930 (<text variable, no debug info>)
6 OP_LONG Type @0x565334a51c60 (__CORE_ADDR), value 140737345035648 (0x7ffff7751d80)
The "print" case finds the function name, because
call_function_by_hand looks up the function by address again.
However, for "ptype", we don't reach that code, because obviously we
don't really call the function.
Unlike minsym references, references to variables with debug info have
a pointer to the variable's symbol in the expression tree, with
OP_VAR_VALUE:
(gdb) ptype main()
...
0 OP_FUNCALL Number of args: 0
3 OP_VAR_VALUE Block @0x0, symbol @0x559bbbd9b358 (main(int, char**))
...
so I don't see why do minsyms need to be different. So to prepare for
fixing the missing function name issue, this commit adds a new
OP_VAR_MSYM_VALUE operator that mimics OP_VAR_VALUE, except that it's
for minsyms instead of debug symbols. For infcalls, we now get
expressions like these:
0 OP_FUNCALL Number of args: 0
3 OP_VAR_MSYM_VALUE Objfile @0x1e41bf0, msymbol @0x7fffe599b000 (getenv)
In the following patch, we'll make OP_FUNCALL extract the function
name from the symbol stored in OP_VAR_VALUE/OP_VAR_MSYM_VALUE.
OP_VAR_MSYM_VALUE will be used more in a later patch in the series
too.
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* ada-lang.c (resolve_subexp): Handle OP_VAR_MSYM_VALUE.
* ax-gdb.c (gen_msym_var_ref): New function.
(gen_expr): Handle OP_VAR_MSYM_VALUE.
* eval.c (evaluate_var_msym_value): New function.
* eval.c (evaluate_subexp_standard): Handle OP_VAR_MSYM_VALUE.
<OP_FUNCALL>: Extract function name from symbol/minsym and pass it
to call_function_by_hand.
* expprint.c (print_subexp_standard, dump_subexp_body_standard):
Handle OP_VAR_MSYM_VALUE.
(union exp_element) <msymbol>: New field.
* minsyms.h (struct type): Forward declare.
(find_minsym_type_and_address): Declare.
* parse.c (write_exp_elt_msym): New function.
(write_exp_msymbol): Delete, refactored as ...
(find_minsym_type_and_address): ... this new function.
(write_exp_msymbol): Reimplement using OP_VAR_MSYM_VALUE.
(operator_length_standard, operator_check_standard): Handle
OP_VAR_MSYM_VALUE.
* std-operator.def (OP_VAR_MSYM_VALUE): New.
(Ref: https://sourceware.org/ml/gdb/2017-06/msg00048.html)
This patch improves GDB support for function aliases defined with
__attribute__ alias. For example, in the test added by this commit,
there is no reference to "func_alias" in the debug info at all, only
to "func"'s definition:
$ nm ./testsuite/outputs/gdb.base/symbol-alias/symbol-alias | grep " func"
00000000004005ae t func
00000000004005ae T func_alias
$ readelf -w ./testsuite/outputs/gdb.base/symbol-alias/symbol-alias | grep func -B 1 -A 8
<1><db>: Abbrev Number: 5 (DW_TAG_subprogram)
<dc> DW_AT_name : (indirect string, offset: 0x111): func
<e0> DW_AT_decl_file : 1
<e1> DW_AT_decl_line : 27
<e2> DW_AT_prototyped : 1
<e2> DW_AT_type : <0xf8>
<e6> DW_AT_low_pc : 0x4005ae
<ee> DW_AT_high_pc : 0xb
<f6> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<f8> DW_AT_GNU_all_call_sites: 1
So all GDB knows about "func_alias" is from the minsym (elf symbol):
(gdb) p func_alias
$1 = {<text variable, no debug info>} 0x4005ae <func>
(gdb) ptype func_alias
type = int ()
(gdb) p func
$2 = {struct S *(void)} 0x4005ae <func>
(gdb) ptype func
type = struct S {
int field1;
int field2;
} *(void)
The result is that calling func_alias from the command line produces
incorrect results.
This is similar (though not exactly the same) to the glibc
errno/__errno_location/__GI___errno_location situation. On glibc,
errno is defined like this:
extern int *__errno_location (void);
#define errno (*__errno_location ())
with __GI___errno_location being an internal alias for
__errno_location. On my system's libc (F23), I do see debug info for
__errno_location, in the form of name vs linkage name:
<1><95a5>: Abbrev Number: 18 (DW_TAG_subprogram)
<95a6> DW_AT_external : 1
<95a6> DW_AT_name : (indirect string, offset: 0x2c26): __errno_location
<95aa> DW_AT_decl_file : 1
<95ab> DW_AT_decl_line : 24
<95ac> DW_AT_linkage_name: (indirect string, offset: 0x2c21): __GI___errno_location
<95b0> DW_AT_prototyped : 1
<95b0> DW_AT_type : <0x9206>
<95b4> DW_AT_low_pc : 0x20f40
<95bc> DW_AT_high_pc : 0x11
<95c4> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<95c6> DW_AT_GNU_all_call_sites: 1
however that doesn't matter in practice, because GDB doesn't record
demangled names anyway, and so we end up with the exact same situation
covered by the testcase.
So the fix is to make the expression parser find a debug symbol for
the same address as the just-found minsym, when a lookup by name
didn't find a debug symbol by name. We now get:
(gdb) p func_alias
$1 = {struct S *(void)} 0x4005ae <func>
(gdb) p __errno_location
$2 = {int *(void)} 0x7ffff6e92830 <__errno_location>
I've made the test exercise variable aliases too, for completeness.
Those already work correctly, because unlike for function aliases, GCC
emits debug information for variable aliases.
Tested on GNU/Linux.
gdb/ChangeLog:
2017-08-21 Pedro Alves <palves@redhat.com>
PR gdb/19487
* c-exp.y (variable production): Handle function aliases.
* minsyms.c (msymbol_is_text): New function.
* minsyms.h (msymbol_is_text): Declare.
* symtab.c (find_function_alias_target): New function.
* symtab.h (find_function_alias_target): Declare.
gdb/testsuite/ChangeLog:
2017-08-21 Pedro Alves <palves@redhat.com>
PR gdb/19487
* gdb.base/symbol-alias.c: New.
* gdb.base/symbol-alias2.c: New.
* gdb.base/symbol-alias.exp: New.
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.
This changes an "int" to a "bool" in the signature for
minimal_symbol_reader::record_full, and then fixes the callers.
2016-10-21 Tom Tromey <tom@tromey.com>
* minsyms.h (minimal_symbol_reader::record_full): "copy_name" now
a bool.
(record, record_with_info): Update.
* minsyms.c (record): Fix indentation.
(record_full): Fix indentation. Update for type change.
* elfread.c (record_minimal_symbol): "copy_name" now a bool.
(elf_symtab_read): "copy_names" now a bool.
(elf_rel_plt_read, elf_read_minimal_symbols): Update.
This changes minimal_symbol_reader to require the objfile to be
passed to the constructor. The class now records the objfile and
automatically uses it later in "install".
This is a minor cleanup that will come in useful in the next patch.
It is separate from the first patch to keep that one a bit simpler to
understand.
2016-10-21 Tom Tromey <tom@tromey.com>
* xcoffread.c (xcoff_initial_scan): Update.
* mipsread.c (mipscoff_symfile_read): Update.
* minsyms.c (minimal_symbol_reader): Add obj argument.
Initialize member.
(install): Remove objfile argument. Update.
* mdebugread.c (elfmdebug_build_psymtabs): Update.
* machoread.c (macho_symfile_read): Update.
* elfread.c (elf_read_minimal_symbols): Update.
* dbxread.c (dbx_symfile_read): Update.
* coffread.c (coff_symfile_read): Update.
* minsyms.h (minimal_symbol_reader): Add m_objfile member.
(constructor): Add objfile argument.
(minimal_symbol_reader::install): Remove objfile argument.
This patch introduced minimal_symbol_reader, a RAII-based class which
replaces the current make_cleanup_discard_minimal_symbols.
2016-10-21 Tom Tromey <tom@tromey.com>
* xcoffread.c (xcoff_initial_scan): Use
minimal_symbol_reader.
* mipsread.c (mipscoff_symfile_read): Use
minimal_symbol_reader.
* minsyms.h (minimal_symbol_reader): New class.
(init_minimal_symbol_collection)
(make_cleanup_discard_minimal_symbols, install_minimal_symbols):
Don't declare.
* minsyms.c (minimal_symbol_reader): Renamed from
init_minimal_symbol_collection, turned into constructor.
(~minimal_symbol_reader): Renamed from
do_discard_minimal_symbols_cleanup, turned into destructor.
(make_cleanup_discard_minimal_symbols): Remove.
(minimal_symbol_reader::install): Rename form
install_minimal_symbols.
* mdebugread.c (elfmdebug_build_psymtabs): Use
minimal_symbol_reader.
* machoread.c (macho_symfile_read): Use
minimal_symbol_reader.
* elfread.c (elf_read_minimal_symbols): Use
minimal_symbol_reader.
* dbxread.c (dbx_symfile_read): Use minimal_symbol_reader.
* coffread.c (coff_symfile_read): Use
minimal_symbol_reader.
minsyms.h incorrectly claims that a couple of functions call
prim_record_minimal_symbol_full with COPY_NAME=0 -- but actually they
pass 1. Passing 1 is the correct behavior, so this patch fixes the
documentation.
I'm checking this in as obvious.
2014-06-16 Tom Tromey <tromey@redhat.com>
* minsyms.h (prim_record_minimal_symbol)
(prim_record_minimal_symbol_and_info): Update comments.
This removes the runtime offsets from minsyms. Instead, these offsets
will now be applied whenever the minsym's address is computed.
This patch redefines MSYMBOL_VALUE_ADDRESS to actually use the offsets
from the given objfile. Then, it updates all the symbol readers,
changing them so that they do not add in the section offset when
creating the symbol.
This change also lets us remove relocation of minsyms from
objfile_relocate1 and also msymbols_sort.
2014-02-26 Tom Tromey <tromey@redhat.com>
* minsyms.c (msymbols_sort): Remove.
* minsyms.h (msymbols_sort): Remove.
* objfiles.c (objfile_relocate1): Don't relocate minsyms.
* symtab.h (MSYMBOL_VALUE_ADDRESS): Use objfile offsets.
* elfread.c (elf_symtab_read): Don't add section offsets.
* xcoffread.c (record_minimal_symbol): Don't add section offset
to minimal symbol address.
* somread.c (text_offset, data_offset): Remove.
(som_symtab_read): Don't add section offsets to minimal symbol
addresses.
* coff-pe-read.c (add_pe_forwarded_sym, read_pe_exported_syms):
Don't add section offsets to minimal symbols.
* coffread.c (coff_symtab_read): Don't add section offsets
to minimal symbol addresses.
* machoread.c (macho_symtab_add_minsym): Don't add section offset
to minimal symbol addresses.
* mipsread.c (read_alphacoff_dynamic_symtab): Don't add
section offset to minimal symbol addresses.
* mdebugread.c (parse_partial_symbols): Don't add section
offset to minimal symbol addresses.
* dbxread.c (read_dbx_dynamic_symtab): Don't add section
offset to minimal symbol addresses.
This introduces minimal_symbol_upper_bound and changes various bits of
code to use it. Since this function is intimately tied to the
implementation of minimal symbol tables, I believe it belongs in
minsyms.c.
The new function is extracted from find_pc_partial_function_gnu_ifunc.
This isn't a "clean" move because the old function interleaved the
caching and the computation; but this doesn't make sense for the new
code.
2014-02-26 Tom Tromey <tromey@redhat.com>
* blockframe.c (find_pc_partial_function_gnu_ifunc): Use
bound minimal symbols. Move code that knows about minsym
table layout...
* minsyms.c (minimal_symbol_upper_bound): ... here. New
function.
* minsyms.h (minimal_symbol_upper_bound): Declare.
* objc-lang.c (find_objc_msgsend): Use bound minimal symbols,
minimal_symbol_upper_bound.
This is another patch in my ongoing series to "split" objfile to share
more read-only data across inferiors. See
http://sourceware.org/gdb/wiki/ObjfileSplitting
When symbols are finally shared, there will be no back-link from the
symbol to its containing objfile, because there may be more than one
such objfile. So, all such back-links must be removed.
One hidden back-link is the msymbol_objfile function. Since
(eventually) a symbol may appear in more than one objfile, trying to
look up the objfile given just a symbol cannot work.
This patch removes msymbol_objfile in favor of using a bound minimal
symbol. It introduces a new function to make this conversion simpler
in some spots.
The bonus of this patch is that using msymbol_objfile is slower than
simply looking up the owning objfile in the first place.
Built and regtested on x86-64 Fedora 18.
* ada-exp.y (write_var_or_type): Use bound_minimal_symbol.
* ada-lang.c (ada_lookup_simple_minsym): Return
bound_minimal_symbol.
* ada-lang.h (ada_lookup_simple_minsym): Update.
* c-exp.y (variable): Use lookup_bound_minimal_symbol.
* f-exp.y (variable): Use lookup_bound_minimal_symbol.
* go-exp.y (variable): Use lookup_bound_minimal_symbol.
* jv-exp.y (push_expression_name): Use lookup_bound_minimal_symbol.
* m2-exp.y (variable): Use lookup_bound_minimal_symbol.
* minsyms.c (msymbol_objfile): Remove.
(lookup_minimal_symbol_internal): New function, from
lookup_minimal_symbol.
(lookup_minimal_symbol): Rewrite using
lookup_minimal_symbol_internal.
(lookup_bound_minimal_symbol): New function.
* minsyms.h (msymbol_objfile): Remove.
(lookup_bound_minimal_symbol): Declare.
* p-exp.y (variable): Use lookup_bound_minimal_symbol.
* parse.c (write_exp_msymbol): Change parameter to a
bound_minimal_symbol.
(write_dollar_variable): Use lookup_bound_minimal_symbol.
* parser-defs.h (write_exp_msymbol): Update.
* printcmd.c (address_info): Use lookup_bound_minimal_symbol.
* symfile.c (simple_read_overlay_table): Use
lookup_bound_minimal_symbol.
* symtab.c (skip_prologue_sal): Don't use msymbol_objfile.
(search_symbols): Likewise.
(print_msymbol_info): Take a bound_minimal_symbol argument.
(symtab_symbol_info, rbreak_command): Update.
* symtab.h (struct symbol_search) <msymbol>: Change type
to bound_minimal_symbol.
* valops.c (find_function_in_inferior): Use
lookup_bound_minimal_symbol.
* value.c (value_fn_field): Use lookup_bound_minimal_symbol.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.