Commit Graph

52 Commits

Author SHA1 Message Date
Andrew Burgess
1d506c26d9 Update copyright year range in header of all files managed by GDB
This commit is the result of the following actions:

  - Running gdb/copyright.py to update all of the copyright headers to
    include 2024,

  - Manually updating a few files the copyright.py script told me to
    update, these files had copyright headers embedded within the
    file,

  - Regenerating gdbsupport/Makefile.in to refresh it's copyright
    date,

  - Using grep to find other files that still mentioned 2023.  If
    these files were updated last year from 2022 to 2023 then I've
    updated them this year to 2024.

I'm sure I've probably missed some dates.  Feel free to fix them up as
you spot them.
2024-01-12 15:49:57 +00:00
Lancelot Six
8082468ffe gdb: Use std::string_view instead of gdb::string_view
Given that GDB now requires a C++17, replace all uses of
gdb::string_view with std::string_view.

This change has mostly been done automatically:
- gdb::string_view -> std::string_view
- #include "gdbsupport/gdb_string_view.h" -> #include <string_view>

One things which got brought up during review is that gdb::stging_view
does support being built from "nullptr" while std::sting_view does not.
Two places are manually adjusted to account for this difference:
gdb/tui/tui-io.c:tui_getc_1 and
gdbsupport/format.h:format_piece::format_piece.

The above automatic change transformed
"gdb::to_string (const gdb::string_view &)" into
"gdb::to_string (const std::string_view &)".  The various direct users
of this function are now explicitly including
"gdbsupport/gdb_string_view.h".  A later patch will remove the users of
gdb::to_string.

The implementation and tests of gdb::string_view are unchanged, they will
be removed in a following patch.

Change-Id: Ibb806a7e9c79eb16a55c87c6e41ad396fecf0207
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>
2023-11-21 11:52:36 +00:00
Tom Tromey
47ef0ac717 Introduce lookup_minimal_symbol_linkage
This introduces a new function, lookup_minimal_symbol_linkage, and
refactors a couple other existing functions to call it.  This function
will be used in a subsequent patch.
2023-05-12 13:25:28 -06:00
Tom Tromey
9675da2535 Use unrelocated_addr in minimal symbols
This changes minimal symbols to use unrelocated_addr.  I believe this
detected a latent bug in add_pe_forwarded_sym.
2023-03-28 15:12:44 -06:00
Joel Brobecker
213516ef31 Update copyright year range in header of all files managed by GDB
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
2023-01-01 17:01:16 +04:00
Simon Marchi
4aeddc50d7 gdb: remove symbol value macros
Remove all macros related to getting and setting some symbol value:

    #define SYMBOL_VALUE(symbol)           (symbol)->value.ivalue
    #define SYMBOL_VALUE_ADDRESS(symbol)                         \
    #define SET_SYMBOL_VALUE_ADDRESS(symbol, new_value)    \
    #define SYMBOL_VALUE_BYTES(symbol)     (symbol)->value.bytes
    #define SYMBOL_VALUE_COMMON_BLOCK(symbol) (symbol)->value.common_block
    #define SYMBOL_BLOCK_VALUE(symbol)     (symbol)->value.block
    #define SYMBOL_VALUE_CHAIN(symbol)     (symbol)->value.chain
    #define MSYMBOL_VALUE(symbol)          (symbol)->value.ivalue
    #define MSYMBOL_VALUE_RAW_ADDRESS(symbol) ((symbol)->value.address + 0)
    #define MSYMBOL_VALUE_ADDRESS(objfile, symbol)                         \
    #define BMSYMBOL_VALUE_ADDRESS(symbol) \
    #define SET_MSYMBOL_VALUE_ADDRESS(symbol, new_value)   \
    #define MSYMBOL_VALUE_BYTES(symbol)    (symbol)->value.bytes
    #define MSYMBOL_BLOCK_VALUE(symbol)    (symbol)->value.block

Replace them with equivalent methods on the appropriate objects.

Change-Id: Iafdab3b8eefc6dc2fd895aa955bf64fafc59ed50
2022-04-11 10:45:36 -04:00
Tom Tromey
f6b3ad5440 Add constructor to bound_minimal_symbol
This adds a constructor to bound_minimal_symbol, to avoid a build
failure with clang that Simon pointed out.

I also took the opportunity to remove some redundant initializations,
and to change one use of push_back to emplace_back, as suggested by
Simon.
2022-02-18 12:58:35 -07:00
Tom Tromey
29ba33db77 Add initializers to bound_minimal_symbol
This adds initializers to bound_minimal_symbol, allowing for the
removal of some calls to memset.
2022-02-11 09:23:56 -07:00
Joel Brobecker
4a94e36819 Automatic Copyright Year update after running gdb/copyright.py
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.

For the avoidance of doubt, all changes in this commits were
performed by the script.
2022-01-01 19:13:23 +04:00
Andrew Burgess
1db66e348a gdb: add obj_section function to bound_minimal_symbol
Add a new obj_section function to bound_minimal_symbol, this just
calls obj_section on the contained minimal_symbol passing in the
contained objfile.

This allows some minor code simplification in a few places.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* breakpoint.c (resolve_sal_pc): Make use of
	bound_minimal_symbol::obj_section.
	* maint.c (maintenance_translate_address): Likewise.
	* minsyms.c (minimal_symbol_upper_bound): Likewise.
	* minsyms.h (struct bound_minimal_symbol) <obj_section>: New
	member function.
	* printcmd.c (info_address_command): Make use of
	bound_minimal_symbol::obj_section.
2021-02-11 09:50:58 +00:00
Joel Brobecker
3666a04883 Update copyright year range in all GDB files
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...

gdb/ChangeLog

        Update copyright year range in copyright header of all GDB files.
2021-01-01 12:12:21 +04:00
Andrew Burgess
733d0a6795 gdb/tui: asm window handles invalid memory and scrolls better
This started as a patch to enable the asm window to handle attempts to
disassemble invalid memory, but it ended up expanding into a
significant rewrite of how the asm window handles scrolling.  These
two things ended up being tied together as it was impossible to
correctly test scrolling into invalid memory when the asm window would
randomly behave weirdly while scrolling.

Things that should work nicely now; scrolling to the bottom or top of
the listing with PageUp, PageDown, Up Arrow, Down Arrow and we should
be able to scroll past small areas of memory that don't have symbols
associated with them.  It should also be possible to scroll to the
start of a section even if there's no symbol at the start of the
section.

Adding tests for this scrolling was a little bit of a problem.  First
I would have liked to add tests for PageUp / PageDown, but the tuiterm
library we use doesn't support these commands right now due to only
emulating a basic ascii terminal.  Changing this to emulate a more
complex terminal would require adding support for more escape sequence
control codes, so I've not tried to tackle that in this patch.

Next, I would have liked to test scrolling to the start or end of the
assembler listing and then trying to scroll even more, however, this
is a problem because in a well behaving GDB a scroll at the start/end
has no effect.  What we need to do is:

  - Move to start of assembler listing,
  - Send scroll up command,
  - Wait for all curses output,
  - Ensure the assembler listing is unchanged, we're still at the
    start of the listing.

The problem is that there is no curses output, so how long do we wait
at step 3?  The same problem exists for scrolling to the bottom of the
assembler listing.  However, when scrolling down you can at least see
the end coming, so I added a test for this case, however, this feels
like an area of code that is massively under tested.

gdb/ChangeLog:

	PR tui/9765
	* minsyms.c (lookup_minimal_symbol_by_pc_section): Update header
	comment, add extra parameter, and update to store previous symbol
	when appropriate.
	* minsyms.h (lookup_minimal_symbol_by_pc_section): Update comment,
	add extra parameter.
	* tui/tui-disasm.c (tui_disassemble): Update header comment,
	remove unneeded parameter, add try/catch around gdb_print_insn,
	rewrite to add items to asm_lines vector.
	(tui_find_backward_disassembly_start_address): New function.
	(tui_find_disassembly_address): Updated throughout.
	(tui_disasm_window::set_contents): Update for changes to
	tui_disassemble.
	(tui_disasm_window::do_scroll_vertical): No need to adjust the
	number of lines to scroll.

gdb/testsuite/ChangeLog:

	PR tui/9765
	* gdb.tui/tui-layout-asm.exp: Add scrolling test for asm window.

Change-Id: I323987c8fd316962c937e73c17d952ccd3cfa66c
2020-01-24 00:10:33 +00:00
Joel Brobecker
b811d2c292 Update copyright year range in all GDB files.
gdb/ChangeLog:

        Update copyright year range in all GDB files.
2020-01-01 10:20:53 +04:00
Christian Biesinger
31edb80295 Change some arguments to gdb::string_view instead of name+len
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
2019-10-29 14:19:59 -05:00
Tom Tromey
4b610737f0 Handle copy relocations
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.
2019-10-02 09:53:17 -06:00
Christian Biesinger
c7ee338a2d Improve some comments about msymbol handling
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.
2019-09-30 11:21:46 -05:00
Tom Tromey
762c164d75 Remove lookup_minimal_symbol_solib_trampoline
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.
2019-06-26 09:50:55 -06:00
Tom Tromey
741d7538b7 Remove minsym termination
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.
2019-03-15 16:02:08 -06:00
Tom Tromey
3db066bcd5 Slightly simplify minsym creation
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.
2019-03-15 16:02:07 -06:00
Joel Brobecker
42a4f53d2b Update copyright year range in all GDB files.
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.
2019-01-01 10:01:51 +04:00
Tom Tromey
af9a216102 Use DISABLE_COPY_AND_ASSIGN in minimal_symbol_reader
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.
2018-12-27 12:29:48 -07:00
Weimin Pan
64cc34d870 Removing lookup_minimal_symbol_and_objfile
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.
2018-05-29 22:37:07 +00:00
Pedro Alves
20944a6e20 Fix stepping past GNU ifunc resolvers (introduce lookup_msym_prefer)
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.
2018-04-26 13:08:47 +01:00
Pedro Alves
ca31ab1d67 Calling ifunc functions when resolver has debug info, user symbol same name
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.
2018-04-26 13:05:29 +01:00
Tom Tromey
41c1efc614 Remove some cleanups from search_minsyms_for_name
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.
2018-04-05 07:39:33 -06:00
Weimin Pan
bce02d8884 aarch64: Make "info address" resolve TLS variables
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.
2018-03-23 22:57:46 -04:00
Joel Brobecker
e2882c8578 Update copyright year range in all GDB files
gdb/ChangeLog:

        Update copyright year range in all GDB files
2018-01-02 07:38:06 +04:00
Pedro Alves
4024cf2b8d Fix setting-breakpoints regression on PPC64 (function descriptors)
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.
2017-11-29 19:25:58 +00:00
Pedro Alves
deeeba559b Use TOLOWER in SYMBOL_HASH_NEXT
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.
2017-11-25 00:33:05 +00:00
Pedro Alves
b5ec771e60 Introduce lookup_name_info and generalize Ada's FULL/WILD name matching
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.
2017-11-08 16:02:24 +00:00
Pedro Alves
74ea4be48e Introduce OP_VAR_MSYM_VALUE
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.
2017-09-04 20:21:13 +01:00
Pedro Alves
bf223d3e80 Handle function aliases better (PR gdb/19487, errno printing)
(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.
2017-08-21 11:34:32 +01:00
Joel Brobecker
61baf725ec update copyright year range in GDB files
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.
2017-01-01 10:52:34 +04:00
Tom Tromey
ce6c454e5a Change minimal_symbol_reader::record_full to take a bool
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.
2016-10-21 14:17:39 -06:00
Tom Tromey
8dddcb8f00 Record minimal symbols directly in reader.
This patch changes minimal symbol creation in two ways.  First, it
removes global variables in favor of members of minimal_symbol_reader.
Second, it changes functions like prim_record_minimal_symbol to be
member functions of minimal_symbol_reader.

2016-10-21  Tom Tromey  <tom@tromey.com>

	* xcoffread.c (record_minimal_symbol, scan_xcoff_symtab): Add
	"reader" argument.  Update.
	(xcoff_initial_scan): Update.
	* symfile.h (mdebug_build_psymtabs): Add "reader" argument.
	* mipsread.c (mipscoff_symfile_read): Update.
	(read_alphacoff_dynamic_symtab): Add "reader" argument.  Update.
	* minsyms.h (minimal_symbol_reader) <record, record_full>:
	Declare.
	<m_msym_bunch, m_msym_bunch_index, m_msym_count>: New members.
	<record_with_info>: New function, renamed from
	prim_record_minimal_symbol_and_info.
	* minsyms.c (msym_bunch, msym_bunch_index, msym_count): Remove
	globals.
	(minimal_symbol_reader): Initialize new members.
	(minimal_symbol_reader::record): Renamed from
	prim_record_minimal_symbol.
	(minimal_symbol_reader::record_full): Renamed from
	prim_record_minimal_symbol_full.
	(prim_record_minimal_symbol_and_info): Move to minsyms.h; rename.
	* mdebugread.c (mdebug_build_psymtabs, parse_partial_symbols)
	(record_minimal_symbol): Add "reader" argument.  Update.
	(elfmdebug_build_psymtabs): Update.
	* machoread.c (macho_symtab_add_minsym, macho_symtab_read): Add
	"reader" argument.  Update.
	(macho_symfile_read): Update.
	* elfread.c (record_minimal_symbol, elf_symtab_read)
	(elf_rel_plt_read): Add "reader" argument.  Update.
	(elf_read_minimal_symbols): Update.
	* dbxread.c (record_minimal_symbol, read_dbx_dynamic_symtab)
	(read_dbx_symtab): Add "reader" argument.  Update.
	(dbx_symfile_read): Update.
	* coffread.c (record_minimal_symbol, coff_symtab_read): Add
	"reader" argument.  Update.
	(coff_symfile_read): Update.
	* coff-pe-read.h (read_pe_exported_syms): Add "reader" argument.
	* coff-pe-read.c (add_pe_exported_sym, add_pe_forwarded_sym)
	(read_pe_exported_syms): Add "reader" argument.  Update.
2016-10-21 14:17:33 -06:00
Tom Tromey
d25e871993 Change minimal_symbol_reader to store objfile
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.
2016-10-21 14:17:33 -06:00
Tom Tromey
873a915e0a Introduce minimal_symbol_reader
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.
2016-10-21 14:17:33 -06:00
Joel Brobecker
618f726fcb GDB copyright headers update after running GDB's copyright.py script.
gdb/ChangeLog:

        Update year range in copyright notice of all files.
2016-01-01 08:43:22 +04:00
Joel Brobecker
32d0add0a6 Update year range in copyright notice of all files owned by the GDB project.
gdb/ChangeLog:

        Update year range in copyright notice of all files.
2015-01-01 13:32:14 +04:00
Tom Tromey
99f4262f2c fix incorrect comments in minsyms.h
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.
2014-06-16 07:53:36 -06:00
Tom Tromey
2273f0ac95 change minsyms not to be relocated at read-time
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.
2014-02-26 12:11:17 -07:00
Tom Tromey
3b7344d5ab use bound_minsym as result for lookup_minimal_symbol et al
This patch changes a few minimal symbol lookup functions to return a
bound_minimal_symbol rather than a pointer to the minsym.  This change
helps prepare gdb for computing a minimal symbol's address at the
point of use.

Note that this changes even those functions that ostensibly search a
single objfile.  That was necessary because, in fact, those functions
can search an objfile and its separate debug objfiles; and it is
important for the caller to know in which objfile the minimal symbol
was actually found.

The bulk of this patch is mechanical.

2014-02-26  Tom Tromey  <tromey@redhat.com>

	* ada-lang.c (ada_update_initial_language): Update.
	(ada_main_name, ada_has_this_exception_support): Update.
	* ada-tasks.c (ada_tasks_inferior_data_sniffer): Update.
	* aix-thread.c (pdc_symbol_addrs, pd_enable): Update.
	* arm-tdep.c (arm_skip_stub): Update.
	* auxv.c (ld_so_xfer_auxv): Update.
	* avr-tdep.c (avr_scan_prologue): Update.
	* ax-gdb.c (gen_var_ref): Update.
	* breakpoint.c (struct breakpoint_objfile_data)
	<overlay_msym, longjmp_msym, terminate_msym, exception_msym>: Change
	type to bound_minimal_symbol.
	(create_overlay_event_breakpoint)
	(create_longjmp_master_breakpoint)
	(create_std_terminate_master_breakpoint)
	(create_exception_master_breakpoint): Update.
	* bsd-uthread.c (bsd_uthread_lookup_address): Update.
	* c-exp.y (classify_name): Update.
	* coffread.c (coff_symfile_read): Update.
	* common/agent.c (agent_look_up_symbols): Update.
	* d-lang.c (d_main_name): Update.
	* dbxread.c (find_stab_function_addr, end_psymtab): Update.
	* dec-thread.c (enable_dec_thread): Update.
	* dwarf2loc.c (call_site_to_target_addr): Update.
	* elfread.c (elf_gnu_ifunc_resolve_by_got): Update.
	* eval.c (evaluate_subexp_standard): Update.
	* findvar.c (struct minsym_lookup_data) <result>: Change type
	to bound_minimal_symbol.
	<objfile>: Remove.
	(minsym_lookup_iterator_cb, default_read_var_value): Update.
	* frame.c (inside_main_func): Update.
	* frv-tdep.c (frv_frame_this_id): Update.
	* gcore.c (call_target_sbrk): Update.
	* glibc-tdep.c (glibc_skip_solib_resolver): Update.
	* gnu-v3-abi.c (gnuv3_get_typeid, gnuv3_skip_trampoline):
	Update.
	* go-lang.c (go_main_name): Update.
	* hppa-hpux-tdep.c (hppa_hpux_skip_trampoline_code)
	(hppa_hpux_find_import_stub_for_addr): Update.
	* hppa-tdep.c (hppa_extract_17,	hppa_lookup_stub_minimal_symbol):
	Update.  Change return type.
	* hppa-tdep.h (hppa_lookup_stub_minimal_symbol): Change return
	type.
	* jit.c (jit_breakpoint_re_set_internal): Update.
	* linux-fork.c (inferior_call_waitpid, checkpoint_command):
	Update.
	* linux-nat.c (get_signo): Update.
	* linux-thread-db.c (inferior_has_bug): Update
	* m32c-tdep.c (m32c_return_value)
	(m32c_m16c_address_to_pointer): Update.
	* m32r-tdep.c (m32r_frame_this_id): Update.
	* m68hc11-tdep.c (m68hc11_get_register_info): Update.
	* machoread.c (macho_resolve_oso_sym_with_minsym): Update.
	* minsyms.c (lookup_minimal_symbol_internal): Rename to
	lookup_minimal_symbol.  Change return type.
	(lookup_minimal_symbol): Remove.
	(lookup_bound_minimal_symbol): Update.
	(lookup_minimal_symbol_text): Change return type.
	(lookup_minimal_symbol_solib_trampoline): Change return type.
	* minsyms.h (lookup_minimal_symbol, lookup_minimal_symbol_text)
	(lookup_minimal_symbol_solib_trampoline): Change return type.
	* mips-linux-tdep.c (mips_linux_skip_resolver): Update.
	* objc-lang.c (lookup_objc_class, lookup_child_selector)
	(value_nsstring, find_imps): Update.
	* obsd-tdep.c (obsd_skip_solib_resolver): Update.
	* p-lang.c (pascal_main_name): Update.
	* ppc-linux-tdep.c (ppc_linux_spe_context_lookup): Update.
	* ppc-sysv-tdep.c (convert_code_addr_to_desc_addr): Update.
	* proc-service.c (ps_pglobal_lookup): Update.
	* ravenscar-thread.c (get_running_thread_msymbol): Change
	return type.
	(has_ravenscar_runtime, get_running_thread_id): Update.
	* remote.c (remote_check_symbols): Update.
	* sol-thread.c (ps_pglobal_lookup): Update.
	* sol2-tdep.c (sol2_skip_solib_resolver): Update.
	* solib-dsbt.c (lm_base): Update.
	* solib-frv.c (lm_base, frv_relocate_section_addresses):
	Update.
	* solib-irix.c (locate_base): Update.
	* solib-som.c (som_solib_create_inferior_hook)
	(som_solib_desire_dynamic_linker_symbols, link_map_start):
	Update.
	* solib-spu.c (spu_enable_break): Update.
	* solib-svr4.c (elf_locate_base, enable_break): Update.
	* spu-tdep.c (spu_get_overlay_table, spu_catch_start)
	(flush_ea_cache): Update.
	* stabsread.c (define_symbol): Update.
	* symfile.c (simple_read_overlay_table): Update.
	* symtab.c (find_pc_sect_line): Update.
	* tracepoint.c (scope_info): Update.
	* tui-disasm.c (tui_get_begin_asm_address): Update.
	* value.c (value_static_field): Update.
2014-02-26 12:11:17 -07:00
Tom Tromey
50e65b1713 introduce minimal_symbol_upper_bound
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.
2014-02-26 12:11:16 -07:00
Joel Brobecker
ecd75fc8ee Update Copyright year range in all files maintained by GDB. 2014-01-01 07:54:24 +04:00
Tom Tromey
7c7b66552d remove msymbol_objfile
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.
2013-08-05 15:51:02 +00:00
Tom Tromey
e6dc44a8f5 * coffread.c (record_minimal_symbol): Update.
* dbxread.c (record_minimal_symbol): Update.
	* elfread.c (record_minimal_symbol): Update.
	* machoread.c (macho_symtab_add_minsym): Update.
	* mdebugread.c (record_minimal_symbol, parse_partial_symbols):
	Update.
	* minsyms.c (prim_record_minimal_symbol): Update.
	(prim_record_minimal_symbol_full): Remove 'bfd_section'
	argument.
	(prim_record_minimal_symbol_and_info): Likewise.
	* minsyms.h (prim_record_minimal_symbol_full)
	(prim_record_minimal_symbol_and_info): Update.
	* symtab.c (allocate_symbol, initialize_symbol)
	(allocate_template_symbol): Initialize SYMBOL_SECTION.
	* xcoffread.c (record_minimal_symbol, scan_xcoff_symtab):
	Update.
2013-04-08 20:13:22 +00:00
Tom Tromey
7cbd4a934e * minsyms.h (struct bound_minimal_symbol): New.
(lookup_minimal_symbol_and_objfile): Return bound_minimal_symbol.
	Remove objfile argument.
	(lookup_minimal_symbol_by_pc_section, lookup_minimal_symbol_by_pc):
	Return bound_minimal_symbol.
	* minsyms.c (lookup_minimal_symbol_by_pc_1)
	(lookup_minimal_symbol_by_pc_section, lookup_minimal_symbol_by_pc):
	Return bound_minimal_symbol.
	(in_gnu_ifunc_stub): Update.
	(lookup_minimal_symbol_and_objfile): Return bound_minimal_symbol.
	Remove 'objfile_p' argument.
	(lookup_solib_trampoline_symbol_by_pc): Update.
	* ada-tasks.c, amd64-windows-tdep.c, arm-tdep.c,
	arm-wince-tdep.c, block.c, blockframe.c, breakpoint.c, btrace.c,
	c-valprint.c, dwarf2loc.c, elfread.c, frame.c, frv-tdep.c,
	glibc-tdep.c, gnu-v2-abi.c, gnu-v3-abi.c, hppa-hpux-tdep.c,
	i386-tdep.c, ia64-tdep.c, infcall.c, infcmd.c, jit.c,
	linux-fork.c, m32c-tdep.c, m68hc11-tdep.c, maint.c,
	mips-tdep.c, p-valprint.c, parse.c, ppc-linux-tdep.c,
	ppc-sysv-tdep.c, printcmd.c, rs6000-tdep.c, sh64-tdep.c,
	stack.c, symtab.c, tui/tui-disasm.c: Update.
2013-04-08 19:59:09 +00:00
Joel Brobecker
28e7fd6234 Update years in copyright notice for the GDB files.
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.
2013-01-01 06:33:28 +00:00
Tom Tromey
c9630d9c13 * minsyms.c (lookup_solib_trampoline_symbol_by_pc): Now static.
* minsyms.h (lookup_solib_trampoline_symbol_by_pc): Don't
	declare.
2012-12-18 19:21:53 +00:00
Joel Brobecker
0b30217134 Copyright year update in most files of the GDB Project.
gdb/ChangeLog:

        Copyright year update in most files of the GDB Project.
2012-01-04 08:17:56 +00:00