Commit Graph

6 Commits

Author SHA1 Message Date
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
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
Pedro Alves
de38d64ad2 Tweak gdbsupport/valid-expr.h for GCC 6, fix build
With GCC 6.4 and 6.5 (at least), unit tests that use
gdbsupport/valid-expr.h's CHECK_VALID fail to compile, with:

 In file included from src/gdb/unittests/offset-type-selftests.c:24:0:
 src/gdb/unittests/offset-type-selftests.c: In substitution of 'template<class Expected, template<class ...> class Op, class ... Args> using is_detected_exact = std::is_same<Expected, typename gdb::detection_detail::detector<gdb::nonesuch, void, Op, Args ...>::type> [with Expected = selftests::offset_type::off_A&; Op = selftests::offset_type::check_valid_expr75::archetype; Args = {selftests::offset_type::off_A, selftests::offset_type::off_B}]':
 src/gdb/unittests/offset-type-selftests.c:75:1:   required from here
 src/gdb/../gdbsupport/valid-expr.h:65:20: error: type/value mismatch at argument 2 in template parameter list for 'template<class Expected, template<class ...> class Op, class ... Args> using is_detected_exact = std::is_same<Expected, typename gdb::detection_detail::detector<gdb::nonesuch, void, Op, Args ...>::type>'
     archetype, TYPES>::value == VALID,   \
		     ^

The important part is the "error: type/value mismatch" error.  Seems
like that GCC doesn't understand that archetype is an alias template,
and is being strict in requiring a template class.

The fix here is then to make archetype a template class, to pacify
GCC.  The resulting code looks like this:

  template <TYPENAMES, typename = decltype (EXPR)>
  struct archetype
  {
  };

  static_assert (gdb::is_detected_exact<archetype<TYPES, EXPR_TYPE>,
 		 archetype, TYPES>::value == VALID, "");

is_detected_exact<Expected, Op, Args> checks whether Op<Args> is type
Expected:

 - For Expected, we pass the explicit EXPR_TYPE, overriding the
   default parameter type of archetype.

 - For Args we don't pass the last template parameter, so archtype
   defaults to the EXPR's decltype.

So in essence, we're really checking whether EXPR_TYPE is the same as
decltype(EXPR).

We need to do the decltype in a template context in order to trigger
SFINAE instead of failing to compile.


The hunk in unittests/enum-flags-selftests.c becomes necessary,
because unlike with the current alias template version, this new
version makes GCC trigger -Wenum-compare warnings as well:

 src/gdb/unittests/enum-flags-selftests.c:328:33: error: comparison between 'enum selftests::enum_flags_tests::RE' and 'enum selftests::enum_flags_tests::RE2' [-Werror=enum-compare]
  CHECK_VALID (true,  bool, RE () != RE2 ())
				  ^
 src/gdb/../gdbsupport/valid-expr.h:61:45: note: in definition of macro 'CHECK_VALID_EXPR_INT'
    template <TYPENAMES, typename = decltype (EXPR)>   \
					      ^

Build-tested with:

 - GCC {4.8.5, 6.4, 6.5, 7.3.1, 9.3.0, 11.0.0-20200910}
 - Clang 10.0.0

gdbsupport/ChangeLog:

	* valid-expr.h (CHECK_VALID_EXPR_INT): Make archetype a template
	class instead of an alias template and adjust static_assert.

gdb/ChangeLog:

	* unittests/enum-flags-selftests.c: Check whether __GNUC__ is
	defined before using '#pragma GCC diagnostic' instead of checking
	__clang__.
2020-09-29 23:48:04 +01:00
Pedro Alves
04902b0995 Rewrite enum_flags, add unit tests, fix problems
This patch started by adding comprehensive unit tests for enum_flags.

For the testing part, it adds:

 - tests of normal expected uses of the API.

 - checks that _invalid_ uses of the API would fail to compile.  I.e.,
   it validates that enum_flags really is a strong type, and that
   incorrect mixing of enum types would be caught at compile time.  It
   pulls that off making use of SFINEA and C++11's decltype/constexpr.

This revealed many holes in the enum_flags API.  For example, the f1
assignment below currently incorrectly fails to compile:

 enum_flags<flags> f1 = FLAG1;
 enum_flags<flags> f2 = FLAG2 | f1;

The unit tests also revealed that this useful use case doesn't work:

    enum flag { FLAG1 = 1, FLAG2 = 2 };
    enum_flags<flag> src = FLAG1;
    enum_flags<flag> f1 = condition ? src : FLAG2;

It fails to compile because enum_flags<flag> and flag are convertible
to each other.

Turns out that making enum_flags be implicitly convertible to the
backing raw enum type was not a good idea.

If we make it convertible to the underlying type instead, we fix that
ternary operator use case, and, we find cases throughout the codebase
that should be using the enum_flags but were using the raw backing
enum instead.  So it's a good change overall.

Also, several operators were missing.

These holes and more are plugged by this patch, by reworking how the
enum_flags operators are implemented, and making use of C++11's
feature of being able to delete methods/functions.

There are cases in gdb/compile/ where we need to call a function in a
C plugin API that expects the raw enum.  To address cases like that,
this adds a "raw()" method to enum_flags.  This way we can keep using
the safer enum_flags to construct the value, and then be explicit when
we need to get at the raw enum.

This makes most of the enum_flags operators constexpr.  Beyond
enabling more compiler optimizations and enabling the new unit tests,
this has other advantages, like making it possible to use operator|
with enum_flags values in switch cases, where only compile-time
constants are allowed:

    enum_flags<flags> f = FLAG1 | FLAG2;
    switch (f)
      {
      case FLAG1 | FLAG2:
	break;
      }

Currently that fails to compile.

It also switches to a different mechanism of enabling the global
operators.  The current mechanism isn't namespace friendly, the new
one is.

It also switches to C++11-style SFINAE -- instead of wrapping the
return type in a SFINAE-friently structure, we use an unnamed template
parameter.  I.e., this:

  template <typename enum_type,
	    typename = is_enum_flags_enum_type_t<enum_type>>
  enum_type
  operator& (enum_type e1, enum_type e2)

instead of:

  template <typename enum_type>
  typename enum_flags_type<enum_type>::type
  operator& (enum_type e1, enum_type e2)

Note that the static_assert inside operator~() was converted to a
couple overloads (signed vs unsigned), because static_assert is too
late for SFINAE-based tests, which is important for the CHECK_VALID
unit tests.

Tested with gcc {4.8, 7.1, 9.3} and clang {5.0.2, 10.0.0}.

gdb/ChangeLog:

	* Makefile.in (SELFTESTS_SRCS): Add
	unittests/enum-flags-selftests.c.
	* btrace.c (ftrace_update_caller, ftrace_fixup_calle): Use
	btrace_function_flags instead of enum btrace_function_flag.
	* compile/compile-c-types.c (convert_qualified): Use
	enum_flags::raw.
	* compile/compile-cplus-symbols.c (convert_one_symbol)
	(convert_symbol_bmsym):
	* compile/compile-cplus-types.c (compile_cplus_convert_method)
	(compile_cplus_convert_struct_or_union_methods)
	(compile_cplus_instance::convert_qualified_base):
	* go-exp.y (parse_string_or_char): Add cast to int.
	* unittests/enum-flags-selftests.c: New file.
	* record-btrace.c (btrace_thread_flag_to_str): Change parameter's
	type to btrace_thread_flags from btrace_thread_flag.
	(record_btrace_cancel_resume, record_btrace_step_thread): Change
	local's type to btrace_thread_flags from btrace_thread_flag.  Add
	cast in DEBUG call.

gdbsupport/ChangeLog:

	* enum-flags.h: Include "traits.h".
	(DEF_ENUM_FLAGS_TYPE): Declare a function instead of defining a
	structure.
	(enum_underlying_type): Update comment.
	(namespace enum_flags_detail): New.  Move struct zero_type here.
	(EnumIsUnsigned, EnumIsSigned): New.
	(class enum_flags): Make most methods constexpr.
	(operator&=, operator|=, operator^=): Take an enum_flags instead
	of an enum_type.  Make rvalue ref versions deleted.
	(operator enum_type()): Delete.
	(operator&, operator|, operator^, operator~): Delete, moved out of
	class.
	(raw()): New method.
	(is_enum_flags_enum_type_t): Declare.
	(ENUM_FLAGS_GEN_BINOP, ENUM_FLAGS_GEN_COMPOUND_ASSIGN)
	(ENUM_FLAGS_GEN_COMP): New.  Use them to reimplement global
	operators.
	(operator~): Now constexpr and reimplemented.
	(operator<<, operator>>): New deleted functions.
	* valid-expr.h (CHECK_VALID_EXPR_5, CHECK_VALID_EXPR_6): New.
2020-09-14 22:21:07 +01:00
Pedro Alves
1945192cb9 Rewrite valid-expr.h's internals in terms of the detection idiom (C++17/N4502)
An earlier attempt at doing this had failed (wouldn't work in GCCs
around 4.8, IIRC), but now that I try again, it works.  I suspect that
my previous attempt did not use the pre C++14-safe void_t (in
traits.h).

I want to switch to this model because:

 - It's the standard detection idiom that folks will learn starting
   with C++17.

 - In the enum_flags unit tests, I have a static_assert that triggers
   a warning (resulting in build error), which GCC does not suppress
   because the warning is not being triggered in the SFINAE context.
   Switching to the detection idiom fixes that.  Alternatively,
   switching to the C++03-style expression-validity checking with a
   varargs overload would allow addressing that, but I think that
   would be going backwards idiomatically speaking.

 - While this patch shows a net increase of lines of code, the magic
   being added to traits.h can be removed in a few years when we start
   requiring C++17.

gdbsupport/ChangeLog:

	* traits.h (struct nonesuch, struct detector, detected_or)
	(detected_or_t, is_detected, detected_t, detected_or)
	(detected_or_t, is_detected_exact, is_detected_convertible): New.
	* valid-expr.h (CHECK_VALID_EXPR_INT): Use gdb::is_detected_exact.
2020-09-14 22:19:31 +01:00
Tom Tromey
01027315f5 Move gdbsupport to the top level
This patch moves the gdbsupport directory to the top level.  This is
the next step in the ongoing project to move gdbserver to the top
level.

The bulk of this patch was created by "git mv gdb/gdbsupport gdbsupport".

This patch then adds a build system to gdbsupport and wires it into
the top level.  Then it changes gdb to use the top-level build.

gdbserver, on the other hand, is not yet changed.  It still does its
own build of gdbsupport.

ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* src-release.sh (GDB_SUPPORT_DIRS): Add gdbsupport.
	* MAINTAINERS: Add gdbsupport.
	* configure: Rebuild.
	* configure.ac (configdirs): Add gdbsupport.
	* gdbsupport: New directory, move from gdb/gdbsupport.
	* Makefile.def (host_modules, dependencies): Add gnulib.
	* Makefile.in: Rebuild.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* nat/x86-linux-dregs.c: Include configh.h.
	* nat/linux-ptrace.c: Include configh.h.
	* nat/linux-btrace.c: Include configh.h.
	* defs.h: Include config.h, bfd.h.
	* configure.ac: Don't source common.host.
	(CONFIG_OBS, CONFIG_SRCS): Remove gdbsupport files.
	* configure: Rebuild.
	* acinclude.m4: Update path.
	* Makefile.in (SUPPORT, LIBSUPPORT, INCSUPPORT): New variables.
	(CONFIG_SRC_SUBDIR): Remove gdbsupport.
	(INTERNAL_CFLAGS_BASE): Add INCSUPPORT.
	(CLIBS): Add LIBSUPPORT.
	(CDEPS): Likewise.
	(COMMON_SFILES): Remove gdbsupport files.
	(HFILES_NO_SRCDIR): Likewise.
	(stamp-version): Update path to create-version.sh.
	(ALLDEPFILES): Remove gdbsupport files.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* server.h: Include config.h.
	* gdbreplay.c: Include config.h.
	* configure: Rebuild.
	* configure.ac: Don't source common.host.
	* acinclude.m4: Update path.
	* Makefile.in (INCSUPPORT): New variable.
	(INCLUDE_CFLAGS): Add INCSUPPORT.
	(SFILES): Update paths.
	(version-generated.c): Update path to create-version.sh.
	(gdbsupport/%-ipa.o, gdbsupport/%.o): Update paths.

gdbsupport/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* common-defs.h: Add GDBSERVER case.  Update includes.
	* acinclude.m4, aclocal.m4, config.in, configure, configure.ac,
	Makefile.am, Makefile.in, README: New files.
	* Moved from ../gdb/gdbsupport/

Change-Id: I07632e7798635c1bab389bf885971e584fb4bb78
2020-01-14 16:25:02 -07:00