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.
An assertion was recently added to array_view::operator[] to ensure we
don't do out of bounds accesses. However, when the array_view is copied
to or from using memcpy, it bypasses that safety.
To address this, add a `copy` free function that copies data from an
array view to another, ensuring that the destination and source array
views have the same size. When copying to or from parts of an
array_view, we are expected to use gdb::array_view::slice, which does
its own bounds check. With all that, any copy operation that goes out
of bounds should be caught by an assertion at runtime.
copy is implemented using std::copy and std::copy_backward, which, at
least on libstdc++, appears to pick memmove when copying trivial data.
So in the end there shouldn't be much difference vs using a bare memcpy,
as we do right now. When copying non-trivial data, std::copy and
std::copy_backward assigns each element in a loop.
To properly support overlapping ranges, we must use std::copy or
std::copy_backward, depending on whether the destination is before the
source or vice-versa. std::copy and std::copy_backward don't support
copying exactly overlapping ranges (where the source range is equal to
the destination range). But in this case, no copy is needed anyway, so
we do nothing.
The order of parameters of the new copy function is based on std::copy
and std::copy_backward, where the source comes before the destination.
Change a few randomly selected spots to use the new function, to show
how it can be used.
Add a test for the new function, testing both with arrays of a trivial
type (int) and of a non-trivial type (foo). Test non-overlapping
ranges as well as three kinds of overlapping ranges: source before dest,
dest before source, and dest == source.
Change-Id: Ibeaca04e0028410fd44ce82f72e60058d6230a03
When building with -std=c++11 and -D_GLIBCXX_DEBUG=1, we get some errors
like:
CXX unittests/array-view-selftests.o
In file included from /home/smarchi/src/binutils-gdb/gdb/utils.h:25,
from /home/smarchi/src/binutils-gdb/gdb/defs.h:630,
from /home/smarchi/src/binutils-gdb/gdb/unittests/array-view-selftests.c:20:
/home/smarchi/src/binutils-gdb/gdb/../gdbsupport/array-view.h: In instantiation of constexpr gdb::array_view<T> gdb::array_view<T>::slice(gdb::array_view<T>::size_type, gdb::array_view<T>::size_type) const [with T = unsigned char; gdb::array_view<T>::size_type = long unsigned int:
/home/smarchi/src/binutils-gdb/gdb/unittests/array-view-selftests.c:532:29: required from here
/home/smarchi/src/binutils-gdb/gdb/../gdbsupport/array-view.h:192:3: error: body of constexpr function constexpr gdb::array_view<T> gdb::array_view<T>::slice(gdb::array_view<T>::size_type, gdb::array_view<T>::size_type) const [with T = unsigned char; gdb::array_view<T>::size_type = long unsigned int not a return-statement
192 | }
| ^
This is because constexpr functions in c++11 can only consist of a
single return statement, so we can't have the gdb_assert in there. Make
the gdb_assert presence conditional to the __cplusplus version, to
enable it only for c++14 and later.
Change-Id: I2ac33f7b4bd1765ddc3ac8d07445b16ac1f340f0
While reading the interface of gdb::array_view, I realized that the
constructor that builds an array_view on top of a contiguous container
(such as std::vector, std::array or even gdb::array_view) can be
missused.
Lets consider the following code sample:
struct Parent
{
Parent (int a): a { a } {}
int a;
};
std::ostream &operator<< (std::ostream& os, const Parent & p)
{ os << "Parent {a=" << p.a << "}"; return os; }
struct Child : public Parent
{
Child (int a, int b): Parent { a }, b { b } {}
int b;
};
std::ostream &operator<< (std::ostream& os, const Child & p)
{ os << "Child {a=" << p.a << ", b=" << p.b << "}"; return os; }
template <typename T>
void print (const gdb::array_view<const T> &p)
{
std::for_each (p.begin (), p.end (), [](const T &p) { std::cout << p << '\n'; });
}
Then with the current interface nothinng prevents this usage of
array_view to be done:
const std::array<Child, 3> elts = {
Child {1, 2},
Child {3, 4},
Child {5, 6}
};
print_all<Parent> (elts);
This compiles fine and produces the following output:
Parent {a=1}
Parent {a=2}
Parent {a=3}
which is obviously wrong. There is nowhere in memory a Parent-like
object for which the A member is 2 and this call to print_all<Parent>
shold not compile at all (calling print_all<Child> is however fine).
This comes down to the fact that a Child* is convertible into a Parent*,
and that an array view is constructed to a pointer to the first element
and a size. The valid type pointed to that can be used with this
constructor are restricted using SFINAE, which requires that a
pointer to a member into the underlying container can be converted into a
pointer the array_view's data type.
This patch proposes to change the constraints on the gdb::array_view
ctor which accepts a container now requires that the (decayed) type of
the elements in the container match the (decayed) type of the array_view
being constructed.
Applying this change required minimum adjustment in GDB codebase, which
are also included in this patch.
Tested by rebuilding.
Add assertions to ensure we don't access an array_view out of bounds.
Enable these assertions only when _GLIBCXX_DEBUG is set, as we did for
gdb::optional.
Change-Id: Iffaee38252405073735ed123c8e57fde6b2c6be3
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.
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
