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.
When building with clang 13 (and -std=gnu++17 to work around an issue in
string_view-selftests.c), we run into a few Wimplicit-exception-spec-mismatch
warnings:
...
src/gdbsupport/new-op.cc:102:1: error: function previously declared with an \
explicit exception specification redeclared with an implicit exception \
specification [-Werror,-Wimplicit-exception-spec-mismatch]
operator delete (void *p)
^
/usr/include/c++/11/new:130:6: note: previous declaration is here
void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
^
...
These are due to recent commit 5fff6115fe "Fix
LD_PRELOAD=/usr/lib64/libasan.so.6 gdb".
Fix this by adding the missing noexcept.
Build on x86_64-linux, using gcc 7.5.0 and clang 13.0.0.
When building with -std=c++11, we run into two Werror=missing-declarations:
...
new-op.cc: In function 'void operator delete(void*, std::size_t)':
new-op.cc:114:1: error: no previous declaration for \
'void operator delete(void*, std::size_t)' [-Werror=missing-declarations]
operator delete (void *p, std::size_t) noexcept
^~~~~~~~
new-op.cc: In function 'void operator delete [](void*, std::size_t)':
new-op.cc:132:1: error: no previous declaration for \
'void operator delete [](void*, std::size_t)' [-Werror=missing-declarations]
operator delete[] (void *p, std::size_t) noexcept
^~~~~~~~
...
These are due to recent commit 5fff6115fe "Fix
LD_PRELOAD=/usr/lib64/libasan.so.6 gdb".
The declarations are provided by <new> (which is included) for c++14 onwards,
but they are missing for c++11.
Fix this by adding the missing declarations.
Tested on x86_64-linux, with gcc 7.5.0, both without (implying -std=gnu++14) and
with -std=c++11.
Currently for a binary compiled normally (without -fsanitize=address) but with
LD_PRELOAD of ASAN one gets:
$ ASAN_OPTIONS=detect_leaks=0:alloc_dealloc_mismatch=1:abort_on_error=1:fast_unwind_on_malloc=0 LD_PRELOAD=/usr/lib64/libasan.so.6 gdb
=================================================================
==1909567==ERROR: AddressSanitizer: alloc-dealloc-mismatch (malloc vs operator delete []) on 0x602000001570
#0 0x7f1c98e5efa7 in operator delete[](void*) (/usr/lib64/libasan.so.6+0xb0fa7)
...
0x602000001570 is located 0 bytes inside of 2-byte region [0x602000001570,0x602000001572)
allocated by thread T0 here:
#0 0x7f1c98e5cd1f in __interceptor_malloc (/usr/lib64/libasan.so.6+0xaed1f)
#1 0x557ee4a42e81 in operator new(unsigned long) (/usr/libexec/gdb+0x74ce81)
SUMMARY: AddressSanitizer: alloc-dealloc-mismatch (/usr/lib64/libasan.so.6+0xb0fa7) in operator delete[](void*)
==1909567==HINT: if you don't care about these errors you may set ASAN_OPTIONS=alloc_dealloc_mismatch=0
==1909567==ABORTING
Despite the code called properly operator new[] and operator delete[].
But GDB's new-op.cc provides its own operator new[] which gets translated into
malloc() (which gets recogized as operatore new(size_t)) but as it does not
translate also operators delete[] Address Sanitizer gets confused.
The question is how many variants of the delete operator need to be provided.
There could be 14 operators new but there are only 4, GDB uses 3 of them.
There could be 16 operators delete but there are only 6, GDB uses 2 of them.
It depends on libraries and compiler which of the operators will get used.
Currently being used:
U operator new[](unsigned long)
U operator new(unsigned long)
U operator new(unsigned long, std::nothrow_t const&)
U operator delete[](void*)
U operator delete(void*, unsigned long)
Tested on x86_64-linux.
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 renames the .c source files in gdbsupport to .cc.
In the gdb directory, there is an argument against renaming the source
files, which is that it makes using some git commands more difficult to
do archeology. Some commands have some kind of "follow" option that
makes git try to follow renames, but it doesn't work in all situations.
Given that we have just moved the gdbsupport directory, that argument
doesn't hold for source files in that directory. I therefore suggest
renaming them to .cc, so that they are automatically recognized as C++
by various tools and editors.
The original motivation behind this is that when building gdbsupport
with clang, I get:
CC agent.o
clang: error: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Werror,-Wdeprecated]
In the gdb/ directory, we make clang happy by passing "-x c++". We
could do this in gdbsupport too, but I think that renaming the files is
a better long-term solution.
gdbserver still does its own build of gdbsupport, so a few changes in
its Makefile are necessary.
gdbsupport/ChangeLog:
* Makefile.am: Rename source files from .c to .cc.
(CC, CFLAGS): Don't override.
(AM_CFLAGS): Rename to ...
(AM_CXXFLAGS): ... this.
* Makefile.in: Re-generate.
* %.c: Rename to %.cc.
gdbserver/ChangeLog:
* Makefile.in: Rename gdbsupport source files from .c to .cc.
