Now that all known uses of VLAs within GDB are removed, remove the
`-Wno-vla-cxx-extension` (which was used to silence clang warnings) and
add `-Wvla`, such that any use of a VLA will trigger a warning.
Change-Id: I69a8d7f93f973743165b0ba46f9c2ea8adb89025
Reviewed-By: Keith Seitz <keiths@redhat.com>
When building with clang 18, I see:
CXX aarch64-linux-tdep.o
/home/smarchi/src/binutils-gdb/gdb/aarch64-linux-tdep.c:1299:26: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]
1299 | gdb_byte za_zeroed[za_bytes];
| ^~~~~~~~
/home/smarchi/src/binutils-gdb/gdb/aarch64-linux-tdep.c:1299:26: note: read of non-const variable 'za_bytes' is not allowed in a constant expression
/home/smarchi/src/binutils-gdb/gdb/aarch64-linux-tdep.c:1282:10: note: declared here
1282 | size_t za_bytes = std::pow (sve_vl_from_vg (svg), 2);
| ^
Since we are using VLAs right now, that warning doesn't make sense for
us. add `-Wno-vla-cxx-extension` to the list of warning flags we try to
enable. If we ever choose to disallow VLAs, we can remove that flag.
Change-Id: Ie41feafc50c343f6e75333d4f836ce32fbeb6d8c
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.
This changes the various gdb-related directories to use
-Wimplicit-fallthrough=5, meaning that only the fallthrough attribute
can be used in switches -- special 'fallthrough' comments will no
longer be usable.
Approved-By: Pedro Alves <pedro@palves.net>
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.
This commit aims to not make use of -Wmissing-prototypes when
compiling with g++.
Use of -Wmissing-prototypes was added with this commit:
commit a0761e34f0
Date: Wed Mar 11 15:15:12 2020 -0400
gdb: enable -Wmissing-prototypes warning
Because clang can provide helpful warnings with this flag.
Unfortunately, g++ doesn't accept this flag, and will give this
warning:
cc1plus: warning: command line option ‘-Wmissing-prototypes’ is valid for C/ObjC but not for C++
In theory the fact that this flag is not supported should be detected
by the configure check in gdbsupport/warning.m4, but for users of
ccache, this check doesn't work due to a long standing ccache issue:
https://github.com/ccache/ccache/issues/738
The ccache problem is that -W... options are reordered on the command
line, and so -Wmissing-prototypes is seen before -Werror. Usually
this doesn't matter, but the above warning (about the flag not being
valid) is issued before the -Werror flag is processed, and so is not
fatal.
There have been two previous attempts to fix this that I'm aware of.
The first is:
https://sourceware.org/pipermail/gdb-patches/2021-September/182148.html
In this attempt, instead of just relying on a compile to check if a
flag is valid, the proposal was to both compile and link. As linking
doesn't go through ccache, we don't suffer from the argument
reordering problem, and the link phase will correctly fail when using
-Wmissing-prototypes with g++. The configure script will then disable
the use of this flag.
This approach was rejected, and the suggestion was to only add the
-Wmissing-prototypes flag if we are compiling with gcc.
The second attempt, attempts this approach, and can be found here:
https://sourceware.org/pipermail/gdb-patches/2021-November/183076.html
This attempt only adds the -Wmissing-prototypes flag is the value of
GCC is not 'yes'. This feels like it is doing the right thing,
unfortunately, the GCC flag is really a 'is gcc like' flag, not a
strict, is gcc check. As such, GCC is set to 'yes' for clang, which
would mean the flag was not included for clang or gcc. The entire
point of the original commit was to add this flag for clang, so
clearly the second attempt is not sufficient either.
In this new attempt I have added gdbsupport/compiler-type.m4, this
file defines AM_GDB_COMPILER_TYPE. This macro sets the variable
GDB_COMPILER_TYPE to either 'gcc', 'clang', or 'unknown'. In future
the list of values might be extended to cover other compilers, if this
is ever useful.
I've then modified gdbsupport/warning.m4 to only add the problematic
-Wmissing-prototypes flag if GDB_COMPILER_TYPE is not 'gcc'.
I've tested this with both gcc and clang and see the expected results,
gcc no longer attempts to use the -Wmissing-prototypes flag, while
clang continues to use it.
When compiling using ccache, I am no longer seeing the warning.
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.
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.
While compiling with clang, I noticed it didn't catch cases where my
function declaration didn't match my function definition. This is
normally caught by gcc with -Wmissing-declarations.
On clang, this is caught by -Wmissing-prototypes instead.
Note that on gcc, -Wmissing-prototypes also exists, but is only valid
for C and Objective-C. It gets correctly rejected by the configure
script since gcc rejects it with:
cc1plus: error: command line option '-Wmissing-prototypes' is valid for C/ObjC but not for C++ -Werror
So this warning flag ends up not used for gcc (which is what we want).
gdb/ChangeLog:
* configure: Re-generate.
gdbserver/ChangeLog:
* configure: Re-generate.
gdbsupport/ChangeLog:
* configure: Re-generate.
* warning.m4: Enable -Wmissing-prototypes.
Commit 85f0dd3ce ("[gdb] Fix -Wstrict-null-sentinel warnings") fixed
some violations of -Wstrict-null-sentinel. If we want to enforce this
warning, I think we should enable it in our warning.m4 file.
gdbsupport/ChangeLog:
* warning.m4: Add -Wstrict-null-sentinel.
* configure: Re-generate.
gdbserver/ChangeLog:
* configure: Re-generate.
gdb/ChangeLog:
* configure: Re-generate.
This file is used by gdbsupport, gdbserver and gdb, so I think it
belongs in gdbsupport. Move it there and update the references the
various acinclude.m4 files.
gdbsupport/ChangeLog:
* warning.m4: Move here, from gdb/warning.m4.
* acinclude.m4: Update warning.m4 path.
* Makefile.in: Re-generate.
gdbserver/ChangeLog:
* acinclude.m4: Update warning.m4 path.
gdb/ChangeLog:
* acinclude: Update warning.m4 path.
* warning.m4: Move to gdbsupport.
