[PATCH] meson.build: Remove the -Wvla-larger-then flag
The flag has a typo in it, it's "...-than=..." and not "...-then=...", so this was in fact never used. Since we're also using -Wvla (without size), we should already get warnings about any variable length arrays anyway, so the additional "-Wvla-larger-than" does not make much sense and thus we can simply drop this. Signed-off-by: Thomas Huth <thuth@redhat.com> --- meson.build | 1 - 1 file changed, 1 deletion(-) diff --git a/meson.build b/meson.build index 4f23f9104e..40c841e777 100644 --- a/meson.build +++ b/meson.build @@ -390,7 +390,6 @@ cc_flags += [ '-Wvariadic-macros', '-Wvector-operation-performance', '-Wvla', - '-Wvla-larger-then=4031', '-Wvolatile-register-var', '-Wwrite-strings', ] -- 2.27.0
On Thu, May 27, 2021 at 12:37:36PM +0200, Thomas Huth wrote:
The flag has a typo in it, it's "...-than=..." and not "...-then=...", so this was in fact never used. Since we're also using -Wvla (without size), we should already get warnings about any variable length arrays anyway, so the additional "-Wvla-larger-than" does not make much sense and thus we can simply drop this.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- meson.build | 1 - 1 file changed, 1 deletion(-)
This makes sense to me and I could not find any possible typo alias anywhere (like we have in virsh, for example). The only thing I am unsure about is whether we want to actually use the proper naming. The reason is that by default this is set to vla-larger-than=PTRDIFF_MAX which is pretty huge number. On the other hand the man page for GCC says it is only effective with -ftree-vrp (-02 and above). I do not see whether using the predefined alloc_max would make sense or not. So I am not against just removing it, but feel free to overrule me as I did not look into this as much as others will be capable of. Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
diff --git a/meson.build b/meson.build index 4f23f9104e..40c841e777 100644 --- a/meson.build +++ b/meson.build @@ -390,7 +390,6 @@ cc_flags += [ '-Wvariadic-macros', '-Wvector-operation-performance', '-Wvla', - '-Wvla-larger-then=4031', '-Wvolatile-register-var', '-Wwrite-strings', ] -- 2.27.0
On Thu, May 27, 2021 at 12:49:28PM +0200, Martin Kletzander wrote:
On Thu, May 27, 2021 at 12:37:36PM +0200, Thomas Huth wrote:
The flag has a typo in it, it's "...-than=..." and not "...-then=...", so this was in fact never used. Since we're also using -Wvla (without size), we should already get warnings about any variable length arrays anyway, so the additional "-Wvla-larger-than" does not make much sense and thus we can simply drop this.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- meson.build | 1 - 1 file changed, 1 deletion(-)
This makes sense to me and I could not find any possible typo alias anywhere (like we have in virsh, for example). The only thing I am unsure about is whether we want to actually use the proper naming. The reason is that by default this is set to vla-larger-than=PTRDIFF_MAX which is pretty huge number. On the other hand the man page for GCC says it is only effective with -ftree-vrp (-02 and above).
The -Wvla-larger-than=PTRDIFF_MAX default is irrelevant though, because we've blocked all use of VLAs by using -Wvla. IOW, AFAICT, -Wvla-larger-than and -Wvla are mutually exclusive from a conceptual POV.
I do not see whether using the predefined alloc_max would make sense or not. So I am not against just removing it, but feel free to overrule me as I did not look into this as much as others will be capable of.
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
diff --git a/meson.build b/meson.build index 4f23f9104e..40c841e777 100644 --- a/meson.build +++ b/meson.build @@ -390,7 +390,6 @@ cc_flags += [ '-Wvariadic-macros', '-Wvector-operation-performance', '-Wvla', - '-Wvla-larger-then=4031', '-Wvolatile-register-var', '-Wwrite-strings', ] -- 2.27.0
Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
On Thu, May 27, 2021 at 12:00:59PM +0100, Daniel P. Berrangé wrote:
On Thu, May 27, 2021 at 12:49:28PM +0200, Martin Kletzander wrote:
On Thu, May 27, 2021 at 12:37:36PM +0200, Thomas Huth wrote:
The flag has a typo in it, it's "...-than=..." and not "...-then=...", so this was in fact never used. Since we're also using -Wvla (without size), we should already get warnings about any variable length arrays anyway, so the additional "-Wvla-larger-than" does not make much sense and thus we can simply drop this.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- meson.build | 1 - 1 file changed, 1 deletion(-)
This makes sense to me and I could not find any possible typo alias anywhere (like we have in virsh, for example). The only thing I am unsure about is whether we want to actually use the proper naming. The reason is that by default this is set to vla-larger-than=PTRDIFF_MAX which is pretty huge number. On the other hand the man page for GCC says it is only effective with -ftree-vrp (-02 and above).
The -Wvla-larger-than=PTRDIFF_MAX default is irrelevant though, because we've blocked all use of VLAs by using -Wvla.
IOW, AFAICT, -Wvla-larger-than and -Wvla are mutually exclusive from a conceptual POV.
Thank I misunderstood and this patch makes complete sense, sorry for the noise and thanks for the correction.
I do not see whether using the predefined alloc_max would make sense or not. So I am not against just removing it, but feel free to overrule me as I did not look into this as much as others will be capable of.
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
diff --git a/meson.build b/meson.build index 4f23f9104e..40c841e777 100644 --- a/meson.build +++ b/meson.build @@ -390,7 +390,6 @@ cc_flags += [ '-Wvariadic-macros', '-Wvector-operation-performance', '-Wvla', - '-Wvla-larger-then=4031', '-Wvolatile-register-var', '-Wwrite-strings', ] -- 2.27.0
Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
On 5/27/21 12:37 PM, Thomas Huth wrote:
The flag has a typo in it, it's "...-than=..." and not "...-then=...", so this was in fact never used. Since we're also using -Wvla (without size), we should already get warnings about any variable length arrays anyway, so the additional "-Wvla-larger-than" does not make much sense and thus we can simply drop this.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- meson.build | 1 - 1 file changed, 1 deletion(-)
Reviewed-by: Ján Tomko <jtomko@redhat.com> Jano
participants (4)
-
Daniel P. Berrangé -
Jano Tomko -
Martin Kletzander -
Thomas Huth