[06/10] v4l2: v4l2_compat: Selectively disable -Wmissing-declarations
diff mbox series

Message ID 20240624192941.22943-7-laurent.pinchart@ideasonboard.com
State Accepted
Headers show
Series
  • libcamera: Enable -Wmissing-declarations
Related show

Commit Message

Laurent Pinchart June 24, 2024, 7:29 p.m. UTC 
_FORTIFY_SOURCE redirects the open*() calls to __open*_2() functions.
The libcamera V4L2 adaptation layer intercepts those functions to
support applications compiled with _FORTIFY_SOURCE. When _FORTIFY_SOURCE
is not enabled, the C library headers will not provide declarations for
the fortified functions, which will cause missing declaration warnings
when we unable them.

Fix this by disabling the -Wmissing-declarations warnings selectively
for the _FORTIFY_SOURCE functions. To avoid sparkling pragmas around,
move the relevant function definitions next to each other.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/v4l2/v4l2_compat.cpp | 43 ++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

Comments

Kieran Bingham June 24, 2024, 9:38 p.m. UTC | #1 
Quoting Laurent Pinchart (2024-06-24 20:29:37)
> _FORTIFY_SOURCE redirects the open*() calls to __open*_2() functions.
> The libcamera V4L2 adaptation layer intercepts those functions to
> support applications compiled with _FORTIFY_SOURCE. When _FORTIFY_SOURCE
> is not enabled, the C library headers will not provide declarations for
> the fortified functions, which will cause missing declaration warnings
> when we unable them.
> 
> Fix this by disabling the -Wmissing-declarations warnings selectively
> for the _FORTIFY_SOURCE functions. To avoid sparkling pragmas around,
> move the relevant function definitions next to each other.

Looks reasonable to keep the fortified versions together. One of either
you or Barnabás will need to rebase though...


Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  src/v4l2/v4l2_compat.cpp | 43 ++++++++++++++++++++++++----------------
>  1 file changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/src/v4l2/v4l2_compat.cpp b/src/v4l2/v4l2_compat.cpp
> index 9dd1577dfbde..8ff93192c3e3 100644
> --- a/src/v4l2/v4l2_compat.cpp
> +++ b/src/v4l2/v4l2_compat.cpp
> @@ -42,12 +42,6 @@ LIBCAMERA_PUBLIC int open(const char *path, int oflag, ...)
>                                                      oflag, mode);
>  }
>  
> -/* _FORTIFY_SOURCE redirects open to __open_2 */
> -LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
> -{
> -       return open(path, oflag);
> -}
> -
>  #ifndef open64
>  LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
>  {
> @@ -58,11 +52,6 @@ LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
>         return V4L2CompatManager::instance()->openat(AT_FDCWD, path,
>                                                      oflag | O_LARGEFILE, mode);
>  }
> -
> -LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
> -{
> -       return open(path, oflag);
> -}
>  #endif
>  
>  LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
> @@ -74,11 +63,6 @@ LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
>         return V4L2CompatManager::instance()->openat(dirfd, path, oflag, mode);
>  }
>  
> -LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
> -{
> -       return openat(dirfd, path, oflag);
> -}
> -
>  #ifndef openat64
>  LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
>  {
> @@ -89,12 +73,37 @@ LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
>         return V4L2CompatManager::instance()->openat(dirfd, path,
>                                                      oflag | O_LARGEFILE, mode);
>  }
> +#endif
> +
> +/*
> + * _FORTIFY_SOURCE redirects open* to __open*_2. Disable the
> + * -Wmissing-declarations warnings, as the functions won't be declared if
> + *  _FORTIFY_SOURCE is not in use.
> + */
> +#pragma GCC diagnostic push
> +#pragma GCC diagnostic ignored "-Wmissing-declarations"
> +
> +LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
> +{
> +       return open(path, oflag);
> +}
> +
> +LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
> +{
> +       return open(path, oflag);
> +}
> +
> +LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
> +{
> +       return openat(dirfd, path, oflag);
> +}
>  
>  LIBCAMERA_PUBLIC int __openat64_2(int dirfd, const char *path, int oflag)
>  {
>         return openat(dirfd, path, oflag);
>  }
> -#endif
> +
> +#pragma GCC diagnostic pop
>  
>  LIBCAMERA_PUBLIC int dup(int oldfd)
>  {
> -- 
> Regards,
> 
> Laurent Pinchart
>
Laurent Pinchart June 25, 2024, 8:12 a.m. UTC | #2 
On Mon, Jun 24, 2024 at 10:38:50PM +0100, Kieran Bingham wrote:
> Quoting Laurent Pinchart (2024-06-24 20:29:37)
> > _FORTIFY_SOURCE redirects the open*() calls to __open*_2() functions.
> > The libcamera V4L2 adaptation layer intercepts those functions to
> > support applications compiled with _FORTIFY_SOURCE. When _FORTIFY_SOURCE
> > is not enabled, the C library headers will not provide declarations for
> > the fortified functions, which will cause missing declaration warnings
> > when we unable them.
> > 
> > Fix this by disabling the -Wmissing-declarations warnings selectively
> > for the _FORTIFY_SOURCE functions. To avoid sparkling pragmas around,
> > move the relevant function definitions next to each other.
> 
> Looks reasonable to keep the fortified versions together. One of either
> you or Barnabás will need to rebase though...

I've pushed Barnabás patches and rebased this series on top.

> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  src/v4l2/v4l2_compat.cpp | 43 ++++++++++++++++++++++++----------------
> >  1 file changed, 26 insertions(+), 17 deletions(-)
> > 
> > diff --git a/src/v4l2/v4l2_compat.cpp b/src/v4l2/v4l2_compat.cpp
> > index 9dd1577dfbde..8ff93192c3e3 100644
> > --- a/src/v4l2/v4l2_compat.cpp
> > +++ b/src/v4l2/v4l2_compat.cpp
> > @@ -42,12 +42,6 @@ LIBCAMERA_PUBLIC int open(const char *path, int oflag, ...)
> >                                                      oflag, mode);
> >  }
> >  
> > -/* _FORTIFY_SOURCE redirects open to __open_2 */
> > -LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
> > -{
> > -       return open(path, oflag);
> > -}
> > -
> >  #ifndef open64
> >  LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
> >  {
> > @@ -58,11 +52,6 @@ LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
> >         return V4L2CompatManager::instance()->openat(AT_FDCWD, path,
> >                                                      oflag | O_LARGEFILE, mode);
> >  }
> > -
> > -LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
> > -{
> > -       return open(path, oflag);
> > -}
> >  #endif
> >  
> >  LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
> > @@ -74,11 +63,6 @@ LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
> >         return V4L2CompatManager::instance()->openat(dirfd, path, oflag, mode);
> >  }
> >  
> > -LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
> > -{
> > -       return openat(dirfd, path, oflag);
> > -}
> > -
> >  #ifndef openat64
> >  LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
> >  {
> > @@ -89,12 +73,37 @@ LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
> >         return V4L2CompatManager::instance()->openat(dirfd, path,
> >                                                      oflag | O_LARGEFILE, mode);
> >  }
> > +#endif
> > +
> > +/*
> > + * _FORTIFY_SOURCE redirects open* to __open*_2. Disable the
> > + * -Wmissing-declarations warnings, as the functions won't be declared if
> > + *  _FORTIFY_SOURCE is not in use.
> > + */
> > +#pragma GCC diagnostic push
> > +#pragma GCC diagnostic ignored "-Wmissing-declarations"
> > +
> > +LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
> > +{
> > +       return open(path, oflag);
> > +}
> > +
> > +LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
> > +{
> > +       return open(path, oflag);
> > +}
> > +
> > +LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
> > +{
> > +       return openat(dirfd, path, oflag);
> > +}
> >  
> >  LIBCAMERA_PUBLIC int __openat64_2(int dirfd, const char *path, int oflag)
> >  {
> >         return openat(dirfd, path, oflag);
> >  }
> > -#endif
> > +
> > +#pragma GCC diagnostic pop
> >  
> >  LIBCAMERA_PUBLIC int dup(int oldfd)
> >  {

Patch
diff mbox series 

diff --git a/src/v4l2/v4l2_compat.cpp b/src/v4l2/v4l2_compat.cpp
index 9dd1577dfbde..8ff93192c3e3 100644
--- a/src/v4l2/v4l2_compat.cpp
+++ b/src/v4l2/v4l2_compat.cpp
@@ -42,12 +42,6 @@  LIBCAMERA_PUBLIC int open(const char *path, int oflag, ...)
 						     oflag, mode);
 }
 
-/* _FORTIFY_SOURCE redirects open to __open_2 */
-LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
-{
-	return open(path, oflag);
-}
-
 #ifndef open64
 LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
 {
@@ -58,11 +52,6 @@  LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
 	return V4L2CompatManager::instance()->openat(AT_FDCWD, path,
 						     oflag | O_LARGEFILE, mode);
 }
-
-LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
-{
-	return open(path, oflag);
-}
 #endif
 
 LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
@@ -74,11 +63,6 @@  LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
 	return V4L2CompatManager::instance()->openat(dirfd, path, oflag, mode);
 }
 
-LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
-{
-	return openat(dirfd, path, oflag);
-}
-
 #ifndef openat64
 LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
 {
@@ -89,12 +73,37 @@  LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
 	return V4L2CompatManager::instance()->openat(dirfd, path,
 						     oflag | O_LARGEFILE, mode);
 }
+#endif
+
+/*
+ * _FORTIFY_SOURCE redirects open* to __open*_2. Disable the
+ * -Wmissing-declarations warnings, as the functions won't be declared if
+ *  _FORTIFY_SOURCE is not in use.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-declarations"
+
+LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
+{
+	return open(path, oflag);
+}
+
+LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
+{
+	return open(path, oflag);
+}
+
+LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
+{
+	return openat(dirfd, path, oflag);
+}
 
 LIBCAMERA_PUBLIC int __openat64_2(int dirfd, const char *path, int oflag)
 {
 	return openat(dirfd, path, oflag);
 }
-#endif
+
+#pragma GCC diagnostic pop
 
 LIBCAMERA_PUBLIC int dup(int oldfd)
 {