It's common for drivers that share same physical components to also
duplicate source code (or at least portions of it). A good example is
both drivers/gpu/drm/amdgpu/* and drivers/gpu/drm/radeon/* have a header
file called atombios.h.

While their contents aren't the same, a lot of their structs have
the exact same names which makes navigating through the code base a bit
messy as cscope will show up 'references' across drivers which aren't
exactly correct.

Add IGNORE_DIRS variable, which specifies which directories
to be ignored from indexing.

Example:
        make ARCH=x86 IGNORE_DIRS="drivers/gpu/drm/radeon tools" cscope

Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
---
Changelog:

- v3: change commit message wording and rst syntax (Req Bagas Sanjaya)
      change makefile variable scope to global, use blank space
      separator and change variable name to IGNORE_DIRS.
      (Req: Vipin Sharma)
- v2: change approach to include everything unless specified by the 
  IGNOREDIRS variable: (Req: Vipin Sharma)
- v1: https://lore.kernel.org/lkml/Y5OKDvbGk4Kro6MK@mail.google.com/
---
 Documentation/kbuild/kbuild.rst | 7 +++++++
 scripts/tags.sh                 | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
index 08f575e6236c..5202186728b4 100644
--- a/Documentation/kbuild/kbuild.rst
+++ b/Documentation/kbuild/kbuild.rst
@@ -278,6 +278,13 @@ To get all available archs you can also specify all. E.g.::
 
     $ make ALLSOURCE_ARCHS=all tags
 
+IGNORE_DIRS
+-----------
+For tags/TAGS/cscope targets, you can choose which directories won't
+be included in the databases, separated by blank space. E.g.::
+
+    $ make IGNORE_DIRS="drivers/gpu/drm/radeon tools" cscope
+
 KBUILD_BUILD_TIMESTAMP
 ----------------------
 Setting this to a date string overrides the timestamp used in the
diff --git a/scripts/tags.sh b/scripts/tags.sh
index e137cf15aae9..1ad45f17179a 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -17,6 +17,13 @@ ignore="$(echo "$RCS_FIND_IGNORE" | sed 's|\\||g' )"
 # tags and cscope files should also ignore MODVERSION *.mod.c files
 ignore="$ignore ( -name *.mod.c ) -prune -o"
 
+# ignore arbitrary directories
+if [ -n "${IGNORE_DIRS}" ]; then
+	for i in ${IGNORE_DIRS}; do
+		ignore="${ignore} ( -path $i ) -prune -o"
+	done
+fi
+
 # Use make KBUILD_ABS_SRCTREE=1 {tags|cscope}
 # to force full paths for a non-O= build
 if [ "${srctree}" = "." -o -z "${srctree}" ]; then
-- 
2.38.1

On Tue, Dec 13, 2022 at 12:26 PM Paulo Miguel Almeida
<paulo.miguel.almeida.rodenas@gmail.com> wrote:
>
> It's common for drivers that share same physical components to also
> duplicate source code (or at least portions of it). A good example is
> both drivers/gpu/drm/amdgpu/* and drivers/gpu/drm/radeon/* have a header
> file called atombios.h.
>
> While their contents aren't the same, a lot of their structs have
> the exact same names which makes navigating through the code base a bit
> messy as cscope will show up 'references' across drivers which aren't
> exactly correct.
>
> Add IGNORE_DIRS variable, which specifies which directories
> to be ignored from indexing.
>
> Example:
>         make ARCH=x86 IGNORE_DIRS="drivers/gpu/drm/radeon tools" cscope
>
> Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
> ---
> Changelog:
>
> - v3: change commit message wording and rst syntax (Req Bagas Sanjaya)
>       change makefile variable scope to global, use blank space
>       separator and change variable name to IGNORE_DIRS.
>       (Req: Vipin Sharma)
> - v2: change approach to include everything unless specified by the
>   IGNOREDIRS variable: (Req: Vipin Sharma)
> - v1: https://lore.kernel.org/lkml/Y5OKDvbGk4Kro6MK@mail.google.com/
> ---
>  Documentation/kbuild/kbuild.rst | 7 +++++++
>  scripts/tags.sh                 | 7 +++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> index 08f575e6236c..5202186728b4 100644
> --- a/Documentation/kbuild/kbuild.rst
> +++ b/Documentation/kbuild/kbuild.rst
> @@ -278,6 +278,13 @@ To get all available archs you can also specify all. E.g.::
>
>      $ make ALLSOURCE_ARCHS=all tags
>
> +IGNORE_DIRS
> +-----------
> +For tags/TAGS/cscope targets, you can choose which directories won't
> +be included in the databases, separated by blank space. E.g.::
> +
> +    $ make IGNORE_DIRS="drivers/gpu/drm/radeon tools" cscope
> +
>  KBUILD_BUILD_TIMESTAMP
>  ----------------------
>  Setting this to a date string overrides the timestamp used in the
> diff --git a/scripts/tags.sh b/scripts/tags.sh
> index e137cf15aae9..1ad45f17179a 100755
> --- a/scripts/tags.sh
> +++ b/scripts/tags.sh
> @@ -17,6 +17,13 @@ ignore="$(echo "$RCS_FIND_IGNORE" | sed 's|\\||g' )"
>  # tags and cscope files should also ignore MODVERSION *.mod.c files
>  ignore="$ignore ( -name *.mod.c ) -prune -o"
>
> +# ignore arbitrary directories
> +if [ -n "${IGNORE_DIRS}" ]; then
> +       for i in ${IGNORE_DIRS}; do
> +               ignore="${ignore} ( -path $i ) -prune -o"
> +       done
> +fi
> +
>  # Use make KBUILD_ABS_SRCTREE=1 {tags|cscope}
>  # to force full paths for a non-O= build
>  if [ "${srctree}" = "." -o -z "${srctree}" ]; then
> --
> 2.38.1
>

Thanks for the patch.

Reviewed-by: Vipin Sharma <vipinsh@google.com>