[PATCH] scripts/tags.sh: Exit gracefully if *tags tool not found

[PATCH] scripts/tags.sh: Exit gracefully if *tags tool not found

[Eugeniu Rosca]

If the needed host utility is not found, current behavior is:

$> make cscope
  GEN     cscope
./scripts/tags.sh: line 140: cscope: command not found
$> make gtags
  GEN     gtags
./scripts/tags.sh: line 145: gtags: command not found
$> make tags
  GEN     tags
xargs: ctags: No such file or directory
sed: can't read tags: No such file or directory
Makefile:1509: recipe for target 'tags' failed
make: *** [tags] Error 2
$> make TAGS
  GEN     TAGS
xargs: etags: No such file or directory
sed: can't read TAGS: No such file or directory
Makefile:1509: recipe for target 'TAGS' failed
make: *** [TAGS] Error 2

This patch allows to exit gracefully in such a situation:

$> make cscope
  GEN     cscope
cscope - not installed?
$> make gtags
  GEN     gtags
gtags - not installed?
$> make tags
  GEN     tags
ctags - not installed?
$> make TAGS
  GEN     TAGS
etags - not installed?

Signed-off-by: Eugeniu Rosca <eugeniu.m.rosca@gmail.com>
---
 scripts/tags.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/scripts/tags.sh b/scripts/tags.sh
index f72f48f..e7f6125 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -289,6 +289,13 @@ xtags()
 	fi
 }
 
+# Check if a specific utility is accessible on the host
+tool_exists() {
+	[ -x "$(which $1 2> /dev/null)" ] || \
+		{ echo "$1 - not installed?" && return 1; }
+	return 0
+}
+
 # Support um (which uses SUBARCH)
 if [ "${ARCH}" = "um" ]; then
 	if [ "$SUBARCH" = "i386" ]; then
@@ -318,20 +325,24 @@ fi
 remove_structs=
 case "$1" in
 	"cscope")
+		tool_exists cscope || exit 0
 		docscope
 		;;
 
 	"gtags")
+		tool_exists gtags || exit 0
 		dogtags
 		;;
 
 	"tags")
+		tool_exists ctags || exit 0
 		rm -f tags
 		xtags ctags
 		remove_structs=y
 		;;
 
 	"TAGS")
+		tool_exists etags || exit 0
 		rm -f TAGS
 		xtags etags
 		remove_structs=y
-- 
2.7.4

Re: [PATCH] scripts/tags.sh: Exit gracefully if *tags tool not found

[Michal Marek]

On 2016-04-24 18:42, Eugeniu Rosca wrote:
> If the needed host utility is not found, current behavior is:
> 
> $> make cscope
>   GEN     cscope
> ./scripts/tags.sh: line 140: cscope: command not found
> $> make gtags
>   GEN     gtags
> ./scripts/tags.sh: line 145: gtags: command not found
> $> make tags
>   GEN     tags
> xargs: ctags: No such file or directory
> sed: can't read tags: No such file or directory
> Makefile:1509: recipe for target 'tags' failed
> make: *** [tags] Error 2
> $> make TAGS
>   GEN     TAGS
> xargs: etags: No such file or directory
> sed: can't read TAGS: No such file or directory
> Makefile:1509: recipe for target 'TAGS' failed
> make: *** [TAGS] Error 2
> 
> This patch allows to exit gracefully in such a situation:
> 
> $> make cscope
>   GEN     cscope
> cscope - not installed?
> $> make gtags
>   GEN     gtags
> gtags - not installed?
> $> make tags
>   GEN     tags
> ctags - not installed?
> $> make TAGS
>   GEN     TAGS
> etags - not installed?

It should fail if it's unable to create the requested file, though.
Appending '|| exit' to the docscope/dogtags/xtags calls should suffice.

Michal

Re: [PATCH] scripts/tags.sh: Exit gracefully if *tags tool not found

[Eugeniu Rosca]

On Mon, Apr 25, 2016 at 02:35:43PM +0200, Michal Marek wrote:
> On 2016-04-24 18:42, Eugeniu Rosca wrote:
> > If the needed host utility is not found, current behavior is:
> > 
> > $> make cscope
> >   GEN     cscope
> > ./scripts/tags.sh: line 140: cscope: command not found
> > $> make gtags
> >   GEN     gtags
> > ./scripts/tags.sh: line 145: gtags: command not found
> > $> make tags
> >   GEN     tags
> > xargs: ctags: No such file or directory
> > sed: can't read tags: No such file or directory
> > Makefile:1509: recipe for target 'tags' failed
> > make: *** [tags] Error 2
> > $> make TAGS
> >   GEN     TAGS
> > xargs: etags: No such file or directory
> > sed: can't read TAGS: No such file or directory
> > Makefile:1509: recipe for target 'TAGS' failed
> > make: *** [TAGS] Error 2
> > 
> > This patch allows to exit gracefully in such a situation:
> > 
> > $> make cscope
> >   GEN     cscope
> > cscope - not installed?
> > $> make gtags
> >   GEN     gtags
> > gtags - not installed?
> > $> make tags
> >   GEN     tags
> > ctags - not installed?
> > $> make TAGS
> >   GEN     TAGS
> > etags - not installed?
> 
> It should fail if it's unable to create the requested file, though.
> Appending '|| exit' to the docscope/dogtags/xtags calls should suffice.
> 
> Michal

Hi Michal,

Late feedback from my end...
I would kindly ask you to select one of the options provided below:

OPTION 1: Append '|| exit' to the docscope/dogtags/xtags calls.
RESULT: This produces more error messages than with the original script:

$> make cscope
  GEN     cscope
./scripts/tags.sh: line 140: cscope: command not found
Makefile:1517: recipe for target 'cscope' failed
make: *** [cscope] Error 127
$> make gtags
  GEN     gtags
./scripts/tags.sh: line 145: gtags: command not found
Makefile:1517: recipe for target 'gtags' failed
make: *** [gtags] Error 127
$> make tags
  GEN     tags
xargs: ctags: No such file or directory
Makefile:1517: recipe for target 'tags' failed
make: *** [tags] Error 127
$> make TAGS
  GEN     TAGS
xargs: etags: No such file or directory
Makefile:1517: recipe for target 'TAGS' failed
make: *** [TAGS] Error 127
$> 

OPTION 2: Append '|| exit 0' to the docscope/dogtags/xtags calls.
RESULT: Cleaner output, but still without suggesting the root-cause:

$> make cscope
GEN     cscope
./scripts/tags.sh: line 140: cscope: command not found
$> make gtags
GEN     gtags
./scripts/tags.sh: line 145: gtags: command not found
$> make tags
GEN     tags
xargs: ctags: No such file or directory
$> make TAGS
GEN     TAGS
xargs: etags: No such file or directory
$>

OPTION 3: Initial patch.
RESULT: Cleaner output, but maybe putting too much infrastructure for
checking against missing utilities?

$> make cscope
GEN     cscope
cscope - not installed?
$> make gtags
GEN     gtags
gtags - not installed?
$> make tags
GEN     tags
ctags - not installed?
$> make TAGS
GEN     TAGS
etags - not installed?

OPTION 4: Something else?
RESULT: ?

Best regards,
Eugeniu.

Re: [PATCH] scripts/tags.sh: Exit gracefully if *tags tool not found

[Michal Marek]

On 2016-05-15 15:44, Eugeniu Rosca wrote:
> I would kindly ask you to select one of the options provided below:
> 
> OPTION 1: Append '|| exit' to the docscope/dogtags/xtags calls.
> RESULT: This produces more error messages than with the original script:
> 
> $> make cscope
>   GEN     cscope
> ./scripts/tags.sh: line 140: cscope: command not found
> Makefile:1517: recipe for target 'cscope' failed
> make: *** [cscope] Error 127
> [...]

This is the correct behavior because a missing tool is an error.

Michal

Re: [PATCH v2] scripts/tags.sh: Handle missing {c,e,g}tags/cscope utilities

[Eugeniu Rosca]

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From 5917e6602bd0e44c4a672bc4ac8c7a323b6300b6 Mon Sep 17 00:00:00 2001
From: Eugeniu Rosca <eugeniu.m.rosca@gmail.com>
Date: Sun, 24 Apr 2016 17:30:53 +0200
Subject: [PATCH v2] scripts/tags.sh: Handle missing {c,e,g}tags/cscope utilities

If the required ctags/etags/gtags/cscope host utility is not found,
current behavior is:

$> make cscope
  GEN     cscope
./scripts/tags.sh: line 140: cscope: command not found
$> make gtags
  GEN     gtags
./scripts/tags.sh: line 145: gtags: command not found
$> make tags
  GEN     tags
xargs: ctags: No such file or directory
sed: can't read tags: No such file or directory
Makefile:1509: recipe for target 'tags' failed
make: *** [tags] Error 2
$> make TAGS
  GEN     TAGS
xargs: etags: No such file or directory
sed: can't read TAGS: No such file or directory
Makefile:1509: recipe for target 'TAGS' failed
make: *** [TAGS] Error 2

Instead of implementing a more graceful handling, this patch only
makes sure that tags.sh script exits immediately upon the first
failure caused by the missing ctags/etags/gtags/cscope tool. By not
altering the exit code, the user will additionally get the failed
recipe in the root Makefile. The output becomes:

$> make cscope
  GEN     cscope
./scripts/tags.sh: line 140: cscope: command not found
Makefile:1517: recipe for target 'cscope' failed
make: *** [cscope] Error 127
$> make gtags
  GEN     gtags
./scripts/tags.sh: line 145: gtags: command not found
Makefile:1517: recipe for target 'gtags' failed
make: *** [gtags] Error 127
$> make tags
  GEN     tags
xargs: ctags: No such file or directory
Makefile:1517: recipe for target 'tags' failed
make: *** [tags] Error 127
$> make TAGS
  GEN     TAGS
xargs: etags: No such file or directory
Makefile:1517: recipe for target 'TAGS' failed
make: *** [TAGS] Error 127

Signed-off-by: Eugeniu Rosca <eugeniu.m.rosca@gmail.com>
---
 scripts/tags.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/tags.sh b/scripts/tags.sh
index f72f48f..96b6dec 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -318,22 +318,22 @@ fi
 remove_structs=
 case "$1" in
 	"cscope")
-		docscope
+		docscope || exit
 		;;
 
 	"gtags")
-		dogtags
+		dogtags || exit
 		;;
 
 	"tags")
 		rm -f tags
-		xtags ctags
+		xtags ctags || exit
 		remove_structs=y
 		;;
 
 	"TAGS")
 		rm -f TAGS
-		xtags etags
+		xtags etags || exit
 		remove_structs=y
 		;;
 esac
-- 
2.7.4