checkpatch: re-enable warnings about split long strings

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]>

---
 devtools/checkpatches.sh | 1 -

 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -1

index a56c41a301c0..3e6081dd673e 100755
@@ -44,7 +44,6 @@ options="$options --show-types"
  options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
  VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
  PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
  LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\

 NEW_TYPEDEFS,COMPARISON_TO_NULL"

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]>

---
 devtools/checkpatches.sh | 1 -
 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]> ---

devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

Quoted 36 lines · Adrien Mazarguil

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]> ---

devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

Quoted 6 lines

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

In my experience, checkpatch is smart enough to recognise when a long line overflows the 80 character limit because of a single long string, so the two options are not mutually exclusive. In other words, long lines are not allowed except in the case where shortening the line involves splitting a string. There may be a small amount of work in getting checkpatch happy, i.e. by putting the string on a line on it's own, but we can indeed have our cake and eat it too in this case.

Quoted 43 lines · Bruce Richardson

Quoted 36 lines · Adrien Mazarguil

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]> ---

devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

Quoted 6 lines

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

Quoted 7 lines

In my experience, checkpatch is smart enough to recognise when a long line overflows the 80 character limit because of a single long string, so the two options are not mutually exclusive. In other words, long lines are not allowed except in the case where shortening the line involves splitting a string. There may be a small amount of work in getting checkpatch happy, i.e. by putting the string on a line on it's own, but we can indeed have our cake and eat it too in this case.

I can't seem to get around warnings without ignoring either SPLIT_STRING or LONG_LINE_STRING as of Linux v4.14-rc3's checkpatch.pl. I think you can only get around them by fooling it somehow. You really need to ignore at least LONG_LINE_STRING to meet the requirements of the commit log.

However SPLIT_STRING still looks necessary to address part of cf75514c8e2e ("devtools: ignore warning on long log string"):

"...lines that make use of PRIx64 with string concatenation will still be
flagged if the beginning of the last string fragment begins after the 80 character threshold."

It's not all that uncommon in my opinion.

Quoted 64 lines · Adrien Mazarguil

Quoted 43 lines · Bruce Richardson

Quoted 36 lines · Adrien Mazarguil

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by Stephen Hemminger <[email protected]> ---

devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

Quoted 6 lines

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

Quoted 7 lines

In my experience, checkpatch is smart enough to recognise when a long line overflows the 80 character limit because of a single long string, so the two options are not mutually exclusive. In other words, long lines are not allowed except in the case where shortening the line involves splitting a string. There may be a small amount of work in getting checkpatch happy, i.e. by putting the string on a line on it's own, but we can indeed have our cake and eat it too in this case.

I can't seem to get around warnings without ignoring either SPLIT_STRING or LONG_LINE_STRING as of Linux v4.14-rc3's checkpatch.pl. I think you can only get around them by fooling it somehow. You really need to ignore at least LONG_LINE_STRING to meet the requirements of the commit log.

However SPLIT_STRING still looks necessary to address part of cf75514c8e2e ("devtools: ignore warning on long log string"):

"...lines that make use of PRIx64 with string concatenation will still be
flagged if the beginning of the last string fragment begins after the 80 character threshold."

Quoted 2 lines

It's not all that uncommon in my opinion.

If you have PRIx64 in it, it's not part of a literal string you would grep, so it's reasonable to split there. The user cannot know what the specific %x formatting character used is.

Quoted 65 lines · Bruce Richardson

Quoted 64 lines · Adrien Mazarguil

Quoted 43 lines · Bruce Richardson

Quoted 36 lines · Adrien Mazarguil

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by: Stephen Hemminger <sthemmin at microsoft.com> --- devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

Quoted 6 lines

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

Quoted 7 lines

In my experience, checkpatch is smart enough to recognise when a long line overflows the 80 character limit because of a single long string, so the two options are not mutually exclusive. In other words, long lines are not allowed except in the case where shortening the line involves splitting a string. There may be a small amount of work in getting checkpatch happy, i.e. by putting the string on a line on it's own, but we can indeed have our cake and eat it too in this case.

I can't seem to get around warnings without ignoring either SPLIT_STRING or LONG_LINE_STRING as of Linux v4.14-rc3's checkpatch.pl. I think you can only get around them by fooling it somehow. You really need to ignore at least LONG_LINE_STRING to meet the requirements of the commit log.

However SPLIT_STRING still looks necessary to address part of cf75514c8e2e ("devtools: ignore warning on long log string"):

"...lines that make use of PRIx64 with string concatenation will still be
flagged if the beginning of the last string fragment begins after the 80 character threshold."

Quoted 5 lines

Quoted 2 lines

It's not all that uncommon in my opinion.

If you have PRIx64 in it, it's not part of a literal string you would grep, so it's reasonable to split there. The user cannot know what the specific %x formatting character used is.

I agree, however in that case checkpatch would complain because our configuration doesn't specify to ignore SPLIT_STRING since there is no comma separator when concatenating them.

My point is that the occasional exception is still necessary for split strings, that ignoring LONG_LINE_STRING must remain either way and unnecessary warnings cause more harm than good (they need to be worked around if we enforce this rule).

In short, long/split strings acceptability assessment should be left to reviewers, as it cannot be automated in all cases through checkpatch.pl.

Quoted 76 lines · On 10/3/2017 11:56 AM, adrien.mazarguil at 6wind.com (Adrien Mazarguil) wrote:

Quoted 65 lines · Bruce Richardson

Quoted 64 lines · Adrien Mazarguil

Quoted 43 lines · Bruce Richardson

Quoted 36 lines · Adrien Mazarguil

Hi Stephen,

Quoted 14 lines · Stephen Hemminger

The Linux kernel style policy about strings is that strings should be always put on one line. This makes sense since a typical use case is for a user to type the error message into a search engine or grep, and it won't be found if split across lines. This patch just re-enables that check.

Yes, lots of DPDK code now splits strings, that doesn't make it right.

Signed-off-by: Stephen Hemminger <sthemmin at microsoft.com> --- devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-)

devtools/checkpatches.sh +0 -0

index a56c41a301c0..3e6081dd673e 100755 ---

Quoted 8 lines

a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 +44,6 @@ options="$options --show-types" options="$options --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\
VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\
-SPLIT_STRING,LONG_LINE_STRING,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\
NEW_TYPEDEFS,COMPARISON_TO_NULL"

I'm not sure, given that the main reason for splitting strings in the first place is to avoid LONG_LINE_STRING warnings, I think we must choose between the two options. If split strings are not allowed, then long lines must be.

Since checkpatches.sh is used by various automated scripts to complain loudly about problems in submissions, the above change prevents maintainers from writing long string at all (can't split and can't go past 80 columns).

Quoted 6 lines

As a result, they will be tempted to cripple their code with nasty workarounds to shut up checkpatches.sh, we don't want that to happen.

Also I think the reasons stated by original commit cf75514c8e2e are still relevant. My vote would be to keep things as is.

Quoted 7 lines

In my experience, checkpatch is smart enough to recognise when a long line overflows the 80 character limit because of a single long string, so the two options are not mutually exclusive. In other words, long lines are not allowed except in the case where shortening the line involves splitting a string. There may be a small amount of work in getting checkpatch happy, i.e. by putting the string on a line on it's own, but we can indeed have our cake and eat it too in this case.

I can't seem to get around warnings without ignoring either SPLIT_STRING or LONG_LINE_STRING as of Linux v4.14-rc3's checkpatch.pl. I think you can only get around them by fooling it somehow. You really need to ignore at least LONG_LINE_STRING to meet the requirements of the commit log.

However SPLIT_STRING still looks necessary to address part of cf75514c8e2e ("devtools: ignore warning on long log string"):

"...lines that make use of PRIx64 with string concatenation will still be
flagged if the beginning of the last string fragment begins after the 80 character threshold."

Quoted 5 lines

Quoted 2 lines

It's not all that uncommon in my opinion.

If you have PRIx64 in it, it's not part of a literal string you would grep, so it's reasonable to split there. The user cannot know what the specific %x formatting character used is.

I agree, however in that case checkpatch would complain because our configuration doesn't specify to ignore SPLIT_STRING since there is no comma separator when concatenating them.

Quoted 8 lines

My point is that the occasional exception is still necessary for split strings, that ignoring LONG_LINE_STRING must remain either way and unnecessary warnings cause more harm than good (they need to be worked around if we enforce this rule).

In short, long/split strings acceptability assessment should be left to reviewers, as it cannot be automated in all cases through checkpatch.pl.

This patch is waiting in patchwork for a long time now.

My experience is same with Adrien's, if 'LONG_LINE_STRING' is not ignored, it will complain about long log messages, so removing 'LONG_LINE_STRING' contradicts with the reason of the patch described in the commit log.

Perhaps it can be an option to remove only 'SPLIT_STRING' from ignore list, to detect split messages.

But overall, I am updating this patch as "Change Requested", if there is a demand for ignoring 'SPLIT_STRING' please send a new version.