[dpdk-dev] [PATCH] devtools: add llx format specifier check

%llx tends to be wrong when used for fixed size, like uint64_t,
variables, adding a warning to double check them.

Signed-off-by: Ferruh Yigit <redacted>
---
Cc: David Marchand <redacted>
Cc: Aaron Conole <aconole@redhat.com>
---
 devtools/checkpatches.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index 78a408ef9823..68005389820a 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh

@@ -118,6 +118,14 @@ check_forbidden_additions() { # <patch>
 		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
 		"$1" || res=1
 
+	# check %llx usage
+	awk -v FOLDERS='lib drivers app examples' \
+		-v EXPRESSIONS='%ll*[xud]' \
+		-v RET_ON_FAIL=1 \
+		-v MESSAGE='Please check %llx usage which tends to be wrong most of the times' \
+		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+		"$1" || res=1
+
 	# svg figures must be included with wildcard extension
 	# because of png conversion for pdf docs
 	awk -v FOLDERS='doc' \

-- 
2.29.2

09/02/2021 16:26, Ferruh Yigit:

%llx tends to be wrong when used for fixed size, like uint64_t,
variables, adding a warning to double check them.

Signed-off-by: Ferruh Yigit <redacted>
---
+	# check %llx usage
+	awk -v FOLDERS='lib drivers app examples' \
+		-v EXPRESSIONS='%ll*[xud]' \
+		-v RET_ON_FAIL=1 \
+		-v MESSAGE='Please check %llx usage which tends to be wrong most of the times' \

+1

It reminds me this old email:
http://mails.dpdk.org/archives/dev/2018-February/091483.html

The title mentions llx, but it should be %ll in general:
	devtools: check %ll format specifier

From: Ferruh Yigit <redacted>

%lx or %llx tend to be wrong for 32-bit platform
if used for fixed size variable like uint64_t.
A checkpatch warning will avoid this common mistake.

Signed-off-by: Ferruh Yigit <redacted>
Signed-off-by: Thomas Monjalon <redacted>
---
v2: proposal to reword the message and comment
---
 devtools/checkpatches.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index db4c7d8301..0e09b2cab8 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh

@@ -69,6 +69,14 @@ check_forbidden_additions() { # <patch>
 		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
 		"$1" || res=1
 
+	# check %l or %ll format specifier
+	awk -v FOLDERS='lib drivers app examples' \
+		-v EXPRESSIONS='%ll*[xud]' \
+		-v RET_ON_FAIL=1 \
+		-v MESSAGE='Using %l format, should it be %PRI*64?' \
+		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+		"$1" || res=1
+
 	# forbid variable declaration inside "for" loop
 	awk -v FOLDERS='.' \
 		-v EXPRESSIONS='for[[:space:]]*\\((char|u?int|unsigned|s?size_t)' \

-- 
2.31.1

On 5/19/2021 8:24 PM, Thomas Monjalon wrote:

Using the %l or %ll format specifier is correct when the variable type is "long
int" or "long long int", it is only wrong if the variable type is fixed size
like 'unit64_t'.

My concern is above warning log may cause people change the correct usage.

That was why I tried to make wording less strict, more like a reminder to double
check the usage.

If we can check that format specifier is used for 'unit64_t' variable, that will
be the best solution but that is very hard to do.
Should we add a little more information to the message to prevent false hit on
the correct usage?

21/05/2021 14:01, Ferruh Yigit:

On 5/19/2021 8:24 PM, Thomas Monjalon wrote:

quoted

From: Ferruh Yigit <redacted>

%lx or %llx tend to be wrong for 32-bit platform
if used for fixed size variable like uint64_t.
A checkpatch warning will avoid this common mistake.

Signed-off-by: Ferruh Yigit <redacted>
Signed-off-by: Thomas Monjalon <redacted>
---
v2: proposal to reword the message and comment
---
+	# check %l or %ll format specifier
+	awk -v FOLDERS='lib drivers app examples' \
+		-v EXPRESSIONS='%ll*[xud]' \
+		-v RET_ON_FAIL=1 \
+		-v MESSAGE='Using %l format, should it be %PRI*64?' \
+		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+		"$1" || res=1

Using the %l or %ll format specifier is correct when the variable type is "long
int" or "long long int", it is only wrong if the variable type is fixed size
like 'unit64_t'.

My concern is above warning log may cause people change the correct usage.

That was why I tried to make wording less strict, more like a reminder to double
check the usage.

This is a question now: "should it be", why do you think it is strict?

If we can check that format specifier is used for 'unit64_t' variable, that will
be the best solution but that is very hard to do.
Should we add a little more information to the message to prevent false hit on
the correct usage?

Your message was:
"Please check %llx usage which tends to be wrong most of the times"
Mine:
"Using %l format, should it be %PRI*64?"

Trying to give more info about what can be wrong while keeping short:

"Using %l format, is it a long variable or should it be %PRI*64?

From: Ferruh Yigit <redacted>

%lx or %llx tend to be wrong for 32-bit platform
if used for fixed size variable like uint64_t.
A checkpatch warning will avoid this common mistake.

Signed-off-by: Ferruh Yigit <redacted>
Signed-off-by: Thomas Monjalon <redacted>
---
v3: more explicit message
v2: proposal to reword the message and comment
---
 devtools/checkpatches.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index ba43f84e64..c30dadd962 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh

@@ -69,6 +69,14 @@ check_forbidden_additions() { # <patch>
 		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
 		"$1" || res=1
 
+	# check %l or %ll format specifier
+	awk -v FOLDERS='lib drivers app examples' \
+		-v EXPRESSIONS='%ll*[xud]' \
+		-v RET_ON_FAIL=1 \
+		-v MESSAGE='Using %l format, prefer %PRI*64 if type is [u]int64_t' \
+		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+		"$1" || res=1
+
 	# forbid variable declaration inside "for" loop
 	awk -v FOLDERS='.' \
 		-v EXPRESSIONS='for[[:space:]]*\\((char|u?int|unsigned|s?size_t)' \

-- 
2.31.1

On 5/21/2021 2:30 PM, Thomas Monjalon wrote:

From: Ferruh Yigit <redacted>

%lx or %llx tend to be wrong for 32-bit platform
if used for fixed size variable like uint64_t.
A checkpatch warning will avoid this common mistake.

Signed-off-by: Ferruh Yigit <redacted>
Signed-off-by: Thomas Monjalon <redacted>

Ack.

Thanks for update.

21/05/2021 15:33, Ferruh Yigit:

On 5/21/2021 2:30 PM, Thomas Monjalon wrote:

quoted

From: Ferruh Yigit <redacted>

%lx or %llx tend to be wrong for 32-bit platform
if used for fixed size variable like uint64_t.
A checkpatch warning will avoid this common mistake.

Signed-off-by: Ferruh Yigit <redacted>
Signed-off-by: Thomas Monjalon <redacted>

Ack.

Thanks for update.

Applied, thanks