Re: [dpdk-dev] [PATCH v2] devtools: check %l format specifier

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?