Suricata

I want to work on this issue.
As per my understanding, I need to add the WARN_UNUSED macro to all the ByteExtract* functions e.g

 int ByteExtractUint16(res, BYTE_LITTLE_ENDIAN, sizeof(uint16_t),
            (const uint8_t *) (input + *offset));

   int WARN_UNUSED ByteExtractUint16(res, BYTE_LITTLE_ENDIAN, sizeof(uint16_t),
            (const uint8_t *) (input + *offset));

Exactly, then the warnings need to be fixed

Do I need to run unit tests to generate those warnings or the clippy tool?

These warnings should come out of clang, not clippy...

I added the macro and ran clang filname.c.

I am getting a bunch of warnings and errors. Were you referring to those and how can I go about fixing those. e.g Following is a portion of the log that I am getting:

In file included from src/util-byte.c:26:
src/suricata-common.h:44:2: warning: "L1 cache line size not detected during build. Assuming 64 bytes." [-W#warnings]
#warning "L1 cache line size not detected during the build. Assuming 64 bytes." 
 ^
In file included from src/util-byte.c:26:
In file included from src/suricata-common.h:141:
/usr/local/include/pcre2.h:969:2: error: PCRE2_CODE_UNIT_WIDTH must be defined before including pcre2.h.
#error PCRE2_CODE_UNIT_WIDTH must be defined before including pcre2.h.
 ^
/usr/local/include/pcre2.h:970:2: error: Use 8, 16, or 32; or 0 for a multi-width application.
#error Use 8, 16, or 32; or 0 for a multi-width application.

EDIT: I don't think they are the warnings I am looking for. I am trying to use scan-build but due to some installation issue its not working for me.
To me, they don't seem to be connected to the changes I made.

When I try to run the Clang check I get errors. One of these is related to #include <pcre2.h> and #include <byteswap.h>.
These files are not found. I searched in my local repo and then Suricata's main repo to make sure I have not messed up the files but confirmed that they are not there. What should I do about this? Should I remove the include statements altogether?

You should compile Suricata with ./configure then make
make will call clang with the right flags, including those for PCRE2

What about something like

diff --git a/src/app-layer-enip-common.c b/src/app-layer-enip-common.c
index 91f06e731..407f7cc05 100644
--- a/src/app-layer-enip-common.c
+++ b/src/app-layer-enip-common.c
@@ -70,8 +70,10 @@ static int ENIPExtractUint16(uint16_t *res, const uint8_t *input, uint16_t *offs
         return 0;
     }

-    ByteExtractUint16(res, BYTE_LITTLE_ENDIAN, sizeof(uint16_t),
-            (const uint8_t *) (input + *offset));
+    if (ByteExtractUint16(res, BYTE_LITTLE_ENDIAN, sizeof(uint16_t),
+                          (const uint8_t *) (input + *offset)) < 0) {
+        return 0;
+    }
     *offset += sizeof(uint16_t);
     return 1;
 }