nimble compile error (IDFGH-11343)

[AxelLin]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

IDF version.

v5.2-dev-3775-gb4268c874a

Operating System used.

Linux

How did you build your project?

Command line with idf.py

If you are using Windows, please specify command line type.

None

What is the expected behavior?

build success.

What is the actual behavior?

/home/axel/esp/esp-idf/components/bt/host/nimble/nimble/nimble/host/src/ble_gap.c: In function 'ble_gap_master_connect_reattempt':
/home/axel/esp/esp-idf/components/bt/host/nimble/nimble/nimble/host/src/ble_gap.c:1036:40: error: storing the address of local variable 'conn' in 'ble_conn_reattempt[idx].cb_arg' [-Werror=dangling-pointer=]
1036 | ble_conn_reattempt[idx].cb_arg = &conn;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
/home/axel/esp/esp-idf/components/bt/host/nimble/nimble/nimble/host/src/ble_gap.c:992:30: note: 'conn' declared here
992 | struct ble_gap_conn_desc conn;
| ^~~~
/home/axel/esp/esp-idf/components/bt/host/nimble/nimble/nimble/host/src/ble_gap.c:130:46: note: 'ble_conn_reattempt' declared here
130 | static struct ble_gap_connect_reattempt_ctxt ble_conn_reattempt[MYNEWT_VAL(BLE_MAX_CONNECTIONS)];
|

Steps to reproduce.

Just build with nimble for esp32c3.

Build or installation Logs.

No response

More Information.

No response

[rahult-github]

Hi @AxelLin ,

May i know which example you attempting to compile ? We tried both peripheral and central and don't see the issue. Also enabled / disabled the ENABLE_CONN_REATTEMPT flag, but don't see the issue.

The code being pointed is not modifed since a year. Is there any specific GCC version being used for this ?

[AxelLin]

@rahult-github
I compile with our application code, not example code.
However, the error message does make sense, I think this needs fix.
/home/axel/esp/esp-idf/components/bt/host/nimble/nimble/nimble/host/src/ble_gap.c:1036:40: error: storing the address of local variable 'conn' in 'ble_conn_reattempt[idx].cb_arg' [-Werror=dangling-pointer=]
1036 | ble_conn_reattempt[idx].cb_arg = &conn;

[AxelLin]

BTW, I didn't hit this issue when I build with v5.1 branch.
And the ble_gap.c file is exactly the same in v5.1 branch and master.
Maybe this is toolchain issue?

[KaeLL]

Seems to be an upstream code issue. cb_arg does become a dangling reference after ble_gap_master_connect_reattempt exits.

[rahult-github]

Hi @AxelLin ,

Not able to hit the issue at my end yet. Will investigate on the toolchain input provided.

In meantime, can you check if attached patch helps ?
dangling_pointer_error.txt

[AxelLin]

Hi @rahult-github
It's strange that I no longer hit the compile error today (even without your path).
I'm closing the issue, sorry for the noise.

[AxelLin]

Hi @AxelLin ,

Not able to hit the issue at my end yet. Will investigate on the toolchain input provided.

In meantime, can you check if attached patch helps ? dangling_pointer_error.txt

Hi @rahult-github
I hit this compile error again, and confirm your patch fixed the compile issue.

[rahult-github]

Hi @AxelLin , noted . Will raise fix internally.

[AxelLin]

Hi @AxelLin , noted . Will raise fix internally.

I reopen this issue because I still cannot find this fix in esp-nimble.

[rahult-github]

Hi @AxelLin , the change is done on master and backported to release/v5.2 and release/v5.1 internally. It should be visible soon on github, once the sync / mirror happens .