https://bugs.openldap.org/show_bug.cgi?id=9545
Issue ID: 9545 Summary: Compile warnings in OpenLDAP 2.4 branch Product: OpenLDAP Version: 2.4.58 Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: libraries Assignee: bugs@openldap.org Reporter: simon.pichugin@gmail.com Target Milestone: ---
There are a few compile warnings that are present in OPENLDAP_REL_ENG_2_4 libraries.
I understand that 2.4 is not in an active development state anymore but I think it's important to keep it as clean as possible as the libraries are actively used by other projects.
The warnings:
tls2.c: In function ‘ldap_int_tls_connect’: tls2.c:378:9: warning: implicit declaration of function ‘ldap_pvt_tls_check_hostname’ [-Wimplicit-function-declaration] 378 | err = ldap_pvt_tls_check_hostname( ld, ssl, host ); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ thr_posix.c: In function ‘ldap_pvt_thread_set_concurrency’: thr_posix.c:93:9: warning: implicit declaration of function ‘pthread_setconcurrency’ [-Wimplicit-function-declaration] 93 | return pthread_setconcurrency( n ); | ^~~~~~~~~~~~~~~~~~~~~~ thr_posix.c: In function ‘ldap_pvt_thread_get_concurrency’: thr_posix.c:107:9: warning: implicit declaration of function ‘pthread_getconcurrency’; did you mean ‘ldap_pvt_thread_get_concurrency’? [-Wimplicit-function-declaration] 107 | return pthread_getconcurrency(); | ^~~~~~~~~~~~~~~~~~~~~~ | ldap_pvt_thread_get_concurrency charray.c: In function ‘ldap_charray2str’: charray.c:269:3: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=] 269 | strncpy( p, *v, len ); | ^~~~~~~~~~~~~~~~~~~~~ charray.c:268:9: note: length computed here 268 | len = strlen( *v ); | ^~~~~~~~~~~~
Additional information: The 'implicit declaration' warnings can be potentially harmful.
If the compiler does not see the declaration of a function _before_ it is called, it assumes the following implicit declaration instead:
int fnc_name();
... which has severe consequences:
1. Only sizeof(int) bytes are read from the return value even if the function returns a different type.
2. Count and type of the arguments passed to the functions are not checked at all because the compiler has no means to know what the callee expects as parameters.