[Compute]: Warnings during the compilation

[vadim2404]

neon_utils.c:15:1: warning: no previous prototype for 'HexDecodeChar' [-Wmissing-prototypes]
   15 | HexDecodeChar(char c)
      | ^~~~~~~~~~~~~
neon_utils.c:33:1: warning: no previous prototype for 'HexDecodeString' [-Wmissing-prototypes]
   33 | HexDecodeString(uint8 *result, char *input, int nbytes)
      | ^~~~~~~~~~~~~~~
neon_utils.c:55:1: warning: no previous prototype for 'pq_getmsgint32_le' [-Wmissing-prototypes]
   55 | pq_getmsgint32_le(StringInfo msg)
      | ^~~~~~~~~~~~~~~~~
neon_utils.c:69:1: warning: no previous prototype for 'pq_getmsgint64_le' [-Wmissing-prototypes]
   69 | pq_getmsgint64_le(StringInfo msg)
      | ^~~~~~~~~~~~~~~~~
neon_utils.c:80:1: warning: no previous prototype for 'pq_sendint32_le' [-Wmissing-prototypes]
   80 | pq_sendint32_le(StringInfo buf, uint32 i)
      | ^~~~~~~~~~~~~~~
neon_utils.c:89:1: warning: no previous prototype for 'pq_sendint64_le' [-Wmissing-prototypes]
   89 | pq_sendint64_le(StringInfo buf, uint64 i)
      | ^~~~~~~~~~~~~~~
neon_utils.c:100:1: warning: no previous prototype for 'disable_core_dump' [-Wmissing-prototypes]
  100 | disable_core_dump()
      | ^~~~~~~~~~~~~~~~~
extension_server.c: In function 'neon_download_extension_file_http':
extension_server.c:37:11: warning: unused variable 'postdata' [-Wunused-variable]
   37 |  char    *postdata;
      |           ^~~~~~~~
extension_server.c: At top level:
extension_server.c:78:1: warning: no previous prototype for 'pg_init_extension_server' [-Wmissing-prototypes]
   78 | pg_init_extension_server()
      | ^~~~~~~~~~~~~~~~~~~~~~~~
control_plane_connector.c: In function 'ConstructDeltaMessage':
control_plane_connector.c:123:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  123 |   HASH_SEQ_STATUS status;
      |   ^~~~~~~~~~~~~~~
control_plane_connector.c:155:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  155 |   HASH_SEQ_STATUS status;
      |   ^~~~~~~~~~~~~~~
control_plane_connector.c:172:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  172 |     char    *encrypted_password = get_role_password(entry->name, &logdetail);
      |     ^~~~
control_plane_connector.c:191:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  191 |  JsonbValue *result = pushJsonbValue(&state, WJB_END_OBJECT, NULL);
      |  ^~~~~~~~~~
control_plane_connector.c: In function 'SendDeltasToControlPlane':
control_plane_connector.c:239:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  239 |  char    *message = ConstructDeltaMessage();
      |  ^~~~
walproposer_pg.c:391:1: warning: no previous prototype for 'replication_feedback_set' [-Wmissing-prototypes]
  391 | replication_feedback_set(PageserverFeedback *rf)
      | ^~~~~~~~~~~~~~~~~~~~~~~~
walproposer.c: In function 'AdvancePollState':
walproposer.c:477:15: warning: unused variable 'wp' [-Wunused-variable]
  477 |  WalProposer *wp = sk->wp;
      |               ^~
walproposer_pg.c: In function 'StartProposerReplication':
walproposer_pg.c:975:13: warning: variable 'currTLI' set but not used [-Wunused-but-set-variable]
  975 |  TimeLineID currTLI;
      |             ^~~~~~~
walproposer.c: At top level:
walproposer.c:1490:1: warning: no previous prototype for 'ParsePageserverFeedbackMessage' [-Wmissing-prototypes]
 1490 | ParsePageserverFeedbackMessage(WalProposer *wp, StringInfo reply_message, PageserverFeedback *rf)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
control_plane_connector.c:251:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  251 |  const int num_retries = 5;
      |  ^~~~~
control_plane_connector.c: In function 'MergeTable':
control_plane_connector.c:350:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  350 |   DbEntry    *entry;
      |   ^~~~~~~
control_plane_connector.c:395:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  395 |   RoleEntry  *entry;
      |   ^~~~~~~~~
control_plane_connector.c: In function 'HandleCreateDb':
control_plane_connector.c:489:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  489 |  DefElem    *downer = NULL;
      |  ^~~~~~~
control_plane_connector.c:499:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  499 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleAlterOwner':
control_plane_connector.c:530:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  530 |  const char *name = strVal(stmt->object);
      |  ^~~~~
control_plane_connector.c:540:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  540 |  const char *new_owner = get_rolespec_name(stmt->newowner);
      |  ^~~~~
control_plane_connector.c: In function 'HandleDbRename':
control_plane_connector.c:553:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  553 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleDropDb':
control_plane_connector.c:590:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  590 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleCreateRole':
control_plane_connector.c:607:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  607 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleAlterRole':
control_plane_connector.c:636:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  636 |  DefElem    *dpass = NULL;
      |  ^~~~~~~
control_plane_connector.c:653:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  653 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleRoleRename':
control_plane_connector.c:[674](https://github.com/neondatabase/neon/actions/runs/7261297170/job/19782211123?pr=6184#step:5:675):2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  674 |  bool  found = false;
      |  ^~~~
control_plane_connector.c: In function 'HandleDropRole':
control_plane_connector.c:[712](https://github.com/neondatabase/neon/actions/runs/7261297170/job/19782211123?pr=6184#step:5:713):2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  712 |  ListCell   *item;
      |  ^~~~~~~~
control_plane_connector.c: At top level:
control_plane_connector.c:807:1: warning: no previous prototype for 'InitControlPlaneConnector' [-Wmissing-prototypes]
  807 | InitControlPlaneConnector()
      | ^~~~~~~~~~~~~~~~~~~~~~~~~
control_plane_connector.c: In function 'InitControlPlaneConnector':
control_plane_connector.c:838:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  838 |  const char *jwt_token = getenv("NEON_CONTROL_PLANE_TOKEN");
      |  ^~~~~
file_cache.c: In function 'neon_get_lfc_stats':
file_cache.c:772:13: warning: 'value' may be used uninitialized in this function [-Wmaybe-uninitialized]
  772 |   values[1] = Int64GetDatum(value);
In file included from /usr/local/pgsql/include/server/postgres.h:47,
                 from hnsw.c:1:
hnsw.c: In function 'hnsw_check_available_memory':
hnsw.c:152:15: warning: format '%n' expects a matching 'int *' argument [-Wformat=]
  152 |   elog(ERROR, "Failed to get amount of RAM: %n");
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/local/pgsql/include/server/utils/elog.h:141:4: note: in definition of macro 'ereport_domain'
  141 |    __VA_ARGS__, errfinish(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
      |    ^~~~~~~~~~~
/usr/local/pgsql/include/server/utils/elog.h:233:2: note: in expansion of macro 'ereport'
  233 |  ereport(elevel, errmsg_internal(__VA_ARGS__))
      |  ^~~~~~~
hnsw.c:152:3: note: in expansion of macro 'elog'
  152 |   elog(ERROR, "Failed to get amount of RAM: %n");
      |   ^~~~
hnsw.c:152:46: note: format string is defined here
  152 |   elog(ERROR, "Failed to get amount of RAM: %n");
      |                                             ~^
      |                                              |
      |                                              int *

[skyzh]

It seems that these warnings cannot be reproduced on the dev server. So I guess it's specific to a compiler version when building our compute node image.

[skyzh]

And we are using gcc 10 https://packages.debian.org/bullseye/gcc in our build image

[vadim2404]

I copied these warnings from CI

[skyzh]

Yep, it's specific to gcc 10 and some combination of compile flags. I'm extracting those info from CI and fixing them.

Also -Wall generates way more warnings than CI. In the future we should enable that, but for now I'll just fix the ones reported in CI.

[skyzh]

Fixed -Wmissing-prototypes first and looking into other types of warnings + treating warnings as errors in CI in the future

[andreasscherbaum]

Newer versions of Ubuntu (GitHub Actions, local Docker on Mac) don't produce this.

[skyzh]

decided not to fix -Wdeclaration-after-statement as it is unlikely to cause any runtime errors and fixing it makes the code harder to read (in my opinion)