On 2024-Apr-03, Tom Lane wrote:
> On my machine, headerscheck does not like this:
>
> $ src/tools/pginclude/headerscheck --cplusplus
> In file included from /tmp/headerscheck.4gTaW5/test.cpp:3:
> ./src/include/libpq/libpq-be-fe-helpers.h: In function 'char*
> libpqsrv_cancel(PGconn*, TimestampTz)':
> ./src/include/libpq/libpq-be-fe-helpers.h:393:10: warning: ISO C++ forbids
> converting a string constant to 'char*' [-Wwrite-strings]
> return "out of memory";
> ^~~~~~~~~~~~~~~
> ./src/include/libpq/libpq-be-fe-helpers.h:421:13: warning: ISO C++ forbids
> converting a string constant to 'char*' [-Wwrite-strings]
> error = "cancel request timed out";
> ^~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The second part of that could easily be fixed by declaring "error" as
> "const char *". As for the first part, can we redefine the whole
> function as returning "const char *"? (If not, this coding is very
> questionable anyway.)
Yeah, this seems to work and I no longer get that complaint from
headerscheck.
--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
>From 0af8c7039b2c8ed80bc0bddacfe4a9abb8f527b3 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Thu, 4 Apr 2024 10:13:07 +0200
Subject: [PATCH] Make libpqsrv_cancel's return type const char *
---
contrib/dblink/dblink.c | 2 +-
contrib/postgres_fdw/connection.c | 2 +-
src/include/libpq/libpq-be-fe-helpers.h | 4 ++--
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index de858e165a..755293456f 100644
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -1347,7 +1347,7 @@ Datum
dblink_cancel_query(PG_FUNCTION_ARGS)
{
PGconn *conn;
- char *msg;
+ const char *msg;
TimestampTz endtime;
dblink_init();
diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index 2532e453c4..cac9d96d33 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -1332,7 +1332,7 @@ pgfdw_cancel_query(PGconn *conn)
static bool
pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)
{
- char *errormsg = libpqsrv_cancel(conn, endtime);
+ const char *errormsg = libpqsrv_cancel(conn, endtime);
if (errormsg != NULL)
ereport(WARNING,
diff --git a/src/include/libpq/libpq-be-fe-helpers.h b/src/include/libpq/libpq-be-fe-helpers.h
index 8be9aa1f2f..fe50829274 100644
--- a/src/include/libpq/libpq-be-fe-helpers.h
+++ b/src/include/libpq/libpq-be-fe-helpers.h
@@ -382,11 +382,11 @@ libpqsrv_get_result(PGconn *conn, uint32 wait_event_info)
* Note: this function leaks a string's worth of memory when reporting
* libpq errors. Make sure to call it in a transient memory context.
*/
-static inline char *
+static inline const char *
libpqsrv_cancel(PGconn *conn, TimestampTz endtime)
{
PGcancelConn *cancel_conn;
- char *error = NULL;
+ const char *error = NULL;
cancel_conn = PQcancelCreate(conn);
if (cancel_conn == NULL)
--
2.39.2
