libpq-fe.h: Don't claim SOCKTYPE in the global namespace

The definition of PGoauthBearerRequest uses a temporary SOCKTYPE macro
to hide the difference between Windows and Berkeley socket handles,
since we don't surface pgsocket in our public API. This macro doesn't
need to escape the header, because implementers will choose the correct
socket type based on their platform, so I #undef'd it immediately after
use.

I didn't namespace that helper, though, so if anyone else needs a
SOCKTYPE macro, libpq-fe.h will now unhelpfully get rid of it. This
doesn't seem too far-fetched, given its proximity to existing POSIX
macro names.

Add a PQ_ prefix to avoid collisions, update and improve the surrounding
documentation, and backpatch.

Reviewed-by: Chao Li <[email protected]>
Discussion: https://postgr.es/m/CAOYmi%2BmrGg%2Bn_X2MOLgeWcj3v_M00gR8uz_D7mM8z%3DdX1JYVbg%40mail.gmail.com
Backpatch-through: 18

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 7ab679a765d71e65ec9ca8d354f8cb52d99e8de9..7d05938feda9f313c275999257e7a05b7662dad4 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -10422,10 +10422,14 @@ typedef struct PGoauthBearerRequest
 
     /* Hook outputs */
 
-    /* Callback implementing a custom asynchronous OAuth flow. */
+    /*
+     * Callback implementing a custom asynchronous OAuth flow. The signature is
+     * platform-dependent: PQ_SOCKTYPE is SOCKET on Windows, and int everywhere
+     * else.
+     */
     PostgresPollingStatusType (*async) (PGconn *conn,
                                         struct PGoauthBearerRequest *request,
-                                        SOCKTYPE *altsock);
+                                        PQ_SOCKTYPE *altsock);
 
     /* Callback to clean up custom allocations. */
     void        (*cleanup) (PGconn *conn, struct PGoauthBearerRequest *request);
@@ -10482,7 +10486,7 @@ typedef struct PGoauthBearerRequest
          hook. When the callback cannot make further progress without blocking,
          it should return either <symbol>PGRES_POLLING_READING</symbol> or
          <symbol>PGRES_POLLING_WRITING</symbol> after setting
-         <literal>*pgsocket</literal> to the file descriptor that will be marked
+         <literal>*altsock</literal> to the file descriptor that will be marked
          ready to read/write when progress can be made again. (This descriptor
          is then provided to the top-level polling loop via
          <function>PQsocket()</function>.) Return <symbol>PGRES_POLLING_OK</symbol>

diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 0852584edae4bf109ae17018887079be3355c259..877a6483b348259ff58a0bbb6ae4a03ca2ef2c74 100644 (file)
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -738,11 +738,15 @@ typedef struct _PGpromptOAuthDevice
    int         expires_in;     /* seconds until user code expires */
 } PGpromptOAuthDevice;
 
-/* for PGoauthBearerRequest.async() */
+/*
+ * For PGoauthBearerRequest.async(). This macro just allows clients to avoid
+ * depending on libpq-int.h or Winsock for the "socket" type; it's undefined
+ * immediately below.
+ */
 #ifdef _WIN32
-#define SOCKTYPE uintptr_t     /* avoids depending on winsock2.h for SOCKET */
+#define PQ_SOCKTYPE uintptr_t  /* avoids depending on winsock2.h for SOCKET */
 #else
-#define SOCKTYPE int
+#define PQ_SOCKTYPE int
 #endif
 
 typedef struct PGoauthBearerRequest
@@ -768,10 +772,13 @@ typedef struct PGoauthBearerRequest
     * blocking during the original call to the PQAUTHDATA_OAUTH_BEARER_TOKEN
     * hook, it may be returned directly, but one of request->async or
     * request->token must be set by the hook.
+    *
+    * The (PQ_SOCKTYPE *) in the signature is a placeholder for the platform's
+    * native socket type: (SOCKET *) on Windows, and (int *) everywhere else.
     */
    PostgresPollingStatusType (*async) (PGconn *conn,
                                        struct PGoauthBearerRequest *request,
-                                       SOCKTYPE * altsock);
+                                       PQ_SOCKTYPE * altsock);
 
    /*
     * Callback to clean up custom allocations. A hook implementation may use
@@ -798,7 +805,7 @@ typedef struct PGoauthBearerRequest
    void       *user;
 } PGoauthBearerRequest;
 
-#undef SOCKTYPE
+#undef PQ_SOCKTYPE
 
 extern char *PQencryptPassword(const char *passwd, const char *user);
 extern char *PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user, const char *algorithm);