Re: Add version macro to libpq-fe.h

Alvaro Herrera <alvaro.herrera@2ndquadrant.com> writes:
> So I'm +1 on adding this "feature macro".

Concretely, how about the attached?  (I also got rid of a recently-added
extra comma.  While the compilers we use might not warn about that,
it seems unwise to assume that no user's compiler will.)

I guess one unresolved question is whether we want to mention these in
the SGML docs.  I vote "no", because it'll raise the maintenance cost
noticeably.  But I can see an argument on the other side.

            regards, tom lane

diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index ec378705ad..4677c51e1b 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -28,6 +28,13 @@ extern "C"
  */
 #include "postgres_ext.h"

+/*
+ * These symbols may be used in compile-time #ifdef tests for the availability
+ * of newer libpq features.
+ */
+#define LIBPQ_HAS_PIPELINING 1
+#define LIBPQ_HAS_TRACE_FLAGS 1
+
 /*
  * Option flags for PQcopyResult
  */
@@ -98,7 +105,7 @@ typedef enum
     PGRES_COPY_BOTH,            /* Copy In/Out data transfer in progress */
     PGRES_SINGLE_TUPLE,            /* single tuple from larger resultset */
     PGRES_PIPELINE_SYNC,        /* pipeline synchronization point */
-    PGRES_PIPELINE_ABORTED,        /* Command didn't run because of an abort
+    PGRES_PIPELINE_ABORTED        /* Command didn't run because of an abort
                                  * earlier in a pipeline */
 } ExecStatusType;