Detect version of libpq library.

TODO.md

@@ -21,17 +21,4 @@ Features that sooner or later will be added to `ngx_postgres`:
 
 * Cancel long-running queries using `PQcancel()`.
 
-* Detect client library version using `PQlibVersion()` (PostgreSQL 9.1+)
-  or exports (for older releases):
-
-      8.0.0 -> PQcancel                  122
-      8.1.0 -> PQregisterThreadLock      125
-      8.1.4 -> PQescapeByteaConn         127
-      8.2.0 -> PQsendDescribePortal      136
-      8.3.0 -> PQconnectionNeedsPassword 140
-      8.4.0 -> PQinitOpenSSL             153
-      8.5.x -> PQinitOpenSSL             153
-      9.0.0 -> PQconnectStartParams      157
-      9.1.x -> PQlibVersion              160
-
 * Detect server version using `PQserverVersion()`.

config

@@ -1,7 +1,7 @@
 ngx_feature_name=
 ngx_feature_run=no
 ngx_feature_incs="#include <libpq-fe.h>"
-ngx_feature_test="PQconndefaults();"
+ngx_feature_test="(void) PQconndefaults();"
 
 if [ -n "$LIBPQ_INC" -o -n "$LIBPQ_LIB" ]; then
     # specified by LIBPQ_INC and LIBPQ_LIB
@@ -76,19 +76,121 @@ else
     fi
 fi
 
-if [ $ngx_found = yes ]; then
-    CORE_INCS="$CORE_INCS $ngx_feature_path"
-    CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+if [ $ngx_found = no ]; then
+   cat << END
+ $0: error: ngx_postgres addon was unable to find the libpq library.
+END
+   exit 1
+fi
+
+ngx_version=`grep nginx_version src/core/nginx.h | sed -e 's/^.* \(.*\)$/\1/'`
+
+if [ -z "$ngx_version" ]; then
+   cat << END
+ $0: error: ngx_postgres addon was unable to detect version of nginx.
+END
+   exit 1
+fi
+
+# work-around for versions of nginx older than nginx-0.9.0
+if [ $ngx_version -ge 9000 ]; then
+    ngx_feature_name="NGX_POSTGRES_LIBRARY_VERSION"
+    ngx_feature_run=value
 else
- cat << END
- $0: error: the ngx_postgres addon requires the libpq library.
+    ngx_feature_name="NGX_POSTGRES_LIBRARY_VERSION_DETECTED"
+    ngx_feature_run=no
+fi
+
+lib_version=90100
+ngx_feature="libpq library version 9.1"
+ngx_feature_test="printf(\"%d\", PQlibVersion())"
+. auto/feature
+
+if [ $ngx_found = no ]; then
+    lib_version=90000
+    ngx_feature="libpq library version 9.0"
+    ngx_feature_test="(void) PQconnectStartParams(NULL, NULL, 0);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80400
+    ngx_feature="libpq library version 8.4"
+    ngx_feature_test="PQinitOpenSSL(0, 0);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80300
+    ngx_feature="libpq library version 8.3"
+    ngx_feature_test="(void) PQconnectionNeedsPassword(NULL);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80200
+    ngx_feature="libpq library version 8.2"
+    ngx_feature_test="(void) PQsendDescribePortal(NULL, NULL);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80104
+    ngx_feature="libpq library version 8.1.4"
+    ngx_feature_test="(void) PQescapeByteaConn(NULL, NULL, 0, 0);
+                      (void) PQregisterThreadLock(NULL);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80100
+    ngx_feature="libpq library version 8.1.0"
+    ngx_feature_test="(void) PQregisterThreadLock(NULL);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80008
+    ngx_feature="libpq library version 8.0.8"
+    ngx_feature_test="(void) PQescapeByteaConn(NULL, NULL, 0, 0);
+                      (void) PQcancel(NULL, NULL, 0);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+    lib_version=80000
+    ngx_feature="libpq library version 8.0.0"
+    ngx_feature_test="(void) PQcancel(NULL, NULL, 0);
+                      printf(\"$lib_version\")"
+    . auto/feature
+fi
+
+if [ $ngx_found = no ]; then
+   cat << END
+ $0: error: ngx_postgres addon was unable to detect version of the libpq library.
 END
- exit 1
+   exit 1
 fi
 
-ngx_addon_name=ngx_postgres_module
+# work-around for versions of nginx older than nginx-0.9.0
+if [ $ngx_version -lt 9000 ]; then
+    have=NGX_POSTGRES_LIBRARY_VERSION value=$lib_version . auto/define
+fi
+
+ngx_addon_name=ngx_postgres
 
 HTTP_MODULES="$HTTP_MODULES ngx_postgres_module"
+
+CORE_INCS="$CORE_INCS $ngx_feature_path"
+CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+
 NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/src/ngx_postgres_escape.c $ngx_addon_dir/src/ngx_postgres_handler.c $ngx_addon_dir/src/ngx_postgres_keepalive.c $ngx_addon_dir/src/ngx_postgres_module.c $ngx_addon_dir/src/ngx_postgres_output.c $ngx_addon_dir/src/ngx_postgres_processor.c $ngx_addon_dir/src/ngx_postgres_rewrite.c $ngx_addon_dir/src/ngx_postgres_upstream.c $ngx_addon_dir/src/ngx_postgres_util.c $ngx_addon_dir/src/ngx_postgres_variable.c"
 NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_addon_dir/src/ngx_postgres_escape.h $ngx_addon_dir/src/ngx_postgres_handler.h $ngx_addon_dir/src/ngx_postgres_keepalive.h $ngx_addon_dir/src/ngx_postgres_module.h $ngx_addon_dir/src/ngx_postgres_output.h $ngx_addon_dir/src/ngx_postgres_processor.h $ngx_addon_dir/src/ngx_postgres_rewrite.h $ngx_addon_dir/src/ngx_postgres_upstream.h $ngx_addon_dir/src/ngx_postgres_util.h $ngx_addon_dir/src/ngx_postgres_variable.h $ngx_addon_dir/src/ngx_postgres_ddebug.h $ngx_addon_dir/src/resty_dbd_stream.h"