Refactor planner's header files.

Create a new header optimizer/optimizer.h, which exposes just the
planner functions that can be used "at arm's length", without need
to access Paths or the other planner-internal data structures defined
in nodes/relation.h.  This is intended to provide the whole planner
API seen by most of the rest of the system; although FDWs still need
to use additional stuff, and more thought is also needed about just
what selfuncs.c should rely on.

The main point of doing this now is to limit the amount of new
#include baggage that will be needed by "planner support functions",
which I expect to introduce later, and which will be in relevant
datatype modules rather than anywhere near the planner.

This commit just moves relevant declarations into optimizer.h from
other header files (a couple of which go away because everything
got moved), and adjusts #include lists to match.  There's further
cleanup that could be done if we want to decide that some stuff
being exposed by optimizer.h doesn't belong in the planner at all,
but I'll leave that for another day.

Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us

8 files changed, 5 insertions, 11 deletions

diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 2e061a5ee36..e52b8063728 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -40,8 +40,7 @@
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
-#include "optimizer/planner.h"
+#include "optimizer/optimizer.h"
 #include "pgstat.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 5975c5206b8..9a20460e762 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -52,7 +52,6 @@
 #include "jit/jit.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
-#include "optimizer/clauses.h"
 #include "parser/parsetree.h"
 #include "rewrite/rewriteManip.h"
 #include "storage/bufmgr.h"
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index ceea3d6d721..b79be91655b 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -39,8 +39,6 @@
 #include "executor/tqueue.h"
 #include "jit/jit.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/planmain.h"
-#include "optimizer/planner.h"
 #include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/datum.h"
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 2a260a71f24..263a0f81279 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -226,8 +226,7 @@
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
-#include "optimizer/tlist.h"
+#include "optimizer/optimizer.h"
 #include "parser/parse_agg.h"
 #include "parser/parse_coerce.h"
 #include "utils/acl.h"
diff --git a/src/backend/executor/nodeGather.c b/src/backend/executor/nodeGather.c
index 70a4e90a05d..69d5a1f2398 100644
--- a/src/backend/executor/nodeGather.c
+++ b/src/backend/executor/nodeGather.c
@@ -38,7 +38,7 @@
 #include "executor/nodeSubplan.h"
 #include "executor/tqueue.h"
 #include "miscadmin.h"
-#include "optimizer/planmain.h"
+#include "optimizer/optimizer.h"
 #include "pgstat.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
diff --git a/src/backend/executor/nodeGatherMerge.c b/src/backend/executor/nodeGatherMerge.c
index 8635865d1e6..4de1d2b484d 100644
--- a/src/backend/executor/nodeGatherMerge.c
+++ b/src/backend/executor/nodeGatherMerge.c
@@ -23,7 +23,7 @@
 #include "executor/tqueue.h"
 #include "lib/binaryheap.h"
 #include "miscadmin.h"
-#include "optimizer/planmain.h"
+#include "optimizer/optimizer.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index cdf1ad09de3..324356ec757 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -37,7 +37,6 @@
 #include "lib/pairingheap.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
 #include "utils/array.h"
 #include "utils/datum.h"
 #include "utils/lsyscache.h"
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 731391f1907..157ac042b82 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -41,7 +41,7 @@
 #include "executor/nodeWindowAgg.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "parser/parse_agg.h"
 #include "parser/parse_coerce.h"
 #include "utils/acl.h"