[Tom Lane <tgl@sss.pgh.pa.us>]

Those of you who've been paying attention to the bootstrap data conversion
thread will know that one of the key ideas is to put everything in the
catalog headers that's of direct use to client-side code into separate
"pg_foo_d.h" headers.  This allows clients to include pg_foo_d.h to get
OID macros or whatever else they need, and not have to worry about whether
the main pg_foo.h header contains backend-only declarations.

Attached is a patch that changes all our frontend code to actually do
things that way.  I propose to push this after the bootstrap conversion
proper.

In the wake of these changes, it'd be possible to reverse the changes
we've made to move extern declarations for backend/catalog/pg_foo.c
functions into separate pg_foo_fn.h headers, which we've done whenever
(a) such externs required backend-only typedefs and (b) we really needed
pg_foo.h to be includable by frontend code.  So it's time to make a
decision whether we want to do that, or leave well enough alone.

I've always felt that the pg_foo_fn.h business was a kluge, and would
be happy to get rid of it.  But one could also argue that it would be
a good design, if we adopted it uniformly instead of haphazardly.
But that'd require more code churn, and there's no longer a lot to be
gained thereby.

Another approach worth discussing is "let's do that, but wait a release
or two to give third-party clients time to adjust to using pg_foo_d.h".
I'm not excited by that though.  I think third parties will just wait to
change till they're forced to, so this wouldn't really reduce the pain
only delay it.  Plus I don't know that we'd ever get around to it;
our track record for doing cleanup things later isn't great.

So I feel that we should either strike while the iron is hot, and
re-merge the pg_foo_fn.h headers now, or decide that we're never
going to do that and we'll just let them be as-is.

Thoughts?

			regards, tom lane

PS: forgot to mention: this patch also gets rid of ecpglib/pg_type.h
entirely, as it's now just a confusingly-named wrapper for pg_type_d.h.

Attachments:

bootstrap-client-fixes-1.patch (text/x-diff, 10.6K) download
diff --git a/contrib/oid2name/oid2name.c b/contrib/oid2name/oid2name.c
index 769e527..63e360c 100644
--- a/contrib/oid2name/oid2name.c
+++ b/contrib/oid2name/oid2name.c
@@ -9,7 +9,7 @@
  */
 #include "postgres_fe.h"
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 #include "fe_utils/connect.h"
 #include "libpq-fe.h"
diff --git a/contrib/vacuumlo/vacuumlo.c b/contrib/vacuumlo/vacuumlo.c
index ab6b17c..7eb474c 100644
--- a/contrib/vacuumlo/vacuumlo.c
+++ b/contrib/vacuumlo/vacuumlo.c
@@ -21,7 +21,7 @@
 #include <termios.h>
 #endif
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 #include "fe_utils/connect.h"
 #include "libpq-fe.h"
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 78990f5..2dbdd3e 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -61,9 +61,8 @@
 
 #include "access/xlog_internal.h"
 #include "catalog/catalog.h"
-#include "catalog/pg_authid.h"
-#include "catalog/pg_class.h"
-#include "catalog/pg_collation.h"
+#include "catalog/pg_authid_d.h"
+#include "catalog/pg_collation_d.h"
 #include "common/file_utils.h"
 #include "common/restricted_token.h"
 #include "common/username.h"
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 0a758f1..e7db78b 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -21,7 +21,7 @@
 
 #include <ctype.h>
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 #include "fe_utils/string_utils.h"
 
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index d066f4f..5d28c82 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -42,17 +42,17 @@
 #include "access/attnum.h"
 #include "access/sysattr.h"
 #include "access/transam.h"
-#include "catalog/pg_aggregate.h"
-#include "catalog/pg_am.h"
-#include "catalog/pg_attribute.h"
-#include "catalog/pg_cast.h"
-#include "catalog/pg_class.h"
-#include "catalog/pg_default_acl.h"
-#include "catalog/pg_largeobject.h"
-#include "catalog/pg_largeobject_metadata.h"
-#include "catalog/pg_proc.h"
-#include "catalog/pg_trigger.h"
-#include "catalog/pg_type.h"
+#include "catalog/pg_aggregate_d.h"
+#include "catalog/pg_am_d.h"
+#include "catalog/pg_attribute_d.h"
+#include "catalog/pg_cast_d.h"
+#include "catalog/pg_class_d.h"
+#include "catalog/pg_default_acl_d.h"
+#include "catalog/pg_largeobject_d.h"
+#include "catalog/pg_largeobject_metadata_d.h"
+#include "catalog/pg_proc_d.h"
+#include "catalog/pg_trigger_d.h"
+#include "catalog/pg_type_d.h"
 #include "libpq/libpq-fs.h"
 
 #include "dumputils.h"
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index 5ce3c5d..d2b0949 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -19,7 +19,7 @@
 #include "pg_backup_utils.h"
 #include "pg_dump.h"
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 /* translator: this is a module name */
 static const char *modulename = gettext_noop("sorter");
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index 876a62a..c3fc519 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -20,7 +20,7 @@
 
 #include "common/string.h"
 #include "catalog/catalog.h"
-#include "catalog/pg_tablespace.h"
+#include "catalog/pg_tablespace_d.h"
 #include "storage/fd.h"
 
 filemap_t  *filemap = NULL;
diff --git a/src/bin/pg_rewind/libpq_fetch.c b/src/bin/pg_rewind/libpq_fetch.c
index 5914b15..fa845bb 100644
--- a/src/bin/pg_rewind/libpq_fetch.c
+++ b/src/bin/pg_rewind/libpq_fetch.c
@@ -23,7 +23,7 @@
 
 #include "libpq-fe.h"
 #include "catalog/catalog.h"
-#include "catalog/pg_type.h"
+#include "catalog/pg_type_d.h"
 #include "fe_utils/connect.h"
 #include "port/pg_bswap.h"
 
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 8d4f254..577db73 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -9,7 +9,7 @@
 
 #include "postgres_fe.h"
 
-#include "catalog/pg_authid.h"
+#include "catalog/pg_authid_d.h"
 #include "fe_utils/string_utils.h"
 #include "mb/pg_wchar.h"
 #include "pg_upgrade.h"
diff --git a/src/bin/pg_upgrade/function.c b/src/bin/pg_upgrade/function.c
index d61fa38..03fd155 100644
--- a/src/bin/pg_upgrade/function.c
+++ b/src/bin/pg_upgrade/function.c
@@ -12,7 +12,7 @@
 #include "pg_upgrade.h"
 
 #include "access/transam.h"
-#include "catalog/pg_language.h"
+#include "catalog/pg_language_d.h"
 
 
 /*
diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index f9f07f4..fd0b44c 100644
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -12,7 +12,7 @@
 #include "pg_upgrade.h"
 
 #include "access/transam.h"
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 
 static void create_rel_filename_map(const char *old_data, const char *new_data,
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index d124127..16e0181 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -37,7 +37,7 @@
 #include "postgres_fe.h"
 
 #include "pg_upgrade.h"
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 #include "common/restricted_token.h"
 #include "fe_utils/string_utils.h"
 
diff --git a/src/bin/pg_upgrade/relfilenode.c b/src/bin/pg_upgrade/relfilenode.c
index 50bee28..ed604f2 100644
--- a/src/bin/pg_upgrade/relfilenode.c
+++ b/src/bin/pg_upgrade/relfilenode.c
@@ -12,7 +12,7 @@
 #include "pg_upgrade.h"
 
 #include <sys/stat.h>
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 #include "access/transam.h"
 
 
diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index 76e9d65..712ed14 100644
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -11,7 +11,7 @@
 
 #include "pg_upgrade.h"
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 #include "fe_utils/string_utils.h"
 
 
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 3560318..4c85f43 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -23,7 +23,7 @@
 #include <sys/stat.h>			/* for stat() */
 #endif
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 #include "portability/instr_time.h"
 
 #include "libpq-fe.h"
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 0c3be1f..de43886 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -14,9 +14,9 @@
 
 #include <ctype.h>
 
-#include "catalog/pg_attribute.h"
-#include "catalog/pg_class.h"
-#include "catalog/pg_default_acl.h"
+#include "catalog/pg_attribute_d.h"
+#include "catalog/pg_class_d.h"
+#include "catalog/pg_default_acl_d.h"
 #include "fe_utils/string_utils.h"
 
 #include "common.h"
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 00287bb..061de8e 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -41,7 +41,7 @@
 
 #include <ctype.h>
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 #include "libpq-fe.h"
 #include "pqexpbuffer.h"
diff --git a/src/bin/scripts/vacuumdb.c b/src/bin/scripts/vacuumdb.c
index 91ebb00..60f8b1c 100644
--- a/src/bin/scripts/vacuumdb.c
+++ b/src/bin/scripts/vacuumdb.c
@@ -16,7 +16,7 @@
 #include <sys/select.h>
 #endif
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 #include "common.h"
 #include "fe_utils/simple_list.h"
diff --git a/src/common/relpath.c b/src/common/relpath.c
index d98050c..f0fa674 100644
--- a/src/common/relpath.c
+++ b/src/common/relpath.c
@@ -19,7 +19,7 @@
 #endif
 
 #include "catalog/catalog.h"
-#include "catalog/pg_tablespace.h"
+#include "catalog/pg_tablespace_d.h"
 #include "common/relpath.h"
 #include "storage/backendid.h"
 
diff --git a/src/fe_utils/print.c b/src/fe_utils/print.c
index ec5ad45..cb9a9a0 100644
--- a/src/fe_utils/print.c
+++ b/src/fe_utils/print.c
@@ -32,7 +32,7 @@
 
 #include "fe_utils/print.h"
 
-#include "catalog/pg_type.h"
+#include "catalog/pg_type_d.h"
 #include "fe_utils/mbprint.h"
 
 
diff --git a/src/interfaces/ecpg/ecpglib/descriptor.c b/src/interfaces/ecpg/ecpglib/descriptor.c
index bdd2518..f38bf34 100644
--- a/src/interfaces/ecpg/ecpglib/descriptor.c
+++ b/src/interfaces/ecpg/ecpglib/descriptor.c
@@ -5,7 +5,8 @@
 
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
-#include "pg_type.h"
+
+#include "catalog/pg_type_d.h"
 
 #include "ecpg-pthread-win32.h"
 #include "ecpgtype.h"
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index 0404385..c1b44d3 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
@@ -19,7 +19,7 @@
 #include <float.h>
 #include <math.h>
 
-#include "pg_type.h"
+#include "catalog/pg_type_d.h"
 
 #include "ecpgtype.h"
 #include "ecpglib.h"
diff --git a/src/interfaces/ecpg/ecpglib/pg_type.h b/src/interfaces/ecpg/ecpglib/pg_type.h
index 79a6cf8..e69de29 100644
--- a/src/interfaces/ecpg/ecpglib/pg_type.h
+++ b/src/interfaces/ecpg/ecpglib/pg_type.h
@@ -1,18 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * pg_type.h
- *	  Interface to generated type OID symbols.
- *
- * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * src/interfaces/ecpg/ecpglib/pg_type.h
- *
- *-------------------------------------------------------------------------
- */
-#ifndef PG_TYPE_H
-#define PG_TYPE_H
-
-#include "catalog/pg_type_d.h"
-
-#endif							/* PG_TYPE_H */
diff --git a/src/interfaces/ecpg/ecpglib/sqlda.c b/src/interfaces/ecpg/ecpglib/sqlda.c
index c1ba989..317d22f 100644
--- a/src/interfaces/ecpg/ecpglib/sqlda.c
+++ b/src/interfaces/ecpg/ecpglib/sqlda.c
@@ -8,7 +8,8 @@
 
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
-#include "pg_type.h"
+
+#include "catalog/pg_type_d.h"
 
 #include "ecpg-pthread-win32.h"
 #include "decimal.h"
diff --git a/src/interfaces/ecpg/ecpglib/typename.c b/src/interfaces/ecpg/ecpglib/typename.c
index 48587e4..9da1cdf 100644
--- a/src/interfaces/ecpg/ecpglib/typename.c
+++ b/src/interfaces/ecpg/ecpglib/typename.c
@@ -3,12 +3,13 @@
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
 
+#include "catalog/pg_type_d.h"
+
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "extern.h"
 #include "sqltypes.h"
 #include "sql3types.h"
-#include "pg_type.h"
 
 /*
  * This function is used to generate the correct type names.
diff --git a/src/tools/findoidjoins/findoidjoins.c b/src/tools/findoidjoins/findoidjoins.c
index 82ef113..cbb7b59 100644
--- a/src/tools/findoidjoins/findoidjoins.c
+++ b/src/tools/findoidjoins/findoidjoins.c
@@ -7,7 +7,7 @@
  */
 #include "postgres_fe.h"
 
-#include "catalog/pg_class.h"
+#include "catalog/pg_class_d.h"
 
 #include "fe_utils/connect.h"
 #include "libpq-fe.h"