Migrate PLtsql node serialization to extension side

Move PLtsql outfuncs/readfuncs code generation entirely to the extension,
eliminating the need for PLtsql-specific headers in the engine's
gen_node_support.pl input files.

Key changes:

- gen_pltsql_node_support.pl now generates pltsql_nodetags.h with
  extension-owned T_PLtsql_* NodeTag values (offset from 1000 to avoid
  collision with engine's NodeTag enum). Includes ABI stability check
  that fails the build if node types are added without updating
  $last_nodetag/$last_nodetag_no.

- Wrapper files pltsql_outfuncs.c and pltsql_readfuncs.c mirror the
  engine's pattern: #include the generated static functions and switch
  fragments, expose public pltsql_outNode() and pltsql_parseNodeString()
  dispatch functions.

- pltsql_serialize_macros.h provides WRITE_*/READ_* macros replicated
  from engine internals (not exposed in any PG header).

- pl_handler.c registers outNode_hook and parseNodeString_hook in
  _PG_init() so the engine's outNode()/parseNodeString() delegate to
  extension code for PLtsql node types.

- pltsql.h includes generated pltsql_nodetags.h for T_PLtsql_* defines.

- Makefile updated: compiles wrapper .o files (not gen .o directly),
  with proper dependency rules for generated files.

Files changed:
  src/pltsql_serialize/gen_pltsql_node_support.pl  - nodetags generation + ABI check
  src/pltsql_serialize/pltsql_outfuncs.c           - new wrapper
  src/pltsql_serialize/pltsql_readfuncs.c          - new wrapper
  src/pltsql_serialize/pltsql_serialize_macros.h   - shared macros
  src/pltsql_serialize/pltsql_node_stubs.c         - custom read/write nodes
  src/pltsql.h                                     - include pltsql_nodetags.h
  src/pl_handler.c                                 - register hooks
  Makefile                                         - build rules

Task: BABEL-6037
Signed-off-by: Manisha Deshpande <mmdeshp@amazon.com>

Author: manisha-deshpande

.gitignore

@@ -45,3 +45,9 @@ contrib/babelfishpg_tsql/src/pl_gram.c
 contrib/babelfishpg_tsql/src/pl_gram.h
 contrib/babelfishpg_tsql/src/pl_gram.output
 
+# PLtsql serialization - auto-generated by gen_pltsql_node_support.pl
+contrib/babelfishpg_tsql/src/pltsql_serialize/pltsql_nodetags.h
+contrib/babelfishpg_tsql/src/pltsql_serialize/pltsql_outfuncs_gen.c
+contrib/babelfishpg_tsql/src/pltsql_serialize/pltsql_outfuncs_switch.c
+contrib/babelfishpg_tsql/src/pltsql_serialize/pltsql_readfuncs_gen.c
+contrib/babelfishpg_tsql/src/pltsql_serialize/pltsql_readfuncs_switch.c

contrib/babelfishpg_tsql/Makefile

@@ -86,6 +86,29 @@ export ANTLR4_RUNTIME_INCLUDE_DIR=/usr/local/include/antlr4-runtime
 export ANTLR4_RUNTIME_LIB_DIR=/usr/local/lib
 
 OBJS += src/pltsql_bulkcopy.o
+OBJS += src/pltsql_serialize/pltsql_node_stubs.o
+
+# PLtsql serialization code generation (babelfishpg_tsql.enable_routine_parse_cache)
+PLTSQL_SER_DIR = src/pltsql_serialize
+PLTSQL_SER_HEADERS = $(PLTSQL_SER_DIR)/pltsql_serializable_1.h $(PLTSQL_SER_DIR)/pltsql_serializable_2.h
+PLTSQL_GEN_SCRIPT = $(PLTSQL_SER_DIR)/gen_pltsql_node_support.pl
+
+$(PLTSQL_SER_DIR)/pltsql_nodetags.h $(PLTSQL_SER_DIR)/pltsql_outfuncs_gen.c $(PLTSQL_SER_DIR)/pltsql_readfuncs_gen.c $(PLTSQL_SER_DIR)/pltsql_outfuncs_switch.c $(PLTSQL_SER_DIR)/pltsql_readfuncs_switch.c: $(PLTSQL_SER_HEADERS) $(PLTSQL_GEN_SCRIPT)
+	$(PERL) $(PLTSQL_GEN_SCRIPT) --outdir $(PLTSQL_SER_DIR) $(PLTSQL_SER_HEADERS)
+
+# Wrapper .c files #include the generated .c files (mirroring engine pattern)
+# so we compile the wrappers, not the gen files directly.
+OBJS += $(PLTSQL_SER_DIR)/pltsql_outfuncs.o
+OBJS += $(PLTSQL_SER_DIR)/pltsql_readfuncs.o
+
+# pltsql_nodetags.h must be generated before any .o that includes pltsql.h
+# The first OBJS entry (src/pl_gram.o) triggers this via implicit ordering,
+# but we make it explicit for safety.
+src/pl_gram.o: $(PLTSQL_SER_DIR)/pltsql_nodetags.h
+
+# Wrapper .o depends on generated .c files (included via #include)
+$(PLTSQL_SER_DIR)/pltsql_outfuncs.o: $(PLTSQL_SER_DIR)/pltsql_outfuncs_gen.c $(PLTSQL_SER_DIR)/pltsql_outfuncs_switch.c
+$(PLTSQL_SER_DIR)/pltsql_readfuncs.o: $(PLTSQL_SER_DIR)/pltsql_readfuncs_gen.c $(PLTSQL_SER_DIR)/pltsql_readfuncs_switch.c
 
 PG_CXXFLAGS += -g -Werror -Wfloat-conversion
 PG_CXXFLAGS += -Wno-deprecated -Wno-error=attributes -Wno-suggest-attribute=format # disable some warnings from ANTLR runtime header

contrib/babelfishpg_tsql/src/pl_handler.c

@@ -98,6 +98,11 @@
 #include "schemacmds.h"
 #include "session.h"
 #include "pltsql.h"
+#include "nodes/readfuncs.h"
+
+/* PLtsql node serialization dispatch (defined in pltsql_serialize/) */
+extern void pltsql_outNode(StringInfo str, const void *obj);
+extern Node *pltsql_parseNodeString(const char *token, int length);
 #include "pltsql_partition.h"
 #include "pltsql_permissions.h"
 #include "pl_explain.h"
@@ -6149,6 +6154,10 @@ _PG_init(void)
 
 	check_pltsql_support_tsql_transactions_hook = pltsql_support_tsql_transactions;
 
+	/* PLtsql node serialization hooks */
+	outNode_hook = pltsql_outNode;
+	parseNodeString_hook = pltsql_parseNodeString;
+
 	inited = true;
 }
 

contrib/babelfishpg_tsql/src/pltsql.h

@@ -5,8 +5,8 @@
  *
  * IMPORTANT: Any struct changes here (adding/removing fields, reordering)
  * must also be reflected in pltsql_serializable_1.h in
- * postgresql_modified_for_babelfish/src/include/pltsql/ to keep the
- * ANTLR parse tree serialization in sync.
+ * src/pltsql_serialize/ to keep the ANTLR parse tree serialization for 
+ * procedure caching in sync (babelfishpg_tsql.enable_routine_parse_cache).
  *
  * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
@@ -33,6 +33,9 @@
 #include "executor/spi.h"
 #include "libpq/libpq-be.h"
 #include "optimizer/planner.h"
+
+/* PLtsql NodeTag values — generated by gen_pltsql_node_support.pl */
+#include "pltsql_serialize/pltsql_nodetags.h"
 #include "utils/expandedrecord.h"
 #include "utils/plancache.h"
 #include "utils/portal.h"