Oninit® SQLMorph — Informix UDR

The headline output. Each input procedure produces a C source file and a CREATE FUNCTION install SQL script. The C registers under the same name as the source SPL so existing callers don't change. Build every UDR in a directory with the generic Makefile published at https://www.oninit.com/sqlmorph/Makefile.

What gets emitted

File	Contents
<name>.c	C source with #include <mi.h> / <miami.h>, the UDREXPORT'd function, all SPL types mapped to mi_* counterparts.
Makefile	Not emitted per procedure — one canonical generic Makefile is published at https://www.oninit.com/sqlmorph/Makefile. Drop it into any bundle directory; it builds every .c and runs every *_install.sql.
<name>_install.sql	DROP PROCEDURE IF EXISTS … then CREATE PROCEDURE … EXTERNAL NAME '$INFORMIXDIR/extend/sqlmorph/<name>.so(<name>)' LANGUAGE C NOT VARIANT.
REPORT.md	Only emitted when constructs were flagged. Every entry has file:line, the construct, and a human-readable note explaining what to review.

Type mapping

SPL type	C type
SMALLINT / INT / INTEGER / SERIAL	mi_smallint / mi_integer (by value)
INT8 / BIGINT / SERIAL8 / BIGSERIAL	mi_int8 (by value)
FLOAT / DOUBLE PRECISION	mi_double_precision
SMALLFLOAT / REAL	mi_real
DECIMAL / NUMERIC / MONEY	mi_decimal *
CHAR / VARCHAR	mi_string *
LVARCHAR / NCHAR / NVARCHAR	mi_lvarchar *
DATE	mi_date (by value)
DATETIME	mi_datetime *
INTERVAL	mi_interval *
BOOLEAN	mi_boolean (by value)
TEXT / BYTE / CLOB / BLOB	MI_LO_HANDLE *

Iterator UDRs — RETURN ... WITH RESUME

SPL procedures that yield rows via RETURN ... WITH RESUME — including the common FOREACH ... RETURN ... WITH RESUME; END FOREACH streaming pattern — compile to a reentrant Informix C UDR. The engine calls the function repeatedly; mi_fp_request(fparam) tells it which phase to run.

Phase	What gets emitted
SET_INIT	Allocate iter_state_t via mi_alloc(sizeof, PER_COMMAND), zero-fill, run all pre-FOREACH initialisers (rewriting locals as state->name), open the cursor with mi_prepare + ONI_EXEC_PREP, and stash the state via mi_fp_setfuncstate.
SET_RETONE	On state->phase >= 1, run the post-yield body of the previous iteration (rotated to the next call's prologue). Then fetch a row; if the cursor is exhausted, run any post-FOREACH code, close the cursor, and call mi_fp_setisdone(fparam, MI_TRUE). Otherwise bind INTO targets, run the pre-yield body, set phase = 1, and return the yielded value.
SET_END	Close the cursor handle. The PER_COMMAND state struct itself is reclaimed by the engine.

The auto-generated iter_state_t holds, in order: a phase counter, an MI_CONNECTION *conn when the body uses in-engine SQL, one field per DEFINE'd local (so values survive across yields), and one MI_STATEMENT *_curN_st per FOREACH cursor in source order. The install SQL gains a WITH (ITERATOR) modifier so the engine knows to dispatch in the request-loop pattern.

String concat (||). SPL a || b compiles to oni_concat((const char *)(a), (const char *)(b)) — a runtime helper in sqlmorph_util.c that allocates a fresh mi-buffer and concatenates two null-terminated strings (NULL operands treated as empty). Nested a || b || c chains nest the call. The reporter only flags a || when an operand is a numeric literal (needs sprintf-style pre-conversion to string).

Multi-column iterators. When the SPL declares RETURNING t1, t2, ... with RETURN a, b WITH RESUME, the emitted UDR returns MI_ROW *. SET_INIT derives a row descriptor via mi_fp_rettype(fparam, 0) + mi_row_desc_create and stashes it on the state. SET_RETONE assembles each yield's columns into state->_row_vals[] (with int-family values cast through (intptr_t), and float / mi_int8 values stored in state-resident scratch slots passed by address) and returns mi_row_create(state->conn, state->_row_desc, _row_vals, _row_nulls). SET_END destroys the row descriptor. The install SQL keeps the SPL RETURNING t1, t2 list verbatim — the row layout is derived at runtime from that signature.

Two iterator shapes ship in the conformance corpus: add_one (trivial single-row yield) and iter_orders (cursor-driven, post-yield body rotation).