stop vendoring the sqlite C code, rework the build

* Use the zig package manager to fetch sqlite directly from upstream
* Integrate the preprocessing tool directly into the build script

This makes it simpler to upgrade the SQLite source code:
* use `zig fetch`
* run `zig build preprocess-headers`

1 files changed, 46 insertions, 8 deletions

diff --git a/c/loadable-ext-sqlite3.h b/c/loadable-ext-sqlite3.h
index df6efef..497515e 100644
--- a/c/loadable-ext-sqlite3.h
+++ b/c/loadable-ext-sqlite3.h
@@ -1,3 +1,4 @@
+/* sqlite3.h edited by the zig-sqlite build script */
 /*
 ** 2001-09-15
 **
@@ -146,9 +147,9 @@ extern "C" {
 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
 ** [sqlite_version()] and [sqlite_source_id()].
 */
-#define SQLITE_VERSION        "3.47.2"
-#define SQLITE_VERSION_NUMBER 3047002
-#define SQLITE_SOURCE_ID      "2024-12-07 20:39:59 2aabe05e2e8cae4847a802ee2daddc1d7413d8fc560254d93ee3e72c14685b6c"
+#define SQLITE_VERSION        "3.48.0"
+#define SQLITE_VERSION_NUMBER 3048000
+#define SQLITE_SOURCE_ID      "2025-01-14 11:05:00 d2fe6b05f38d9d7cd78c5d252e99ac59f1aea071d669830c1ffe4e8966e84010"
 
 /*
 ** CAPI3REF: Run-Time Library Version Numbers
@@ -1085,6 +1086,11 @@ struct sqlite3_io_methods {
 ** pointed to by the pArg argument.  This capability is used during testing
 ** and only needs to be supported when SQLITE_TEST is defined.
 **
+** <li>[[SQLITE_FCNTL_NULL_IO]]
+** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
+** or file handle for the [sqlite3_file] object such that it will no longer
+** read or write to the database file.
+**
 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
 ** be advantageous to block on the next WAL lock if the lock is not immediately
@@ -1238,6 +1244,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_EXTERNAL_READER        40
 #define SQLITE_FCNTL_CKSM_FILE              41
 #define SQLITE_FCNTL_RESET_CACHE            42
+#define SQLITE_FCNTL_NULL_IO                43
 
 /* deprecated names */
 #define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
@@ -2607,10 +2614,14 @@ struct sqlite3_mem_methods {
 ** deleted by the most recently completed INSERT, UPDATE or DELETE
 ** statement on the database connection specified by the only parameter.
 ** The two functions are identical except for the type of the return value
-** and that if the number of rows modified by the most recent INSERT, UPDATE
+** and that if the number of rows modified by the most recent INSERT, UPDATE,
 ** or DELETE is greater than the maximum value supported by type "int", then
 ** the return value of sqlite3_changes() is undefined. ^Executing any other
 ** type of SQL statement does not modify the value returned by these functions.
+** For the purposes of this interface, a CREATE TABLE AS SELECT statement
+** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
+** added to the new table by the CREATE TABLE AS SELECT statement are not
+** counted.
 **
 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
@@ -4085,11 +4096,22 @@ typedef struct sqlite3_stmt sqlite3_stmt;
 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
 ** to return an error (error code SQLITE_ERROR) if the statement uses
 ** any virtual tables.
+**
+** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
+** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
+** errors from being sent to the error log defined by
+** [SQLITE_CONFIG_LOG].  This can be used, for example, to do test
+** compiles to see if some SQL syntax is well-formed, without generating
+** messages on the global error log when it is not.  If the test compile
+** fails, the sqlite3_prepare_v3() call returns the same error indications
+** with or without this flag; it just omits the call to [sqlite3_log()] that
+** logs the error.
 ** </dl>
 */
 #define SQLITE_PREPARE_PERSISTENT              0x01
 #define SQLITE_PREPARE_NORMALIZE               0x02
 #define SQLITE_PREPARE_NO_VTAB                 0x04
+#define SQLITE_PREPARE_DONT_LOG                0x10
 
 /*
 ** CAPI3REF: Compiling An SQL Statement
@@ -10321,7 +10343,7 @@ typedef struct sqlite3_snapshot {
 #ifdef __cplusplus
 }  /* End of the 'extern "C"' block */
 #endif
-#endif /* SQLITE3_H */
+/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
 
 /******** Begin file sqlite3rtree.h *********/
 /*
@@ -12318,14 +12340,29 @@ struct Fts5PhraseIter {
 **   value returned by xInstCount(), SQLITE_RANGE is returned.  Otherwise,
 **   output variable (*ppToken) is set to point to a buffer containing the
 **   matching document token, and (*pnToken) to the size of that buffer in
-**   bytes. This API is not available if the specified token matches a
-**   prefix query term. In that case both output variables are always set
-**   to 0.
+**   bytes.
 **
 **   The output text is not a copy of the document text that was tokenized.
 **   It is the output of the tokenizer module. For tokendata=1 tables, this
 **   includes any embedded 0x00 and trailing data.
 **
+**   This API may be slow in some cases if the token identified by parameters
+**   iIdx and iToken matched a prefix token in the query. In most cases, the
+**   first call to this API for each prefix token in the query is forced
+**   to scan the portion of the full-text index that matches the prefix
+**   token to collect the extra data required by this API. If the prefix
+**   token matches a large number of token instances in the document set,
+**   this may be a performance problem.
+**
+**   If the user knows in advance that a query may use this API for a
+**   prefix token, FTS5 may be configured to collect all required data as part
+**   of the initial querying of the full-text index, avoiding the second scan
+**   entirely. This also causes prefix queries that do not use this API to
+**   run more slowly and use more memory. FTS5 may be configured in this way
+**   either on a per-table basis using the [FTS5 insttoken | 'insttoken']
+**   option, or on a per-query basis using the
+**   [fts5_insttoken | fts5_insttoken()] user function.
+**
 **   This API can be quite slow if used with an FTS5 table created with the
 **   "detail=none" or "detail=column" option.
 **
@@ -12759,3 +12796,4 @@ struct fts5_api {
 #endif /* _FTS5_H */
 
 /******** End of fts5.h *********/
+#endif /* SQLITE3_H */