Export the column-metadata APIs to WASM. Doing so requires a non-default build of sqlite3.c, so this is a proof-of-concept branch saved just in case SQLITE_ENABLE_COLUMN_METADATA ever becomes the default for sqlite3.c.

FossilOrigin-Name: 59db3f639d1073678805dea26a4686eddfb238f055aa90bd429fc7fd33241502

ext/wasm/GNUmakefile

@@ -260,7 +260,8 @@ SQLITE_OPT.full-featured := \
   -DSQLITE_ENABLE_RTREE \
   -DSQLITE_ENABLE_SESSION \
   -DSQLITE_ENABLE_STMTVTAB \
-  -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+  -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION \
+  -DSQLITE_ENABLE_COLUMN_METADATA
 
 ifeq (0,$(wasm-bare-bones))
   # The so-called canonical build is full-featured:

ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-extras

@@ -1,12 +1,27 @@
+_sqlite3_column_database_name
+_sqlite3_column_origin_name
+_sqlite3_column_table_name
+_sqlite3_create_module
+_sqlite3_create_module_v2
 _sqlite3_create_window_function
-_sqlite3_progress_handler
-_sqlite3_set_authorizer
+_sqlite3_declare_vtab
+_sqlite3_drop_modules
 _sqlite3_preupdate_blobwrite
 _sqlite3_preupdate_count
 _sqlite3_preupdate_depth
 _sqlite3_preupdate_hook
 _sqlite3_preupdate_new
 _sqlite3_preupdate_old
+_sqlite3_progress_handler
+_sqlite3_set_authorizer
+_sqlite3_vtab_collation
+_sqlite3_vtab_distinct
+_sqlite3_vtab_in
+_sqlite3_vtab_in_first
+_sqlite3_vtab_in_next
+_sqlite3_vtab_nochange
+_sqlite3_vtab_on_conflict
+_sqlite3_vtab_rhs_value
 _sqlite3changegroup_add
 _sqlite3changegroup_add_strm
 _sqlite3changegroup_delete
@@ -49,15 +64,3 @@ _sqlite3session_object_config
 _sqlite3session_patchset
 _sqlite3session_patchset_strm
 _sqlite3session_table_filter
-_sqlite3_create_module
-_sqlite3_create_module_v2
-_sqlite3_declare_vtab
-_sqlite3_drop_modules
-_sqlite3_vtab_collation
-_sqlite3_vtab_distinct
-_sqlite3_vtab_in
-_sqlite3_vtab_in_first
-_sqlite3_vtab_in_next
-_sqlite3_vtab_nochange
-_sqlite3_vtab_on_conflict
-_sqlite3_vtab_rhs_value

ext/wasm/api/sqlite3-api-glue.c-pp.js

@@ -368,6 +368,14 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     );
   }/* sqlite3_set_authorizer() */
 
+  if( !!wasm.exports.sqlite3_column_origin_name ){
+    wasm.bindingSignatures.push(
+      ["sqlite3_column_database_name","string", "sqlite3_stmt*", "int"],
+      ["sqlite3_column_origin_name","string", "sqlite3_stmt*", "int"],
+      ["sqlite3_column_table_name","string", "sqlite3_stmt*", "int"]
+    );
+  }
+
   if(false && wasm.compileOptionUsed('SQLITE_ENABLE_NORMALIZE')){
     /* ^^^ "the problem" is that this is an optional feature and the
        build-time function-export list does not currently take

ext/wasm/api/sqlite3-wasm.c

@@ -135,9 +135,12 @@
 
 /*
 ** If SQLITE_WASM_BARE_BONES is defined, undefine most of the ENABLE
-** macros.
+** macros. This will, when using the canonical makefile, also elide
+** any C functions from the WASM exports which are listed in
+** ./EXPORT_FUNCTIONS.sqlite3-extras.
 */
 #ifdef SQLITE_WASM_BARE_BONES
+#  undef  SQLITE_ENABLE_COLUMN_METADATA
 #  undef  SQLITE_ENABLE_DBPAGE_VTAB
 #  undef  SQLITE_ENABLE_DBSTAT_VTAB
 #  undef  SQLITE_ENABLE_EXPLAIN_COMMENTS

ext/wasm/tester1.c-pp.js

@@ -3302,7 +3302,7 @@ globalThis.sqlite3InitModule = sqlite3InitModule;
           .assert(true === await u3.removeVfs())
           .assert(false === await P3b.removeVfs());
       }
-    }/*OPFS SAH Pool sanity checks*/)
+    }/*OPFS SAH Pool sanity checks*/);
 
   ////////////////////////////////////////////////////////////////////////
   T.g('Misc. APIs')
@@ -3353,6 +3353,16 @@ globalThis.sqlite3InitModule = sqlite3InitModule;
       T.assert( 1===n )
         .assert( 0===capi.sqlite3_stmt_busy(stmt) )
         .assert( !stmt.isBusy() );
+
+      if( wasm.exports.sqlite3_column_origin_name ){
+        log("Column metadata APIs enabled");
+        T.assert( "t" === capi.sqlite3_column_table_name(stmt, 0))
+          .assert("a" === capi.sqlite3_column_origin_name(stmt, 0))
+          .assert("main" === capi.sqlite3_column_database_name(stmt, 0))
+      }else{
+        log("Column metadata APIs not enabled");
+      } // column metadata APIs
+
       stmt.finalize();
       db.close();
     })
@@ -3364,7 +3374,7 @@ globalThis.sqlite3InitModule = sqlite3InitModule;
       capi.sqlite3_interrupt(db);
       T.assert( 0!==capi.sqlite3_is_interrupted(db) );
       db.close();
-    })
+    });
 
   ////////////////////////////////////////////////////////////////////////
   T.g('Bug Reports')