Code to automatically create eponymous virtual tables for read-only pragmas.

Compiles, but does not yet work.

FossilOrigin-Name: 988a61e8b03f302c69d11898d1ea95f002cba1a5

manifest

@@ -1,5 +1,5 @@
-C Do\smore\spragma\sprocessing\sfrom\stables\srather\sthan\sin-line\scode.
+C Code\sto\sautomatically\screate\seponymous\svirtual\stables\sfor\sread-only\spragmas.\nCompiles,\sbut\sdoes\snot\syet\swork.
-D 2016-12-15T16:01:17.867
+D 2016-12-15T20:59:03.895
 F Makefile.in c194b58fe00c370a48ac6ae6945e92a7781db1c8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -334,7 +334,7 @@ F src/btmutex.c bc87dd3b062cc26edfe79918de2200ccb8d41e73
 F src/btree.c b2055dff0b94e03eaad48a760984a2d8e39244e6
 F src/btree.h 2349a588abcd7e0c04f984e15c5c777b61637583
 F src/btreeInt.h 10c4b77c2fb399580babbcc7cf652ac10dba796e
-F src/build.c e2b32766847eb16d4314c99067571ae08b888dfe
+F src/build.c 43c9c2bde195267364e92833b36e78f6c5afc66a
 F src/callback.c 2e76147783386374bf01b227f752c81ec872d730
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 9f2296a4e5d26ebf0e0d95a0af4628f1ea694e7a
@@ -381,8 +381,8 @@ F src/parse.y 29153738a7322054359320eb00b5a4cd44389f20
 F src/pcache.c 51070ec9b8251bbf9c6ea3d35fd96a458752929e
 F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
 F src/pcache1.c e3967219b2a92b9edcb9324a4ba75009090d3953
-F src/pragma.c 78f85cf6c668b084702bb305bd4980b4813afa70
+F src/pragma.c b2421f23af876cb7a2f9aca09e803e207a4750f1
-F src/pragma.h 7dff1007ade3aabf8b2e467107b4506940c0ad86
+F src/pragma.h f9b221b2c8949ea941dbee49934299e4ed5af41c
 F src/prepare.c b1140c3d0cf59bc85ace00ce363153041b424b7a
 F src/printf.c f94da4935d1dd25420ac50c6745db1deb35e07c1
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
@@ -393,7 +393,7 @@ F src/shell.c f1c7fde7a83421e6ed620df41d200674a2327e65
 F src/sqlite.h.in e8e2d108d82647f0a812fdb74accf91c1ec08ddc
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
-F src/sqliteInt.h 657a892d885253768c82f1e04e8053468b13cb6a
+F src/sqliteInt.h adbe80409c2926d91e5485789e5bf69313cd54b0
 F src/sqliteLimit.h c0373387c287c8d0932510b5547ecde31b5da247
 F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
 F src/table.c 5226df15ab9179b9ed558d89575ea0ce37b03fc9
@@ -464,7 +464,7 @@ F src/vdbeblob.c f4f98ea672b242f807c08c92c7faaa79e5091b65
 F src/vdbemem.c d3fd85b7b7ef3eb75de29c6d7e1d10d3ca78b4fd
 F src/vdbesort.c bb34eed4fb52e11ac037dccea4ee3190594c7f9e
 F src/vdbetrace.c 41963d5376f0349842b5fc4aaaaacd7d9cdc0834
-F src/vtab.c 2d5db3fd68c41c5a7476e43e79eb54181fa01713
+F src/vtab.c 24f3412e26511701cda951a32b7b33b693cdf450
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 40c543f0a2195d1b0dc88ef12142bea690009344
 F src/wal.h 06b2a0b599cc0f53ea97f497cf8c6b758c999f71
@@ -1474,7 +1474,7 @@ F tool/mkmsvcmin.tcl 2f12f7fa8858bbe61cf81820a2da96c79ed1ca8d
 F tool/mkopcodec.tcl d1b6362bd3aa80d5520d4d6f3765badf01f6c43c
 F tool/mkopcodeh.tcl a01d2c1d8a6205b03fc635adf3735b4c523befd3
 F tool/mkopts.tcl 66ac10d240cc6e86abd37dc908d50382f84ff46e
-F tool/mkpragmatab.tcl 999d7da2b77e83f24de01c3c8f90dc66411ce6d2
+F tool/mkpragmatab.tcl a30ee93515135466fc49ae881f75da07ebcafd19
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
 F tool/mksqlite3c-noext.tcl fef88397668ae83166735c41af99d79f56afaabb
 F tool/mksqlite3c.tcl 06b2e6a0f21cc0a5d70fbbd136b3e0a96470645e
@@ -1536,10 +1536,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 9cae4c2e300e20304ced0dc8c1415c4922185928
+P a88ca3524b97f296dffc68335466b3767a681747
-R d8e6c9c98262f0aea48f528b484866a4
+R 23c19e6ab9e9f56bda2263bb45958620
-T *branch * table-driven-pragma
+T *branch * pragma-as-vtab
-T *sym-table-driven-pragma *
+T *sym-pragma-as-vtab *
-T -sym-trunk *
+T -sym-table-driven-pragma *
 U drh
-Z 7260d2e6fdce7485555b88e6d856ce9f
+Z 91a2192a11c3bfa409136450c9378cb1

manifest.uuid

@@ -1 +1 @@
-a88ca3524b97f296dffc68335466b3767a681747
+988a61e8b03f302c69d11898d1ea95f002cba1a5

src/build.c

@@ -352,6 +352,9 @@ Table *sqlite3LocateTable(
       ** CREATE, then check to see if it is the name of an virtual table that
       ** can be an eponymous virtual table. */
       Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
+      if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
+        pMod = sqlite3PragmaVtabRegister(pParse->db, zName);
+      }
       if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
         return pMod->pEpoTab;
       }

src/pragma.c

@@ -167,7 +167,7 @@ static int changeTempStorage(Parse *pParse, const char *zStorageType){
 */
 static void setPragmaResultColumnNames(
   Vdbe *v,                     /* The query under construction */
-  const struct sPragmaNames *pPragma    /* The pragma */
+  const PragmaName *pPragma    /* The pragma */
 ){
   u8 n = pPragma->nPragCName;
   sqlite3VdbeSetNumCols(v, n==0 ? 1 : n);
@@ -275,6 +275,26 @@ const char *sqlite3JournalModename(int eMode){
   return azModeName[eMode];
 }
 
+/*
+** Locate a pragma in the aPragmaName[] array.
+*/
+static const PragmaName *pragmaLocate(const char *zName){
+  int upr, lwr, mid, rc;
+  lwr = 0;
+  upr = ArraySize(aPragmaName)-1;
+  while( lwr<=upr ){
+    mid = (lwr+upr)/2;
+    rc = sqlite3_stricmp(zName, aPragmaName[mid].zName);
+    if( rc==0 ) break;
+    if( rc<0 ){
+      upr = mid - 1;
+    }else{
+      lwr = mid + 1;
+    }
+  }
+  return lwr>upr ? 0 : &aPragmaName[mid];
+}
+
 /*
 ** Process a pragma statement.  
 **
@@ -303,12 +323,11 @@ void sqlite3Pragma(
   Token *pId;            /* Pointer to <id> token */
   char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
   int iDb;               /* Database index for <database> */
-  int lwr, upr, mid = 0;       /* Binary search bounds */
   int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
   sqlite3 *db = pParse->db;    /* The database connection */
   Db *pDb;                     /* The specific database being pragmaed */
   Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
-  const struct sPragmaNames *pPragma;
+  const PragmaName *pPragma;   /* The pragma */
 
   if( v==0 ) return;
   sqlite3VdbeRunOnlyOnce(v);
@@ -380,20 +399,8 @@ void sqlite3Pragma(
   }
 
   /* Locate the pragma in the lookup table */
-  lwr = 0;
+  pPragma = pragmaLocate(zLeft);
-  upr = ArraySize(aPragmaNames)-1;
+  if( pPragma==0 ) goto pragma_out;
-  while( lwr<=upr ){
-    mid = (lwr+upr)/2;
-    rc = sqlite3_stricmp(zLeft, aPragmaNames[mid].zName);
-    if( rc==0 ) break;
-    if( rc<0 ){
-      upr = mid - 1;
-    }else{
-      lwr = mid + 1;
-    }
-  }
-  if( lwr>upr ) goto pragma_out;
-  pPragma = &aPragmaNames[mid];
 
   /* Make sure the database schema is loaded if the pragma requires that */
   if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
@@ -1950,5 +1957,302 @@ pragma_out:
   sqlite3DbFree(db, zLeft);
   sqlite3DbFree(db, zRight);
 }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*****************************************************************************
+** Implementation of an eponymous virtual table that runs a pragma.
+**
+*/
+typedef struct PragmaVtab PragmaVtab;
+typedef struct PragmaVtabCursor PragmaVtabCursor;
+struct PragmaVtab {
+  sqlite3_vtab base;        /* Base class.  Must be first */
+  sqlite3 *db;              /* The database connection to which it belongs */
+  const PragmaName *pName;  /* Name of the pragma */
+  u8 nHidden;               /* Number of hidden columns */
+  u8 iHidden;               /* Index of the first hidden column */
+};
+struct PragmaVtabCursor {
+  sqlite3_vtab_cursor base; /* Base class.  Must be first */
+  sqlite3_stmt *pPragma;    /* The pragma statement to run */
+  sqlite_int64 iRowid;      /* Current rowid */
+  char *azArg[2];           /* Value of the argument and schema */
+};
+
+/* 
+** Pragma virtual table module xConnect method.
+*/
+static int pragmaVtabConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  const PragmaName *pPragma = (const PragmaName*)pAux;
+  PragmaVtab *pTab = 0;
+  int rc;
+  int i, j;
+  char cSep = '(';
+  StrAccum acc;
+  char zBuf[200];
+
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
+  sqlite3StrAccumAppendAll(&acc, "CREATE TABLE x");
+  for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){
+    sqlite3StrAccumAppend(&acc, &cSep, 1);
+    sqlite3StrAccumAppendAll(&acc, pragCName[j]);
+    cSep = ',';
+  }
+  j = 0;
+  if( pPragma->mPragFlg & PragFlg_Result1 ){
+    sqlite3StrAccumAppendAll(&acc, ",arg HIDDEN");
+    j++;
+  }
+  if( pPragma->mPragFlg & (PragFlg_SchemaOpt|PragFlg_SchemaReq) ){
+    sqlite3StrAccumAppendAll(&acc, ",schema HIDDEN");
+    j++;
+  }
+  sqlite3StrAccumAppend(&acc, ")", 1);
+  sqlite3StrAccumFinish(&acc);
+  assert( strlen(zBuf) < sizeof(zBuf)-1 );
+  rc = sqlite3_declare_vtab(db, zBuf);
+  if( rc==SQLITE_OK ){
+    pTab = (PragmaVtab*)sqlite3_malloc(sizeof(PragmaVtab));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pTab, 0, sizeof(PragmaVtab));
+      pTab->pName = pPragma;
+      pTab->db = db;
+      pTab->iHidden = i;
+      pTab->nHidden = j;
+    }
+  }else{
+    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+  }
+
+  *ppVtab = (sqlite3_vtab*)pTab;
+  return rc;
+}
+
+/* 
+** Pragma virtual table module xDisconnect method.
+*/
+static int pragmaVtabDisconnect(sqlite3_vtab *pVtab){
+  PragmaVtab *pTab = (PragmaVtab*)pVtab;
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/* Figure out the best index to use to search a pragma virtual table.
+**
+** There are not really any index choices.  But we want to encourage the
+** query planner to give == constraints on as many hidden parameters as
+** possible, and especially on the first hidden parameter.  So return a
+** high cost if hidden parameters are unconstrained.
+*/
+static int pragmaVtabBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  PragmaVtab *pTab = (PragmaVtab*)tab;
+  const struct sqlite3_index_constraint *pConstraint;
+  int i, j;
+  int seen[2];
+
+  if( pTab->nHidden==0 ){ return SQLITE_OK; }
+  pConstraint = pIdxInfo->aConstraint;
+  seen[0] = 0;
+  seen[1] = 0;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
+    if( pConstraint->iColumn < pTab->iHidden ) continue;
+    j = pConstraint->iColumn - pTab->iHidden;
+    assert( j < 2 );
+    if( seen[j] ) continue;
+    seen[j] = i;
+  }
+  if( seen[0]==0 ){
+    pIdxInfo->estimatedCost = (double)2147483647;
+    pIdxInfo->estimatedRows = 2147483647;
+    return SQLITE_OK;
+  }
+  j = seen[0];
+  pIdxInfo->aConstraintUsage[j].argvIndex = 1;
+  pIdxInfo->aConstraintUsage[j].omit = 1;
+  if( seen[1]==0 ) return SQLITE_OK;
+  pIdxInfo->estimatedCost = (double)20;
+  pIdxInfo->estimatedRows = 20;
+  j = seen[1];
+  pIdxInfo->aConstraintUsage[j].argvIndex = 2;
+  pIdxInfo->aConstraintUsage[j].omit = 1;
+  return SQLITE_OK;
+}
+
+/* Create a new cursor for the pragma virtual table */
+static int pragmaVtabOpen(sqlite3_vtab *pVtab, sqlite3_vtab_cursor **ppCursor){
+  PragmaVtabCursor *pCsr;
+  pCsr = (PragmaVtabCursor*)sqlite3_malloc(sizeof(*pCsr));
+  if( pCsr==0 ) return SQLITE_NOMEM;
+  memset(pCsr, 0, sizeof(PragmaVtabCursor));
+  pCsr->base.pVtab = pVtab;
+  *ppCursor = &pCsr->base;
+  return SQLITE_OK;
+}
+
+/* Clear all content from pragma virtual table cursor. */
+static void pragmaVtabCursorClear(PragmaVtabCursor *pCsr){
+  int i;
+  sqlite3_finalize(pCsr->pPragma);
+  pCsr->pPragma = 0;
+  for(i=0; i<ArraySize(pCsr->azArg); i++){
+    sqlite3_free(pCsr->azArg[i]);
+    pCsr->azArg[i] = 0;
+  }
+}
+
+/* Close a pragma virtual table cursor */
+static int pragmaVtabClose(sqlite3_vtab_cursor *cur){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)cur;
+  pragmaVtabCursorClear(pCsr);
+  return SQLITE_OK;
+}
+
+/* Advance the pragma virtual table cursor to the next row */
+static int pragmaVtabNext(sqlite3_vtab_cursor *pVtabCursor){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  int rc = SQLITE_OK;
+
+  /* Increment the xRowid value */
+  pCsr->iRowid++;
+  if( pCsr->pPragma ){
+    if( SQLITE_ROW!=sqlite3_step(pCsr->pPragma) ){
+      rc = sqlite3_finalize(pCsr->pPragma);
+      pCsr->pPragma = 0;
+      pragmaVtabCursorClear(pCsr);
+    }
+  }
+  return rc;
+}
+
+/* 
+** Pragma virtual table module xFilter method.
+*/
+static int pragmaVtabFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
+  int rc;
+  int i;
+  StrAccum acc;
+  char *zSql;
+
+  pragmaVtabCursorClear(pCsr);
+  for(i=0; i<argc; i++){
+    assert( i<ArraySize(pCsr->azArg) );
+    pCsr->azArg[i] = sqlite3_mprintf("%s", sqlite3_value_text(argv[i]));
+    if( pCsr->azArg[i]==0 ){
+      return SQLITE_NOMEM;
+    }
+  }
+  sqlite3StrAccumInit(&acc, 0, 0, 0, pTab->db->aLimit[SQLITE_MAX_SQL_LENGTH]);
+  sqlite3StrAccumAppendAll(&acc, "PRAGMA ");
+  if( pCsr->azArg[1] ){
+    sqlite3XPrintf(&acc, "%Q.", pCsr->azArg[1]);
+  }
+  sqlite3StrAccumAppendAll(&acc, pTab->pName->zName);
+  if( pCsr->azArg[0] ){
+    sqlite3XPrintf(&acc, "=%Q", pCsr->azArg[0]);
+  }
+  zSql = sqlite3StrAccumFinish(&acc);
+  if( zSql==0 ) return SQLITE_NOMEM;
+  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pPragma, 0);
+  sqlite3_free(zSql);
+  if( rc!=SQLITE_OK ){
+    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
+    return rc;
+  }
+  return pragmaVtabNext(pVtabCursor);
+}
+
+/*
+** Pragma virtual table module xEof method.
+*/
+static int pragmaVtabEof(sqlite3_vtab_cursor *pVtabCursor){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  return (pCsr->pPragma==0);
+}
+
+/* The xColumn method simply returns the corresponding column from
+** the PRAGMA.  
+*/
+static int pragmaVtabColumn(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  sqlite3_context *ctx, 
+  int i
+){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
+  if( i<pTab->iHidden ){
+    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pPragma, i));
+  }else{
+    sqlite3_result_text(ctx, pCsr->azArg[i-pTab->iHidden],-1,SQLITE_TRANSIENT);
+  }
+  return SQLITE_OK;
+}
+
+/* 
+** Pragma virtual table module xRowid method.
+*/
+static int pragmaVtabRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *p){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  *p = pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/* The pragma virtual table object */
+static const sqlite3_module pragmaVtabModule = {
+  0,                           /* iVersion */
+  0,                           /* xCreate - create a table */
+  pragmaVtabConnect,           /* xConnect - connect to an existing table */
+  pragmaVtabBestIndex,         /* xBestIndex - Determine search strategy */
+  pragmaVtabDisconnect,        /* xDisconnect - Disconnect from a table */
+  0,                           /* xDestroy - Drop a table */
+  pragmaVtabOpen,              /* xOpen - open a cursor */
+  pragmaVtabClose,             /* xClose - close a cursor */
+  pragmaVtabFilter,            /* xFilter - configure scan constraints */
+  pragmaVtabNext,              /* xNext - advance a cursor */
+  pragmaVtabEof,               /* xEof */
+  pragmaVtabColumn,            /* xColumn - read data */
+  pragmaVtabRowid,             /* xRowid - read data */
+  0,                           /* xUpdate - write data */
+  0,                           /* xBegin - begin transaction */
+  0,                           /* xSync - sync transaction */
+  0,                           /* xCommit - commit transaction */
+  0,                           /* xRollback - rollback transaction */
+  0,                           /* xFindFunction - function overloading */
+  0,                           /* xRename - rename the table */
+  0,                           /* xSavepoint */
+  0,                           /* xRelease */
+  0                            /* xRollbackTo */
+};
+
+/*
+** Check to see if zTabName is really the name of a pragma.  If it is,
+** then register an eponymous virtual table for that pragma and return
+** a pointer to the Module object for the new virtual table.
+*/
+Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){
+  const PragmaName *pName;
+  assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );
+  pName = pragmaLocate(zName+7);
+  if( pName==0 ) return 0;
+  if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;
+  assert( sqlite3HashFind(&db->aModule, zName)==0 );
+  return sqlite3VtabCreateModule(db, zName, &pragmaVtabModule, 0, 0);
+}
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #endif /* SQLITE_OMIT_PRAGMA */

src/pragma.h

@@ -114,14 +114,15 @@ static const char *const pragCName[] = {
 };
 
 /* Definitions of all built-in pragmas */
-static const struct sPragmaNames {
+typedef struct PragmaName {
   const char *const zName; /* Name of pragma */
   u8 ePragTyp;             /* PragTyp_XXX value */
   u8 mPragFlg;             /* Zero or more PragFlg_XXX values */
   u8 iPragCName;           /* Start of column names in pragCName[] */
   u8 nPragCName;           /* Num of col names. 0 means use pragma name */
   u32 iArg;                /* Extra argument */
-} aPragmaNames[] = {
+} PragmaName;
+static const PragmaName aPragmaName[] = {
 #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
  {/* zName:     */ "activate_extensions",
   /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,

src/sqliteInt.h

@@ -3563,6 +3563,9 @@ u32 sqlite3ExprListFlags(const ExprList*);
 int sqlite3Init(sqlite3*, char**);
 int sqlite3InitCallback(void*, int, char**, char**);
 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+Module *sqlite3PragmaVtabRegister(sqlite3*,const char *zName);
+#endif
 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
 void sqlite3ResetOneSchema(sqlite3*,int);
 void sqlite3CollapseDatabaseArray(sqlite3*);
@@ -4077,6 +4080,13 @@ void sqlite3AutoLoadExtensions(sqlite3*);
    int sqlite3VtabSavepoint(sqlite3 *, int, int);
    void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);
    VTable *sqlite3GetVTable(sqlite3*, Table*);
+   Module *sqlite3VtabCreateModule(
+     sqlite3*,
+     const char*,
+     const sqlite3_module*,
+     void*,
+     void(*)(void*)
+   );
 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
 #endif
 int sqlite3VtabEponymousTableInit(Parse*,Module*);

src/vtab.c

@@ -29,26 +29,19 @@ struct VtabCtx {
 };
 
 /*
-** The actual function that does the work of creating a new module.
+** Construct and install a Module object for a virtual table.  When this
-** This function implements the sqlite3_create_module() and
+** routine is called, it is guaranteed that all appropriate locks are held
-** sqlite3_create_module_v2() interfaces.
+** and the module is not already part of the connection.
 */
-static int createModule(
+Module *sqlite3VtabCreateModule(
   sqlite3 *db,                    /* Database in which module is registered */
   const char *zName,              /* Name assigned to this module */
   const sqlite3_module *pModule,  /* The definition of the module */
   void *pAux,                     /* Context pointer for xCreate/xConnect */
   void (*xDestroy)(void *)        /* Module destructor function */
 ){
-  int rc = SQLITE_OK;
-  int nName;
-
-  sqlite3_mutex_enter(db->mutex);
-  nName = sqlite3Strlen30(zName);
-  if( sqlite3HashFind(&db->aModule, zName) ){
-    rc = SQLITE_MISUSE_BKPT;
-  }else{
   Module *pMod;
+  int nName = sqlite3Strlen30(zName);
   pMod = (Module *)sqlite3DbMallocRawNN(db, sizeof(Module) + nName + 1);
   if( pMod ){
     Module *pDel;
@@ -66,10 +59,31 @@ static int createModule(
       sqlite3DbFree(db, pDel);
     }
   }
+  return pMod;
+}
+
+/*
+** The actual function that does the work of creating a new module.
+** This function implements the sqlite3_create_module() and
+** sqlite3_create_module_v2() interfaces.
+*/
+static int createModule(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+){
+  int rc = SQLITE_OK;
+
+  sqlite3_mutex_enter(db->mutex);
+  if( sqlite3HashFind(&db->aModule, zName) ){
+    rc = SQLITE_MISUSE_BKPT;
+  }else{
+    (void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy);
   }
   rc = sqlite3ApiExit(db, rc);
   if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
-
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }

tool/mkpragmatab.tcl

@@ -495,7 +495,7 @@ puts $fd "\175;"
 # Generate the lookup table
 #
 puts $fd "\n/* Definitions of all built-in pragmas */"
-puts $fd "static const struct sPragmaNames \173"
+puts $fd "typedef struct PragmaName \173"
 puts $fd "  const char *const zName; /* Name of pragma */"
 puts $fd "  u8 ePragTyp;             /* PragTyp_XXX value */"
 puts $fd "  u8 mPragFlg;             /* Zero or more PragFlg_XXX values */"
@@ -503,7 +503,8 @@ puts $fd {  u8 iPragCName;           /* Start of column names in pragCName[] */}
 puts $fd "  u8 nPragCName;          \
 /* Num of col names. 0 means use pragma name */"
 puts $fd "  u32 iArg;                /* Extra argument */"
-puts $fd "\175 aPragmaNames\[\] = \173"
+puts $fd "\175 PragmaName;"
+puts $fd "static const PragmaName aPragmaName\[\] = \173"
 
 set current_if {}
 set spacer [format {    %26s } {}]