Import SQLite 3.7.6.3.

third_party/sqlite/src/src/alter.c

Index: third_party/sqlite/src/src/alter.c
diff --git a/third_party/sqlite/src/src/alter.c b/third_party/sqlite/src/src/alter.c
index 819d5bbf8f4486636bb6dbe791ce2b1b1b7f5cbc..aa3fa929f82353aeaeb73d61a73c812af0620507 100644
--- a/third_party/sqlite/src/src/alter.c
+++ b/third_party/sqlite/src/src/alter.c
@@ -11,8 +11,6 @@
 *************************************************************************
 ** This file contains C code routines that used to generate VDBE code
 ** that implements the ALTER TABLE command.
-**
-** $Id: alter.c,v 1.62 2009/07/24 17:58:53 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -85,6 +83,69 @@ static void renameTableFunc(
   }
 }
 
+/*
+** This C function implements an SQL user function that is used by SQL code
+** generated by the ALTER TABLE ... RENAME command to modify the definition
+** of any foreign key constraints that use the table being renamed as the 
+** parent table. It is passed three arguments:
+**
+**   1) The complete text of the CREATE TABLE statement being modified,
+**   2) The old name of the table being renamed, and
+**   3) The new name of the table being renamed.
+**
+** It returns the new CREATE TABLE statement. For example:
+**
+**   sqlite_rename_parent('CREATE TABLE t1(a REFERENCES t2)', 't2', 't3')
+**       -> 'CREATE TABLE t1(a REFERENCES t3)'
+*/
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+static void renameParentFunc(
+  sqlite3_context *context,
+  int NotUsed,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  char *zOutput = 0;
+  char *zResult;
+  unsigned char const *zInput = sqlite3_value_text(argv[0]);
+  unsigned char const *zOld = sqlite3_value_text(argv[1]);
+  unsigned char const *zNew = sqlite3_value_text(argv[2]);
+
+  unsigned const char *z;         /* Pointer to token */
+  int n;                          /* Length of token z */
+  int token;                      /* Type of token */
+
+  UNUSED_PARAMETER(NotUsed);
+  for(z=zInput; *z; z=z+n){
+    n = sqlite3GetToken(z, &token);
+    if( token==TK_REFERENCES ){
+      char *zParent;
+      do {
+        z += n;
+        n = sqlite3GetToken(z, &token);
+      }while( token==TK_SPACE );
+
+      zParent = sqlite3DbStrNDup(db, (const char *)z, n);
+      if( zParent==0 ) break;
+      sqlite3Dequote(zParent);
+      if( 0==sqlite3StrICmp((const char *)zOld, zParent) ){
+        char *zOut = sqlite3MPrintf(db, "%s%.*s\"%w\"", 
+            (zOutput?zOutput:""), z-zInput, zInput, (const char *)zNew
+        );
+        sqlite3DbFree(db, zOutput);
+        zOutput = zOut;
+        zInput = &z[n];
+      }
+      sqlite3DbFree(db, zParent);
+    }
+  }
+
+  zResult = sqlite3MPrintf(db, "%s%s", (zOutput?zOutput:""), zInput), 
+  sqlite3_result_text(context, zResult, -1, SQLITE_DYNAMIC);
+  sqlite3DbFree(db, zOutput);
+}
+#endif
+
 #ifndef SQLITE_OMIT_TRIGGER
 /* This function is used by SQL generated to implement the
 ** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER 
@@ -165,16 +226,70 @@ static void renameTriggerFunc(
 /*
 ** Register built-in functions used to help implement ALTER TABLE
 */
-void sqlite3AlterFunctions(sqlite3 *db){
-  sqlite3CreateFunc(db, "sqlite_rename_table", 2, SQLITE_UTF8, 0,
-                         renameTableFunc, 0, 0);
+void sqlite3AlterFunctions(void){
+  static SQLITE_WSD FuncDef aAlterTableFuncs[] = {
+    FUNCTION(sqlite_rename_table,   2, 0, 0, renameTableFunc),
 #ifndef SQLITE_OMIT_TRIGGER
-  sqlite3CreateFunc(db, "sqlite_rename_trigger", 2, SQLITE_UTF8, 0,
-                         renameTriggerFunc, 0, 0);
+    FUNCTION(sqlite_rename_trigger, 2, 0, 0, renameTriggerFunc),
+#endif
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+    FUNCTION(sqlite_rename_parent,  3, 0, 0, renameParentFunc),
 #endif
+  };
+  int i;
+  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
+  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAlterTableFuncs);
+
+  for(i=0; i<ArraySize(aAlterTableFuncs); i++){
+    sqlite3FuncDefInsert(pHash, &aFunc[i]);
+  }
 }
 
 /*
+** This function is used to create the text of expressions of the form:
+**
+**   name=<constant1> OR name=<constant2> OR ...
+**
+** If argument zWhere is NULL, then a pointer string containing the text 
+** "name=<constant>" is returned, where <constant> is the quoted version
+** of the string passed as argument zConstant. The returned buffer is
+** allocated using sqlite3DbMalloc(). It is the responsibility of the
+** caller to ensure that it is eventually freed.
+**
+** If argument zWhere is not NULL, then the string returned is 
+** "<where> OR name=<constant>", where <where> is the contents of zWhere.
+** In this case zWhere is passed to sqlite3DbFree() before returning.
+** 
+*/
+static char *whereOrName(sqlite3 *db, char *zWhere, char *zConstant){
+  char *zNew;
+  if( !zWhere ){
+    zNew = sqlite3MPrintf(db, "name=%Q", zConstant);
+  }else{
+    zNew = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, zConstant);
+    sqlite3DbFree(db, zWhere);
+  }
+  return zNew;
+}
+
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+/*
+** Generate the text of a WHERE expression which can be used to select all
+** tables that have foreign key constraints that refer to table pTab (i.e.
+** constraints for which pTab is the parent table) from the sqlite_master
+** table.
+*/
+static char *whereForeignKeys(Parse *pParse, Table *pTab){
+  FKey *p;
+  char *zWhere = 0;
+  for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
+    zWhere = whereOrName(pParse->db, zWhere, p->pFrom->zName);
+  }
+  return zWhere;
+}
+#endif
+
+/*
 ** Generate the text of a WHERE expression which can be used to select all
 ** temporary triggers on table pTab from the sqlite_temp_master table. If
 ** table pTab has no temporary triggers, or is itself stored in the 
@@ -183,7 +298,6 @@ void sqlite3AlterFunctions(sqlite3 *db){
 static char *whereTempTriggers(Parse *pParse, Table *pTab){
   Trigger *pTrig;
   char *zWhere = 0;
-  char *tmp = 0;
   const Schema *pTempSchema = pParse->db->aDb[1].pSchema; /* Temp db schema */
 
   /* If the table is not located in the temp-db (in which case NULL is 
@@ -195,16 +309,15 @@ static char *whereTempTriggers(Parse *pParse, Table *pTab){
     sqlite3 *db = pParse->db;
     for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){
       if( pTrig->pSchema==pTempSchema ){
-        if( !zWhere ){
-          zWhere = sqlite3MPrintf(db, "name=%Q", pTrig->zName);
-        }else{
-          tmp = zWhere;
-          zWhere = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, pTrig->zName);
-          sqlite3DbFree(db, tmp);
-        }
+        zWhere = whereOrName(db, zWhere, pTrig->zName);
       }
     }
   }
+  if( zWhere ){
+    char *zNew = sqlite3MPrintf(pParse->db, "type='trigger' AND (%s)", zWhere);
+    sqlite3DbFree(pParse->db, zWhere);
+    zWhere = zNew;
+  }
   return zWhere;
 }
 
@@ -239,7 +352,7 @@ static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
   }
 #endif
 
-  /* Drop the table and index from the internal schema */
+  /* Drop the table and index from the internal schema.  */
   sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
 
   /* Reload the table, index and permanent trigger schemas. */
@@ -258,6 +371,22 @@ static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
 }
 
 /*
+** Parameter zName is the name of a table that is about to be altered
+** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
+** If the table is a system table, this function leaves an error message
+** in pParse->zErr (system tables may not be altered) and returns non-zero.
+**
+** Or, if zName is not a system table, zero is returned.
+*/
+static int isSystemTable(Parse *pParse, const char *zName){
+  if( sqlite3Strlen30(zName)>6 && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
+    sqlite3ErrorMsg(pParse, "table %s may not be altered", zName);
+    return 1;
+  }
+  return 0;
+}
+
+/*
 ** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
 ** command. 
 */
@@ -278,7 +407,9 @@ void sqlite3AlterRenameTable(
   char *zWhere = 0;         /* Where clause to locate temp triggers */
 #endif
   VTable *pVTab = 0;        /* Non-zero if this is a v-tab with an xRename() */
-  
+  int savedDbFlags;         /* Saved value of db->flags */
+
+  savedDbFlags = db->flags;  
   if( NEVER(db->mallocFailed) ) goto exit_rename_table;
   assert( pSrc->nSrc==1 );
   assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
@@ -287,6 +418,7 @@ void sqlite3AlterRenameTable(
   if( !pTab ) goto exit_rename_table;
   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
   zDb = db->aDb[iDb].zName;
+  db->flags |= SQLITE_PreferBuiltin;
 
   /* Get a NULL terminated version of the new table name. */
   zName = sqlite3NameFromToken(db, pName);
@@ -304,14 +436,11 @@ void sqlite3AlterRenameTable(
   /* Make sure it is not a system table being altered, or a reserved name
   ** that the table is being renamed to.
   */
-  if( sqlite3Strlen30(pTab->zName)>6 
-   && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7)
-  ){
-    sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
+  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
     goto exit_rename_table;
   }
-  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
-    goto exit_rename_table;
+  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
+    exit_rename_table;
   }
 
 #ifndef SQLITE_OMIT_VIEW
@@ -370,6 +499,21 @@ void sqlite3AlterRenameTable(
   zTabName = pTab->zName;
   nTabName = sqlite3Utf8CharLen(zTabName, -1);
 
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+  if( db->flags&SQLITE_ForeignKeys ){
+    /* If foreign-key support is enabled, rewrite the CREATE TABLE 
+    ** statements corresponding to all child tables of foreign key constraints
+    ** for which the renamed table is the parent table.  */
+    if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
+      sqlite3NestedParse(pParse, 
+          "UPDATE \"%w\".%s SET "
+              "sql = sqlite_rename_parent(sql, %Q, %Q) "
+              "WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
+      sqlite3DbFree(db, zWhere);
+    }
+  }
+#endif
+
   /* Modify the sqlite_master table to use the new table name. */
   sqlite3NestedParse(pParse,
       "UPDATE %Q.%s SET "
@@ -421,12 +565,25 @@ void sqlite3AlterRenameTable(
   }
 #endif
 
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+  if( db->flags&SQLITE_ForeignKeys ){
+    FKey *p;
+    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
+      Table *pFrom = p->pFrom;
+      if( pFrom!=pTab ){
+        reloadTableSchema(pParse, p->pFrom, pFrom->zName);
+      }
+    }
+  }
+#endif
+
   /* Drop and reload the internal table schema. */
   reloadTableSchema(pParse, pTab, zName);
 
 exit_rename_table:
   sqlite3SrcListDelete(db, pSrc);
   sqlite3DbFree(db, zName);
+  db->flags = savedDbFlags;
 }
 
 
@@ -515,6 +672,11 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
     sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
     return;
   }
+  if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
+    sqlite3ErrorMsg(pParse, 
+        "Cannot add a REFERENCES column with non-NULL default value");
+    return;
+  }
   if( pCol->notNull && !pDflt ){
     sqlite3ErrorMsg(pParse, 
         "Cannot add a NOT NULL column with default value NULL");
@@ -541,9 +703,11 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
   if( zCol ){
     char *zEnd = &zCol[pColDef->n-1];
+    int savedDbFlags = db->flags;
     while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
       *zEnd-- = '\0';
     }
+    db->flags |= SQLITE_PreferBuiltin;
     sqlite3NestedParse(pParse, 
         "UPDATE \"%w\".%s SET "
           "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
@@ -552,6 +716,7 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
       zTab
     );
     sqlite3DbFree(db, zCol);
+    db->flags = savedDbFlags;
   }
 
   /* If the default value of the new column is NULL, then set the file
@@ -607,6 +772,9 @@ void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
     sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
     goto exit_begin_add_column;
   }
+  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
+    goto exit_begin_add_column;
+  }
 
   assert( pTab->addColOffset>0 );
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
@@ -622,7 +790,6 @@ void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   if( !pNew ) goto exit_begin_add_column;
   pParse->pNewTable = pNew;
   pNew->nRef = 1;
-  pNew->dbMem = pTab->dbMem;
   pNew->nCol = pTab->nCol;
   assert( pNew->nCol>0 );
   nAlloc = (((pNew->nCol-1)/8)*8)+8;