Change the way generated columns are computed so that no column is computed

inside branch code that might not be taken.  Ticket [4fc08501f4e56692]

FossilOrigin-Name: 9e07b48934e9a972dcf62e3538b3b21ffa044c553feba0441675ac0bbe13bcb2

manifest

@@ -1,5 +1,5 @@
-C Minor\ssimplification\sto\sthe\schanges\sfrom\scheck-in\s[36c11ad51f].
+C Change\sthe\sway\sgenerated\scolumns\sare\scomputed\sso\sthat\sno\scolumn\sis\scomputed\ninside\sbranch\scode\sthat\smight\snot\sbe\staken.\s\sTicket\s[4fc08501f4e56692]
-D 2019-11-06T19:25:45.811
+D 2019-11-06T22:19:07.236
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -478,7 +478,7 @@ F src/date.c e1d8ac7102f3f283e63e13867acb0efa33861cf34f0faf4cdbaf9fa7a1eb7041
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c c12833de69cb655751487d2c5a59607e36be1c58ba1f4bd536609909ad47b319
 F src/delete.c c371a9f3517a4dd6a0b56ebab9588408eddf1eac0277b67b09e030bff99ee1fa
-F src/expr.c 254238a94328ab88b473dcce4b656afd488cb03fced627ad90fb4676c5fe417f
+F src/expr.c fad49e282d0aaa899becf5b2c4ed405aae1c872f0e952903c221adbf83b370b5
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 92a248ec0fa4ed8ab60c98d9b188ce173aaf218f32e7737ba77deb2a684f9847
 F src/func.c ed33e38cd642058182a31a3f518f2e34f4bbe53aa483335705c153c4d3e50b12
@@ -487,7 +487,7 @@ F src/hash.c 8d7dda241d0ebdafb6ffdeda3149a412d7df75102cecfc1021c98d6219823b19
 F src/hash.h 9d56a9079d523b648774c1784b74b89bd93fac7b365210157482e4319a468f38
 F src/hwtime.h 747c1bbe9df21a92e9c50f3bbec1de841dc5e5da
 F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
-F src/insert.c 4da4e4f8a0e0ae8ff57a5e26bf04448649702a5ad123119afab80dfb9a5e06c0
+F src/insert.c 6e40e8aaa3840255614c7f39c061ab2d0f1f46095d5f8ce63650e9c17425a3e4
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 4ddc65ae13c0d93db0ceedc8b14a28c8c260513448b0eb8c5a2ac375e3b6a85d
 F src/main.c 20c6325c581123b8771ecb938f60d7e31c8152be01b4bf8e5eefbb74671ea86f
@@ -531,7 +531,7 @@ F src/shell.c.in c06961f202f3cc50b819744b7331d3caea3d79d958402f4900b066824855746
 F src/sqlite.h.in 5ba20664cede7f4e6861541fad1f17bac50f7bf576b40a8784c54f9126a9edd4
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h cef696ce3293242c67b2339763608427bf72ee66f1f3a05389ac2a7b46001c31
-F src/sqliteInt.h 3ab4cce57fcda91b6b5377ba7d56dfb011d55b6a4a7d643c31dbefa06e00828a
+F src/sqliteInt.h a9afee1875df1784bf2fb5d02aece62a6a93dfd082b43bb4d5d2b5295a0042ae
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1021,7 +1021,7 @@ F test/fuzzer1.test 3d4c4b7e547aba5e5511a2991e3e3d07166cfbb8
 F test/fuzzer2.test a85ef814ce071293bce1ad8dffa217cbbaad4c14
 F test/fuzzerfault.test 8792cd77fd5bce765b05d0c8e01b9edcf8af8536
 F test/gcfault.test dd28c228a38976d6336a3fc42d7e5f1ad060cb8c
-F test/gencol1.test 9b0da1c019e6081c7d4862ed05afb56bf4fef0d0311ee88123147af635626546
+F test/gencol1.test 963d951f228b5f588bde3f6ed484fba517fd404d0b126d5ba9ed2334ea8f34d1
 F test/genesis.tcl 1e2e2e8e5cc4058549a154ff1892fe5c9de19f98
 F test/having.test e4098a4b8962f9596035c3b87a8928a10648acc509f1bb8d6f96413bbf79a1b3
 F test/hexlit.test 4a6a5f46e3c65c4bf1fa06f5dd5a9507a5627751
@@ -1849,7 +1849,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 36c11ad51fe9ab1bde0b98d0ea9b8588e07d168cd8027486749372894941ad93
+P 7bc8205dd9c1657c736a9c6a1a90dd9dad442accfbb77d296eaae2c09ab46bd1
-R 80e9f354c0a8ad398e848628e32a33df
+R f50edf50f4c4c65865633f57ab8f6227
-U mistachkin
+U drh
-Z c30d3c02879affde565b3a131605c576
+Z d609942b70a972c6842c87e626766609

manifest.uuid

@@ -1 +1 @@
-7bc8205dd9c1657c736a9c6a1a90dd9dad442accfbb77d296eaae2c09ab46bd1
+9e07b48934e9a972dcf62e3538b3b21ffa044c553feba0441675ac0bbe13bcb2

src/expr.c

@@ -3645,16 +3645,7 @@ expr_code_doover:
           iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
           if( pCol->colFlags & COLFLAG_GENERATED ){
-            if( pCol->colFlags & COLFLAG_BUSY ){
-              sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
-                              pCol->zName);
-              return 0;
-            }
-            pCol->colFlags |= COLFLAG_BUSY;
-            if( pCol->colFlags & COLFLAG_NOTAVAIL ){
             sqlite3ExprCodeGeneratedColumn(pParse, pCol, iSrc);
-            }
-            pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
             return iSrc;
           }else
 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */

src/insert.c

@@ -201,6 +201,16 @@ static int readsTable(Parse *p, int iDb, Table *pTab){
   return 0;
 }
 
+/* This walker callback will compute the union of colFlags flags for all
+** references columns in a CHECK constraint or generated column expression.
+*/
+static int exprColumnFlagUnion(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN ){
+    pWalker->eCode |= pWalker->u.pTab->aCol[pExpr->iColumn].colFlags;
+  }
+  return WRC_Continue;
+}
+
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
 /*
 ** All regular columns for table pTab have been puts into registers
@@ -215,7 +225,10 @@ void sqlite3ComputeGeneratedColumns(
   Table *pTab       /* The table */
 ){
   int i;
-  int nv;
+  Walker w;
+  Column *pRedo;
+  int eProgress;
+
   /* Because there can be multiple generated columns that refer to one another,
   ** this is a two-pass algorithm.  On the first pass, mark all generated
   ** columns as "not available".
@@ -227,29 +240,43 @@ void sqlite3ComputeGeneratedColumns(
       pTab->aCol[i].colFlags |= COLFLAG_NOTAVAIL;
     }
   }
+
+  w.u.pTab = pTab;
+  w.xExprCallback = exprColumnFlagUnion;
+  w.xSelectCallback = 0;
+  w.xSelectCallback2 = 0;
+
   /* On the second pass, compute the value of each NOT-AVAILABLE column.
   ** Companion code in the TK_COLUMN case of sqlite3ExprCodeTarget() will
   ** compute dependencies and mark remove the COLSPAN_NOTAVAIL mark, as
   ** they are needed.
   */
   pParse->iSelfTab = -iRegStore;
-  for(i=nv=0; i<pTab->nCol; i++){
+  do{
-    u32 colFlags = pTab->aCol[i].colFlags;
+    eProgress = 0;
-    if( (colFlags & COLFLAG_NOTAVAIL)!=0 ){
+    pRedo = 0;
-      assert( colFlags & COLFLAG_GENERATED );
+    for(i=0; i<pTab->nCol; i++){
-      if( colFlags & COLFLAG_VIRTUAL ){
+      Column *pCol = pTab->aCol + i;
-        /* Virtual columns go at the end */
+      if( (pCol->colFlags & COLFLAG_NOTAVAIL)!=0 ){
-        assert( pTab->nNVCol+nv == sqlite3TableColumnToStorage(pTab,i) );
+        int x;
-        sqlite3ExprCodeGeneratedColumn(pParse, &pTab->aCol[i],
+        pCol->colFlags |= COLFLAG_BUSY;
-                                       iRegStore+pTab->nNVCol+nv);
+        w.eCode = 0;
-      }else{
+        sqlite3WalkExpr(&w, pCol->pDflt);
-        /* Stored columns go in column order */
+        pCol->colFlags &= ~COLFLAG_BUSY;
-        assert( i-nv == sqlite3TableColumnToStorage(pTab,i) );
+        if( w.eCode & COLFLAG_NOTAVAIL ){
-        sqlite3ExprCodeGeneratedColumn(pParse, &pTab->aCol[i], iRegStore+i-nv);
+          pRedo = pCol;
+          continue;
         }
-      pTab->aCol[i].colFlags &= ~COLFLAG_NOTAVAIL;
+        eProgress = 1;
+        assert( pCol->colFlags & COLFLAG_GENERATED );
+        x = sqlite3TableColumnToStorage(pTab, i) + iRegStore;
+        sqlite3ExprCodeGeneratedColumn(pParse, pCol, x);
+        pCol->colFlags &= ~COLFLAG_NOTAVAIL;
       }
-    if( (colFlags & COLFLAG_VIRTUAL)!=0 ) nv++;
+    }
+  }while( pRedo && eProgress );
+  if( pRedo ){
+    sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pRedo->zName);
   }
   pParse->iSelfTab = 0;
 }

src/sqliteInt.h

@@ -3546,7 +3546,7 @@ struct Walker {
   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
   void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
   int walkerDepth;                          /* Number of subqueries */
-  u8 eCode;                                 /* A small processing code */
+  u16 eCode;                                /* A small processing code */
   union {                                   /* Extra data for callback */
     NameContext *pNC;                         /* Naming context */
     int n;                                    /* A counter */
@@ -3562,6 +3562,7 @@ struct Walker {
     struct WindowRewrite *pRewrite;           /* Window rewrite context */
     struct WhereConst *pConst;                /* WHERE clause constants */
     struct RenameCtx *pRename;                /* RENAME COLUMN context */
+    struct Table *pTab;                       /* Table of generated column */
   } u;
 };
 

test/gencol1.test

@@ -222,4 +222,16 @@ do_execsql_test gencol1-7.20 {
   SELECT 99 FROM t0 WHERE 0 = t0.c2 OR t0.c1 BETWEEN t0.c2 AND 1;  
 } {}
 
+# 2019-11-06 ticket 4fc08501f4e56692
+do_execsql_test gencol1-8.10 {
+  DROP TABLE IF EXISTS t0;
+  CREATE TABLE t0(
+    c0 AS (('a', 9) < ('b', c1)),
+    c1 AS (1),
+    c2 CHECK (1 = c1)
+  );
+  INSERT INTO t0 VALUES (0),(99);
+  SELECT * FROM t0;
+} {1 1 0 1 1 99}
+
 finish_test