Further simplification and modularization of the EXPLAIN logic.

FossilOrigin-Name: aee1c12f4227cea9e8c6295cee3ec11797422c31b48c9468f176eb52f8261fe8

manifest

@@ -1,5 +1,5 @@
-C Begin\sbreaking\sappear\sthe\ssqlite3VdbeList()\sroutine\sinto\ssubroutines\sthat\ncan\sbe\sreused\sby\sthe\sbytecode()\stable.
+C Further\ssimplification\sand\smodularization\sof\sthe\sEXPLAIN\slogic.
-D 2020-03-23T17:24:46.014
+D 2020-03-23T19:14:11.433
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -607,7 +607,7 @@ F src/vdbe.c c1c123c6248fa88940b932a00bcc75056921b6d046d45a82566cb97415d2299c
 F src/vdbe.h 07b8c636a87df8b6e58f29d6badd7f10d5844353deff1d7c88ed1c2bfe3bbd35
 F src/vdbeInt.h 198e552a1a8945061c7576d3d7f8c8603300bbbb9ba0a337184bf13a7cdda65d
 F src/vdbeapi.c 1252d80c548711e47a6d84dae88ed4e95d3fbb4e7bd0eaa1347299af7efddf02
-F src/vdbeaux.c 46991da5699ff4986c15264c46d6300a56c008b758adade974dcebb5b9dba74e
+F src/vdbeaux.c a041e907fed078029e6d7608f62acf9d69ea262d515b00254f8736eff5f4d363
 F src/vdbeblob.c 253ed82894924c362a7fa3079551d3554cd1cdace39aa833da77d3bc67e7c1b1
 F src/vdbemem.c 39b942ecca179f4f30a32b54579a85d74ccaefa5af2a0ad2700abe5ef0768b22
 F src/vdbesort.c 2be76d26998ce2b3324cdcc9f6443728e54b6c7677c553ad909c7d7cfab587df
@@ -821,7 +821,7 @@ F test/descidx1.test edc8adee58d491b06c7157c50364eaf1c3605c9c19f8093cb1ea2b6184f
 F test/descidx2.test a0ba347037ff3b811f4c6ceca5fd0f9d5d72e74e59f2d9de346a9d2f6ad78298
 F test/descidx3.test 953c831df7ea219c73826dfbf2f6ee02d95040725aa88ccb4fa43d1a1999b926
 F test/diskfull.test 106391384780753ea6896b7b4f005d10e9866b6e
-F test/distinct.test 8b6c652f0b2d477f0830884736f2a1cd2e8f7fc10a04aa6d571a401fa13ed88b
+F test/distinct.test e7d0cf371944dd0cbedff86420744e2f1ea2b528156451c97eb6ff41a99b9236
 F test/distinct2.test 11b0594c932098e969d084ba45ab81d5040f4d4e766db65d49146705a305ed98
 F test/distinctagg.test 1a6ef9c87a58669438fc771450d7a72577417376
 F test/e_blobbytes.test 439a945953b35cb6948a552edaec4dc31fd70a05
@@ -1861,7 +1861,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2795f0d633577e0de66b389d9e8e44c55e85975bdc62f1a0b8f93959d19b22bf
+P 2c4dd79fbd4b9f72634a732abb9ed833cd8c9b05fe1e10af8f23e6d6ec023c7c
-R d0c0c7fad919870cffac31ef6d1a6170
+R 4748d2ea6081821a30c83e5089756745
 U drh
-Z bedd18e23757a54ddb7ae33ec04cb1e6
+Z 573498e339f1a839323caa9c87282f78

manifest.uuid

@@ -1 +1 @@
-2c4dd79fbd4b9f72634a732abb9ed833cd8c9b05fe1e10af8f23e6d6ec023c7c
+aee1c12f4227cea9e8c6295cee3ec11797422c31b48c9468f176eb52f8261fe8

src/vdbeaux.c

@@ -1464,11 +1464,10 @@ static int translateP(char c, const Op *pOp){
 **       "PX@PY+1" ->  "r[X..X+Y]"    or "r[x]" if y is 0
 **       "PY..PY"  ->  "r[X..Y]"      or "r[x]" if y<=x
 */
-static int displayComment(
+static char *displayComment(
+  sqlite3 *db,       /* Optional - Oom error reporting only */
   const Op *pOp,     /* The opcode to be commented */
-  const char *zP4,   /* Previously obtained value for P4 */
+  const char *zP4    /* Previously obtained value for P4 */
-  char *zTemp,       /* Write result here */
-  int nTemp          /* Space available in zTemp[] */
 ){
   const char *zOpName;
   const char *zSynopsis;
@@ -1476,8 +1475,8 @@ static int displayComment(
   int ii;
   char zAlt[50];
   StrAccum x;
-  sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
 
+  sqlite3StrAccumInit(&x, 0, 0, 0, SQLITE_MAX_LENGTH);
   zOpName = sqlite3OpcodeName(pOp->opcode);
   nOpName = sqlite3Strlen30(zOpName);
   if( zOpName[nOpName+1] ){
@@ -1544,8 +1543,10 @@ static int displayComment(
   }else if( pOp->zComment ){
     sqlite3_str_appendall(&x, pOp->zComment);
   }
-  sqlite3StrAccumFinish(&x);
+  if( (x.accError & SQLITE_NOMEM)!=0 && db!=0 ){
-  return x.nChar;
+    sqlite3OomFault(db);
+  }
+  return sqlite3StrAccumFinish(&x);
 }
 #endif /* SQLITE_DEBUG */
 
@@ -1628,11 +1629,11 @@ static void displayP4Expr(StrAccum *p, Expr *pExpr){
 ** Compute a string that describes the P4 parameter for an opcode.
 ** Use zTemp for any required temporary buffer space.
 */
-static char *displayP4(Op *pOp, char *zTemp, int nTemp){
+static char *displayP4(sqlite3 *db, Op *pOp){
-  char *zP4 = zTemp;
+  char *zP4 = 0;
   StrAccum x;
-  assert( nTemp>=20 );
+
-  sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
+  sqlite3StrAccumInit(&x, 0, 0, 0, SQLITE_MAX_LENGTH);
   switch( pOp->p4type ){
     case P4_KEYINFO: {
       int j;
@@ -1718,34 +1719,31 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
       for(i=1; i<=n; i++){
         sqlite3_str_appendf(&x, ",%d", ai[i]);
       }
-      zTemp[0] = '[';
+      if( !x.accError ) x.zText[0] = '[';
       sqlite3_str_append(&x, "]", 1);
       break;
     }
     case P4_SUBPROGRAM: {
-      sqlite3_str_appendf(&x, "program");
+      zP4 = "program";
       break;
     }
     case P4_DYNBLOB:
     case P4_ADVANCE: {
-      zTemp[0] = 0;
       break;
     }
     case P4_TABLE: {
-      sqlite3_str_appendf(&x, "%s", pOp->p4.pTab->zName);
+      zP4 = pOp->p4.pTab->zName;
       break;
     }
     default: {
       zP4 = pOp->p4.z;
-      if( zP4==0 ){
-        zP4 = zTemp;
-        zTemp[0] = 0;
-      }
     }
   }
-  sqlite3StrAccumFinish(&x);
+  if( zP4 ) sqlite3_str_appendall(&x, zP4);
-  assert( zP4!=0 );
+  if( (x.accError & SQLITE_NOMEM)!=0 && db!=0 ){
-  return zP4;
+    sqlite3OomFault(db);
+  }
+  return sqlite3StrAccumFinish(&x);
 }
 #endif /* VDBE_DISPLAY_P4 */
 
@@ -1835,24 +1833,25 @@ void sqlite3VdbeLeave(Vdbe *p){
 */
 void sqlite3VdbePrintOp(FILE *pOut, int pc, VdbeOp *pOp){
   char *zP4;
-  char zPtr[50];
+  char *zCom;
-  char zCom[100];
   static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";
   if( pOut==0 ) pOut = stdout;
-  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
+  zP4 = displayP4(0, pOp);
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-  displayComment(pOp, zP4, zCom, sizeof(zCom));
+  zCom = displayComment(0, pOp, zP4);
 #else
-  zCom[0] = 0;
+  zCom = 0;
 #endif
   /* NB:  The sqlite3OpcodeName() function is implemented by code created
   ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the
   ** information from the vdbe.c source text */
   fprintf(pOut, zFormat1, pc, 
       sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
-      zCom
+      zCom ? zCom : ""
   );
   fflush(pOut);
+  sqlite3_free(zP4);
+  sqlite3_free(zCom);
 }
 #endif
 
@@ -2133,76 +2132,41 @@ int sqlite3VdbeList(
       rc = SQLITE_ERROR;
       sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
     }else{
-      char *zP4;
+      char *zP4 = displayP4(db, pOp);
-      if( p->explain==1 ){
+      if( p->explain==2 ){
-        pMem->flags = MEM_Int;
+        sqlite3VdbeMemSetInt64(pMem, pOp->p1);
-        pMem->u.i = i;                                /* Program counter */
+        sqlite3VdbeMemSetInt64(pMem+1, pOp->p2);
-        pMem++;
+        sqlite3VdbeMemSetInt64(pMem+2, pOp->p3);
-    
+        sqlite3VdbeMemSetStr(pMem+3, zP4, -1, SQLITE_UTF8, sqlite3_free);     
-        pMem->flags = MEM_Static|MEM_Str|MEM_Term;
+        p->nResColumn = 4;
-        pMem->z = (char*)sqlite3OpcodeName(pOp->opcode); /* Opcode */
-        assert( pMem->z!=0 );
-        pMem->n = sqlite3Strlen30(pMem->z);
-        pMem->enc = SQLITE_UTF8;
-        pMem++;
-      }
-
-      pMem->flags = MEM_Int;
-      pMem->u.i = pOp->p1;                          /* P1 */
-      pMem++;
-
-      pMem->flags = MEM_Int;
-      pMem->u.i = pOp->p2;                          /* P2 */
-      pMem++;
-
-      pMem->flags = MEM_Int;
-      pMem->u.i = pOp->p3;                          /* P3 */
-      pMem++;
-
-      if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
-        assert( p->db->mallocFailed );
-        return SQLITE_ERROR;
-      }
-      pMem->flags = MEM_Str|MEM_Term;
-      zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
-      if( zP4!=pMem->z ){
-        pMem->n = 0;
-        sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
       }else{
-        assert( pMem->z!=0 );
+        sqlite3VdbeMemSetInt64(pMem+0, i);
-        pMem->n = sqlite3Strlen30(pMem->z);
+        sqlite3VdbeMemSetStr(pMem+1, (char*)sqlite3OpcodeName(pOp->opcode),
-        pMem->enc = SQLITE_UTF8;
+                             -1, SQLITE_UTF8, SQLITE_STATIC);
-      }
+        sqlite3VdbeMemSetInt64(pMem+2, pOp->p1);
-      pMem++;
+        sqlite3VdbeMemSetInt64(pMem+3, pOp->p2);
-
+        sqlite3VdbeMemSetInt64(pMem+4, pOp->p3);
-      if( p->explain==1 ){
+        /* pMem+5 for p4 is done last */
-        if( sqlite3VdbeMemClearAndResize(pMem, 4) ){
+        sqlite3VdbeMemSetInt64(pMem+6, pOp->p5);
-          assert( p->db->mallocFailed );
-          return SQLITE_ERROR;
-        }
-        pMem->flags = MEM_Str|MEM_Term;
-        pMem->n = 2;
-        sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5);   /* P5 */
-        pMem->enc = SQLITE_UTF8;
-        pMem++;
-    
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-        if( sqlite3VdbeMemClearAndResize(pMem, 500) ){
+        {
-          assert( p->db->mallocFailed );
+          char *zCom = displayComment(db, pOp, zP4);
-          return SQLITE_ERROR;
+          sqlite3VdbeMemSetStr(pMem+7, zCom, -1, SQLITE_UTF8, sqlite3_free);
         }
-        pMem->flags = MEM_Str|MEM_Term;
-        pMem->n = displayComment(pOp, zP4, pMem->z, 500);
-        pMem->enc = SQLITE_UTF8;
 #else
-        pMem->flags = MEM_Null;                       /* Comment */
+        sqlite3VdbeMemSetNull(pMem+7);
 #endif
+        sqlite3VdbeMemSetStr(pMem+5, zP4, -1, SQLITE_UTF8, sqlite3_free);
+        p->nResColumn = 8;
+      }
+      p->pResultSet = pMem;
+      if( db->mallocFailed ){
+        p->rc = SQLITE_NOMEM;
+        rc = SQLITE_ERROR;
+      }else{
+        p->rc = SQLITE_OK;
+        rc = SQLITE_ROW;
       }
-
-      p->nResColumn = 8 - 4*(p->explain-1);
-      p->pResultSet = &p->aMem[1];
-      p->rc = SQLITE_OK;
-      rc = SQLITE_ROW;
     }
   }
   return rc;

test/distinct.test

@@ -51,8 +51,8 @@ proc do_temptables_test {tn sql temptables} {
     set ret ""
     db eval "EXPLAIN [set sql]" {
       if {$opcode == "OpenEphemeral" || $opcode == "SorterOpen"} { 
-        if {$p5 != "08" && $p5!="00"} { error "p5 = $p5" }
+        if {$p5!=8 && $p5!=0} { error "p5 = $p5" }
-        if {$p5 == "08"} {
+        if {$p5==8} {
           lappend ret hash
         } else {
           lappend ret btree