From c9b39288aeff95dfc49f8edc247ddb705a502000 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 3 Oct 2016 16:33:14 +0000
Subject: [PATCH] Size and performance optimizations on the
 sqlite3ExprAssignVarNumber() routine.

FossilOrigin-Name: 109852e51e2cc2674940ba3e5097a92e66f88bb8
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/expr.c    | 42 ++++++++++++++++++++----------------------
 3 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/manifest b/manifest
index 7b46688fd3..f923ed6655 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Avoid\sunnecessary\sstrlen()\scalls\sin\ssqlite3ExprAssignVarNumber()\sby\spassing\sin\nthe\stoken\slength\sfrom\sthe\sparser.
-D 2016-10-03T15:28:24.522
+C Size\sand\sperformance\soptimizations\son\sthe\ssqlite3ExprAssignVarNumber()\sroutine.
+D 2016-10-03T16:33:14.952
 F Makefile.in 6fd48ffcf7c2deea7499062d1f3747f986c19678
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 5151cc64c4c05f3455f4f692ad11410a810d937f
@@ -339,7 +339,7 @@ F src/ctime.c e77f3dc297b4b65c96da78b4ae4272fdfae863d7
 F src/date.c 95c9a8d00767e7221a8e9a31f4e913fc8029bf6b
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c cb3f6300df24c26c609778b2731f82644b5532ec
-F src/expr.c cf99b1a327b4eb0a85d59f1c01d82bc2a318c544
+F src/expr.c aac0b8d39373ce8f1d47829ce12c3d7af90c46a6
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c b9ca262f6ad4d030a3cab737ebf9b0b3c8b4ac80
 F src/func.c 29cc9acb170ec1387b9f63eb52cd85f8de96c771
@@ -1525,7 +1525,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 5bb7cde0731d23411e9df02a957010f94203397b
-R ff4f5cc57903ee66db0f97f1966e5988
+P d15ae2e530cffea60263f203ac5f89b6790f4bd5
+R 02650575d610a64473014408e653c2e2
 U drh
-Z 380867cb8aabea21260823e30d45c1c4
+Z 400dafa0c844d13dbe01d3e4d393d771
diff --git a/manifest.uuid b/manifest.uuid
index 55acf477e4..b497f8d346 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d15ae2e530cffea60263f203ac5f89b6790f4bd5
\ No newline at end of file
+109852e51e2cc2674940ba3e5097a92e66f88bb8
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index dd0c3cc061..6d2ec437ff 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -953,13 +953,13 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
     assert( z[0]=='?' );
     pExpr->iColumn = (ynVar)(++pParse->nVar);
   }else{
-    ynVar x = 0;
+    ynVar x;
     if( z[0]=='?' ){
       /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
       ** use it as the variable number */
       i64 i;
       int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
-      pExpr->iColumn = x = (ynVar)i;
+      x = (ynVar)i;
       testcase( i==0 );
       testcase( i==1 );
       testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
@@ -967,7 +967,7 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
       if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
         sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
             db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
-        x = 0;
+        return;
       }
       if( i>pParse->nVar ){
         pParse->nVar = (int)i;
@@ -978,33 +978,31 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
       ** has never appeared before, reuse the same variable number
       */
       ynVar i;
-      for(i=0; i<pParse->nzVar; i++){
+      for(i=x=0; i<pParse->nzVar; i++){
         if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
-          pExpr->iColumn = x = (ynVar)i+1;
+          x = (ynVar)i+1;
           break;
         }
       }
-      if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
+      if( x==0 ) x = (ynVar)(++pParse->nVar);
     }
-    if( x>0 ){
-      if( x>pParse->nzVar ){
-        char **a;
-        a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
-        if( a==0 ){
-          assert( db->mallocFailed ); /* Error reported through mallocFailed */
-          return;
-        }
-        pParse->azVar = a;
-        memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
-        pParse->nzVar = x;
-      }
-      if( z[0]!='?' || pParse->azVar[x-1]==0 ){
-        sqlite3DbFree(db, pParse->azVar[x-1]);
-        pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
+    pExpr->iColumn = x;
+    if( x>pParse->nzVar ){
+      char **a;
+      a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
+      if( a==0 ){
+        assert( db->mallocFailed ); /* Error reported through mallocFailed */
+        return;
       }
+      pParse->azVar = a;
+      memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
+      pParse->nzVar = x;
+    }
+    if( pParse->azVar[x-1]==0 ){
+      pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
     }
   } 
-  if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
+  if( pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
     sqlite3ErrorMsg(pParse, "too many SQL variables");
   }
 }