Additional changes to reduce stack usage. The SQLITE_SMALL_STACK compile-time

option is now available. (CVS 6708)

FossilOrigin-Name: baea79fd0cfeb860973846c3f2776776c87f0ae3

4 files changed, 41 insertions, 24 deletions

diff --git a/src/func.c b/src/func.c
index 893406ceb..673b77e30 100644
--- a/src/func.c
+++ b/src/func.c
@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.236 2009/05/28 01:00:55 drh Exp $
+** $Id: func.c,v 1.237 2009/06/03 01:24:54 drh Exp $
 */
 #include "sqliteInt.h"
 #include <stdlib.h>
@@ -247,7 +247,7 @@ static void substrFunc(
 static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   int n = 0;
   double r;
-  char zBuf[500];  /* larger than the %f representation of the largest double */
+  char *zBuf;
   assert( argc==1 || argc==2 );
   if( argc==2 ){
     if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
@@ -257,9 +257,14 @@ static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   }
   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
   r = sqlite3_value_double(argv[0]);
-  sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
-  sqlite3AtoF(zBuf, &r);
-  sqlite3_result_double(context, r);
+  zBuf = sqlite3_mprintf("%.*f",n,r);
+  if( zBuf==0 ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    sqlite3AtoF(zBuf, &r);
+    sqlite3_free(zBuf);
+    sqlite3_result_double(context, r);
+  }
 }
 #endif
 
diff --git a/src/loadext.c b/src/loadext.c
index 0c1b5dd6a..1fa6aa39a 100644
--- a/src/loadext.c
+++ b/src/loadext.c
@@ -12,7 +12,7 @@
 ** This file contains code used to dynamically load extensions into
 ** the SQLite library.
 **
-** $Id: loadext.c,v 1.59 2009/05/20 02:40:46 drh Exp $
+** $Id: loadext.c,v 1.60 2009/06/03 01:24:54 drh Exp $
 */
 
 #ifndef SQLITE_CORE
@@ -354,6 +354,7 @@ static int sqlite3LoadExtension(
   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
   char *zErrmsg = 0;
   void **aHandle;
+  const int nMsg = 300;
 
   if( pzErrMsg ) *pzErrMsg = 0;
 
@@ -377,12 +378,14 @@ static int sqlite3LoadExtension(
   handle = sqlite3OsDlOpen(pVfs, zFile);
   if( handle==0 ){
     if( pzErrMsg ){
-      char zErr[256];
-      zErr[sizeof(zErr)-1] = '\0';
-      sqlite3_snprintf(sizeof(zErr)-1, zErr, 
-          "unable to open shared library [%s]", zFile);
-      sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
-      *pzErrMsg = sqlite3DbStrDup(0, zErr);
+      zErrmsg = sqlite3StackAllocZero(db, nMsg);
+      if( zErrmsg ){
+        sqlite3_snprintf(nMsg, zErrmsg, 
+            "unable to open shared library [%s]", zFile);
+        sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
+        *pzErrMsg = sqlite3DbStrDup(0, zErrmsg);
+        sqlite3StackFree(db, zErrmsg);
+      }
     }
     return SQLITE_ERROR;
   }
@@ -390,12 +393,14 @@ static int sqlite3LoadExtension(
                    sqlite3OsDlSym(pVfs, handle, zProc);
   if( xInit==0 ){
     if( pzErrMsg ){
-      char zErr[256];
-      zErr[sizeof(zErr)-1] = '\0';
-      sqlite3_snprintf(sizeof(zErr)-1, zErr,
-          "no entry point [%s] in shared library [%s]", zProc,zFile);
-      sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
-      *pzErrMsg = sqlite3DbStrDup(0, zErr);
+      zErrmsg = sqlite3StackAllocZero(db, nMsg);
+      if( zErrmsg ){
+        sqlite3_snprintf(nMsg, zErrmsg,
+            "no entry point [%s] in shared library [%s]", zProc,zFile);
+        sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
+        *pzErrMsg = sqlite3DbStrDup(0, zErrmsg);
+        sqlite3StackFree(db, zErrmsg);
+      }
       sqlite3OsDlClose(pVfs, handle);
     }
     return SQLITE_ERROR;
diff --git a/src/printf.c b/src/printf.c
index a2c79c5b5..d8d838693 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -5,7 +5,7 @@
 ** an historical reference.  Most of the "enhancements" have been backed
 ** out so that the functionality is now the same as standard printf().
 **
-** $Id: printf.c,v 1.103 2009/05/04 20:20:16 drh Exp $
+** $Id: printf.c,v 1.104 2009/06/03 01:24:54 drh Exp $
 **
 **************************************************************************
 **
@@ -189,11 +189,14 @@ static void appendSpace(StrAccum *pAccum, int N){
 
 /*
 ** On machines with a small stack size, you can redefine the
-** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
-** smaller values some %f conversions may go into an infinite loop.
+** SQLITE_PRINT_BUF_SIZE to be less than 350.
 */
 #ifndef SQLITE_PRINT_BUF_SIZE
-# define SQLITE_PRINT_BUF_SIZE 350
+# if defined(SQLITE_SMALL_STACK)
+#   define SQLITE_PRINT_BUF_SIZE 50
+# else
+#   define SQLITE_PRINT_BUF_SIZE 350
+# endif
 #endif
 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
 
diff --git a/src/where.c b/src/where.c
index 48651ceb9..d0f0b01d6 100644
--- a/src/where.c
+++ b/src/where.c
@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.399 2009/05/28 01:00:55 drh Exp $
+** $Id: where.c,v 1.400 2009/06/03 01:24:54 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -132,7 +132,11 @@ struct WhereClause {
   int nTerm;               /* Number of terms */
   int nSlot;               /* Number of entries in a[] */
   WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
-  WhereTerm aStatic[4];    /* Initial static space for a[] */
+#if defined(SQLITE_SMALL_STACK)
+  WhereTerm aStatic[1];    /* Initial static space for a[] */
+#else
+  WhereTerm aStatic[8];    /* Initial static space for a[] */
+#endif
 };
 
 /*