[sql] Import reference version of SQLite 3.10.2.

third_party/sqlite/sqlite-src-3100200/src/util.c

 /*
 ** 2001 September 15
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
 ** Utility functions used throughout sqlite.
 **
 ** This file contains functions for allocating memory, comparing
 ** strings, and stuff like that.
 **
 */
 #include "sqliteInt.h"
 #include <stdarg.h>
-#ifdef SQLITE_HAVE_ISNAN
+#if HAVE_ISNAN || SQLITE_HAVE_ISNAN
 # include <math.h>
 #endif
 
 /*
 ** Routine needed to support the testcase() macro.
 */
 #ifdef SQLITE_COVERAGE_TEST
 void sqlite3Coverage(int x){
   static unsigned dummy = 0;
   dummy += (unsigned)x;
@@ skipping 20 matching lines @@
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Return true if the floating point value is Not a Number (NaN).
 **
 ** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN.
 ** Otherwise, we have our own implementation that works on most systems.
 */
 int sqlite3IsNaN(double x){
   int rc;   /* The value return */
-#if !defined(SQLITE_HAVE_ISNAN)
+#if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN
   /*
   ** Systems that support the isnan() library function should probably
   ** make use of it by compiling with -DSQLITE_HAVE_ISNAN.  But we have
   ** found that many systems do not have a working isnan() function so
   ** this implementation is provided as an alternative.
   **
   ** This NaN test sometimes fails if compiled on GCC with -ffast-math.
   ** On the other hand, the use of -ffast-math comes with the following
   ** warning:
   **
   **      This option [-ffast-math] should never be turned on by any
   **      -O option since it can result in incorrect output for programs
   **      which depend on an exact implementation of IEEE or ISO 
   **      rules/specifications for math functions.
   **
   ** Under MSVC, this NaN test may fail if compiled with a floating-
   ** point precision mode other than /fp:precise.  From the MSDN 
   ** documentation:
   **
   **      The compiler [with /fp:precise] will properly handle comparisons 
   **      involving NaN. For example, x != x evaluates to true if x is NaN 
   **      ...
   */
 #ifdef __FAST_MATH__
 # error SQLite will not work correctly with the -ffast-math option of GCC.
 #endif
   volatile double y = x;
   volatile double z = y;
   rc = (y!=z);
-#else  /* if defined(SQLITE_HAVE_ISNAN) */
+#else  /* if HAVE_ISNAN */
   rc = isnan(x);
-#endif /* SQLITE_HAVE_ISNAN */
+#endif /* HAVE_ISNAN */
   testcase( rc );
   return rc;
 }
 #endif /* SQLITE_OMIT_FLOATING_POINT */
 
 /*
 ** Compute a string length that is limited to what can be stored in
 ** lower 30 bits of a 32-bit signed integer.
 **
 ** The value returned will never be negative.  Nor will it ever be greater
 ** than the actual length of the string.  For very long strings (greater
 ** than 1GiB) the value returned might be less than the true string length.
 */
 int sqlite3Strlen30(const char *z){
-  const char *z2 = z;
   if( z==0 ) return 0;
-  while( *z2 ){ z2++; }
-  return 0x3fffffff & (int)(z2 - z);
+  return 0x3fffffff & (int)strlen(z);
 }
 
 /*
 ** Set the current error code to err_code and clear any prior error message.
 */
 void sqlite3Error(sqlite3 *db, int err_code){
   assert( db!=0 );
   db->errCode = err_code;
   if( db->pErr ) sqlite3ValueSetNull(db->pErr);
 }
@@ skipping 122 matching lines @@
 ** there is no consistency, we will define our own.
 **
 ** IMPLEMENTATION-OF: R-30243-02494 The sqlite3_stricmp() and
 ** sqlite3_strnicmp() APIs allow applications and extensions to compare
 ** the contents of two buffers containing UTF-8 strings in a
 ** case-independent fashion, using the same definition of "case
 ** independence" that SQLite uses internally when comparing identifiers.
 */
 int sqlite3_stricmp(const char *zLeft, const char *zRight){
   register unsigned char *a, *b;
+  if( zLeft==0 ){
+    return zRight ? -1 : 0;
+  }else if( zRight==0 ){
+    return 1;
+  }
   a = (unsigned char *)zLeft;
   b = (unsigned char *)zRight;
   while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
   return UpperToLower[*a] - UpperToLower[*b];
 }
 int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
   register unsigned char *a, *b;
+  if( zLeft==0 ){
+    return zRight ? -1 : 0;
+  }else if( zRight==0 ){
+    return 1;
+  }
   a = (unsigned char *)zLeft;
   b = (unsigned char *)zRight;
   while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
   return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
 }
 
 /*
 ** The string z[] is an text representation of a real number.
 ** Convert this string to a double and write it into *pResult.
 **
@@ skipping 269 matching lines @@
   if( u>LARGEST_INT64 ){
     *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64;
   }else if( neg ){
     *pNum = -(i64)u;
   }else{
     *pNum = (i64)u;
   }
   testcase( i==18 );
   testcase( i==19 );
   testcase( i==20 );
-  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr || nonNum ){
+  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum)
+       || i>19*incr || nonNum ){
     /* zNum is empty or contains non-numeric text or is longer
     ** than 19 digits (thus guaranteeing that it is too large) */
     return 1;
   }else if( i<19*incr ){
     /* Less than 19 digits, so we know that it fits in 64 bits */
     assert( u<=LARGEST_INT64 );
     return 0;
   }else{
     /* zNum is a 19-digit numbers.  Compare it against 9223372036854775808. */
     c = compare2pow63(zNum, incr);
@@ skipping 77 matching lines @@
       u = u*16 + sqlite3HexToInt(zNum[i]);
     }
     if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){
       memcpy(pValue, &u, 4);
       return 1;
     }else{
       return 0;
     }
   }
 #endif
+  while( zNum[0]=='0' ) zNum++;
   for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
     v = v*10 + c;
   }
 
   /* The longest decimal representation of a 32 bit integer is 10 digits:
   **
   **             1234567890
   **     2^31 -> 2147483648
   */
   testcase( i==10 );
@@ skipping 170 matching lines @@
   b &= SLOT_2_0;
   s = a;
   /* s: p0<<14 | p2 (masked) */
 
   p++;
   a = a<<14;
   a |= *p;
   /* a: p0<<28 | p2<<14 | p4 (unmasked) */
   if (!(a&0x80))
   {
-    /* we can skip these cause they were (effectively) done above in calc'ing s */
+    /* we can skip these cause they were (effectively) done above
+    ** while calculating s */
     /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
     /* b &= (0x7f<<14)|(0x7f); */
     b = b<<7;
     a |= b;
     s = s>>18;
     *v = ((u64)s)<<32 | a;
     return 5;
   }
 
   /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
@@ skipping 200 matching lines @@
     return n;
   }
 #endif
 }
 
 /*
 ** Return the number of bytes that will be needed to store the given
 ** 64-bit integer.
 */
 int sqlite3VarintLen(u64 v){
-  int i = 0;
-  do{
-    i++;
-    v >>= 7;
-  }while( v!=0 && ALWAYS(i<9) );
+  int i;
+  for(i=1; (v >>= 7)!=0; i++){ assert( i<9 ); }
   return i;
 }
 
 
 /*
 ** Read or write a four-byte big-endian integer value.
 */
 u32 sqlite3Get4byte(const u8 *p){
+#if SQLITE_BYTEORDER==4321
+  u32 x;
+  memcpy(&x,p,4);
+  return x;
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(__GNUC__) && GCC_VERSION>=4003000
+  u32 x;
+  memcpy(&x,p,4);
+  return __builtin_bswap32(x);
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(_MSC_VER) && _MSC_VER>=1300
+  u32 x;
+  memcpy(&x,p,4);
+  return _byteswap_ulong(x);
+#else
   testcase( p[0]&0x80 );
   return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+#endif
 }
 void sqlite3Put4byte(unsigned char *p, u32 v){
+#if SQLITE_BYTEORDER==4321
+  memcpy(p,&v,4);
+#elif SQLITE_BYTEORDER==1234 && defined(__GNUC__) && GCC_VERSION>=4003000
+  u32 x = __builtin_bswap32(v);
+  memcpy(p,&x,4);
+#elif SQLITE_BYTEORDER==1234 && defined(_MSC_VER) && _MSC_VER>=1300
+  u32 x = _byteswap_ulong(v);
+  memcpy(p,&x,4);
+#else
   p[0] = (u8)(v>>24);
   p[1] = (u8)(v>>16);
   p[2] = (u8)(v>>8);
   p[3] = (u8)v;
+#endif
 }
 
 
 
 /*
 ** Translate a single byte of Hex into an integer.
 ** This routine only works if h really is a valid hexadecimal
 ** character:  0..9a..fA..F
 */
 u8 sqlite3HexToInt(int h){
@@ skipping 265 matching lines @@
   if( x<10 ) return 1;
   n = x%10;
   x /= 10;
   if( n>=5 ) n -= 2;
   else if( n>=1 ) n -= 1;
   if( x>=3 ){
     return x>60 ? (u64)LARGEST_INT64 : (n+8)<<(x-3);
   }
   return (n+8)>>(3-x);
 }