Use one place to define max length of double

Introduce new constant PHP_DOUBLE_MAX_LENGTH for that purpose

Author: bukka

ext/json/json.c

@@ -33,14 +33,6 @@
 #include "php_json_parser.h"
 #include <zend_exceptions.h>
 
-#include <float.h>
-#if defined(DBL_MANT_DIG) && defined(DBL_MIN_EXP)
-#define NUM_BUF_SIZE (3 + DBL_MANT_DIG - DBL_MIN_EXP)
-#else
-#define NUM_BUF_SIZE 1080
-#endif
-
-
 static PHP_MINFO_FUNCTION(json);
 static PHP_FUNCTION(json_encode);
 static PHP_FUNCTION(json_decode);

ext/json/json_encoder.c

@@ -31,14 +31,6 @@
 #include "php_json.h"
 #include <zend_exceptions.h>
 
-/* double limits */
-#include <float.h>
-#if defined(DBL_MANT_DIG) && defined(DBL_MIN_EXP)
-#define PHP_JSON_DOUBLE_MAX_LENGTH (3 + DBL_MANT_DIG - DBL_MIN_EXP)
-#else
-#define PHP_JSON_DOUBLE_MAX_LENGTH 1080
-#endif
-
 static const char digits[] = "0123456789abcdef";
 
 static void php_json_escape_string(smart_str *buf, char *s, size_t len, int options);
@@ -103,11 +95,11 @@ static inline int php_json_is_valid_double(double d) /* {{{ */
 static inline void php_json_encode_double(smart_str *buf, double d, int options) /* {{{ */
 {
 	size_t len;
-	char num[PHP_JSON_DOUBLE_MAX_LENGTH];
+	char num[PHP_DOUBLE_MAX_LENGTH];
 
 	php_gcvt(d, (int)PG(serialize_precision), '.', 'e', num);
 	len = strlen(num);
-	if (options & PHP_JSON_PRESERVE_ZERO_FRACTION && strchr(num, '.') == NULL && len < PHP_JSON_DOUBLE_MAX_LENGTH - 2) {
+	if (options & PHP_JSON_PRESERVE_ZERO_FRACTION && strchr(num, '.') == NULL && len < PHP_DOUBLE_MAX_LENGTH - 2) {
 		num[len++] = '.';
 		num[len++] = '0';
 		num[len] = '\0';

ext/standard/var.c

@@ -35,17 +35,6 @@
 
 #define COMMON (is_ref ? "&" : "")
 
-/* Copied from main/spprintf.c and use the same buffer size
- *
- * NUM_BUF_SIZE is the size of the buffer used for arithmetic conversions
- *
- * XXX: this is a magic number; do not decrease it
- * Emax = 1023
- * NDIG = 320
- * NUM_BUF_SIZE >= strlen("-") + Emax + strlrn(".") + NDIG + strlen("E+1023") + 1;
- */
-#define NUM_BUF_SIZE		2048
-
 static void php_array_element_dump(zval *zv, zend_ulong index, zend_string *key, int level) /* {{{ */
 {
 	if (key == NULL) { /* numeric key */
@@ -447,7 +436,7 @@ static void php_object_element_export(zval *zv, zend_ulong index, zend_string *k
 PHPAPI void php_var_export_ex(zval *struc, int level, smart_str *buf) /* {{{ */
 {
 	HashTable *myht;
-	char tmp_str[NUM_BUF_SIZE];
+	char tmp_str[PHP_DOUBLE_MAX_LENGTH];
 	zend_string *ztmp, *ztmp2;
 	zend_ulong index;
 	zend_string *key;
@@ -853,7 +842,7 @@ static void php_var_serialize_intern(smart_str *buf, zval *struc, php_serialize_
 			return;
 
 		case IS_DOUBLE: {
-			char tmp_str[NUM_BUF_SIZE];
+			char tmp_str[PHP_DOUBLE_MAX_LENGTH];
 			smart_str_appendl(buf, "d:", 2);
 			php_gcvt(Z_DVAL_P(struc), (int)PG(serialize_precision), '.', 'E', tmp_str);
 			smart_str_appends(buf, tmp_str);

main/php.h

@@ -231,6 +231,14 @@ char *strerror(int);
 #define INT_MIN (- INT_MAX - 1)
 #endif
 
+/* double limits */
+#include <float.h>
+#if defined(DBL_MANT_DIG) && defined(DBL_MIN_EXP)
+#define PHP_DOUBLE_MAX_LENGTH (3 + DBL_MANT_DIG - DBL_MIN_EXP)
+#else
+#define PHP_DOUBLE_MAX_LENGTH 1080
+#endif
+
 #define PHP_GCC_VERSION ZEND_GCC_VERSION
 #define PHP_ATTRIBUTE_MALLOC ZEND_ATTRIBUTE_MALLOC
 #define PHP_ATTRIBUTE_FORMAT ZEND_ATTRIBUTE_FORMAT

main/spprintf.c

@@ -152,13 +152,9 @@
 
 /*
  * NUM_BUF_SIZE is the size of the buffer used for arithmetic conversions
- *
- * XXX: this is a magic number; do not decrease it
- * Emax = 1023
- * NDIG = 320
- * NUM_BUF_SIZE >= strlen("-") + Emax + strlrn(".") + NDIG + strlen("E+1023") + 1;
+ * which can be at most max length of double
  */
-#define NUM_BUF_SIZE		2048
+#define NUM_BUF_SIZE PHP_DOUBLE_MAX_LENGTH
 
 #define NUM(c) (c - '0')