[RFC] Add bcfloor, bcceil and bcround to BCMath (#13096)

Implementation for the "Adding bcround, bcfloor and bcceil to BCMath" RFC: https://wiki.php.net/rfc/adding_bcround_bcfloor_bcceil_to_bcmath

* Separated round mode into separate header file

Co-authored-by: Gina Peter Banyard <girgias@php.net>

Author: SakiTakamachi

Zend/Optimizer/zend_func_infos.h

@@ -27,6 +27,9 @@ static const func_info_t func_infos[] = {
 	F1("bcpowmod", MAY_BE_STRING),
 	F1("bcpow", MAY_BE_STRING),
 	F1("bcsqrt", MAY_BE_STRING),
+	F1("bcfloor", MAY_BE_STRING),
+	F1("bcceil", MAY_BE_STRING),
+	F1("bcround", MAY_BE_STRING),
 	FN("bzopen", MAY_BE_RESOURCE|MAY_BE_FALSE),
 	F1("bzerror", MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_STRING|MAY_BE_ARRAY_OF_LONG|MAY_BE_ARRAY_OF_STRING),
 	F1("cal_from_jd", MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_STRING|MAY_BE_ARRAY_OF_LONG|MAY_BE_ARRAY_OF_STRING|MAY_BE_ARRAY_OF_NULL),

ext/bcmath/bcmath.c

@@ -643,6 +643,96 @@ PHP_FUNCTION(bccomp)
 }
 /* }}} */
 
+/* {{{ floor or ceil */
+static void bcfloor_or_bcceil(INTERNAL_FUNCTION_PARAMETERS, bool is_floor)
+{
+	zend_string *numstr;
+	bc_num num, result;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_STR(numstr)
+	ZEND_PARSE_PARAMETERS_END();
+
+	bc_init_num(&num);
+	bc_init_num(&result);
+
+	if (php_str2num(&num, ZSTR_VAL(numstr)) == FAILURE) {
+		zend_argument_value_error(1, "is not well-formed");
+		goto cleanup;
+	}
+
+	bc_floor_or_ceil(num, is_floor, &result);
+	RETVAL_STR(bc_num2str_ex(result, 0));
+
+	cleanup: {
+		bc_free_num(&num);
+		bc_free_num(&result);
+	};
+}
+/* }}} */
+
+/* {{{ Returns floor of num */
+PHP_FUNCTION(bcfloor)
+{
+	bcfloor_or_bcceil(INTERNAL_FUNCTION_PARAM_PASSTHRU, true);
+}
+/* }}} */
+
+/* {{{ Returns ceil of num */
+PHP_FUNCTION(bcceil)
+{
+	bcfloor_or_bcceil(INTERNAL_FUNCTION_PARAM_PASSTHRU, false);
+}
+/* }}} */
+
+/* {{{ Returns num rounded to the digits specified by precision. */
+PHP_FUNCTION(bcround)
+{
+	zend_string *numstr;
+	zend_long precision = 0;
+	zend_long mode = PHP_ROUND_HALF_UP;
+	bc_num num, result;
+
+	ZEND_PARSE_PARAMETERS_START(1, 3)
+		Z_PARAM_STR(numstr)
+		Z_PARAM_OPTIONAL
+		Z_PARAM_LONG(precision)
+		Z_PARAM_LONG(mode)
+	ZEND_PARSE_PARAMETERS_END();
+
+	switch (mode) {
+		case PHP_ROUND_HALF_UP:
+		case PHP_ROUND_HALF_DOWN:
+		case PHP_ROUND_HALF_EVEN:
+		case PHP_ROUND_HALF_ODD:
+		case PHP_ROUND_CEILING:
+		case PHP_ROUND_FLOOR:
+		case PHP_ROUND_TOWARD_ZERO:
+		case PHP_ROUND_AWAY_FROM_ZERO:
+			break;
+		default:
+			zend_argument_value_error(3, "must be a valid rounding mode (PHP_ROUND_*)");
+			return;
+	}
+
+	bc_init_num(&num);
+	bc_init_num(&result);
+
+	if (php_str2num(&num, ZSTR_VAL(numstr)) == FAILURE) {
+		zend_argument_value_error(1, "is not well-formed");
+		goto cleanup;
+	}
+
+	bc_round(num, precision, mode, &result);
+	RETVAL_STR(bc_num2str_ex(result, result->n_scale));
+
+	cleanup: {
+		bc_free_num(&num);
+		bc_free_num(&result);
+	};
+}
+/* }}} */
+
 /* {{{ Sets default scale parameter for all bc math functions */
 PHP_FUNCTION(bcscale)
 {

ext/bcmath/bcmath.stub.php

@@ -29,3 +29,12 @@ function bcsqrt(string $num, ?int $scale = null): string {}
 function bccomp(string $num1, string $num2, ?int $scale = null): int {}
 
 function bcscale(?int $scale = null): int {}
+
+/** @refcount 1 */
+function bcfloor(string $num): string {}
+
+/** @refcount 1 */
+function bcceil(string $num): string {}
+
+/** @refcount 1 */
+function bcround(string $num, int $precision = 0, int $mode = PHP_ROUND_HALF_UP): string {}

ext/bcmath/bcmath_arginfo.h

@@ -7,8 +7,8 @@ if test "$PHP_BCMATH" != "no"; then
   PHP_NEW_EXTENSION(bcmath, bcmath.c \
 libbcmath/src/add.c libbcmath/src/div.c libbcmath/src/init.c libbcmath/src/neg.c libbcmath/src/raisemod.c libbcmath/src/sub.c \
 libbcmath/src/compare.c libbcmath/src/divmod.c libbcmath/src/int2num.c libbcmath/src/num2long.c libbcmath/src/output.c libbcmath/src/recmul.c \
-libbcmath/src/sqrt.c libbcmath/src/zero.c libbcmath/src/doaddsub.c libbcmath/src/nearzero.c libbcmath/src/num2str.c libbcmath/src/raise.c \
-libbcmath/src/rmzero.c libbcmath/src/str2num.c,
+libbcmath/src/sqrt.c libbcmath/src/zero.c libbcmath/src/doaddsub.c libbcmath/src/floor_or_ceil.c libbcmath/src/nearzero.c libbcmath/src/num2str.c \
+libbcmath/src/raise.c libbcmath/src/rmzero.c libbcmath/src/round.c libbcmath/src/str2num.c,
           $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
   PHP_ADD_BUILD_DIR($ext_builddir/libbcmath/src)
   AC_DEFINE(HAVE_BCMATH, 1, [Whether you have bcmath])

ext/bcmath/config.m4

@@ -7,7 +7,8 @@ if (PHP_BCMATH == "yes") {
 	ADD_SOURCES("ext/bcmath/libbcmath/src", "add.c div.c init.c neg.c \
 		raisemod.c sub.c compare.c divmod.c int2num.c \
 		num2long.c output.c recmul.c sqrt.c zero.c doaddsub.c \
-		nearzero.c num2str.c raise.c rmzero.c str2num.c", "bcmath");
+		floor_or_ceil.c nearzero.c num2str.c raise.c rmzero.c str2num.c \
+		round.c", "bcmath");
 
 	AC_DEFINE('HAVE_BCMATH', 1, 'Have BCMATH library');
 }

ext/bcmath/config.w32

@@ -58,7 +58,9 @@ typedef struct bc_struct {
 #include "zend.h"
 #include <stdbool.h>
 #include "zend_string.h"
-#include "../../php_bcmath.h" /* Needed for BCG() macro */
+
+/* Needed for BCG() macro and PHP_ROUND_XXX */
+#include "../../php_bcmath.h"
 
 /* The base used in storing the numbers in n_value above.
    Currently, this MUST be 10. */
@@ -125,6 +127,10 @@ bool bc_modulo(bc_num num1, bc_num num2, bc_num *resul, size_t scale);
 
 bool bc_divmod(bc_num num1, bc_num num2, bc_num *quo, bc_num *rem, size_t scale);
 
+void bc_floor_or_ceil(bc_num num, bool is_floor, bc_num *result);
+
+void bc_round(bc_num num, zend_long places, zend_long mode, bc_num *result);
+
 typedef enum {
 	OK,
 	BASE_HAS_FRACTIONAL,

ext/bcmath/libbcmath/src/bcmath.h

@@ -0,0 +1,57 @@
+/*
+   +----------------------------------------------------------------------+
+   | Copyright (c) The PHP Group                                          |
+   +----------------------------------------------------------------------+
+   | This source file is subject to version 3.01 of the PHP license,      |
+   | that is bundled with this package in the file LICENSE, and is        |
+   | available through the world-wide-web at the following url:           |
+   | https://www.php.net/license/3_01.txt                                 |
+   | If you did not receive a copy of the PHP license and are unable to   |
+   | obtain it through the world-wide-web, please send a note to          |
+   | license@php.net so we can mail you a copy immediately.               |
+   +----------------------------------------------------------------------+
+   | Authors: Saki Takamachi <saki@php.net>                               |
+   +----------------------------------------------------------------------+
+*/
+
+#include "bcmath.h"
+#include "private.h"
+#include <stddef.h>
+
+void bc_floor_or_ceil(bc_num num, bool is_floor, bc_num *result)
+{
+	/* clear result */
+	bc_free_num(result);
+
+	/*  Initialize result */
+	*result = bc_new_num(num->n_len, 0);
+	(*result)->n_sign = num->n_sign;
+
+	/* copy integer part */
+	memcpy((*result)->n_value, num->n_value, num->n_len);
+
+	/* If the number is positive and we are flooring, then nothing else needs to be done.
+	 * Similarly, if the number is negative and we are ceiling, then nothing else needs to be done. */
+	if (num->n_scale == 0 || (*result)->n_sign == (is_floor ? PLUS : MINUS)) {
+		return;
+	}
+
+	/* check fractional part. */
+	size_t count = num->n_scale;
+	const char *nptr = num->n_value + num->n_len;
+	while ((count > 0) && (*nptr == 0)) {
+		count--;
+		nptr++;
+	}
+
+	/* If all digits past the decimal point are 0 */
+	if (count == 0) {
+		return;
+	}
+
+	/* Increment the absolute value of the result by 1 and add sign information */
+	bc_num tmp = _bc_do_add(*result, BCG(_one_), 0);
+	tmp->n_sign = (*result)->n_sign;
+	bc_free_num(result);
+	*result = tmp;
+}