Refactor bc_raisemod() to get rid of Zend dependencies

This seperates the concerns of throwing exceptions back into the PHP_FUNCTION instead of being the responsability of the library

Author: Girgias

ext/bcmath/bcmath.c

@@ -420,15 +420,15 @@ PHP_FUNCTION(bcmod)
 /* {{{ Returns the value of an arbitrary precision number raised to the power of another reduced by a modulus */
 PHP_FUNCTION(bcpowmod)
 {
-	zend_string *left, *right, *modulus;
+	zend_string *base, *exponent, *modulus;
 	zend_long scale_param;
 	bool scale_param_is_null = 1;
-	bc_num first, second, mod, result;
+	bc_num bc_base, bc_expo, bc_modulus, result;
 	int scale = BCG(bc_precision);
 
 	ZEND_PARSE_PARAMETERS_START(3, 4)
-		Z_PARAM_STR(left)
-		Z_PARAM_STR(right)
+		Z_PARAM_STR(base)
+		Z_PARAM_STR(exponent)
 		Z_PARAM_STR(modulus)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_LONG_OR_NULL(scale_param, scale_param_is_null)
@@ -443,34 +443,53 @@ PHP_FUNCTION(bcpowmod)
 		scale = (int) scale_param;
 	}
 
-	bc_init_num(&first);
-	bc_init_num(&second);
-	bc_init_num(&mod);
+	bc_init_num(&bc_base);
+	bc_init_num(&bc_expo);
+	bc_init_num(&bc_modulus);
 	bc_init_num(&result);
 
-	if (php_str2num(&first, ZSTR_VAL(left)) == FAILURE) {
+	if (php_str2num(&bc_base, ZSTR_VAL(base)) == FAILURE) {
 		zend_argument_value_error(1, "is not well-formed");
 		goto cleanup;
 	}
 
-	if (php_str2num(&second, ZSTR_VAL(right)) == FAILURE) {
+	if (php_str2num(&bc_expo, ZSTR_VAL(exponent)) == FAILURE) {
 		zend_argument_value_error(2, "is not well-formed");
 		goto cleanup;
 	}
 
-	if (php_str2num(&mod, ZSTR_VAL(modulus)) == FAILURE) {
+	if (php_str2num(&bc_modulus, ZSTR_VAL(modulus)) == FAILURE) {
 		zend_argument_value_error(3, "is not well-formed");
 		goto cleanup;
 	}
 
-	if (bc_raisemod(first, second, mod, &result, scale) == SUCCESS) {
-		RETVAL_STR(bc_num2str_ex(result, scale));
+	raise_mod_status status = bc_raisemod(bc_base, bc_expo, bc_modulus, &result, scale);
+	switch (status) {
+		case BASE_HAS_FRACTIONAL:
+			zend_argument_value_error(1, "cannot have a fractional part");
+			goto cleanup;
+		case EXPO_HAS_FRACTIONAL:
+			zend_argument_value_error(2, "cannot have a fractional part");
+			goto cleanup;
+		case EXPO_IS_NEGATIVE:
+			zend_argument_value_error(2, "must be greater than or equal to 0");
+			goto cleanup;
+		case MOD_HAS_FRACTIONAL:
+			zend_argument_value_error(3, "cannot have a fractional part");
+			goto cleanup;
+		case MOD_IS_ZERO:
+			zend_throw_exception_ex(zend_ce_division_by_zero_error, 0, "Modulo by zero");
+			goto cleanup;
+		case OK:
+			RETVAL_STR(bc_num2str_ex(result, scale));
+			break;
+		EMPTY_SWITCH_DEFAULT_CASE();
 	}
 
 	cleanup: {
-		bc_free_num(&first);
-		bc_free_num(&second);
-		bc_free_num(&mod);
+		bc_free_num(&bc_base);
+		bc_free_num(&bc_expo);
+		bc_free_num(&bc_modulus);
 		bc_free_num(&result);
 	};
 }

ext/bcmath/libbcmath/src/bcmath.h

@@ -124,7 +124,16 @@ int bc_modulo(bc_num num1, bc_num num2, bc_num *resul, size_t scale);
 
 int bc_divmod(bc_num num1, bc_num num2, bc_num *quo, bc_num *rem, size_t scale);
 
-int bc_raisemod(bc_num base, bc_num expo, bc_num mo, bc_num *result, size_t scale);
+typedef enum {
+	OK,
+	BASE_HAS_FRACTIONAL,
+	EXPO_HAS_FRACTIONAL,
+	EXPO_IS_NEGATIVE,
+	MOD_HAS_FRACTIONAL,
+	MOD_IS_ZERO
+} raise_mod_status;
+
+raise_mod_status bc_raisemod(bc_num base, bc_num expo, bc_num mod, bc_num *result, size_t scale);
 
 void bc_raise(bc_num num1, bc_num num2, bc_num *resul, size_t scale);
 

ext/bcmath/libbcmath/src/raisemod.c

@@ -30,43 +30,32 @@
 *************************************************************************/
 
 #include "bcmath.h"
-#include "config.h"
-#include "zend_result.h"
-#include "zend_exceptions.h"
 #include <stddef.h>
 
 /* Raise BASE to the EXPO power, reduced modulo MOD.  The result is placed in RESULT. */
-zend_result bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, size_t scale)
+raise_mod_status bc_raisemod(bc_num base, bc_num expo, bc_num mod, bc_num *result, size_t scale)
 {
 	bc_num power, exponent, modulus, parity, temp;
 	size_t rscale;
 
 	/* Check the base for scale digits. */
 	if (base->n_scale != 0) {
-		/* 1st argument from PHP_FUNCTION(bcpowmod) */
-		zend_argument_value_error(1, "cannot have a fractional part");
-		return FAILURE;
+		return BASE_HAS_FRACTIONAL;
 	}
 	/* Check the exponent for scale digits. */
 	if (expo->n_scale != 0) {
-		/* 2nd argument from PHP_FUNCTION(bcpowmod) */
-		zend_argument_value_error(2, "cannot have a fractional part");
-		return FAILURE;
+		return EXPO_HAS_FRACTIONAL;
 	}
 	if (bc_is_neg(expo)) {
-		zend_argument_value_error(2, "must be greater than or equal to 0");
-		return FAILURE;
+		return EXPO_IS_NEGATIVE;
 	}
 	/* Check the modulus for scale digits. */
 	if (mod->n_scale != 0) {
-		/* 3rd argument from PHP_FUNCTION(bcpowmod) */
-		zend_argument_value_error(3, "cannot have a fractional part");
-		return FAILURE;
+		return MOD_HAS_FRACTIONAL;
 	}
 	/* Modulus cannot be 0 */
 	if (bc_is_zero(mod)) {
-		zend_throw_exception_ex(zend_ce_division_by_zero_error, 0, "Modulo by zero");
-		return FAILURE;
+		return MOD_IS_ZERO;
 	}
 
 	/* Set initial values. */
@@ -100,5 +89,5 @@ zend_result bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, s
 	bc_free_num (result);
 	bc_free_num (&parity);
 	*result = temp;
-	return SUCCESS;	/* Everything is OK. */
+	return OK;
 }