Constify char * arguments of APIs

Closes GH-5676.

49 files changed, 239 insertions, 189 deletions

diff --git a/ext/com_dotnet/com_olechar.c b/ext/com_dotnet/com_olechar.c
index 665773b120..7eda51b73b 100644
--- a/ext/com_dotnet/com_olechar.c
+++ b/ext/com_dotnet/com_olechar.c
@@ -26,7 +26,7 @@
 #include "php_com_dotnet_internal.h"
 
 
-PHP_COM_DOTNET_API OLECHAR *php_com_string_to_olestring(char *string, size_t string_len, int codepage)
+PHP_COM_DOTNET_API OLECHAR *php_com_string_to_olestring(const char *string, size_t string_len, int codepage)
 {
 	OLECHAR *olestring = NULL;
 	DWORD flags = codepage == CP_UTF8 ? 0 : MB_PRECOMPOSED | MB_ERR_INVALID_CHARS;
diff --git a/ext/com_dotnet/com_typeinfo.c b/ext/com_dotnet/com_typeinfo.c
index acd2e3d512..ffd2400f75 100644
--- a/ext/com_dotnet/com_typeinfo.c
+++ b/ext/com_dotnet/com_typeinfo.c
@@ -260,7 +260,7 @@ ITypeLib *php_com_cache_typelib(ITypeLib* TL, char *cache_key, zend_long cache_k
 	return result;
 }
 
-PHP_COM_DOTNET_API ITypeLib *php_com_load_typelib_via_cache(char *search_string,
+PHP_COM_DOTNET_API ITypeLib *php_com_load_typelib_via_cache(const char *search_string,
 	int codepage, int *cached)
 {
 	ITypeLib *TL;
diff --git a/ext/com_dotnet/php_com_dotnet_internal.h b/ext/com_dotnet/php_com_dotnet_internal.h
index 8521277083..4974bb78e3 100644
--- a/ext/com_dotnet/php_com_dotnet_internal.h
+++ b/ext/com_dotnet/php_com_dotnet_internal.h
@@ -82,7 +82,7 @@ int php_com_saproxy_create(zend_object *com_object, zval *proxy_out, zval *index
 /* com_olechar.c */
 PHP_COM_DOTNET_API char *php_com_olestring_to_string(OLECHAR *olestring,
 		size_t *string_len, int codepage);
-PHP_COM_DOTNET_API OLECHAR *php_com_string_to_olestring(char *string,
+PHP_COM_DOTNET_API OLECHAR *php_com_string_to_olestring(const char *string,
 		size_t string_len, int codepage);
 
 
@@ -130,7 +130,7 @@ PHP_COM_DOTNET_API void php_com_wrap_variant(zval *z, VARIANT *v,
 PHP_COM_DOTNET_API int php_com_safearray_get_elem(VARIANT *array, VARIANT *dest, LONG dim1);
 
 /* com_typeinfo.c */
-PHP_COM_DOTNET_API ITypeLib *php_com_load_typelib_via_cache(char *search_string,
+PHP_COM_DOTNET_API ITypeLib *php_com_load_typelib_via_cache(const char *search_string,
 		int codepage, int *cached);
 PHP_COM_DOTNET_API ITypeLib *php_com_load_typelib(char *search_string, int codepage);
 PHP_COM_DOTNET_API int php_com_import_typelib(ITypeLib *TL, int mode,
diff --git a/ext/date/php_date.c b/ext/date/php_date.c
index 51c56afb3c..a908fed2c7 100644
--- a/ext/date/php_date.c
+++ b/ext/date/php_date.c
@@ -617,7 +617,7 @@ static const char *php_date_short_day_name(timelib_sll y, timelib_sll m, timelib
 /* }}} */
 
 /* {{{ date_format - (gm)date helper */
-static zend_string *date_format(char *format, size_t format_len, timelib_time *t, int localtime)
+static zend_string *date_format(const char *format, size_t format_len, timelib_time *t, int localtime)
 {
 	smart_str            string = {0};
 	size_t               i;
@@ -798,7 +798,7 @@ static void php_date(INTERNAL_FUNCTION_PARAMETERS, int localtime)
 }
 /* }}} */
 
-PHPAPI zend_string *php_format_date(char *format, size_t format_len, time_t ts, int localtime) /* {{{ */
+PHPAPI zend_string *php_format_date(const char *format, size_t format_len, time_t ts, int localtime) /* {{{ */
 {
 	timelib_time   *t;
 	timelib_tzinfo *tzi;
@@ -982,14 +982,14 @@ PHPAPI void php_date_set_tzdb(timelib_tzdb *tzdb)
 /* }}} */
 
 /* {{{ php_parse_date: Backwards compatibility function */
-PHPAPI zend_long php_parse_date(char *string, zend_long *now)
+PHPAPI zend_long php_parse_date(const char *string, zend_long *now)
 {
 	timelib_time *parsed_time;
 	timelib_error_container *error = NULL;
 	int           error2;
 	zend_long   retval;
 
-	parsed_time = timelib_strtotime(string, strlen(string), &error, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
+	parsed_time = timelib_strtotime((char *) string, strlen(string), &error, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
 	if (error->error_count) {
 		timelib_time_dtor(parsed_time);
 		timelib_error_container_dtor(error);
@@ -2187,7 +2187,7 @@ static void php_date_get_current_time_with_fraction(time_t *sec, suseconds_t *us
 #endif
 }
 
-PHPAPI int php_date_initialize(php_date_obj *dateobj, /*const*/ char *time_str, size_t time_str_len, char *format, zval *timezone_object, int ctor) /* {{{ */
+PHPAPI int php_date_initialize(php_date_obj *dateobj, const char *time_str, size_t time_str_len, const char *format, zval *timezone_object, int ctor) /* {{{ */
 {
 	timelib_time   *now;
 	timelib_tzinfo *tzi = NULL;
@@ -2202,9 +2202,18 @@ PHPAPI int php_date_initialize(php_date_obj *dateobj, /*const*/ char *time_str,
 		timelib_time_dtor(dateobj->time);
 	}
 	if (format) {
-		dateobj->time = timelib_parse_from_format(format, time_str_len ? time_str : "", time_str_len ? time_str_len : 0, &err, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
+		if (time_str_len == 0) {
+			time_str = "";
+		}
+		// TODO: drop this const casts
+		dateobj->time = timelib_parse_from_format((char *) format, (char *) time_str, time_str_len, &err, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
 	} else {
-		dateobj->time = timelib_strtotime(time_str_len ? time_str : "now", time_str_len ? time_str_len : sizeof("now") -1, &err, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
+		if (time_str_len == 0) {
+			time_str = "now";
+			time_str_len = sizeof("now") - 1;
+		}
+		// TODO: drop this const casts
+		dateobj->time = timelib_strtotime((char *) time_str, time_str_len, &err, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
 	}
 
 	/* update last errors and warnings */
diff --git a/ext/date/php_date.h b/ext/date/php_date.h
index 1ab7b3ccd9..b89438e0c5 100644
--- a/ext/date/php_date.h
+++ b/ext/date/php_date.h
@@ -108,14 +108,14 @@ ZEND_END_MODULE_GLOBALS(date)
 PHPAPI time_t php_time(void);
 
 /* Backwards compatibility wrapper */
-PHPAPI zend_long php_parse_date(char *string, zend_long *now);
+PHPAPI zend_long php_parse_date(const char *string, zend_long *now);
 PHPAPI void php_mktime(INTERNAL_FUNCTION_PARAMETERS, int gmt);
 PHPAPI int php_idate(char format, time_t ts, int localtime);
 
 #define _php_strftime php_strftime
 
 PHPAPI void php_strftime(INTERNAL_FUNCTION_PARAMETERS, int gm);
-PHPAPI zend_string *php_format_date(char *format, size_t format_len, time_t ts, int localtime);
+PHPAPI zend_string *php_format_date(const char *format, size_t format_len, time_t ts, int localtime);
 
 /* Mechanism to set new TZ database */
 PHPAPI void php_date_set_tzdb(timelib_tzdb *tzdb);
@@ -131,7 +131,7 @@ PHPAPI zend_class_entry *php_date_get_period_ce(void);
 
 /* Functions for creating DateTime objects, and initializing them from a string */
 PHPAPI zval *php_date_instantiate(zend_class_entry *pce, zval *object);
-PHPAPI int php_date_initialize(php_date_obj *dateobj, /*const*/ char *time_str, size_t time_str_len, char *format, zval *timezone_object, int ctor);
+PHPAPI int php_date_initialize(php_date_obj *dateobj, const char *time_str, size_t time_str_len, const char *format, zval *timezone_object, int ctor);
 
 
 #endif /* PHP_DATE_H */
diff --git a/ext/filter/filter.c b/ext/filter/filter.c
index 8feae0a3df..0e01c30097 100644
--- a/ext/filter/filter.c
+++ b/ext/filter/filter.c
@@ -75,7 +75,7 @@ static const filter_list_entry filter_list[] = {
 #define PARSE_SESSION 6
 #endif
 
-static unsigned int php_sapi_filter(int arg, char *var, char **val, size_t val_len, size_t *new_val_len);
+static unsigned int php_sapi_filter(int arg, const char *var, char **val, size_t val_len, size_t *new_val_len);
 static unsigned int php_sapi_filter_init(void);
 
 /* {{{ filter_module_entry
@@ -360,7 +360,7 @@ handle_default:
 }
 /* }}} */
 
-static unsigned int php_sapi_filter(int arg, char *var, char **val, size_t val_len, size_t *new_val_len) /* {{{ */
+static unsigned int php_sapi_filter(int arg, const char *var, char **val, size_t val_len, size_t *new_val_len) /* {{{ */
 {
 	zval  new_var, raw_var;
 	zval *array_ptr = NULL, *orig_array_ptr = NULL;
diff --git a/ext/json/json.c b/ext/json/json.c
index 68990f5ca4..1797c00c9c 100644
--- a/ext/json/json.c
+++ b/ext/json/json.c
@@ -195,7 +195,7 @@ static const char *php_json_get_error_msg(php_json_error_code error_code) /* {{{
 }
 /* }}} */
 
-PHP_JSON_API int php_json_decode_ex(zval *return_value, char *str, size_t str_len, zend_long options, zend_long depth) /* {{{ */
+PHP_JSON_API int php_json_decode_ex(zval *return_value, const char *str, size_t str_len, zend_long options, zend_long depth) /* {{{ */
 {
 	php_json_parser parser;
 
diff --git a/ext/json/json_parser.y b/ext/json/json_parser.y
index 4705e498a6..8802d18439 100644
--- a/ext/json/json_parser.y
+++ b/ext/json/json_parser.y
@@ -301,7 +301,7 @@ static const php_json_parser_methods default_parser_methods =
 
 PHP_JSON_API void php_json_parser_init_ex(php_json_parser *parser,
 		zval *return_value,
-		char *str,
+		const char *str,
 		size_t str_len,
 		int options,
 		int max_depth,
@@ -317,7 +317,7 @@ PHP_JSON_API void php_json_parser_init_ex(php_json_parser *parser,
 
 PHP_JSON_API void php_json_parser_init(php_json_parser *parser,
 		zval *return_value,
-		char *str,
+		const char *str,
 		size_t str_len,
 		int options,
 		int max_depth)
diff --git a/ext/json/json_scanner.re b/ext/json/json_scanner.re
index 5b571e6dd2..03ccdde58b 100644
--- a/ext/json/json_scanner.re
+++ b/ext/json/json_scanner.re
@@ -91,7 +91,7 @@ static int php_json_ucs2_to_int(php_json_scanner *s, int size)
 	return php_json_ucs2_to_int_ex(s, size, 1);
 }
 
-void php_json_scanner_init(php_json_scanner *s, char *str, size_t str_len, int options)
+void php_json_scanner_init(php_json_scanner *s, const char *str, size_t str_len, int options)
 {
 	s->cursor = (php_json_ctype *) str;
 	s->limit = (php_json_ctype *) str + str_len;
diff --git a/ext/json/php_json.h b/ext/json/php_json.h
index 4fc7ded7d4..ee8affa1d1 100644
--- a/ext/json/php_json.h
+++ b/ext/json/php_json.h
@@ -98,9 +98,9 @@ ZEND_TSRMLS_CACHE_EXTERN()
 
 PHP_JSON_API int php_json_encode_ex(smart_str *buf, zval *val, int options, zend_long depth);
 PHP_JSON_API int php_json_encode(smart_str *buf, zval *val, int options);
-PHP_JSON_API int php_json_decode_ex(zval *return_value, char *str, size_t str_len, zend_long options, zend_long depth);
+PHP_JSON_API int php_json_decode_ex(zval *return_value, const char *str, size_t str_len, zend_long options, zend_long depth);
 
-static inline int php_json_decode(zval *return_value, char *str, int str_len, zend_bool assoc, zend_long depth)
+static inline int php_json_decode(zval *return_value, const char *str, int str_len, zend_bool assoc, zend_long depth)
 {
 	return php_json_decode_ex(return_value, str, str_len, assoc ? PHP_JSON_OBJECT_AS_ARRAY : 0, depth);
 }
diff --git a/ext/json/php_json_parser.h b/ext/json/php_json_parser.h
index 05f7a061c6..dc0453f4fa 100644
--- a/ext/json/php_json_parser.h
+++ b/ext/json/php_json_parser.h
@@ -61,7 +61,7 @@ struct _php_json_parser {
 PHP_JSON_API void php_json_parser_init_ex(
 		php_json_parser *parser,
 		zval *return_value,
-		char *str,
+		const char *str,
 		size_t str_len,
 		int options,
 		int max_depth,
@@ -70,7 +70,7 @@ PHP_JSON_API void php_json_parser_init_ex(
 PHP_JSON_API void php_json_parser_init(
 		php_json_parser *parser,
 		zval *return_value,
-		char *str,
+		const char *str,
 		size_t str_len,
 		int options,
 		int max_depth);
diff --git a/ext/json/php_json_scanner.h b/ext/json/php_json_scanner.h
index 7a2d841703..e5a4979591 100644
--- a/ext/json/php_json_scanner.h
+++ b/ext/json/php_json_scanner.h
@@ -40,7 +40,7 @@ typedef struct _php_json_scanner {
 } php_json_scanner;
 
 
-void php_json_scanner_init(php_json_scanner *scanner, char *str, size_t str_len, int options);
+void php_json_scanner_init(php_json_scanner *scanner, const char *str, size_t str_len, int options);
 int php_json_scan(php_json_scanner *s);
 
 #endif	/* PHP_JSON_SCANNER_H */
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index ef8f39f7a9..aa81410c82 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -4798,7 +4798,7 @@ static int accel_finish_startup(void)
 		int (*orig_header_handler)(sapi_header_struct *sapi_header, sapi_header_op_enum op, sapi_headers_struct *sapi_headers) = sapi_module.header_handler;
 		int (*orig_send_headers)(sapi_headers_struct *sapi_headers) = sapi_module.send_headers;
 		void (*orig_send_header)(sapi_header_struct *sapi_header, void *server_context)= sapi_module.send_header;
-		char *(*orig_getenv)(char *name, size_t name_len) = sapi_module.getenv;
+		char *(*orig_getenv)(const char *name, size_t name_len) = sapi_module.getenv;
 		size_t (*orig_ub_write)(const char *str, size_t str_length) = sapi_module.ub_write;
 		void (*orig_flush)(void *server_context) = sapi_module.flush;
 		uint32_t orig_compiler_options = CG(compiler_options);
diff --git a/ext/openssl/openssl.c b/ext/openssl/openssl.c
index 1a0ec6719f..b2c5cefc70 100644
--- a/ext/openssl/openssl.c
+++ b/ext/openssl/openssl.c
@@ -6888,7 +6888,7 @@ static void php_openssl_load_cipher_mode(struct php_openssl_cipher_mode *mode, c
 }
 /* }}} */
 
-static int php_openssl_validate_iv(char **piv, size_t *piv_len, size_t iv_required_len,
+static int php_openssl_validate_iv(const char **piv, size_t *piv_len, size_t iv_required_len,
 		zend_bool *free_iv, EVP_CIPHER_CTX *cipher_ctx, struct php_openssl_cipher_mode *mode) /* {{{ */
 {
 	char *iv_new;
@@ -6942,9 +6942,9 @@ static int php_openssl_validate_iv(char **piv, size_t *piv_len, size_t iv_requir
 
 static int php_openssl_cipher_init(const EVP_CIPHER *cipher_type,
 		EVP_CIPHER_CTX *cipher_ctx, struct php_openssl_cipher_mode *mode,
-		char **ppassword, size_t *ppassword_len, zend_bool *free_password,
-		char **piv, size_t *piv_len, zend_bool *free_iv,
-		char *tag, int tag_len, zend_long options, int enc)  /* {{{ */
+		const char **ppassword, size_t *ppassword_len, zend_bool *free_password,
+		const char **piv, size_t *piv_len, zend_bool *free_iv,
+		const char *tag, int tag_len, zend_long options, int enc)  /* {{{ */
 {
 	unsigned char *key;
 	int key_len, password_len;
@@ -7014,8 +7014,8 @@ static int php_openssl_cipher_init(const EVP_CIPHER *cipher_type,
 
 static int php_openssl_cipher_update(const EVP_CIPHER *cipher_type,
 		EVP_CIPHER_CTX *cipher_ctx, struct php_openssl_cipher_mode *mode,
-		zend_string **poutbuf, int *poutlen, char *data, size_t data_len,
-		char *aad, size_t aad_len, int enc)  /* {{{ */
+		zend_string **poutbuf, int *poutlen, const char *data, size_t data_len,
+		const char *aad, size_t aad_len, int enc)  /* {{{ */
 {
 	int i = 0;
 
@@ -7025,7 +7025,7 @@ static int php_openssl_cipher_update(const EVP_CIPHER *cipher_type,
 		return FAILURE;
 	}
 
-	if (mode->is_aead && !EVP_CipherUpdate(cipher_ctx, NULL, &i, (unsigned char *)aad, (int)aad_len)) {
+	if (mode->is_aead && !EVP_CipherUpdate(cipher_ctx, NULL, &i, (const unsigned char *) aad, (int) aad_len)) {
 		php_openssl_store_errors();
 		php_error_docref(NULL, E_WARNING, "Setting of additional application data failed");
 		return FAILURE;
@@ -7034,7 +7034,7 @@ static int php_openssl_cipher_update(const EVP_CIPHER *cipher_type,
 	*poutbuf = zend_string_alloc((int)data_len + EVP_CIPHER_block_size(cipher_type), 0);
 
 	if (!EVP_CipherUpdate(cipher_ctx, (unsigned char*)ZSTR_VAL(*poutbuf),
-					&i, (unsigned char *)data, (int)data_len)) {
+					&i, (const unsigned char *)data, (int)data_len)) {
 		/* we don't show warning when we fail but if we ever do, then it should look like this:
 		if (mode->is_single_run_aead && !enc) {
 			php_error_docref(NULL, E_WARNING, "Tag verifycation failed");
@@ -7054,7 +7054,14 @@ static int php_openssl_cipher_update(const EVP_CIPHER *cipher_type,
 /* }}} */
 
 
-PHP_OPENSSL_API zend_string* php_openssl_encrypt(char *data, size_t data_len, char *method, size_t method_len, char *password, size_t password_len, zend_long options, char *iv, size_t iv_len, zval *tag, zend_long tag_len, char *aad, size_t aad_len)
+PHP_OPENSSL_API zend_string* php_openssl_encrypt(
+	const char *data, size_t data_len,
+	const char *method, size_t method_len,
+	const char *password, size_t password_len,
+	zend_long options,
+	const char *iv, size_t iv_len,
+	zval *tag, zend_long tag_len,
+	const char *aad, size_t aad_len)
 {
 	const EVP_CIPHER *cipher_type;
 	EVP_CIPHER_CTX *cipher_ctx;
@@ -7130,10 +7137,10 @@ PHP_OPENSSL_API zend_string* php_openssl_encrypt(char *data, size_t data_len, ch
 	}
 
 	if (free_password) {
-		efree(password);
+		efree((void *) password);
 	}
 	if (free_iv) {
-		efree(iv);
+		efree((void *) iv);
 	}
 	EVP_CIPHER_CTX_reset(cipher_ctx);
 	EVP_CIPHER_CTX_free(cipher_ctx);
@@ -7163,7 +7170,14 @@ PHP_FUNCTION(openssl_encrypt)
 }
 /* }}} */
 
-PHP_OPENSSL_API zend_string* php_openssl_decrypt(char *data, size_t data_len, char *method, size_t method_len, char *password, size_t password_len, zend_long options, char *iv, size_t iv_len, char *tag, zend_long tag_len, char *aad, size_t aad_len)
+PHP_OPENSSL_API zend_string* php_openssl_decrypt(
+	const char *data, size_t data_len,
+	const char *method, size_t method_len,
+	const char *password, size_t password_len,
+	zend_long options,
+	const char *iv, size_t iv_len,
+	const char *tag, zend_long tag_len,
+	const char *aad, size_t aad_len)
 {
 	const EVP_CIPHER *cipher_type;
 	EVP_CIPHER_CTX *cipher_ctx;
@@ -7222,10 +7236,10 @@ PHP_OPENSSL_API zend_string* php_openssl_decrypt(char *data, size_t data_len, ch
 	}
 
 	if (free_password) {
-		efree(password);
+		efree((void *) password);
 	}
 	if (free_iv) {
-		efree(iv);
+		efree((void *) iv);
 	}
 	if (base64_str) {
 		zend_string_release_ex(base64_str, 0);
@@ -7262,7 +7276,7 @@ PHP_FUNCTION(openssl_decrypt)
 }
 /* }}} */
 
-PHP_OPENSSL_API zend_long php_openssl_cipher_iv_length(char *method)
+PHP_OPENSSL_API zend_long php_openssl_cipher_iv_length(const char *method)
 {
 	const EVP_CIPHER *cipher_type;
 
diff --git a/ext/openssl/php_openssl.h b/ext/openssl/php_openssl.h
index f786772f58..0ae0f9698c 100644
--- a/ext/openssl/php_openssl.h
+++ b/ext/openssl/php_openssl.h
@@ -92,16 +92,24 @@ php_stream_transport_factory_func php_openssl_ssl_socket_factory;
 
 void php_openssl_store_errors();
 
-PHP_OPENSSL_API zend_long php_openssl_cipher_iv_length(char *method);
+PHP_OPENSSL_API zend_long php_openssl_cipher_iv_length(const char *method);
 PHP_OPENSSL_API zend_string* php_openssl_random_pseudo_bytes(zend_long length);
-PHP_OPENSSL_API zend_string* php_openssl_encrypt(char *data, size_t data_len,
-		char *method, size_t method_len, char *password,
-		size_t password_len, zend_long options, char *iv, size_t iv_len,
-		zval *tag, zend_long tag_len, char *aad, size_t add_len);
-PHP_OPENSSL_API zend_string* php_openssl_decrypt(char *data, size_t data_len,
-		char *method, size_t method_len, char *password,
-		size_t password_len, zend_long options, char *iv, size_t iv_len,
-		char *tag, zend_long tag_len, char *aad, size_t add_len);
+PHP_OPENSSL_API zend_string* php_openssl_encrypt(
+	const char *data, size_t data_len,
+	const char *method, size_t method_len,
+	const char *password, size_t password_len,
+	zend_long options,
+	const char *iv, size_t iv_len,
+	zval *tag, zend_long tag_len,
+	const char *aad, size_t aad_len);
+PHP_OPENSSL_API zend_string* php_openssl_decrypt(
+	const char *data, size_t data_len,
+	const char *method, size_t method_len,
+	const char *password, size_t password_len,
+	zend_long options,
+	const char *iv, size_t iv_len,
+	const char *tag, zend_long tag_len,
+	const char *aad, size_t aad_len);
 
 PHP_MINIT_FUNCTION(openssl);
 PHP_MSHUTDOWN_FUNCTION(openssl);
diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index 9f67bff14c..55f9d2db7b 100644
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -555,12 +555,12 @@ static zend_string **make_subpats_table(uint32_t num_subpats, pcre_cache_entry *
 
 /* {{{ static calculate_unit_length */
 /* Calculates the byte length of the next character. Assumes valid UTF-8 for PCRE2_UTF. */
-static zend_always_inline size_t calculate_unit_length(pcre_cache_entry *pce, char *start)
+static zend_always_inline size_t calculate_unit_length(pcre_cache_entry *pce, const char *start)
 {
 	size_t unit_len;
 
 	if (pce->compile_options & PCRE2_UTF) {
-		char *end = start;
+		const char *end = start;
 
 		/* skip continuation bytes */
 		while ((*++end & 0xC0) == 0x80);
@@ -1038,7 +1038,7 @@ static inline void add_offset_pair(
 /* }}} */
 
 static void populate_subpat_array(
-		zval *subpats, char *subject, PCRE2_SIZE *offsets, zend_string **subpat_names,
+		zval *subpats, const char *subject, PCRE2_SIZE *offsets, zend_string **subpat_names,
 		uint32_t num_subpats, int count, const PCRE2_SPTR mark, zend_long flags) {
 	zend_bool offset_capture = (flags & PREG_OFFSET_CAPTURE) != 0;
 	zend_bool unmatched_as_null = (flags & PREG_UNMATCHED_AS_NULL) != 0;
@@ -1531,7 +1531,7 @@ static int preg_get_backref(char **str, int *backref)
 
 /* {{{ preg_do_repl_func
  */
-static zend_string *preg_do_repl_func(zend_fcall_info *fci, zend_fcall_info_cache *fcc, char *subject, PCRE2_SIZE *offsets, zend_string **subpat_names, uint32_t num_subpats, int count, const PCRE2_SPTR mark, zend_long flags)
+static zend_string *preg_do_repl_func(zend_fcall_info *fci, zend_fcall_info_cache *fcc, const char *subject, PCRE2_SIZE *offsets, zend_string **subpat_names, uint32_t num_subpats, int count, const PCRE2_SPTR mark, zend_long flags)
 {
 	zend_string *result_str;
 	zval		 retval;			/* Function return value */
@@ -1570,7 +1570,7 @@ static zend_string *preg_do_repl_func(zend_fcall_info *fci, zend_fcall_info_cach
  */
 PHPAPI zend_string *php_pcre_replace(zend_string *regex,
 							  zend_string *subject_str,
-							  char *subject, size_t subject_len,
+							  const char *subject, size_t subject_len,
 							  zend_string *replace_str,
 							  size_t limit, size_t *replace_count)
 {
@@ -1596,7 +1596,7 @@ PHPAPI zend_string *php_pcre_replace(zend_string *regex,
 /* }}} */
 
 /* {{{ php_pcre_replace_impl() */
-PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *subject_str, char *subject, size_t subject_len, zend_string *replace_str, size_t limit, size_t *replace_count)
+PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *subject_str, const char *subject, size_t subject_len, zend_string *replace_str, size_t limit, size_t *replace_count)
 {
 	uint32_t		 options;			/* Execution options */
 	int				 count;				/* Count of matched subpatterns */
@@ -1610,10 +1610,10 @@ PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *su
 	size_t			 last_end_offset;	/* Where the last search ended */
 	char			*walkbuf,			/* Location of current replacement in the result */
 					*walk,				/* Used to walk the replacement string */
-					*match,				/* The current match */
-					*piece,				/* The current piece of subject */
-					*replace_end,		/* End of replacement string */
 					 walk_last;			/* Last walked character */
+	const char		*match,				/* The current match */
+					*piece,				/* The current piece of subject */
+					*replace_end;		/* End of replacement string */
 	size_t			result_len; 		/* Length of result */
 	zend_string		*result;			/* Result of replacement */
 	pcre2_match_data *match_data;
@@ -1838,7 +1838,7 @@ error:
 /* }}} */
 
 /* {{{ php_pcre_replace_func_impl() */
-static zend_string *php_pcre_replace_func_impl(pcre_cache_entry *pce, zend_string *subject_str, char *subject, size_t subject_len, zend_fcall_info *fci, zend_fcall_info_cache *fcc, size_t limit, size_t *replace_count, zend_long flags)
+static zend_string *php_pcre_replace_func_impl(pcre_cache_entry *pce, zend_string *subject_str, const char *subject, size_t subject_len, zend_fcall_info *fci, zend_fcall_info_cache *fcc, size_t limit, size_t *replace_count, zend_long flags)
 {
 	uint32_t		 options;			/* Execution options */
 	int				 count;				/* Count of matched subpatterns */
@@ -1849,7 +1849,7 @@ static zend_string *php_pcre_replace_func_impl(pcre_cache_entry *pce, zend_strin
 	size_t			 alloc_len;			/* Actual allocated length */
 	PCRE2_SIZE		 start_offset;		/* Where the new search starts */
 	size_t			 last_end_offset;	/* Where the last search ended */
-	char			*match,				/* The current match */
+	const char		*match,				/* The current match */
 					*piece;				/* The current piece of subject */
 	size_t			result_len; 		/* Length of result */
 	zend_string		*result;			/* Result of replacement */
diff --git a/ext/pcre/php_pcre.h b/ext/pcre/php_pcre.h
index 4666f11b78..808b671bb8 100644
--- a/ext/pcre/php_pcre.h
+++ b/ext/pcre/php_pcre.h
@@ -25,7 +25,7 @@
 
 #include <locale.h>
 
-PHPAPI zend_string *php_pcre_replace(zend_string *regex, zend_string *subject_str, char *subject, size_t subject_len, zend_string *replace_str, size_t limit, size_t *replace_count);
+PHPAPI zend_string *php_pcre_replace(zend_string *regex, zend_string *subject_str, const char *subject, size_t subject_len, zend_string *replace_str, size_t limit, size_t *replace_count);
 PHPAPI pcre2_code* pcre_get_compiled_regex(zend_string *regex, uint32_t *capture_count);
 PHPAPI pcre2_code* pcre_get_compiled_regex_ex(zend_string *regex, uint32_t *capture_count, uint32_t *preg_options, uint32_t *coptions);
 
@@ -53,7 +53,7 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache_ex(zend_string *regex, in
 PHPAPI void  php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str, zval *return_value,
 	zval *subpats, int global, int use_flags, zend_long flags, zend_off_t start_offset);
 
-PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *subject_str, char *subject, size_t subject_len, zend_string *replace_str,
+PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *subject_str, const char *subject, size_t subject_len, zend_string *replace_str,
 	size_t limit, size_t *replace_count);
 
 PHPAPI void  php_pcre_split_impl(  pcre_cache_entry *pce, zend_string *subject_str, zval *return_value,
diff --git a/ext/pdo/pdo_sql_parser.re b/ext/pdo/pdo_sql_parser.re
index 31da8ffdf9..ee0ce7168d 100644
--- a/ext/pdo/pdo_sql_parser.re
+++ b/ext/pdo/pdo_sql_parser.re
@@ -36,12 +36,12 @@
 #define YYFILL(n)		{ RET(PDO_PARSER_EOI); }
 
 typedef struct Scanner {
-	char 	*ptr, *cur, *tok, *end;
+	const char *ptr, *cur, *tok, *end;
 } Scanner;
 
 static int scan(Scanner *s)
 {
-	char *cursor = s->cur;
+	const char *cursor = s->cur;
 
 	s->tok = cursor;
 	/*!re2c
@@ -68,9 +68,9 @@ static int scan(Scanner *s)
 }
 
 struct placeholder {
-	char *pos;
+	const char *pos;
 	size_t len;
-	size_t qlen;		/* quoted length of value */
+	size_t qlen;	/* quoted length of value */
 	char *quoted;	/* quoted value */
 	int freeq;
 	int bindno;
@@ -81,11 +81,12 @@ static void free_param_name(zval *el) {
 	efree(Z_PTR_P(el));
 }
 
-PDO_API int pdo_parse_params(pdo_stmt_t *stmt, char *inquery, size_t inquery_len,
+PDO_API int pdo_parse_params(pdo_stmt_t *stmt, const char *inquery, size_t inquery_len,
 	char **outquery, size_t *outquery_len)
 {
 	Scanner s;
-	char *ptr, *newbuffer;
+	const char *ptr;
+	char *newbuffer;
 	ptrdiff_t t;
 	uint32_t bindno = 0;
 	int ret = 0, escapes = 0;
diff --git a/ext/pdo/php_pdo_driver.h b/ext/pdo/php_pdo_driver.h
index 7f4861db20..2fd3b00e99 100644
--- a/ext/pdo/php_pdo_driver.h
+++ b/ext/pdo/php_pdo_driver.h
@@ -677,7 +677,7 @@ PDO_API int php_pdo_parse_data_source(const char *data_source,
 PDO_API zend_class_entry *php_pdo_get_dbh_ce(void);
 PDO_API zend_class_entry *php_pdo_get_exception(void);
 
-PDO_API int pdo_parse_params(pdo_stmt_t *stmt, char *inquery, size_t inquery_len,
+PDO_API int pdo_parse_params(pdo_stmt_t *stmt, const char *inquery, size_t inquery_len,
 	char **outquery, size_t *outquery_len);
 
 PDO_API void pdo_raise_impl_error(pdo_dbh_t *dbh, pdo_stmt_t *stmt,
diff --git a/ext/phar/phar_object.c b/ext/phar/phar_object.c
index d67c4dee47..351d342c53 100644
--- a/ext/phar/phar_object.c
+++ b/ext/phar/phar_object.c
@@ -168,12 +168,12 @@ static int phar_file_action(phar_archive_data *phar, phar_entry_info *info, char
 		case PHAR_MIME_OTHER:
 			/* send headers, output file contents */
 			efree(basename);
-			ctr.line_len = spprintf(&(ctr.line), 0, "Content-type: %s", mime_type);
+			ctr.line_len = spprintf((char **) &(ctr.line), 0, "Content-type: %s", mime_type);
 			sapi_header_op(SAPI_HEADER_REPLACE, &ctr);
-			efree(ctr.line);
-			ctr.line_len = spprintf(&(ctr.line), 0, "Content-length: %u", info->uncompressed_filesize);
+			efree((void *) ctr.line);
+			ctr.line_len = spprintf((char **) &(ctr.line), 0, "Content-length: %u", info->uncompressed_filesize);
 			sapi_header_op(SAPI_HEADER_REPLACE, &ctr);
-			efree(ctr.line);
+			efree((void *) ctr.line);
 
 			if (FAILURE == sapi_send_headers()) {
 				zend_bailout();
@@ -790,9 +790,9 @@ PHP_METHOD(Phar, webPhar)
 			ctr.response_code = 0;
 
 			if (path_info[strlen(path_info)-1] == '/') {
-				ctr.line_len = spprintf(&(ctr.line), 4096, "Location: %s%s", path_info, entry + 1);
+				ctr.line_len = spprintf((char **) &(ctr.line), 4096, "Location: %s%s", path_info, entry + 1);
 			} else {
-				ctr.line_len = spprintf(&(ctr.line), 4096, "Location: %s%s", path_info, entry);
+				ctr.line_len = spprintf((char **) &(ctr.line), 4096, "Location: %s%s", path_info, entry);
 			}
 
 			if (not_cgi) {
@@ -805,7 +805,7 @@ PHP_METHOD(Phar, webPhar)
 
 			sapi_header_op(SAPI_HEADER_REPLACE, &ctr);
 			sapi_send_headers();
-			efree(ctr.line);
+			efree((void *) ctr.line);
 			zend_bailout();
 		}
 	}
diff --git a/ext/session/php_session.h b/ext/session/php_session.h
index 6f96644024..73f8bf31c8 100644
--- a/ext/session/php_session.h
+++ b/ext/session/php_session.h
@@ -247,7 +247,7 @@ PHPAPI zend_string *php_session_create_id(PS_CREATE_SID_ARGS);
 PHPAPI int php_session_validate_sid(PS_VALIDATE_SID_ARGS);
 PHPAPI int php_session_update_timestamp(PS_UPDATE_TIMESTAMP_ARGS);
 
-PHPAPI void session_adapt_url(const char *, size_t, char **, size_t *);
+PHPAPI void session_adapt_url(const char *url, size_t url_len, char **new_url, size_t *new_len);
 
 PHPAPI int php_session_destroy(void);
 PHPAPI void php_add_session_var(zend_string *name);
@@ -260,12 +260,11 @@ PHPAPI int php_session_register_serializer(const char *name,
 	        zend_string *(*encode)(PS_SERIALIZER_ENCODE_ARGS),
 	        int (*decode)(PS_SERIALIZER_DECODE_ARGS));
 
-PHPAPI void php_session_set_id(char *id);
 PHPAPI int php_session_start(void);
 PHPAPI int php_session_flush(int write);
 
-PHPAPI const ps_module *_php_find_ps_module(char *name);
-PHPAPI const ps_serializer *_php_find_ps_serializer(char *name);
+PHPAPI const ps_module *_php_find_ps_module(const char *name);
+PHPAPI const ps_serializer *_php_find_ps_serializer(const char *name);
 
 PHPAPI int php_session_valid_key(const char *key);
 PHPAPI int php_session_reset_id(void);
diff --git a/ext/session/session.c b/ext/session/session.c
index 993f6a063f..418a89d883 100644
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -1374,7 +1374,7 @@ static int php_session_send_cookie(void) /* {{{ */
 }
 /* }}} */
 
-PHPAPI const ps_module *_php_find_ps_module(char *name) /* {{{ */
+PHPAPI const ps_module *_php_find_ps_module(const char *name) /* {{{ */
 {
 	const ps_module *ret = NULL;
 	const ps_module **mod;
@@ -1390,7 +1390,7 @@ PHPAPI const ps_module *_php_find_ps_module(char *name) /* {{{ */
 }
 /* }}} */
 
-PHPAPI const ps_serializer *_php_find_ps_serializer(char *name) /* {{{ */
+PHPAPI const ps_serializer *_php_find_ps_serializer(const char *name) /* {{{ */
 {
 	const ps_serializer *ret = NULL;
 	const ps_serializer *mod;
@@ -1648,10 +1648,10 @@ static int php_session_reset(void) /* {{{ */
 /* This API is not used by any PHP modules including session currently.
    session_adapt_url() may be used to set Session ID to target url without
    starting "URL-Rewriter" output handler. */
-PHPAPI void session_adapt_url(const char *url, size_t urllen, char **new, size_t *newlen) /* {{{ */
+PHPAPI void session_adapt_url(const char *url, size_t url_len, char **new_url, size_t *new_len) /* {{{ */
 {
 	if (APPLY_TRANS_SID && (PS(session_status) == php_session_active)) {
-		*new = php_url_scanner_adapt_single_url(url, urllen, PS(session_name), ZSTR_VAL(PS(id)), newlen, 1);
+		*new_url = php_url_scanner_adapt_single_url(url, url_len, PS(session_name), ZSTR_VAL(PS(id)), new_len, 1);
 	}
 }
 /* }}} */
diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c
index 090f11e0ab..883b5d45c5 100755
--- a/ext/standard/basic_functions.c
+++ b/ext/standard/basic_functions.c
@@ -1472,13 +1472,13 @@ PHP_FUNCTION(error_log)
 /* }}} */
 
 /* For BC (not binary-safe!) */
-PHPAPI int _php_error_log(int opt_err, char *message, char *opt, char *headers) /* {{{ */
+PHPAPI int _php_error_log(int opt_err, const char *message, const char *opt, const char *headers) /* {{{ */
 {
 	return _php_error_log_ex(opt_err, message, (opt_err == 3) ? strlen(message) : 0, opt, headers);
 }
 /* }}} */
 
-PHPAPI int _php_error_log_ex(int opt_err, char *message, size_t message_len, char *opt, char *headers) /* {{{ */
+PHPAPI int _php_error_log_ex(int opt_err, const char *message, size_t message_len, const char *opt, const char *headers) /* {{{ */
 {
 	php_stream *stream = NULL;
 	size_t nbytes;
@@ -1870,7 +1870,7 @@ PHP_FUNCTION(register_shutdown_function)
 }
 /* }}} */
 
-PHPAPI zend_bool register_user_shutdown_function(char *function_name, size_t function_len, php_shutdown_function_entry *shutdown_function_entry) /* {{{ */
+PHPAPI zend_bool register_user_shutdown_function(const char *function_name, size_t function_len, php_shutdown_function_entry *shutdown_function_entry) /* {{{ */
 {
 	if (!BG(user_shutdown_function_names)) {
 		ALLOC_HASHTABLE(BG(user_shutdown_function_names));
@@ -1882,7 +1882,7 @@ PHPAPI zend_bool register_user_shutdown_function(char *function_name, size_t fun
 }
 /* }}} */
 
-PHPAPI zend_bool remove_user_shutdown_function(char *function_name, size_t function_len) /* {{{ */
+PHPAPI zend_bool remove_user_shutdown_function(const char *function_name, size_t function_len) /* {{{ */
 {
 	if (BG(user_shutdown_function_names)) {
 		return zend_hash_str_del(BG(user_shutdown_function_names), function_name, function_len) != FAILURE;
diff --git a/ext/standard/basic_functions.h b/ext/standard/basic_functions.h
index 147bc1dd3a..00727668dc 100644
--- a/ext/standard/basic_functions.h
+++ b/ext/standard/basic_functions.h
@@ -47,8 +47,8 @@ PHP_RSHUTDOWN_FUNCTION(user_filters);
 PHP_RSHUTDOWN_FUNCTION(browscap);
 
 /* Left for BC (not binary safe!) */
-PHPAPI int _php_error_log(int opt_err, char *message, char *opt, char *headers);
-PHPAPI int _php_error_log_ex(int opt_err, char *message, size_t message_len, char *opt, char *headers);
+PHPAPI int _php_error_log(int opt_err, const char *message, const char *opt, const char *headers);
+PHPAPI int _php_error_log_ex(int opt_err, const char *message, size_t message_len, const char *opt, const char *headers);
 PHPAPI int php_prefix_varname(zval *result, zend_string *prefix, const char *var_name, size_t var_name_len, zend_bool add_underscore);
 
 #define MT_N (624)
@@ -150,8 +150,8 @@ typedef struct _php_shutdown_function_entry {
 	int arg_count;
 } php_shutdown_function_entry;
 
-PHPAPI extern zend_bool register_user_shutdown_function(char *function_name, size_t function_len, php_shutdown_function_entry *shutdown_function_entry);
-PHPAPI extern zend_bool remove_user_shutdown_function(char *function_name, size_t function_len);
+PHPAPI extern zend_bool register_user_shutdown_function(const char *function_name, size_t function_len, php_shutdown_function_entry *shutdown_function_entry);
+PHPAPI extern zend_bool remove_user_shutdown_function(const char *function_name, size_t function_len);
 PHPAPI extern zend_bool append_user_shutdown_function(php_shutdown_function_entry shutdown_function_entry);
 
 PHPAPI void php_call_shutdown_functions(void);
diff --git a/ext/standard/dl.c b/ext/standard/dl.c
index ed387761a8..f70ab6fbb5 100644
--- a/ext/standard/dl.c
+++ b/ext/standard/dl.c
@@ -70,7 +70,7 @@ PHPAPI PHP_FUNCTION(dl)
 
 /* {{{ php_load_shlib
  */
-PHPAPI void *php_load_shlib(char *path, char **errp)
+PHPAPI void *php_load_shlib(const char *path, char **errp)
 {
 	void *handle;
 	char *err;
@@ -98,7 +98,7 @@ PHPAPI void *php_load_shlib(char *path, char **errp)
 
 /* {{{ php_load_extension
  */
-PHPAPI int php_load_extension(char *filename, int type, int start_now)
+PHPAPI int php_load_extension(const char *filename, int type, int start_now)
 {
 	void *handle;
 	char *libpath;
@@ -243,35 +243,47 @@ PHPAPI int php_load_extension(char *filename, int type, int start_now)
 }
 /* }}} */
 
-/* {{{ php_dl
- */
-PHPAPI void php_dl(char *file, int type, zval *return_value, int start_now)
+#else
+
+static void php_dl_error(const char *filename)
 {
-	/* Load extension */
-	if (php_load_extension(file, type, start_now) == FAILURE) {
-		RETVAL_FALSE;
-	} else {
-		RETVAL_TRUE;
-	}
+    php_error_docref(NULL, E_WARNING, "Cannot dynamically load %s - dynamic modules are not supported", filename);
 }
-/* }}} */
 
-PHP_MINFO_FUNCTION(dl)
+PHPAPI void *php_load_shlib(const char *path, char **errp)
 {
-	php_info_print_table_row(2, "Dynamic Library Support", "enabled");
+    php_dl_error(filename);
+    (*errp) = estrdup("No DL support");
 }
 
-#else
-
-PHPAPI void php_dl(char *file, int type, zval *return_value, int start_now)
+PHPAPI int php_load_extension(const char *filename, int type, int start_now)
 {
-	php_error_docref(NULL, E_WARNING, "Cannot dynamically load %s - dynamic modules are not supported", file);
-	RETVAL_FALSE;
+    php_dl_error(filename);
+
+    return FAILURE;
 }
 
-PHP_MINFO_FUNCTION(dl)
+#endif
+
+/* {{{ php_dl
+ */
+PHPAPI void php_dl(const char *file, int type, zval *return_value, int start_now)
 {
-	PUTS("Dynamic Library support not available<br />.\n");
+    /* Load extension */
+    if (php_load_extension(file, type, start_now) == FAILURE) {
+        RETVAL_FALSE;
+    } else {
+        RETVAL_TRUE;
+    }
 }
+/* }}} */
 
+PHP_MINFO_FUNCTION(dl)
+{
+#if defined(HAVE_LIBDL)
+#define PHP_DL_SUPPORT_STATUS "enabled"
+#else
+#define PHP_DL_SUPPORT_STATUS "unavailable"
 #endif
+    php_info_print_table_row(2, "Dynamic Library Support", PHP_DL_SUPPORT_STATUS);
+}
diff --git a/ext/standard/dl.h b/ext/standard/dl.h
index d51df044d2..9d13b97ff7 100644
--- a/ext/standard/dl.h
+++ b/ext/standard/dl.h
@@ -19,9 +19,9 @@
 #ifndef DL_H
 #define DL_H
 
-PHPAPI int php_load_extension(char *filename, int type, int start_now);
-PHPAPI void php_dl(char *file, int type, zval *return_value, int start_now);
-PHPAPI void *php_load_shlib(char *path, char **errp);
+PHPAPI int php_load_extension(const char *filename, int type, int start_now);
+PHPAPI void php_dl(const char *file, int type, zval *return_value, int start_now);
+PHPAPI void *php_load_shlib(const char *path, char **errp);
 
 /* dynamic loading functions */
 PHPAPI PHP_FUNCTION(dl);
diff --git a/ext/standard/exec.c b/ext/standard/exec.c
index 9935e2b34c..8ba205a9ed 100644
--- a/ext/standard/exec.c
+++ b/ext/standard/exec.c
@@ -111,7 +111,7 @@ static size_t handle_line(int type, zval *array, char *buf, size_t bufl) {
  * If type==3, output will be printed binary, no lines will be saved or returned (passthru)
  *
  */
-PHPAPI int php_exec(int type, char *cmd, zval *array, zval *return_value)
+PHPAPI int php_exec(int type, const char *cmd, zval *array, zval *return_value)
 {
 	FILE *fp;
 	char *buf;
@@ -282,7 +282,7 @@ PHP_FUNCTION(passthru)
 
    *NOT* safe for binary strings
 */
-PHPAPI zend_string *php_escape_shell_cmd(char *str)
+PHPAPI zend_string *php_escape_shell_cmd(const char *str)
 {
 	register size_t x, y;
 	size_t l = strlen(str);
@@ -389,7 +389,7 @@ PHPAPI zend_string *php_escape_shell_cmd(char *str)
 
 /* {{{ php_escape_shell_arg
  */
-PHPAPI zend_string *php_escape_shell_arg(char *str)
+PHPAPI zend_string *php_escape_shell_arg(const char *str)
 {
 	size_t x, y = 0;
 	size_t l = strlen(str);
diff --git a/ext/standard/exec.h b/ext/standard/exec.h
index 97edbd099a..6ad9ee0b40 100644
--- a/ext/standard/exec.h
+++ b/ext/standard/exec.h
@@ -20,8 +20,8 @@
 PHP_MINIT_FUNCTION(proc_open);
 PHP_MINIT_FUNCTION(exec);
 
-PHPAPI zend_string *php_escape_shell_cmd(char *);
-PHPAPI zend_string *php_escape_shell_arg(char *);
-PHPAPI int php_exec(int type, char *cmd, zval *array, zval *return_value);
+PHPAPI zend_string *php_escape_shell_cmd(const char *str);
+PHPAPI zend_string *php_escape_shell_arg(const char *str);
+PHPAPI int php_exec(int type, const char *cmd, zval *array, zval *return_value);
 
 #endif /* EXEC_H */
diff --git a/ext/standard/head.c b/ext/standard/head.c
index 657510de5b..06496f04aa 100644
--- a/ext/standard/head.c
+++ b/ext/standard/head.c
@@ -34,15 +34,17 @@ PHP_FUNCTION(header)
 {
 	zend_bool rep = 1;
 	sapi_header_line ctr = {0};
+	char *line;
 	size_t len;
 
 	ZEND_PARSE_PARAMETERS_START(1, 3)
-		Z_PARAM_STRING(ctr.line, len)
+		Z_PARAM_STRING(line, len)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_BOOL(rep)
 		Z_PARAM_LONG(ctr.response_code)
 	ZEND_PARSE_PARAMETERS_END();
 
+	ctr.line = line;
 	ctr.line_len = (uint32_t)len;
 	sapi_header_op(rep ? SAPI_HEADER_REPLACE:SAPI_HEADER_ADD, &ctr);
 }
@@ -53,13 +55,15 @@ PHP_FUNCTION(header)
 PHP_FUNCTION(header_remove)
 {
 	sapi_header_line ctr = {0};
+	char *line = NULL;
 	size_t len = 0;
 
 	ZEND_PARSE_PARAMETERS_START(0, 1)
 		Z_PARAM_OPTIONAL
-		Z_PARAM_STRING(ctr.line, len)
+		Z_PARAM_STRING(line, len)
 	ZEND_PARSE_PARAMETERS_END();
 
+	ctr.line = line;
 	ctr.line_len = (uint32_t)len;
 	sapi_header_op(ZEND_NUM_ARGS() == 0 ? SAPI_HEADER_DELETE_ALL : SAPI_HEADER_DELETE, &ctr);
 }
diff --git a/ext/standard/html.c b/ext/standard/html.c
index e1a0799375..8e5b65d80c 100644
--- a/ext/standard/html.c
+++ b/ext/standard/html.c
@@ -367,7 +367,7 @@ static inline unsigned int get_next_char(
 /* {{{ entity_charset determine_charset
  * Returns the charset identifier based on an explicitly provided charset,
  * the internal_encoding and default_charset ini settings, or UTF-8 by default. */
-static enum entity_charset determine_charset(char *charset_hint, zend_bool quiet)
+static enum entity_charset determine_charset(const char *charset_hint, zend_bool quiet)
 {
 	if (!charset_hint || !*charset_hint) {
 		charset_hint = get_default_charset();
@@ -979,7 +979,7 @@ static entity_table_opt determine_entity_table(int all, int doctype)
  * only the basic ones, i.e., those in basic_entities_ex + the numeric entities
  * that correspond to quotes.
  */
-PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int flags, char *hint_charset)
+PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int flags, const char *hint_charset)
 {
 	zend_string *ret;
 	enum entity_charset charset;
@@ -1015,7 +1015,7 @@ PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int fl
 }
 /* }}} */
 
-PHPAPI zend_string *php_escape_html_entities(const unsigned char *old, size_t oldlen, int all, int flags, char *hint_charset)
+PHPAPI zend_string *php_escape_html_entities(const unsigned char *old, size_t oldlen, int all, int flags, const char *hint_charset)
 {
 	return php_escape_html_entities_ex(old, oldlen, all, flags, hint_charset, 1, /* quiet */ 0);
 }
@@ -1103,7 +1103,7 @@ static inline void find_entity_for_char_basic(
 
 /* {{{ php_escape_html_entities
  */
-PHPAPI zend_string *php_escape_html_entities_ex(const unsigned char *old, size_t oldlen, int all, int flags, char *hint_charset, zend_bool double_encode, zend_bool quiet)
+PHPAPI zend_string *php_escape_html_entities_ex(const unsigned char *old, size_t oldlen, int all, int flags, const char *hint_charset, zend_bool double_encode, zend_bool quiet)
 {
 	size_t cursor, maxlen, len;
 	zend_string *replaced;
diff --git a/ext/standard/html.h b/ext/standard/html.h
index 818ee1a0ca..3aee85cd87 100644
--- a/ext/standard/html.h
+++ b/ext/standard/html.h
@@ -44,9 +44,9 @@
 
 void register_html_constants(INIT_FUNC_ARGS);
 
-PHPAPI zend_string *php_escape_html_entities(const unsigned char *old, size_t oldlen, int all, int flags, char *hint_charset);
-PHPAPI zend_string *php_escape_html_entities_ex(const unsigned char *old, size_t oldlen, int all, int flags, char *hint_charset, zend_bool double_encode, zend_bool quiet);
-PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int flags, char *hint_charset);
+PHPAPI zend_string *php_escape_html_entities(const unsigned char *old, size_t oldlen, int all, int flags, const char *hint_charset);
+PHPAPI zend_string *php_escape_html_entities_ex(const unsigned char *old, size_t oldlen, int all, int flags, const char *hint_charset, zend_bool double_encode, zend_bool quiet);
+PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int flags, const char *hint_charset);
 PHPAPI unsigned int php_next_utf8_char(const unsigned char *str, size_t str_len, size_t *cursor, int *status);
 
 #endif /* HTML_H */
diff --git a/ext/standard/http.c b/ext/standard/http.c
index 4b6866d3f8..386a0df1eb 100644
--- a/ext/standard/http.c
+++ b/ext/standard/http.c
@@ -25,7 +25,7 @@ PHPAPI int php_url_encode_hash_ex(HashTable *ht, smart_str *formstr,
 				const char *num_prefix, size_t num_prefix_len,
 				const char *key_prefix, size_t key_prefix_len,
 				const char *key_suffix, size_t key_suffix_len,
-			  zval *type, char *arg_sep, int enc_type)
+			  zval *type, const char *arg_sep, int enc_type)
 {
 	zend_string *key = NULL;
 	char *newprefix, *p;
diff --git a/ext/standard/image.c b/ext/standard/image.c
index e967aaeee0..147a146e5c 100644
--- a/ext/standard/image.c
+++ b/ext/standard/image.c
@@ -1293,7 +1293,7 @@ PHP_FUNCTION(image_type_to_extension)
 
 /* {{{ php_imagetype
    detect filetype from first bytes */
-PHPAPI int php_getimagetype(php_stream * stream, char *input, char *filetype)
+PHPAPI int php_getimagetype(php_stream * stream, const char *input, char *filetype)
 {
 	char tmp[12];
     int twelve_bytes_read;
diff --git a/ext/standard/info.c b/ext/standard/info.c
index 8a090d20e5..262e95ae27 100644
--- a/ext/standard/info.c
+++ b/ext/standard/info.c
@@ -57,7 +57,7 @@ static ZEND_COLD int php_info_print_html_esc(const char *str, size_t len) /* {{{
 	size_t written;
 	zend_string *new_str;
 
-	new_str = php_escape_html_entities((unsigned char *) str, len, 0, ENT_QUOTES, "utf-8");
+	new_str = php_escape_html_entities((const unsigned char *) str, len, 0, ENT_QUOTES, "utf-8");
 	written = php_output_write(ZSTR_VAL(new_str), ZSTR_LEN(new_str));
 	zend_string_free(new_str);
 	return written;
@@ -249,9 +249,9 @@ PHPAPI ZEND_COLD void ZEND_COLD php_info_print_style(void)
 
 /* {{{ php_info_html_esc
  */
-PHPAPI ZEND_COLD zend_string *php_info_html_esc(char *string)
+PHPAPI ZEND_COLD zend_string *php_info_html_esc(const char *string)
 {
-	return php_escape_html_entities((unsigned char *) string, strlen(string), 0, ENT_QUOTES, NULL);
+	return php_escape_html_entities((const unsigned char *) string, strlen(string), 0, ENT_QUOTES, NULL);
 }
 /* }}} */
 
@@ -1095,7 +1095,7 @@ PHPAPI ZEND_COLD void php_info_print_hr(void) /* {{{ */
 }
 /* }}} */
 
-PHPAPI ZEND_COLD void php_info_print_table_colspan_header(int num_cols, char *header) /* {{{ */
+PHPAPI ZEND_COLD void php_info_print_table_colspan_header(int num_cols, const char *header) /* {{{ */
 {
 	int spaces;
 
diff --git a/ext/standard/info.h b/ext/standard/info.h
index 95eec2d2ad..cb9a4930a9 100644
--- a/ext/standard/info.h
+++ b/ext/standard/info.h
@@ -52,13 +52,12 @@
 #define ZEND_LOGO_DATA_URI "data:image/png;base64,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"
 
 BEGIN_EXTERN_C()
-PHPAPI zend_string *php_info_html_esc(char *string);
-PHPAPI void php_info_html_esc_write(char *string, int str_len);
+PHPAPI zend_string *php_info_html_esc(const char *string);
 PHPAPI void php_print_info_htmlhead(void);
 PHPAPI void php_print_info(int flag);
 PHPAPI void php_print_style(void);
 PHPAPI void php_info_print_style(void);
-PHPAPI void php_info_print_table_colspan_header(int num_cols, char *header);
+PHPAPI void php_info_print_table_colspan_header(int num_cols, const char *header);
 PHPAPI void php_info_print_table_header(int num_cols, ...);
 PHPAPI void php_info_print_table_row(int num_cols, ...);
 PHPAPI void php_info_print_table_row_ex(int num_cols, const char *, ...);
diff --git a/ext/standard/mail.c b/ext/standard/mail.c
index 096f432c9a..7b8cb08236 100644
--- a/ext/standard/mail.c
+++ b/ext/standard/mail.c
@@ -386,7 +386,7 @@ void php_mail_log_to_file(char *filename, char *message, size_t message_size) {
 }
 
 
-static int php_mail_detect_multiple_crlf(char *hdr) {
+static int php_mail_detect_multiple_crlf(const char *hdr) {
 	/* This function detects multiple/malformed multiple newlines. */
 
 	if (!hdr || !strlen(hdr)) {
@@ -425,7 +425,7 @@ static int php_mail_detect_multiple_crlf(char *hdr) {
 
 /* {{{ php_mail
  */
-PHPAPI int php_mail(char *to, char *subject, char *message, char *headers, char *extra_cmd)
+PHPAPI int php_mail(const char *to, const char *subject, const char *message, const char *headers, const char *extra_cmd)
 {
 #ifdef PHP_WIN32
 	int tsm_err;
@@ -436,14 +436,15 @@ PHPAPI int php_mail(char *to, char *subject, char *message, char *headers, char
 	char *sendmail_path = INI_STR("sendmail_path");
 	char *sendmail_cmd = NULL;
 	char *mail_log = INI_STR("mail.log");
-	char *hdr = headers;
+	const char *hdr = headers;
+	char *ahdr = NULL;
 #if PHP_SIGCHILD
 	void (*sig_handler)() = NULL;
 #endif
 
 #define MAIL_RET(val) \
-	if (hdr != headers) {	\
-		efree(hdr);	\
+	if (ahdr != NULL) {	\
+		efree(ahdr);	\
 	}	\
 	return val;	\
 
@@ -486,10 +487,11 @@ PHPAPI int php_mail(char *to, char *subject, char *message, char *headers, char
 		f = php_basename(tmp, strlen(tmp), NULL, 0);
 
 		if (headers != NULL && *headers) {
-			spprintf(&hdr, 0, "X-PHP-Originating-Script: " ZEND_LONG_FMT ":%s\r\n%s", php_getuid(), ZSTR_VAL(f), headers);
+			spprintf(&ahdr, 0, "X-PHP-Originating-Script: " ZEND_LONG_FMT ":%s\r\n%s", php_getuid(), ZSTR_VAL(f), headers);
 		} else {
-			spprintf(&hdr, 0, "X-PHP-Originating-Script: " ZEND_LONG_FMT ":%s", php_getuid(), ZSTR_VAL(f));
+			spprintf(&ahdr, 0, "X-PHP-Originating-Script: " ZEND_LONG_FMT ":%s", php_getuid(), ZSTR_VAL(f));
 		}
+		hdr = ahdr;
 		zend_string_release_ex(f, 0);
 	}
 
diff --git a/ext/standard/math.c b/ext/standard/math.c
index ca6c1f4b9d..fe23a189c2 100644
--- a/ext/standard/math.c
+++ b/ext/standard/math.c
@@ -1026,8 +1026,8 @@ PHPAPI zend_string *_php_math_number_format(double d, int dec, char dec_point, c
 	return _php_math_number_format_ex(d, dec, &dec_point, 1, &thousand_sep, 1);
 }
 
-PHPAPI zend_string *_php_math_number_format_ex(double d, int dec, char *dec_point,
-		size_t dec_point_len, char *thousand_sep, size_t thousand_sep_len)
+PHPAPI zend_string *_php_math_number_format_ex(double d, int dec, const char *dec_point,
+		size_t dec_point_len, const char *thousand_sep, size_t thousand_sep_len)
 {
 	zend_string *res;
 	zend_string *tmpbuf;
diff --git a/ext/standard/php_http.h b/ext/standard/php_http.h
index 728ea33fd1..b77cd0bda3 100644
--- a/ext/standard/php_http.h
+++ b/ext/standard/php_http.h
@@ -24,7 +24,7 @@ PHPAPI int php_url_encode_hash_ex(HashTable *ht, smart_str *formstr,
 				const char *num_prefix, size_t num_prefix_len,
 				const char *key_prefix, size_t key_prefix_len,
 				const char *key_suffix, size_t key_suffix_len,
-				zval *type, char *arg_sep, int enc_type);
+				zval *type, const char *arg_sep, int enc_type);
 #define php_url_encode_hash(ht, formstr)	php_url_encode_hash_ex((ht), (formstr), NULL, 0, NULL, 0, NULL, 0, NULL)
 
 #endif
diff --git a/ext/standard/php_image.h b/ext/standard/php_image.h
index d532496ea6..3649e62198 100644
--- a/ext/standard/php_image.h
+++ b/ext/standard/php_image.h
@@ -50,7 +50,7 @@ typedef enum
 
 PHP_MINIT_FUNCTION(imagetypes);
 
-PHPAPI int php_getimagetype(php_stream *stream, char *input, char *filetype);
+PHPAPI int php_getimagetype(php_stream *stream, const char *input, char *filetype);
 
 PHPAPI char * php_image_type_to_mime_type(int image_type);
 
diff --git a/ext/standard/php_mail.h b/ext/standard/php_mail.h
index 3a2ccdc4b1..2a561d5523 100644
--- a/ext/standard/php_mail.h
+++ b/ext/standard/php_mail.h
@@ -20,7 +20,7 @@
 PHP_MINFO_FUNCTION(mail);
 
 PHPAPI zend_string *php_mail_build_headers(HashTable *headers);
-PHPAPI extern int php_mail(char *to, char *subject, char *message, char *headers, char *extra_cmd);
+PHPAPI extern int php_mail(const char *to, const char *subject, const char *message, const char *headers, const char *extra_cmd);
 
 #define PHP_MAIL_BUILD_HEADER_CHECK(target, s, key, val) \
 do { \
diff --git a/ext/standard/php_math.h b/ext/standard/php_math.h
index a8d1f2dbf3..c3ce7cc728 100644
--- a/ext/standard/php_math.h
+++ b/ext/standard/php_math.h
@@ -18,9 +18,9 @@
 #ifndef PHP_MATH_H
 #define PHP_MATH_H
 
-PHPAPI double _php_math_round(double, int, int);
-PHPAPI zend_string *_php_math_number_format(double, int, char, char);
-PHPAPI zend_string *_php_math_number_format_ex(double, int, char *, size_t, char *, size_t);
+PHPAPI double _php_math_round(double value, int places, int mode);
+PHPAPI zend_string *_php_math_number_format(double d, int dec, char dec_point, char thousand_sep);
+PHPAPI zend_string *_php_math_number_format_ex(double d, int dec, const char *dec_point, size_t dec_point_len, const char *thousand_sep, size_t thousand_sep_len);
 PHPAPI zend_string * _php_math_longtobase(zval *arg, int base);
 PHPAPI zend_long _php_math_basetolong(zval *arg, int base);
 PHPAPI void _php_math_basetozval(zend_string *str, int base, zval *ret);
diff --git a/ext/standard/php_string.h b/ext/standard/php_string.h
index 7a813c2610..43e50dffc1 100644
--- a/ext/standard/php_string.h
+++ b/ext/standard/php_string.h
@@ -42,22 +42,22 @@ PHPAPI zend_string *php_string_tolower(zend_string *s);
 PHPAPI char *php_strtr(char *str, size_t len, const char *str_from, const char *str_to, size_t trlen);
 PHPAPI zend_string *php_addslashes(zend_string *str);
 PHPAPI void php_stripslashes(zend_string *str);
-PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, char *what, size_t what_len);
-PHPAPI zend_string *php_addcslashes(zend_string *str, char *what, size_t what_len);
+PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, const char *what, size_t what_len);
+PHPAPI zend_string *php_addcslashes(zend_string *str, const char *what, size_t what_len);
 PHPAPI void php_stripcslashes(zend_string *str);
-PHPAPI zend_string *php_basename(const char *s, size_t len, char *suffix, size_t sufflen);
+PHPAPI zend_string *php_basename(const char *s, size_t len, const char *suffix, size_t sufflen);
 PHPAPI size_t php_dirname(char *str, size_t len);
 PHPAPI char *php_stristr(char *s, char *t, size_t s_len, size_t t_len);
 PHPAPI zend_string *php_str_to_str(const char *haystack, size_t length, const char *needle,
 		size_t needle_len, const char *str, size_t str_len);
-PHPAPI zend_string *php_trim(zend_string *str, char *what, size_t what_len, int mode);
+PHPAPI zend_string *php_trim(zend_string *str, const char *what, size_t what_len, int mode);
 PHPAPI size_t php_strip_tags(char *rbuf, size_t len, const char *allow, size_t allow_len);
 PHPAPI size_t php_strip_tags_ex(char *rbuf, size_t len, const char *allow, size_t allow_len, zend_bool allow_tag_spaces);
 PHPAPI void php_implode(const zend_string *delim, HashTable *arr, zval *return_value);
 PHPAPI void php_explode(const zend_string *delim, zend_string *str, zval *return_value, zend_long limit);
 
-PHPAPI size_t php_strspn(char *s1, char *s2, char *s1_end, char *s2_end);
-PHPAPI size_t php_strcspn(char *s1, char *s2, char *s1_end, char *s2_end);
+PHPAPI size_t php_strspn(const char *s1, const char *s2, const char *s1_end, const char *s2_end);
+PHPAPI size_t php_strcspn(const char *s1, const char *s2, const char *s1_end, const char *s2_end);
 
 PHPAPI int string_natural_compare_function_ex(zval *result, zval *op1, zval *op2, zend_bool case_insensitive);
 PHPAPI int string_natural_compare_function(zval *result, zval *op1, zval *op2);
diff --git a/ext/standard/php_uuencode.h b/ext/standard/php_uuencode.h
index 82549f56d1..5d5c84a9b3 100644
--- a/ext/standard/php_uuencode.h
+++ b/ext/standard/php_uuencode.h
@@ -17,7 +17,7 @@
 #ifndef PHP_UUENCODE_H
 #define PHP_UUENCODE_H
 
-PHPAPI zend_string *php_uudecode(char *src, size_t src_len);
-PHPAPI zend_string *php_uuencode(char *src, size_t src_len);
+PHPAPI zend_string *php_uudecode(const char *src, size_t src_len);
+PHPAPI zend_string *php_uuencode(const char *src, size_t src_len);
 
 #endif /* PHP_UUENCODE_H */
diff --git a/ext/standard/sha1.c b/ext/standard/sha1.c
index 269fe8a947..562e6e9de6 100644
--- a/ext/standard/sha1.c
+++ b/ext/standard/sha1.c
@@ -21,7 +21,7 @@
 #include "sha1.h"
 #include "md5.h"
 
-PHPAPI void make_sha1_digest(char *sha1str, unsigned char *digest)
+PHPAPI void make_sha1_digest(char *sha1str, const unsigned char *digest)
 {
 	make_digest_ex(sha1str, digest, 20);
 }
diff --git a/ext/standard/sha1.h b/ext/standard/sha1.h
index 81a9cae460..c904969dd3 100644
--- a/ext/standard/sha1.h
+++ b/ext/standard/sha1.h
@@ -29,6 +29,6 @@ typedef struct {
 PHPAPI void PHP_SHA1Init(PHP_SHA1_CTX *);
 PHPAPI void PHP_SHA1Update(PHP_SHA1_CTX *, const unsigned char *, size_t);
 PHPAPI void PHP_SHA1Final(unsigned char[20], PHP_SHA1_CTX *);
-PHPAPI void make_sha1_digest(char *sha1str, unsigned char *digest);
+PHPAPI void make_sha1_digest(char *sha1str, const unsigned char *digest);
 
 #endif
diff --git a/ext/standard/string.c b/ext/standard/string.c
index 06ad0f2d24..635f5daf8f 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -765,7 +765,7 @@ static inline int php_charmask(const unsigned char *input, size_t len, char *mas
  * mode 3 : trim left and right
  * what indicates which chars are to be trimmed. NULL->default (' \t\n\r\v\0')
  */
-static zend_always_inline zend_string *php_trim_int(zend_string *str, char *what, size_t what_len, int mode)
+static zend_always_inline zend_string *php_trim_int(zend_string *str, const char *what, size_t what_len, int mode)
 {
 	const char *start = ZSTR_VAL(str);
 	const char *end = start + ZSTR_LEN(str);
@@ -793,7 +793,7 @@ static zend_always_inline zend_string *php_trim_int(zend_string *str, char *what
 				}
 			}
 		} else {
-			php_charmask((unsigned char*)what, what_len, mask);
+			php_charmask((const unsigned char *) what, what_len, mask);
 
 			if (mode & 1) {
 				while (start != end) {
@@ -857,7 +857,7 @@ static zend_always_inline zend_string *php_trim_int(zend_string *str, char *what
  * mode 3 : trim left and right
  * what indicates which chars are to be trimmed. NULL->default (' \t\n\r\v\0')
  */
-PHPAPI zend_string *php_trim(zend_string *str, char *what, size_t what_len, int mode)
+PHPAPI zend_string *php_trim(zend_string *str, const char *what, size_t what_len, int mode)
 {
 	return php_trim_int(str, what, what_len, mode);
 }
@@ -1508,7 +1508,7 @@ PHP_FUNCTION(strtolower)
 
 /* {{{ php_basename
  */
-PHPAPI zend_string *php_basename(const char *s, size_t len, char *suffix, size_t suffix_len)
+PHPAPI zend_string *php_basename(const char *s, size_t len, const char *suffix, size_t suffix_len)
 {
 	/* State 0 is directly after a directory separator (or at the start of the string).
 	 * State 1 is everything else. */
@@ -1745,7 +1745,7 @@ PHPAPI char *php_stristr(char *s, char *t, size_t s_len, size_t t_len)
 
 /* {{{ php_strspn
  */
-PHPAPI size_t php_strspn(char *s1, char *s2, char *s1_end, char *s2_end)
+PHPAPI size_t php_strspn(const char *s1, const char *s2, const char *s1_end, const char *s2_end)
 {
 	register const char *p = s1, *spanp;
 	register char c = *p;
@@ -1763,7 +1763,7 @@ cont:
 
 /* {{{ php_strcspn
  */
-PHPAPI size_t php_strcspn(char *s1, char *s2, char *s1_end, char *s2_end)
+PHPAPI size_t php_strcspn(const char *s1, const char *s2, const char *s1_end, const char *s2_end)
 {
 	register const char *p, *spanp;
 	register char c = *s1;
@@ -2720,7 +2720,7 @@ PHP_FUNCTION(ucwords)
 		RETURN_EMPTY_STRING();
 	}
 
-	php_charmask((unsigned char *)delims, delims_len, mask);
+	php_charmask((const unsigned char *) delims, delims_len, mask);
 
 	ZVAL_STRINGL(return_value, ZSTR_VAL(str), ZSTR_LEN(str));
 	r = Z_STRVAL_P(return_value);
@@ -3642,7 +3642,7 @@ PHPAPI void php_stripcslashes(zend_string *str)
 
 /* {{{ php_addcslashes_str
  */
-PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, char *what, size_t wlength)
+PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, const char *what, size_t wlength)
 {
 	char flags[256];
 	char *target;
@@ -3651,7 +3651,7 @@ PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, char *what,
 	size_t  newlen;
 	zend_string *new_str = zend_string_safe_alloc(4, len, 0, 0);
 
-	php_charmask((unsigned char *)what, wlength, flags);
+	php_charmask((const unsigned char *) what, wlength, flags);
 
 	for (source = str, end = source + len, target = ZSTR_VAL(new_str); source < end; source++) {
 		c = *source;
@@ -3685,7 +3685,7 @@ PHPAPI zend_string *php_addcslashes_str(const char *str, size_t len, char *what,
 
 /* {{{ php_addcslashes
  */
-PHPAPI zend_string *php_addcslashes(zend_string *str, char *what, size_t wlength)
+PHPAPI zend_string *php_addcslashes(zend_string *str, const char *what, size_t wlength)
 {
 	return php_addcslashes_str(ZSTR_VAL(str), ZSTR_LEN(str), what, wlength);
 }
@@ -5909,7 +5909,7 @@ PHP_FUNCTION(str_word_count)
 	}
 
 	if (char_list) {
-		php_charmask((unsigned char *)char_list, char_list_len, ch);
+		php_charmask((const unsigned char *) char_list, char_list_len, ch);
 	}
 
 	p = ZSTR_VAL(str);
diff --git a/ext/standard/url_scanner_ex.h b/ext/standard/url_scanner_ex.h
index a756db6586..6252fdce54 100644
--- a/ext/standard/url_scanner_ex.h
+++ b/ext/standard/url_scanner_ex.h
@@ -24,10 +24,10 @@ PHP_RINIT_FUNCTION(url_scanner_ex);
 PHP_RSHUTDOWN_FUNCTION(url_scanner_ex);
 
 PHPAPI char *php_url_scanner_adapt_single_url(const char *url, size_t urllen, const char *name, const char *value, size_t *newlen, int encode);
-PHPAPI int php_url_scanner_add_session_var(char *name, size_t name_len, char *value, size_t value_len, int encode);
+PHPAPI int php_url_scanner_add_session_var(const char *name, size_t name_len, const char *value, size_t value_len, int encode);
 PHPAPI int php_url_scanner_reset_session_var(zend_string *name, int encode);
 PHPAPI int php_url_scanner_reset_session_vars(void);
-PHPAPI int php_url_scanner_add_var(char *name, size_t name_len, char *value, size_t value_len, int encode);
+PHPAPI int php_url_scanner_add_var(const char *name, size_t name_len, const char *value, size_t value_len, int encode);
 PHPAPI int php_url_scanner_reset_var(zend_string *name, int encode);
 PHPAPI int php_url_scanner_reset_vars(void);
 
diff --git a/ext/standard/url_scanner_ex.re b/ext/standard/url_scanner_ex.re
index d80bd0d2a1..bef17733e2 100644
--- a/ext/standard/url_scanner_ex.re
+++ b/ext/standard/url_scanner_ex.re
@@ -725,7 +725,7 @@ static void php_url_scanner_output_handler(char *output, size_t output_len, char
 	php_url_scanner_session_handler_impl(output, output_len, handled_output, handled_output_len, mode, 0);
 }
 
-static inline int php_url_scanner_add_var_impl(char *name, size_t name_len, char *value, size_t value_len, int encode, int type)
+static inline int php_url_scanner_add_var_impl(const char *name, size_t name_len, const char *value, size_t value_len, int encode, int type)
 {
 	smart_str sname = {0};
 	smart_str svalue = {0};
@@ -758,9 +758,9 @@ static inline int php_url_scanner_add_var_impl(char *name, size_t name_len, char
 		smart_str_appendl(&sname, ZSTR_VAL(encoded), ZSTR_LEN(encoded)); zend_string_free(encoded);
 		encoded = php_raw_url_encode(value, value_len);
 		smart_str_appendl(&svalue, ZSTR_VAL(encoded), ZSTR_LEN(encoded)); zend_string_free(encoded);
-		encoded = php_escape_html_entities_ex((unsigned char*)name, name_len, 0, ENT_QUOTES|ENT_SUBSTITUTE, NULL, /* double_encode */ 0, /* quiet */ 1);
+		encoded = php_escape_html_entities_ex((const unsigned char *) name, name_len, 0, ENT_QUOTES|ENT_SUBSTITUTE, NULL, /* double_encode */ 0, /* quiet */ 1);
 		smart_str_appendl(&hname, ZSTR_VAL(encoded), ZSTR_LEN(encoded)); zend_string_free(encoded);
-		encoded = php_escape_html_entities_ex((unsigned char*)value, value_len, 0, ENT_QUOTES|ENT_SUBSTITUTE, NULL, /* double_encode */ 0, /* quiet */ 1);
+		encoded = php_escape_html_entities_ex((const unsigned char *) value, value_len, 0, ENT_QUOTES|ENT_SUBSTITUTE, NULL, /* double_encode */ 0, /* quiet */ 1);
 		smart_str_appendl(&hvalue, ZSTR_VAL(encoded), ZSTR_LEN(encoded)); zend_string_free(encoded);
 	} else {
 		smart_str_appendl(&sname, name, name_len);
@@ -788,13 +788,13 @@ static inline int php_url_scanner_add_var_impl(char *name, size_t name_len, char
 }
 
 
-PHPAPI int php_url_scanner_add_session_var(char *name, size_t name_len, char *value, size_t value_len, int encode)
+PHPAPI int php_url_scanner_add_session_var(const char *name, size_t name_len, const char *value, size_t value_len, int encode)
 {
 	return php_url_scanner_add_var_impl(name, name_len, value, value_len, encode, 1);
 }
 
 
-PHPAPI int php_url_scanner_add_var(char *name, size_t name_len, char *value, size_t value_len, int encode)
+PHPAPI int php_url_scanner_add_var(const char *name, size_t name_len, const char *value, size_t value_len, int encode)
 {
 	return php_url_scanner_add_var_impl(name, name_len, value, value_len, encode, 0);
 }
@@ -860,7 +860,7 @@ static inline int php_url_scanner_reset_var_impl(zend_string *name, int encode,
 		encoded = php_raw_url_encode(ZSTR_VAL(name), ZSTR_LEN(name));
 		smart_str_appendl(&sname, ZSTR_VAL(encoded), ZSTR_LEN(encoded));
 		zend_string_free(encoded);
-		encoded = php_escape_html_entities_ex((unsigned char *)ZSTR_VAL(name), ZSTR_LEN(name), 0, ENT_QUOTES|ENT_SUBSTITUTE, SG(default_charset), /* double_encode */ 0, /* quiet */ 1);
+		encoded = php_escape_html_entities_ex((const unsigned char *) ZSTR_VAL(name), ZSTR_LEN(name), 0, ENT_QUOTES|ENT_SUBSTITUTE, SG(default_charset), /* double_encode */ 0, /* quiet */ 1);
 		smart_str_appendl(&hname, ZSTR_VAL(encoded), ZSTR_LEN(encoded));
 		zend_string_free(encoded);
 	} else {
diff --git a/ext/standard/uuencode.c b/ext/standard/uuencode.c
index 036e190f24..b00ddb520d 100644
--- a/ext/standard/uuencode.c
+++ b/ext/standard/uuencode.c
@@ -61,10 +61,11 @@
 
 #define PHP_UU_DEC(c) (((c) - ' ') & 077)
 
-PHPAPI zend_string *php_uuencode(char *src, size_t src_len) /* {{{ */
+PHPAPI zend_string *php_uuencode(const char *src, size_t src_len) /* {{{ */
 {
 	size_t len = 45;
-	unsigned char *p, *s, *e, *ee;
+	unsigned char *p;
+	const unsigned char *s, *e, *ee;
 	zend_string *dest;
 
 	/* encoded length is ~ 38% greater than the original
@@ -125,10 +126,11 @@ PHPAPI zend_string *php_uuencode(char *src, size_t src_len) /* {{{ */
 }
 /* }}} */
 
-PHPAPI zend_string *php_uudecode(char *src, size_t src_len) /* {{{ */
+PHPAPI zend_string *php_uudecode(const char *src, size_t src_len) /* {{{ */
 {
 	size_t len, total_len=0;
-	char *s, *e, *p, *ee;
+	char *p;
+	const char *s, *e, *ee;
 	zend_string *dest;
 
 	dest = zend_string_alloc((size_t) ceil(src_len * 0.75), 0);