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Update jerry-port and jerry-ext (#4907)

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Notable changes:
  - Updated and the port API interface, new functions have been added
    and some have been changed. The port library is now cleaned up to
    not have any dependency on jerry-core, as it should be. The port library
    is now strictly a collection of functions that implement
    embedding/platform specific behavior.
  - The default port implementation has been split for windows and unix.
    Implemented port functions have been categorized and reorganized,
    and marked with attribute((weak)) for better reusability.
  - External context allocation has been moved to the port API instead
    of a core API callback. The iterface has also been extended with a
    function to free the allocated context. When external context is
    enabled, jerry_init now automatically calls the port implementation
    to allocate the context and jerry_cleanup automatically calls the port
    to free the context.
  - jerry_port_log has been changed to no longer require formatting to
    be implemented by the port. The reason beind this is that it was vague what
    format specifiers were used by the engine, and in what manner. The port
    function now takes a zero-terminated string, and should only implement
    how the string should be logged.
  - Logging and log message formatting is now handled by the core jerry library
    where it can be implemented as necessary. Logging can be done through a new
    core API function, which uses the port to output the final log message.
  - Log level has been moved into jerry-core, and an API function has
    been added to set the log level. It should be the library that
    filters log messages based on the requested log level, instead of
    logging everything and requiring the user to do so.
  - Module resolving logic has been moved into jerry-core. There's no
    reason to have it in the port library and requiring embedders to
    duplicate the code. It also added an unnecessary dependency on
    jerry-core to the port. Platform specific behavior is still used through
    the port API, like resolving module specifiers, and reading source file
    contents. If necessary, the resolving logic can still be overridden as
    previously.
  - The jerry-ext library has also been cleaned up, and many utility
    functions have been added that previously were implemented in
    jerry-main. This allows easier reusability for some common operations,
    like printing unhandled exceptions or providing a repl console.
  - Debugger interaction with logged/printed messages has been fixed, so
    that it's no longer the port implementations responsibility to send
    the output to the debugger, as the port should have no notion of what a
    debugger is.  The printing and logging functions will now pass the
    result message to the debugger, if connected.
  - Cleaned up TZA handling in the date port implementation, and simplified
    the API function prototype.
  - Moved property access helper functions that use ASCII strings as
    keys from jerry-ext to the core API.

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai@inf.u-szeged.hu
This commit is contained in:
Dániel Bátyai
2022-01-20 13:53:47 +01:00
committed by GitHub
parent 79fd540ec9
commit ac1c48eeff
170 changed files with 4201 additions and 5698 deletions
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docs/05.PORT-API.md
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@@ -1,6 +1,6 @@
# Reference
## Termination
## Process management
It is questionable whether a library should be able to terminate an application. Any API function can signal an error (ex.: cannot allocate memory), so the engine use the termination approach with this port function.
@@ -24,202 +24,14 @@ Error codes
```c
typedef enum
{
ERR_OUT_OF_MEMORY = 10,
ERR_REF_COUNT_LIMIT = 12,
ERR_DISABLED_BYTE_CODE = 13,
ERR_FAILED_INTERNAL_ASSERTION = 120
JERRY_FATAL_OUT_OF_MEMORY = 10,
JERRY_FATAL_REF_COUNT_LIMIT = 12,
JERRY_FATAL_DISABLED_BYTE_CODE = 13,
JERRY_FATAL_UNTERMINATED_GC_LOOPS = 14,
JERRY_FATAL_FAILED_ASSERTION = 120
} jerry_fatal_code_t;
```
## I/O
These are the only I/O functions jerry calls.
```c
/**
* Jerry log levels. The levels are in severity order
* where the most serious levels come first.
*/
typedef enum
{
JERRY_LOG_LEVEL_ERROR, /**< the engine will terminate after the message is printed */
JERRY_LOG_LEVEL_WARNING, /**< a request is aborted, but the engine continues its operation */
JERRY_LOG_LEVEL_DEBUG, /**< debug messages from the engine, low volume */
JERRY_LOG_LEVEL_TRACE /**< detailed info about engine internals, potentially high volume */
} jerry_log_level_t;
/**
* Display or log a debug/error message, and sends it to the debugger client as well.
* The function should implement a printf-like interface, where the first argument
* specifies the log level and the second argument specifies a format string on how
* to stringify the rest of the parameter list.
*
* This function is only called with messages coming from the jerry engine as
* the result of some abnormal operation or describing its internal operations
* (e.g., data structure dumps or tracing info).
*
* It should be the port that decides whether error and debug messages are logged to
* the console, or saved to a database or to a file.
*
* Example: a libc-based port may implement this with vfprintf(stderr) or
* vfprintf(logfile), or both, depending on log level.
*
* Note:
* This port function is called by jerry-core when JERRY_LOGGING is
* enabled. It is also common practice though to use this function in
* application code.
*/
void jerry_port_log (jerry_log_level_t level, const char *fmt, ...);
```
The `jerry_port_print_char` is currently not used by the jerry-core directly.
However, it provides a port specific way for `jerry-ext` components to print
information.
```c
/**
* Print a character to stdout.
*/
void jerry_port_print_char (char c);
```
### Jerry Module system
The port API provides optional functions that can be used by the
user application to resolve modules. If no callback is provided
to `jerry_module_link`, the `jerry_port_module_resolve` function
is used for resolving modules.
```c
/**
* Opens file with the given path and reads its source.
* @return the source of the file
*/
uint8_t *
jerry_port_read_source (const char *file_name_p, /**< file name */
size_t *out_size_p) /**< [out] read bytes */
{
// open file from given path
// return its source
} /* jerry_port_read_source */
/**
* Release the previously opened file's content.
*/
void
jerry_port_release_source (uint8_t *buffer_p) /**< buffer to free */
{
free (buffer_p);
} /* jerry_port_release_source */
/**
* Default module resolver.
*
* @return a module object if resolving is successful, an error otherwise
*/
jerry_value_t
jerry_port_module_resolve (const jerry_value_t specifier, /**< module specifier string */
const jerry_value_t referrer, /**< parent module */
void *user_p) /**< user data */
{
// Resolves a module using the specifier string. If a referrer is a module,
// and specifier is a relative path, the base path should be the directory
// part extracted from the path of the referrer module.
// The callback function of jerry_module_link may call this function
// if it cannot resolve a module. Furthermore if the callback is NULL,
// this function is used for resolving modules.
// The default implementation only resolves ECMAScript modules, and does
// not (currently) use the user data.
} /* jerry_port_module_resolve */
/**
* Release known modules.
*/
void
jerry_port_module_release (const jerry_value_t realm) /**< if this argument is object, release only those modules,
* which realm value is equal to this argument. */
{
// This function releases the known modules, forcing their reload
// when resolved again later. The released modules can be filtered
// by realms. This function is only called by user applications.
} /* jerry_port_module_release */
```
## Date
```c
/**
* Get local time zone adjustment, in milliseconds, for the given timestamp.
* The timestamp can be specified in either UTC or local time, depending on
* the value of is_utc. Adding the value returned from this function to
* a timestamp in UTC time should result in local time for the current time
* zone, and subtracting it from a timestamp in local time should result in
* UTC time.
*
* Ideally, this function should satisfy the stipulations applied to LocalTZA
* in section 20.3.1.7 of the ECMAScript version 9.0 spec.
*
* See Also:
* ECMA-262 v9, 20.3.1.7
*
* Note:
* This port function is called by jerry-core when
* JERRY_BUILTIN_DATE is set to 1. Otherwise this function is
* not used.
*
* @param unix_ms The unix timestamp we want an offset for, given in
* millisecond precision (could be now, in the future,
* or in the past). As with all unix timestamps, 0 refers to
* 1970-01-01, a day is exactly 86 400 000 milliseconds, and
* leap seconds cause the same second to occur twice.
* @param is_utc Is the given timestamp in UTC time? If false, it is in local
* time.
*
* @return milliseconds between local time and UTC for the given timestamp,
* if available
*. 0 if not available / we are in UTC.
*/
double jerry_port_get_local_time_zone_adjustment (double unix_ms, bool is_utc);
/**
* Get system time
*
* Note:
* This port function is called by jerry-core when
* JERRY_BUILTIN_DATE is set to 1. It is also common practice
* in application code to use this function for the initialization of the
* random number generator.
*
* @return milliseconds since Unix epoch
*/
double jerry_port_get_current_time (void);
```
## External context
Allow user to provide external buffer for isolated engine contexts, so that user
can configure the heap size at runtime and run multiple JS applications
simultaneously.
```c
/**
* Get the current context of the engine. Each port should provide its own
* implementation of this interface.
*
* Note:
* This port function is called by jerry-core when
* JERRY_EXTERNAL_CONTEXT is enabled. Otherwise this function is not
* used.
*
* @return the pointer to the engine context.
*/
struct jerry_context_t *jerry_port_get_current_context (void);
```
## Sleep
```c
/**
* Makes the process sleep for a given time.
@@ -233,158 +45,237 @@ struct jerry_context_t *jerry_port_get_current_context (void);
void jerry_port_sleep (uint32_t sleep_time);
```
# How to port JerryScript
## External context
This section describes a basic port implementation which was created for Unix based systems.
## Termination
Allows the user to provide external buffer for isolated engine contexts, so that user
can configure the heap size at runtime and run multiple JS applications
simultaneously.
```c
#include <stdlib.h>
#include "jerryscript-port.h"
/**
* Default implementation of jerry_port_fatal.
* Allocate a new context for the engine.
*
* This port function is called by jerry_init when JERRY_EXTERNAL_CONTEXT is enabled. Otherwise this function is not
* used. The engine will pass the size required for the context structure. An implementation must make sure to
* allocate at least this amount.
*
* Excess allocated space will be used as the engine heap when jerryscript is configured to use it's internal allocator,
* this can be used to control the internal heap size.
*
* NOTE: The allocated memory must be pointer-aligned, otherwise the behavior is
* undefined.
*
* @param context_size: the size of the internal context structure
*
* @return total size of the allocated buffer
*/
void jerry_port_fatal (jerry_fatal_code_t code)
{
exit (code);
} /* jerry_port_fatal */
size_t jerry_port_context_alloc (size_t context_size);
```
```c
/**
* Get the currently active context of the engine.
*
* This port function is called by jerry-core when JERRY_EXTERNAL_CONTEXT is enabled.
* Otherwise this function is not used.
*
* @return the pointer to the currently used engine context.
*/
struct jerry_context_t *jerry_port_context_get (void);
```
```c
/**
* Free the currently used context.
*
* This port function is called by jerry_cleanup when JERRY_EXTERNAL_CONTEXT is enabled.
* Otherwise this function is not used.
*
* @return the pointer to the engine context.
*/
void jerry_port_context_free (void);
```
## I/O
```c
#include <stdarg.h>
#include "jerryscript-port.h"
/**
* Provide log message implementation for the engine.
* Display or log a debug/error message.
*
* Note:
* This example ignores the log level.
* The message is passed as a zero-terminated string. Messages may be logged in parts, which
* will result in multiple calls to this functions. The implementation should consider
* this before appending or prepending strings to the argument.
*
* This function is called with messages coming from the jerry engine as
* the result of some abnormal operation or describing its internal operations
* (e.g., data structure dumps or tracing info).
*
* The implementation can decide whether error and debug messages are logged to
* the console, or saved to a database or to a file.
*/
void
jerry_port_log (jerry_log_level_t level, /**< log level */
const char *format, /**< format string */
...) /**< parameters */
{
va_list args;
va_start (args, format);
vfprintf (stderr, format, args);
va_end (args);
} /* jerry_port_log */
void jerry_port_log (const char *message_p);
```
```c
/**
* Print a character to stdout with putchar.
* Print a single character to standard output.
*
* This port function is never called from jerry-core directly, it is only used by jerry-ext components to print
* information.
*
* @param byte: the byte to print.
*/
void
jerry_port_print_char (char c)
{
putchar (c);
} /* jerry_port_print_char */
void jerry_port_print_byte (jerry_char_t byte);
```
```c
/**
* Print a buffer to standard output
*
* This port function is never called from jerry-core directly, it is only used by jerry-ext components to print
* information.
*
* @param buffer_p: input buffer
* @param buffer_size: data size
*/
void jerry_port_print_buffer (const jerry_char_t *buffer_p, jerry_size_t buffer_size);
```
```c
/**
* Read a line from standard input.
*
* The implementation should allocate storage necessary for the string. The result string should include the ending line
* terminator character(s) and should be zero terminated.
*
* An implementation may return NULL to signal that the end of input is reached, or an error occured.
*
* When a non-NULL value is returned, the caller will pass the returned value to `jerry_port_line_free` when the line is
* no longer needed. This can be used to finalize dynamically allocated buffers if necessary.
*
* This port function is never called from jerry-core directly, it is only used by some jerry-ext components that
* require user input.
*
* @param out_size_p: size of the input string in bytes, excluding terminating zero byte
*
* @return pointer to the buffer storing the string,
* or NULL if end of input
*/
jerry_char_t *jerry_port_line_read (jerry_size_t *out_size_p);
```
```c
/**
* Free a line buffer allocated by jerry_port_line_read
*
* @param buffer_p: buffer returned by jerry_port_line_read
*/
void jerry_port_line_free (jerry_char_t *buffer_p);
```
## Filesystem
```
/**
* Canonicalize a file path.
*
* If possible, the implementation should resolve symbolic links and other directory references found in the input path,
* and create a fully canonicalized file path as the result.
*
* The function may return with NULL in case an error is encountered, in which case the calling operation will not
* proceed.
*
* The implementation should allocate storage for the result path as necessary. Non-NULL return values will be passed
* to `jerry_port_path_free` when the result is no longer needed by the caller, which can be used to finalize
* dynamically allocated buffers.
*
* NOTE: The implementation must not return directly with the input, as the input buffer is released after the call.
*
* @param path_p: zero-terminated string containing the input path
* @param path_size: size of the input path string in bytes, excluding terminating zero
*
* @return buffer with the normalized path if the operation is successful,
* NULL otherwise
*/
jerry_char_t *jerry_port_path_normalize (const jerry_char_t *path_p, jerry_size_t path_size);
```
```c
/**
* Free a path buffer returned by jerry_port_path_normalize.
*
* @param path_p: the path buffer to free
*/
void jerry_port_path_free (jerry_char_t *path_p);
```
```c
/**
* Get the offset of the basename component in the input path.
*
* The implementation should return the offset of the first character after the last path separator found in the path.
* This is used by the caller to split the path into a directory name and a file name.
*
* @param path_p: input zero-terminated path string
*
* @return offset of the basename component in the input path
*/
jerry_size_t jerry_port_path_base (const jerry_char_t *path_p);
```
```c
/**
* Open a source file and read its contents into a buffer.
*
* When the source file is no longer needed by the caller, the returned pointer will be passed to
* `jerry_port_source_free`, which can be used to finalize the buffer.
*
* @param file_name_p: Path that points to the source file in the filesystem.
* @param out_size_p: The opened file's size in bytes.
*
* @return pointer to the buffer which contains the content of the file.
*/
jerry_char_t *jerry_port_source_read (const char *file_name_p, jerry_size_t *out_size_p);
```
```c
/**
* Free a source file buffer.
*
* @param buffer_p: buffer returned by jerry_port_source_read
*/
void jerry_port_source_free (jerry_char_t *buffer_p);
```
## Date
```c
#include <time.h>
#include <sys/time.h>
#include "jerryscript-port.h"
/**
* Default implementation of jerry_port_get_local_time_zone_adjustment.
*/
double jerry_port_get_local_time_zone_adjustment (double unix_ms, /**< ms since unix epoch */
bool is_utc) /**< is the time above in UTC? */
{
struct tm tm;
time_t now = (time_t) (unix_ms / 1000);
localtime_r (&now, &tm);
if (!is_utc)
{
now -= tm.tm_gmtoff;
localtime_r (&now, &tm);
}
return ((double) tm.tm_gmtoff) * 1000;
} /* jerry_port_get_local_time_zone_adjustment */
/**
* Default implementation of jerry_port_get_current_time.
*/
double jerry_port_get_current_time (void)
{
struct timeval tv;
if (gettimeofday (&tv, NULL) != 0)
{
return 0;
}
return ((double) tv.tv_sec) * 1000.0 + ((double) tv.tv_usec) / 1000.0;
} /* jerry_port_get_current_time */
```
## External context
```c
#include "jerryscript-port.h"
#include "jerryscript-port-default.h"
/**
* Pointer to the current context.
* Note that it is a global variable, and is not a thread safe implementation.
*/
static jerry_context_t *current_context_p = NULL;
/**
* Set the current_context_p as the passed pointer.
*/
void
jerry_port_default_set_current_context (jerry_context_t *context_p) /**< points to the created context */
{
current_context_p = context_p;
} /* jerry_port_default_set_current_context */
/**
* Get the current context.
* Get local time zone adjustment in milliseconds for the given input time.
*
* @return the pointer to the current context
* The argument is a time value representing milliseconds since unix epoch.
*
* Ideally, this function should satisfy the stipulations applied to LocalTZA
* in section 21.4.1.7 of the ECMAScript version 12.0, as if called with isUTC true.
*
* This port function can be called by jerry-core when JERRY_BUILTIN_DATE is enabled.
* Otherwise this function is not used.
*
* @param unix_ms: time value in milliseconds since unix epoch
*
* @return local time offset in milliseconds applied to UTC for the given time value
*/
jerry_context_t *
jerry_port_get_current_context (void)
{
return current_context_p;
} /* jerry_port_get_current_context */
int32_t jerry_port_local_tza (double unix_ms);
```
## Sleep
```c
#include "jerryscript-port.h"
#include "jerryscript-port-default.h"
#ifdef HAVE_TIME_H
#include <time.h>
#elif defined (HAVE_UNISTD_H)
#include <unistd.h>
#endif /* HAVE_TIME_H */
#if defined (JERRY_DEBUGGER) && (JERRY_DEBUGGER == 1)
void jerry_port_sleep (uint32_t sleep_time)
{
#ifdef HAVE_TIME_H
nanosleep (&(const struct timespec)
{
(time_t) sleep_time / 1000, ((long int) sleep_time % 1000) * 1000000L /* Seconds, nanoseconds */
}
, NULL);
#elif defined (HAVE_UNISTD_H)
usleep ((useconds_t) sleep_time * 1000);
#endif /* HAVE_TIME_H */
(void) sleep_time;
} /* jerry_port_sleep */
#endif /* defined (JERRY_DEBUGGER) && (JERRY_DEBUGGER == 1) */
/**
* Get the current system time in UTC.
*
* This port function is called by jerry-core when JERRY_BUILTIN_DATE is enabled.
* It can also be used in the implementing application to initialize the random number generator.
*
* @return milliseconds since Unix epoch
*/
double jerry_port_current_time (void);
```