[ci skip] Migrate Coding standards docs to Markdown

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========================
PHP Coding Standards
========================
# PHP coding standards
This file lists several standards that any programmer adding or changing
code in PHP should follow. Since this file was added at a very late
stage of the development of PHP v3.0, the code base does not fully
follow it, but new features are going in that general direction. Many
sections have been recoded to use these rules.
This file lists several standards that any programmer adding or changing code in
PHP should follow. Since this file was added at a very late stage of the
development of PHP v3.0, the code base does not fully follow it, but new
features are going in that general direction. Many sections have been recoded to
use these rules.
Code Implementation
-------------------
## Code implementation
0. Document your code in source files and the manual. [tm]
1. Document your code in source files and the manual. (tm)
1. Functions that are given pointers to resources should not free them
2. Functions that are given pointers to resources should not free them.
For instance, ``function int mail(char *to, char *from)`` should NOT free
to and/or from.
For instance, `function int mail(char *to, char *from)` should NOT free to
and/or from.
Exceptions:
Exceptions:
- The function's designated behavior is freeing that resource. E.g. efree()
* The function's designated behavior is freeing that resource. E.g.
`efree()`
- The function is given a boolean argument, that controls whether or not
the function may free its arguments (if true - the function must free its
arguments, if false - it must not)
* The function is given a boolean argument, that controls whether or not the
function may free its arguments (if true - the function must free its
arguments, if false - it must not)
- Low-level parser routines, that are tightly integrated with the token
cache and the bison code for minimum memory copying overhead.
* Low-level parser routines, that are tightly integrated with the token
cache and the bison code for minimum memory copying overhead.
2. Functions that are tightly integrated with other functions within the
same module, and rely on each other non-trivial behavior, should be
documented as such and declared 'static'. They should be avoided if
possible.
3. Functions that are tightly integrated with other functions within the same
module, and rely on each other non-trivial behavior, should be documented as
such and declared `static`. They should be avoided if possible.
3. Use definitions and macros whenever possible, so that constants have
meaningful names and can be easily manipulated. The only exceptions
to this rule are 0 and 1, when used as false and true (respectively).
Any other use of a numeric constant to specify different behavior
or actions should be done through a #define.
4. Use definitions and macros whenever possible, so that constants have
meaningful names and can be easily manipulated. The only exceptions to this
rule are 1 and 2, when used as `false` and `true` (respectively). Any other
use of a numeric constant to specify different behavior or actions should be
done through a `#define`.
4. When writing functions that deal with strings, be sure to remember
that PHP holds the length property of each string, and that it
shouldn't be calculated with strlen(). Write your functions in such
a way so that they'll take advantage of the length property, both
for efficiency and in order for them to be binary-safe.
Functions that change strings and obtain their new lengths while
doing so, should return that new length, so it doesn't have to be
recalculated with strlen() (e.g. php_addslashes())
5. When writing functions that deal with strings, be sure to remember that PHP
holds the length property of each string, and that it shouldn't be
calculated with `strlen()`. Write your functions in such a way so that
they'll take advantage of the length property, both for efficiency and in
order for them to be binary-safe. Functions that change strings and obtain
their new lengths while doing so, should return that new length, so it
doesn't have to be recalculated with `strlen()` (e.g. `php_addslashes()`).
5. NEVER USE strncat(). If you're absolutely sure you know what you're doing,
6. NEVER USE `strncat()`. If you're absolutely sure you know what you're doing,
check its man page again, and only then, consider using it, and even then,
try avoiding it.
6. Use ``PHP_*`` macros in the PHP source, and ``ZEND_*`` macros in the Zend
part of the source. Although the ``PHP_*`` macro's are mostly aliased to the
``ZEND_*`` macros it gives a better understanding on what kind of macro
you're calling.
7. Use `PHP_*` macros in the PHP source, and `ZEND_*` macros in the Zend part of
the source. Although the `PHP_*` macros are mostly aliased to the `ZEND_*`
macros it gives a better understanding on what kind of macro you're calling.
7. When commenting out code using a #if statement, do NOT use 0 only. Instead
use "<git username here>_0". For example, #if FOO_0, where FOO is your
git user foo. This allows easier tracking of why code was commented out,
especially in bundled libraries.
8. When commenting out code using a `#if` statement, do NOT use `0` only.
Instead use `"<git username here>_0"`. For example, `#if FOO_0`, where `FOO`
is your git user `foo`. This allows easier tracking of why code was
commented out, especially in bundled libraries.
8. Do not define functions that are not available. For instance, if a
library is missing a function, do not define the PHP version of the
function, and do not raise a run-time error about the function not
existing. End users should use function_exists() to test for the
existence of a function
9. Do not define functions that are not available. For instance, if a library is
missing a function, do not define the PHP version of the function, and do
not raise a run-time error about the function not existing. End users should
use `function_exists()` to test for the existence of a function.
9. Prefer emalloc(), efree(), estrdup(), etc. to their standard C library
counterparts. These functions implement an internal "safety-net"
mechanism that ensures the deallocation of any unfreed memory at the
end of a request. They also provide useful allocation and overflow
information while running in debug mode.
10. Prefer `emalloc()`, `efree()`, `estrdup()`, etc. to their standard C library
counterparts. These functions implement an internal "safety-net" mechanism
that ensures the deallocation of any unfreed memory at the end of a request.
They also provide useful allocation and overflow information while running
in debug mode.
In almost all cases, memory returned to the engine must be allocated
using emalloc().
In almost all cases, memory returned to the engine must be allocated using
`emalloc()`.
The use of malloc() should be limited to cases where a third-party
library may need to control or free the memory, or when the memory in
question needs to survive between multiple requests.
The use of `malloc()` should be limited to cases where a third-party library
may need to control or free the memory, or when the memory in question needs
to survive between multiple requests.
User Functions/Methods Naming Conventions
------------------
## User functions/methods naming conventions
1. Function names for user-level functions should be enclosed with in
the PHP_FUNCTION() macro. They should be in lowercase, with words
underscore delimited, with care taken to minimize the letter count.
Abbreviations should not be used when they greatly decrease the
readability of the function name itself::
1. Function names for user-level functions should be enclosed with in the
`PHP_FUNCTION()` macro. They should be in lowercase, with words underscore
delimited, with care taken to minimize the letter count. Abbreviations
should not be used when they greatly decrease the readability of the
function name itself:
Good:
'str_word_count'
'array_key_exists'
```php
str_word_count
array_key_exists
```
Ok:
'date_interval_create_from_date_string'
(could be 'date_intvl_create_from_date_str'?)
'get_html_translation_table'
(could be 'html_get_trans_table'?)
```php
date_interval_create_from_date_string
// Could be 'date_intvl_create_from_date_str'?
get_html_translation_table()
// Could be 'html_get_trans_table'?
```
Bad:
'hw_GetObjectByQueryCollObj'
'pg_setclientencoding'
'jf_n_s_i'
2. If they are part of a "parent set" of functions, that parent should
be included in the user function name, and should be clearly related
to the parent program or function family. This should be in the form
of ``parent_*``::
```php
hw_GetObjectByQueryCollObj
pg_setclientencoding
jf_n_s_i
```
A family of 'foo' functions, for example:
2. If they are part of a "parent set" of functions, that parent should be
included in the user function name, and should be clearly related to the
parent program or function family. This should be in the form of `parent_*`:
A family of `foo` functions, for example:
Good:
'foo_select_bar'
'foo_insert_baz'
'foo_delete_baz'
```php
foo_select_bar
foo_insert_baz
foo_delete_baz
```
Bad:
'fooselect_bar'
'fooinsertbaz'
'delete_foo_baz'
3. Function names used by user functions should be prefixed
with ``_php_``, and followed by a word or an underscore-delimited list of
words, in lowercase letters, that describes the function. If applicable,
they should be declared 'static'.
```php
fooselect_bar
fooinsertbaz
delete_foo_baz
```
4. Variable names must be meaningful. One letter variable names must be
avoided, except for places where the variable has no real meaning or
a trivial meaning (e.g. for (i=0; i<100; i++) ...).
3. Function names used by user functions should be prefixed with `_php_`, and
followed by a word or an underscore-delimited list of words, in lowercase
letters, that describes the function. If applicable, they should be declared
`static`.
5. Variable names should be in lowercase. Use underscores to separate
between words.
4. Variable names must be meaningful. One letter variable names must be avoided,
except for places where the variable has no real meaning or a trivial
meaning (e.g. `for (i=0; i<100; i++) ...`).
6. Method names follow the 'studlyCaps' (also referred to as 'bumpy case'
or 'camel caps') naming convention, with care taken to minimize the
letter count. The initial letter of the name is lowercase, and each
letter that starts a new 'word' is capitalized::
5. Variable names should be in lowercase. Use underscores to separate between
words.
6. Method names follow the *studlyCaps* (also referred to as *bumpy case* or
*camel caps*) naming convention, with care taken to minimize the letter
count. The initial letter of the name is lowercase, and each letter that
starts a new `word` is capitalized:
Good:
'connect()'
'getData()'
'buildSomeWidget()'
```php
connect()
getData()
buildSomeWidget()
```
Bad:
'get_Data()'
'buildsomewidget'
'getI()'
7. Class names should be descriptive nouns in PascalCase and as short as
```php
get_Data()
buildsomewidget()
getI()
```
7. Class names should be descriptive nouns in *PascalCase* and as short as
possible. Each word in the class name should start with a capital letter,
without underscore delimiters. The class name should be prefixed with the
name of the "parent set" (e.g. the name of the extension) if no namespaces
@ -162,161 +175,168 @@ User Functions/Methods Naming Conventions
not allowed if they are not widely adopted and recognized as such.
Good:
'Curl'
'CurlResponse'
'HTTPStatusCode'
'URL'
'BTreeMap' (B-tree Map)
'Id' (Identifier)
'ID' (Identity Document)
'Char' (Character)
'Intl' (Internationalization)
'Radar' (Radio Detecting and Ranging)
```php
Curl
CurlResponse
HTTPStatusCode
URL
BTreeMap // B-tree Map
Id // Identifier
ID // Identity Document
Char // Character
Intl // Internationalization
Radar // Radio Detecting and Ranging
```
Bad:
'curl'
'curl_response'
'HttpStatusCode'
'Url'
'BtreeMap'
'ID' (Identifier)
'CHAR'
'INTL'
'RADAR' (Radio Detecting and Ranging)
Internal Function Naming Conventions
----------------------
```php
curl
curl_response
HttpStatusCode
Url
BtreeMap
ID // Identifier
CHAR
INTL
RADAR // Radio Detecting and Ranging
```
1. Functions that are part of the external API should be named
'php_modulename_function()' to avoid symbol collision. They should be in
lowercase, with words underscore delimited. Exposed API must be defined
in 'php_modulename.h'.
## Internal function naming conventions
1. Functions that are part of the external API should be named
`php_modulename_function()` to avoid symbol collision. They should be in
lowercase, with words underscore delimited. Exposed API must be defined in
`php_modulename.h`.
```c
PHPAPI char *php_session_create_id(PS_CREATE_SID_ARGS);
```
Unexposed module function should be static and should not be defined in
'php_modulename.h'.
`php_modulename.h`.
```c
static int php_session_destroy()
```
2. Main module source file must be named 'modulename.c'.
2. Main module source file must be named `modulename.c`.
3. Header file that is used by other sources must be named 'php_modulename.h'.
3. Header file that is used by other sources must be named `php_modulename.h`.
## Syntax and indentation
Syntax and indentation
----------------------
1. Never use C++ style comments (i.e. `//` comment). Always use C-style comments
instead. PHP is written in C, and is aimed at compiling under any ANSI-C
compliant compiler. Even though many compilers accept C++-style comments in
C code, you have to ensure that your code would compile with other compilers
as well. The only exception to this rule is code that is Win32-specific,
because the Win32 port is MS-Visual C++ specific, and this compiler is known
to accept C++-style comments in C code.
1. Never use C++ style comments (i.e. // comment). Always use C-style
comments instead. PHP is written in C, and is aimed at compiling
under any ANSI-C compliant compiler. Even though many compilers
accept C++-style comments in C code, you have to ensure that your
code would compile with other compilers as well.
The only exception to this rule is code that is Win32-specific,
because the Win32 port is MS-Visual C++ specific, and this compiler
is known to accept C++-style comments in C code.
2. Use K&R-style. Of course, we can't and don't want to force anybody to use a
style he or she is not used to, but, at the very least, when you write code
that goes into the core of PHP or one of its standard modules, please
maintain the K&R style. This applies to just about everything, starting with
indentation and comment styles and up to function declaration syntax. Also
see [Indentstyle](http://www.catb.org/~esr/jargon/html/I/indent-style.html).
2. Use K&R-style. Of course, we can't and don't want to
force anybody to use a style he or she is not used to, but,
at the very least, when you write code that goes into the core
of PHP or one of its standard modules, please maintain the K&R
style. This applies to just about everything, starting with
indentation and comment styles and up to function declaration
syntax. Also see Indentstyle.
Indentstyle: http://www.catb.org/~esr/jargon/html/I/indent-style.html
3. Be generous with whitespace and braces. Keep one empty line between the
3. Be generous with whitespace and braces. Keep one empty line between the
variable declaration section and the statements in a block, as well as
between logical statement groups in a block. Maintain at least one empty
line between two functions, preferably two. Always prefer::
between logical statement groups in a block. Maintain at least one empty
line between two functions, preferably two. Always prefer:
```c
if (foo) {
bar;
}
```
to:
```c
if(foo)bar;
```
4. When indenting, use the tab character. A tab is expected to represent
four spaces. It is important to maintain consistency in indenture so
that definitions, comments, and control structures line up correctly.
4. When indenting, use the tab character. A tab is expected to represent four
spaces. It is important to maintain consistency in indenture so that
definitions, comments, and control structures line up correctly.
5. Preprocessor statements (#if and such) MUST start at column one. To
indent preprocessor directives you should put the # at the beginning
of a line, followed by any number of whitespace.
5. Preprocessor statements (`#if` and such) MUST start at column one. To indent
preprocessor directives you should put the `#` at the beginning of a line,
followed by any number of whitespace.
Testing
-------
## Testing
1. Extensions should be well tested using *.phpt tests. Read about that
at https://qa.php.net/write-test.php.
1. Extensions should be well tested using `*.phpt` tests. Read about that at
[qa.php.net](https://qa.php.net/write-test.php) documentation.
Documentation and Folding Hooks
-------------------------------
## Documentation and folding hooks
In order to make sure that the online documentation stays in line with
the code, each user-level function should have its user-level function
prototype before it along with a brief one-line description of what the
function does. It would look like this::
In order to make sure that the online documentation stays in line with the code,
each user-level function should have its user-level function prototype before it
along with a brief one-line description of what the function does. It would look
like this:
/* {{{ proto int abs(int number)
Returns the absolute value of the number */
PHP_FUNCTION(abs)
{
...
}
/* }}} */
```c
/* {{{ proto int abs(int number)
Returns the absolute value of the number */
PHP_FUNCTION(abs)
{
...
}
/* }}} */
```
The {{{ symbols are the default folding symbols for the folding mode in
Emacs and vim (set fdm=marker). Folding is very useful when dealing with
large files because you can scroll through the file quickly and just unfold
the function you wish to work on. The }}} at the end of each function marks
the end of the fold, and should be on a separate line.
The `{{{` symbols are the default folding symbols for the folding mode in Emacs
and vim (`set fdm=marker`). Folding is very useful when dealing with large files
because you can scroll through the file quickly and just unfold the function you
wish to work on. The `}}}` at the end of each function marks the end of the
fold, and should be on a separate line.
The "proto" keyword there is just a helper for the doc/genfuncsummary script
which generates a full function summary. Having this keyword in front of the
The `proto` keyword there is just a helper for the `doc/genfuncsummary` script
which generates a full function summary. Having this keyword in front of the
function prototypes allows us to put folds elsewhere in the code without
messing up the function summary.
Optional arguments are written like this::
Optional arguments are written like this:
/* {{{ proto object imap_header(int stream_id, int msg_no [, int from_length [, int subject_length [, string default_host]]])
Returns a header object with the defined parameters */
```c
/* {{{ proto object imap_header(int stream_id, int msg_no [, int from_length [, int subject_length [, string default_host]]])
Returns a header object with the defined parameters */
```
And yes, please keep the prototype on a single line, even if that line
is massive.
And yes, please keep the prototype on a single line, even if that line is
massive.
New and Experimental Functions
-----------------------------------
To reduce the problems normally associated with the first public
implementation of a new set of functions, it has been suggested
that the first implementation include a file labeled 'EXPERIMENTAL'
in the function directory, and that the functions follow the
standard prefixing conventions during their initial implementation.
## New and experimental functions
The file labelled 'EXPERIMENTAL' should include the following
information::
To reduce the problems normally associated with the first public implementation
of a new set of functions, it has been suggested that the first implementation
include a file labeled `EXPERIMENTAL` in the function directory, and that the
functions follow the standard prefixing conventions during their initial
implementation.
Any authoring information (known bugs, future directions of the module).
Ongoing status notes which may not be appropriate for Git comments.
The file labelled `EXPERIMENTAL` should include the following information:
In general new features should go to PECL or experimental branches until
there are specific reasons for directly adding it to the core distribution.
* Any authoring information (known bugs, future directions of the module).
* Ongoing status notes which may not be appropriate for Git comments.
Aliases & Legacy Documentation
-----------------------------------
You may also have some deprecated aliases with close to duplicate
names, for example, somedb_select_result and somedb_selectresult. For
documentation purposes, these will only be documented by the most
current name, with the aliases listed in the documentation for
the parent function. For ease of reference, user-functions with
completely different names, that alias to the same function (such as
highlight_file and show_source), will be separately documented. The
proto should still be included, describing which function is aliased.
In general new features should go to PECL or experimental branches until there
are specific reasons for directly adding it to the core distribution.
Backwards compatible functions and names should be maintained as long
as the code can be reasonably be kept as part of the codebase. See the
README in the PHP documentation repository for more information on
documentation.
## Aliases & legacy documentation
You may also have some deprecated aliases with close to duplicate names, for
example, `somedb_select_result` and `somedb_selectresult`. For documentation
purposes, these will only be documented by the most current name, with the
aliases listed in the documentation for the parent function. For ease of
reference, user-functions with completely different names, that alias to the
same function (such as `highlight_file` and `show_source`), will be separately
documented. The proto should still be included, describing which function is
aliased.
Backwards compatible functions and names should be maintained as long as the
code can be reasonably be kept as part of the codebase. See the `README` in the
PHP documentation repository for more information on documentation.

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@ -246,7 +246,7 @@ included.
## Checklist for submitting contribution
- Read [CODING_STANDARDS](/CODING_STANDARDS) before you start working.
- Read [Coding standards](/CODING_STANDARDS.md) before you start working.
- Update git source just before running your final `diff` and before testing.
- Add in-line comments and/or have external documentation ready. Use only
`/* */` style comments, not `//`.

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@ -123,7 +123,7 @@ See further documents in the repository for more information on how to
contribute:
- [Contributing to PHP](/CONTRIBUTING.md)
- [PHP coding standards](/CODING_STANDARDS)
- [PHP coding standards](/CODING_STANDARDS.md)
- [Mailinglist rules](/docs/mailinglist-rules.md)
- [PHP release process](/docs/release-process.md)

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@ -93,7 +93,7 @@ SOURCE AND HEADER FILE NAME
php_extension_name_function()
See also CODING_STANDARDS.
See also CODING_STANDARDS.md.
OPTIONS

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@ -961,7 +961,7 @@ PHPAPI size_t php_printf(const char *format, ...)
/* php_verror is called from php_error_docref<n> functions.
* Its purpose is to unify error messages and automatically generate clickable
* html error messages if correcponding ini setting (html_errors) is activated.
* See: CODING_STANDARDS for details.
* See: CODING_STANDARDS.md for details.
*/
PHPAPI ZEND_COLD void php_verror(const char *docref, const char *params, int type, const char *format, va_list args)
{
@ -1160,7 +1160,7 @@ PHPAPI ZEND_COLD void php_verror(const char *docref, const char *params, int typ
/* }}} */
/* {{{ php_error_docref0 */
/* See: CODING_STANDARDS for details. */
/* See: CODING_STANDARDS.md for details. */
PHPAPI ZEND_COLD void php_error_docref0(const char *docref, int type, const char *format, ...)
{
va_list args;
@ -1172,7 +1172,7 @@ PHPAPI ZEND_COLD void php_error_docref0(const char *docref, int type, const char
/* }}} */
/* {{{ php_error_docref1 */
/* See: CODING_STANDARDS for details. */
/* See: CODING_STANDARDS.md for details. */
PHPAPI ZEND_COLD void php_error_docref1(const char *docref, const char *param1, int type, const char *format, ...)
{
va_list args;
@ -1184,7 +1184,7 @@ PHPAPI ZEND_COLD void php_error_docref1(const char *docref, const char *param1,
/* }}} */
/* {{{ php_error_docref2 */
/* See: CODING_STANDARDS for details. */
/* See: CODING_STANDARDS.md for details. */
PHPAPI ZEND_COLD void php_error_docref2(const char *docref, const char *param1, const char *param2, int type, const char *format, ...)
{
char *params;