ControlStructuresOptimizer::isFollowedByElse() - Code Metrics - s9e/TextFormatter - Measure and Improve Code Quality continuously with Scrutinizer

ControlStructuresOptimizer::isFollowedByElse() A
last analyzed 2025-05-02 21:56 UTC

↳ Parent: ControlStructuresOptimizer

Complexity

Conditions	3
Paths	3

Size

Total Lines	17
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	7
CRAP Score	3

Importance

Changes

Metric	Value
eloc	6
dl	0
loc	17
ccs	7
cts	7
cp	1
rs	10
c	0
b	0
f	0
cc	3
nc	3
nop	0
crap	3

<?php

/**
* @package   s9e\TextFormatter
* @copyright Copyright (c) The s9e authors
* @license   http://www.opensource.org/licenses/mit-license.php The MIT License
*/
namespace s9e\TextFormatter\Configurator\RendererGenerators\PHP;

/**
* Optimize the control structures of a script
*
* Removes brackets in control structures wherever possible. Prevents the generation of EXT_STMT
* opcodes where they're not strictly required.
*/
class ControlStructuresOptimizer extends AbstractOptimizer
{
	/**
	* @var integer Number of braces encountered in current source
	*/
	protected $braces;

	/**
	* @var array Current context
	*/
	protected $context;

	/**
	* Test whether current block ends with an if or elseif control structure
	*
	* @return bool
	*/
	protected function blockEndsWithIf()
	{
		return in_array($this->context['lastBlock'], [T_IF, T_ELSEIF], true);
	}

	/**
	* Test whether the token at current index is a control structure
	*
	* @return bool
	*/
	protected function isControlStructure()
	{
		return in_array(
			$this->tokens[$this->i][0],
			[T_ELSE, T_ELSEIF, T_FOR, T_FOREACH, T_IF, T_WHILE],
			true
		);
	}

	/**
	* Test whether current block is followed by an elseif/else structure
	*
	* @return bool
	*/
	protected function isFollowedByElse()
	{
		if ($this->i > $this->cnt - 4)
		{
			// It doesn't have room for another block
			return false;
		}

		// Compute the index of the next non-whitespace token
		$k = $this->i + 1;

		if ($this->tokens[$k][0] === T_WHITESPACE)
		{
			++$k;
		}

		return in_array($this->tokens[$k][0], [T_ELSEIF, T_ELSE], true);
	}

	/**
	* Test whether braces must be preserved in current context
	*
	* @return bool
	*/
	protected function mustPreserveBraces()
	{
		// If current block ends with if/elseif and is followed by elseif/else, we must preserve
		// its braces to prevent it from merging with the outer elseif/else. IOW, we must preserve
		// the braces if "if{if{}}else" would become "if{if else}"
		return ($this->blockEndsWithIf() && $this->isFollowedByElse());
	}

	/**
	* Optimize control structures in stored tokens
	*
	* @return void
	*/
	protected function optimizeTokens()
	{
		while (++$this->i < $this->cnt)
		{
			if ($this->tokens[$this->i] === ';')
			{
				++$this->context['statements'];
			}
			elseif ($this->tokens[$this->i] === '{')
			{
				++$this->braces;
			}
			elseif ($this->tokens[$this->i] === '}')
			{
				if ($this->context['braces'] === $this->braces)
				{
					$this->processEndOfBlock();
				}

				--$this->braces;
			}
			elseif ($this->isControlStructure())
			{
				$this->processControlStructure();
			}
		}
	}

	/**
	* Process the control structure starting at current index
	*
	* @return void
	*/
	protected function processControlStructure()
	{
		// Save the index so we can rewind back to it in case of failure
		$savedIndex = $this->i;

		// Count this control structure in this context's statements unless it's an elseif/else
		// in which case it's already been counted as part of the if
		if (!in_array($this->tokens[$this->i][0], [T_ELSE, T_ELSEIF], true))
		{
			++$this->context['statements'];
		}

		// If the control structure is anything but an "else", skip its condition to reach the first
		// brace or statement
		if ($this->tokens[$this->i][0] !== T_ELSE)
		{
			$this->skipCondition();
		}

		$this->skipWhitespace();

		// Abort if this control structure does not use braces
		if ($this->tokens[$this->i] !== '{')
		{
			// Rewind all the way to the original token
			$this->i = $savedIndex;

			return;
		}

		++$this->braces;

		// Replacement for the first brace
		$replacement = [T_WHITESPACE, ''];

		// Add a space after "else" if the brace is removed and it's not followed by whitespace or a
		// variable
		if ($this->tokens[$savedIndex][0]  === T_ELSE
		 && $this->tokens[$this->i + 1][0] !== T_VARIABLE
		 && $this->tokens[$this->i + 1][0] !== T_WHITESPACE)
		{
			$replacement = [T_WHITESPACE, ' '];
		}

		// Record the token of the control structure (T_IF, T_WHILE, etc...) in the current context
		$this->context['lastBlock'] = $this->tokens[$savedIndex][0];

		// Create a new context
		$this->context = [
			'braces'      => $this->braces,
			'index'       => $this->i,
			'lastBlock'   => null,
			'parent'      => $this->context,
			'replacement' => $replacement,
			'savedIndex'  => $savedIndex,
			'statements'  => 0
		];
	}

	/**
	* Process the block ending at current index
	*
	* @return void
	*/
	protected function processEndOfBlock()
	{
		if ($this->context['statements'] < 2 && !$this->mustPreserveBraces())
		{
			$this->removeBracesInCurrentContext();
		}

		$this->context = $this->context['parent'];

		// Propagate the "lastBlock" property upwards to handle multiple nested if statements
		$this->context['parent']['lastBlock'] = $this->context['lastBlock'];
	}

	/**
	* Remove the braces surrounding current context
	*
	* @return void
	*/
	protected function removeBracesInCurrentContext()
	{
		// Replace the first brace with the saved replacement
		$this->tokens[$this->context['index']] = $this->context['replacement'];

		// Remove the second brace or replace it with a semicolon if there are no statements in this
		// block
		$this->tokens[$this->i] = ($this->context['statements']) ? [T_WHITESPACE, ''] : ';';

		// Remove the whitespace before braces. This is mainly cosmetic
		foreach ([$this->context['index'] - 1, $this->i - 1] as $tokenIndex)
		{
			if ($this->tokens[$tokenIndex][0] === T_WHITESPACE)
			{
				$this->tokens[$tokenIndex][1] = '';
			}
		}

		// Test whether the current block followed an else statement then test whether this
		// else was followed by an if
		if ($this->tokens[$this->context['savedIndex']][0] === T_ELSE)
		{
			$j = 1 + $this->context['savedIndex'];

			while ($this->tokens[$j][0] === T_WHITESPACE
			    || $this->tokens[$j][0] === T_COMMENT
			    || $this->tokens[$j][0] === T_DOC_COMMENT)
			{
				++$j;
			}

			if ($this->tokens[$j][0] === T_IF)
			{
				// Replace if with elseif
				$this->tokens[$j] = [T_ELSEIF, 'elseif'];

				// Remove the original else
				$j = $this->context['savedIndex'];
				$this->tokens[$j] = [T_WHITESPACE, ''];

				// Remove any whitespace before the original else
				if ($this->tokens[$j - 1][0] === T_WHITESPACE)
				{
					$this->tokens[$j - 1][1] = '';
				}

				// Unindent what was the else's content
				$this->unindentBlock($j, $this->i - 1);

				// Ensure that the brace after the now-removed "else" was not replaced with a space
				$this->tokens[$this->context['index']] = [T_WHITESPACE, ''];
			}
		}

		$this->changed = true;
	}

	/**
	* {@inheritdoc}
	*/
	protected function reset($php)
	{
		parent::reset($php);

		$this->braces  = 0;
		$this->context = [
			'braces'      => 0,
			'index'       => -1,
			'parent'      => [],
			'preventElse' => false,
			'savedIndex'  => 0,
			'statements'  => 0
		];
	}

	/**
	* Skip the condition of a control structure
	*
	* @return void
	*/
	protected function skipCondition()
	{
		// Reach the opening parenthesis
		$this->skipToString('(');

		// Iterate through tokens until we have a match for every left parenthesis
		$parens = 0;
		while (++$this->i < $this->cnt)
		{
			if ($this->tokens[$this->i] === ')')
			{
				if ($parens)
				{
					--$parens;
				}
				else
				{
					break;
				}
			}
			elseif ($this->tokens[$this->i] === '(')
			{
				++$parens;
			}
		}
	}
}

1		<?php
2
3		/**
4		* @package s9e\TextFormatter
5		* @copyright Copyright (c) The s9e authors
6		* @license http://www.opensource.org/licenses/mit-license.php The MIT License
7		*/
8		namespace s9e\TextFormatter\Configurator\RendererGenerators\PHP;
9
10		/**
11		* Optimize the control structures of a script
12		*
13		* Removes brackets in control structures wherever possible. Prevents the generation of EXT_STMT
14		* opcodes where they're not strictly required.
15		*/
16		class ControlStructuresOptimizer extends AbstractOptimizer
17		{
18		/**
19		* @var integer Number of braces encountered in current source
20		*/
21		protected $braces;
22
23		/**
24		* @var array Current context
25		*/
26		protected $context;
27
28		/**
29		* Test whether current block ends with an if or elseif control structure
30		*
31		* @return bool
32		*/
33	26	protected function blockEndsWithIf()
34		{
35	26	return in_array($this->context['lastBlock'], [T_IF, T_ELSEIF], true);
36		}
37
38		/**
39		* Test whether the token at current index is a control structure
40		*
41		* @return bool
42		*/
43	28	protected function isControlStructure()
44		{
45	28	return in_array(
46	28	$this->tokens[$this->i][0],
47	28	[T_ELSE, T_ELSEIF, T_FOR, T_FOREACH, T_IF, T_WHILE],
48	28	true
49		);
50		}
51
52		/**
53		* Test whether current block is followed by an elseif/else structure
54		*
55		* @return bool
56		*/
57	6	protected function isFollowedByElse()
58		{
59	6	if ($this->i > $this->cnt - 4)
60		{
61		// It doesn't have room for another block
62	3	return false;
63		}
64
65		// Compute the index of the next non-whitespace token
66	3	$k = $this->i + 1;
67
68	3	if ($this->tokens[$k][0] === T_WHITESPACE)
69		{
70	1	++$k;
71		}
72
73	3	return in_array($this->tokens[$k][0], [T_ELSEIF, T_ELSE], true);
74		}
75
76		/**
77		* Test whether braces must be preserved in current context
78		*
79		* @return bool
80		*/
81	26	protected function mustPreserveBraces()
82		{
83		// If current block ends with if/elseif and is followed by elseif/else, we must preserve
84		// its braces to prevent it from merging with the outer elseif/else. IOW, we must preserve
85		// the braces if "if{if{}}else" would become "if{if else}"
86	26	return ($this->blockEndsWithIf() && $this->isFollowedByElse());
87		}
88
89		/**
90		* Optimize control structures in stored tokens
91		*
92		* @return void
93		*/
94	28	protected function optimizeTokens()
95		{
96	28	while (++$this->i < $this->cnt)
97		{
98	28	if ($this->tokens[$this->i] === ';')
99		{
100	22	++$this->context['statements'];
101		}
102	28	elseif ($this->tokens[$this->i] === '{')
103		{
104	1	++$this->braces;
105		}
106	28	elseif ($this->tokens[$this->i] === '}')
107		{
108	28	if ($this->context['braces'] === $this->braces)
109		{
110	27	$this->processEndOfBlock();
111		}
112
113	28	--$this->braces;
114		}
115	28	elseif ($this->isControlStructure())
116		{
117	28	$this->processControlStructure();
118		}
119		}
120		}
121
122		/**
123		* Process the control structure starting at current index
124		*
125		* @return void
126		*/
127	28	protected function processControlStructure()
128		{
129		// Save the index so we can rewind back to it in case of failure
130	28	$savedIndex = $this->i;
131
132		// Count this control structure in this context's statements unless it's an elseif/else
133		// in which case it's already been counted as part of the if
134	28	if (!in_array($this->tokens[$this->i][0], [T_ELSE, T_ELSEIF], true))
135		{
136	28	++$this->context['statements'];
137		}
138
139		// If the control structure is anything but an "else", skip its condition to reach the first
140		// brace or statement
141	28	if ($this->tokens[$this->i][0] !== T_ELSE)
142		{
143	28	$this->skipCondition();
144		}
145
146	28	$this->skipWhitespace();
147
148		// Abort if this control structure does not use braces
149	28	if ($this->tokens[$this->i] !== '{')
150		{
151		// Rewind all the way to the original token
152	1	$this->i = $savedIndex;
153
154	1	return;
155		}
156
157	27	++$this->braces;
158
159		// Replacement for the first brace
160	27	$replacement = [T_WHITESPACE, ''];
161
162		// Add a space after "else" if the brace is removed and it's not followed by whitespace or a
163		// variable
164	27	if ($this->tokens[$savedIndex][0] === T_ELSE
165	27	&& $this->tokens[$this->i + 1][0] !== T_VARIABLE
166	27	&& $this->tokens[$this->i + 1][0] !== T_WHITESPACE)
167		{
168	9	$replacement = [T_WHITESPACE, ' '];
169		}
170
171		// Record the token of the control structure (T_IF, T_WHILE, etc...) in the current context
172	27	$this->context['lastBlock'] = $this->tokens[$savedIndex][0];
173
174		// Create a new context
175	27	$this->context = [
176	27	'braces' => $this->braces,
177	27	'index' => $this->i,
178		'lastBlock' => null,
179	27	'parent' => $this->context,
180	27	'replacement' => $replacement,
181	27	'savedIndex' => $savedIndex,
182	27	'statements' => 0
183		];
184		}
185
186		/**
187		* Process the block ending at current index
188		*
189		* @return void
190		*/
191	27	protected function processEndOfBlock()
192		{
193	27	if ($this->context['statements'] < 2 && !$this->mustPreserveBraces())
194		{
195	26	$this->removeBracesInCurrentContext();
196		}
197
198	27	$this->context = $this->context['parent'];
199
200		// Propagate the "lastBlock" property upwards to handle multiple nested if statements
201	27	$this->context['parent']['lastBlock'] = $this->context['lastBlock'];
202		}
203
204		/**
205		* Remove the braces surrounding current context
206		*
207		* @return void
208		*/
209	26	protected function removeBracesInCurrentContext()
210		{
211		// Replace the first brace with the saved replacement
212	26	$this->tokens[$this->context['index']] = $this->context['replacement'];
213
214		// Remove the second brace or replace it with a semicolon if there are no statements in this
215		// block
216	26	$this->tokens[$this->i] = ($this->context['statements']) ? [T_WHITESPACE, ''] : ';';
217
218		// Remove the whitespace before braces. This is mainly cosmetic
219	26	foreach ([$this->context['index'] - 1, $this->i - 1] as $tokenIndex)
220		{
221	26	if ($this->tokens[$tokenIndex][0] === T_WHITESPACE)
222		{
223	22	$this->tokens[$tokenIndex][1] = '';
224		}
225		}
226
227		// Test whether the current block followed an else statement then test whether this
228		// else was followed by an if
229	26	if ($this->tokens[$this->context['savedIndex']][0] === T_ELSE)
230		{
231	16	$j = 1 + $this->context['savedIndex'];
232
233	16	while ($this->tokens[$j][0] === T_WHITESPACE
234	16	\|\| $this->tokens[$j][0] === T_COMMENT
235	16	\|\| $this->tokens[$j][0] === T_DOC_COMMENT)
236		{
237	16	++$j;
238		}
239
240	16	if ($this->tokens[$j][0] === T_IF)
241		{
242		// Replace if with elseif
243	4	$this->tokens[$j] = [T_ELSEIF, 'elseif'];
244
245		// Remove the original else
246	4	$j = $this->context['savedIndex'];
247	4	$this->tokens[$j] = [T_WHITESPACE, ''];
248
249		// Remove any whitespace before the original else
250	4	if ($this->tokens[$j - 1][0] === T_WHITESPACE)
251		{
252	3	$this->tokens[$j - 1][1] = '';
253		}
254
255		// Unindent what was the else's content
256	4	$this->unindentBlock($j, $this->i - 1);
257
258		// Ensure that the brace after the now-removed "else" was not replaced with a space
259	4	$this->tokens[$this->context['index']] = [T_WHITESPACE, ''];
260		}
261		}
262
263	26	$this->changed = true;
264		}
265
266		/**
267		* {@inheritdoc}
268		*/
269	28	protected function reset($php)
270		{
271	28	parent::reset($php);
272
273	28	$this->braces = 0;
274	28	$this->context = [
275		'braces' => 0,
276		'index' => -1,
277		'parent' => [],
278		'preventElse' => false,
279		'savedIndex' => 0,
280		'statements' => 0
281		];
282		}
283
284		/**
285		* Skip the condition of a control structure
286		*
287		* @return void
288		*/
289	28	protected function skipCondition()
290		{
291		// Reach the opening parenthesis
292	28	$this->skipToString('(');
293
294		// Iterate through tokens until we have a match for every left parenthesis
295	28	$parens = 0;
296	28	while (++$this->i < $this->cnt)
297		{
298	28	if ($this->tokens[$this->i] === ')')
299		{
300	28	if ($parens)
301		{
302	1	--$parens;
303		}
304		else
305		{
306	28	break;
307		}
308		}
309	28	elseif ($this->tokens[$this->i] === '(')
310		{
311	1	++$parens;
312		}
313		}
314		}
315		}

s9e / TextFormatter

ControlStructuresOptimizer::isFollowedByElse() A last analyzed 2025-05-02 21:56 UTC

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ControlStructuresOptimizer::isFollowedByElse() A
last analyzed 2025-05-02 21:56 UTC