diff --git a/UPGRADE-4.0.md b/UPGRADE-4.0.md
index d6ba16c8..ea54f592 100644
--- a/UPGRADE-4.0.md
+++ b/UPGRADE-4.0.md
@@ -19,4 +19,5 @@ source code, while running on a newer version.
 
 ### Removed functionality
 
-* Removed `type` subnode on `Class`, `ClassMethod` and `Property` nodes. Use `flags` instead.
\ No newline at end of file
+* Removed `type` subnode on `Class`, `ClassMethod` and `Property` nodes. Use `flags` instead.
+* The `ClassConst::isStatic()` method has been removed. Constants cannot have a static modifier.
\ No newline at end of file
diff --git a/lib/PhpParser/Comment.php b/lib/PhpParser/Comment.php
index f8463da7..9408d4cf 100644
--- a/lib/PhpParser/Comment.php
+++ b/lib/PhpParser/Comment.php
@@ -115,7 +115,12 @@ class Comment implements \JsonSerializable
     }
 
     /**
-     * @return float
+     * Get length of shortest whitespace prefix (at the start of a line).
+     *
+     * If there is a line with no prefix whitespace, 0 is a valid return value.
+     *
+     * @param string $str String to check
+     * @return int Length in characters. Tabs count as single characters.
      */
     private function getShortestWhitespacePrefixLen($str) {
         $lines = explode("\n", $str);
diff --git a/lib/PhpParser/Error.php b/lib/PhpParser/Error.php
index 4ea3beb0..e372c52a 100644
--- a/lib/PhpParser/Error.php
+++ b/lib/PhpParser/Error.php
@@ -131,7 +131,11 @@ class Error extends \RuntimeException
     }
 
     /**
-     * @return string
+     * Formats message including line and column information.
+     *
+     * @param string $code Source code associated with the error, for calculation of the columns
+     *
+     * @return string Formatted message
      */
     public function getMessageWithColumnInfo($code) {
         return sprintf(
@@ -141,6 +145,14 @@ class Error extends \RuntimeException
         );
     }
 
+    /**
+     * Converts a file offset into a column.
+     *
+     * @param string $code Source code that $pos indexes into
+     * @param int    $pos  0-based position in $code
+     *
+     * @return int 1-based column (relative to start of line)
+     */
     private function toColumn($code, $pos) {
         if ($pos > strlen($code)) {
             throw new \RuntimeException('Invalid position information');
diff --git a/lib/PhpParser/Lexer.php b/lib/PhpParser/Lexer.php
index 29775c4f..96066fd3 100644
--- a/lib/PhpParser/Lexer.php
+++ b/lib/PhpParser/Lexer.php
@@ -118,6 +118,8 @@ class Lexer
     }
 
     /**
+     * Check whether comment token is unterminated.
+     *
      * @return bool
      */
     private function isUnterminatedComment($token) {
@@ -127,6 +129,8 @@ class Lexer
     }
 
     /**
+     * Check whether an error *may* have occurred during tokenization.
+     *
      * @return bool
      */
     private function errorMayHaveOccurred() {
diff --git a/lib/PhpParser/Lexer/Emulative.php b/lib/PhpParser/Lexer/Emulative.php
index 974b1d64..bdc39783 100644
--- a/lib/PhpParser/Lexer/Emulative.php
+++ b/lib/PhpParser/Lexer/Emulative.php
@@ -49,21 +49,22 @@ class Emulative extends \PhpParser\Lexer
         }
     }
 
-    /*
-     * Checks if the code is potentially using features that require emulation.
-     */
     /**
-     * @return int|false
+     * Checks if the code is potentially using features that require emulation.
+     *
+     * @param string $code Code to check
+     *
+     * @return bool
      */
     protected function requiresEmulation($code) {
         if (version_compare(PHP_VERSION, self::PHP_7_0, '>=')) {
             return false;
         }
 
-        return preg_match('(\?\?|<=>|yield[ \n\r\t]+from)', $code);
+        return (bool) preg_match('(\?\?|<=>|yield[ \n\r\t]+from)', $code);
     }
 
-    /*
+    /**
      * Emulates tokens for newer PHP versions.
      */
     protected function emulateTokens() {
diff --git a/lib/PhpParser/Node/Scalar/String_.php b/lib/PhpParser/Node/Scalar/String_.php
index 50c6e167..d5cf5f4d 100644
--- a/lib/PhpParser/Node/Scalar/String_.php
+++ b/lib/PhpParser/Node/Scalar/String_.php
@@ -112,7 +112,11 @@ class String_ extends Scalar
     }
 
     /**
-     * @return string
+     * Converts a Unicode code point to its UTF-8 encoded representation.
+     *
+     * @param int $num Code point
+     *
+     * @return string UTF-8 representation of code point
      */
     private static function codePointToUtf8($num) {
         if ($num <= 0x7F) {
diff --git a/lib/PhpParser/Node/Stmt/ClassConst.php b/lib/PhpParser/Node/Stmt/ClassConst.php
index 8f9f4f9c..4d5ac107 100644
--- a/lib/PhpParser/Node/Stmt/ClassConst.php
+++ b/lib/PhpParser/Node/Stmt/ClassConst.php
@@ -29,6 +29,8 @@ class ClassConst extends Node\Stmt
     }
 
     /**
+     * Whether constant is explicitly or implicitly public.
+     *
      * @return bool
      */
     public function isPublic() {
@@ -37,6 +39,8 @@ class ClassConst extends Node\Stmt
     }
 
     /**
+     * Whether constant is protected.
+     *
      * @return bool
      */
     public function isProtected() {
@@ -44,16 +48,11 @@ class ClassConst extends Node\Stmt
     }
 
     /**
+     * Whether constant is private.
+     *
      * @return bool
      */
     public function isPrivate() {
         return (bool) ($this->flags & Class_::MODIFIER_PRIVATE);
     }
-
-    /**
-     * @return bool
-     */
-    public function isStatic() {
-        return (bool) ($this->flags & Class_::MODIFIER_STATIC);
-    }
 }
diff --git a/lib/PhpParser/Node/Stmt/ClassMethod.php b/lib/PhpParser/Node/Stmt/ClassMethod.php
index 276c83a7..58c7301f 100644
--- a/lib/PhpParser/Node/Stmt/ClassMethod.php
+++ b/lib/PhpParser/Node/Stmt/ClassMethod.php
@@ -64,6 +64,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is explicitly or implicitly public.
+     *
      * @return bool
      */
     public function isPublic() {
@@ -72,6 +74,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is protected.
+     *
      * @return bool
      */
     public function isProtected() {
@@ -79,6 +83,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is private.
+     *
      * @return bool
      */
     public function isPrivate() {
@@ -86,6 +92,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is abstract.
+     *
      * @return bool
      */
     public function isAbstract() {
@@ -93,6 +101,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is final.
+     * #
      * @return bool
      */
     public function isFinal() {
@@ -100,6 +110,8 @@ class ClassMethod extends Node\Stmt implements FunctionLike
     }
 
     /**
+     * Whether the method is static.
+     *
      * @return bool
      */
     public function isStatic() {
diff --git a/lib/PhpParser/Node/Stmt/Class_.php b/lib/PhpParser/Node/Stmt/Class_.php
index 07a7ba7d..6b78ebbc 100644
--- a/lib/PhpParser/Node/Stmt/Class_.php
+++ b/lib/PhpParser/Node/Stmt/Class_.php
@@ -55,6 +55,8 @@ class Class_ extends ClassLike
     }
 
     /**
+     * Whether the class is explicitly abstract.
+     *
      * @return bool
      */
     public function isAbstract() {
@@ -62,6 +64,8 @@ class Class_ extends ClassLike
     }
 
     /**
+     * Whether the class is final.
+     *
      * @return bool
      */
     public function isFinal() {
@@ -69,6 +73,8 @@ class Class_ extends ClassLike
     }
 
     /**
+     * Whether the class is anonymous.
+     *
      * @return bool
      */
     public function isAnonymous() {
diff --git a/lib/PhpParser/Node/Stmt/Property.php b/lib/PhpParser/Node/Stmt/Property.php
index 051e61f4..2b373be5 100644
--- a/lib/PhpParser/Node/Stmt/Property.php
+++ b/lib/PhpParser/Node/Stmt/Property.php
@@ -29,6 +29,8 @@ class Property extends Node\Stmt
     }
 
     /**
+     * Whether the property is explicitly or implicitly public.
+     *
      * @return bool
      */
     public function isPublic() {
@@ -37,6 +39,8 @@ class Property extends Node\Stmt
     }
 
     /**
+     * Whether the property is protected.
+     *
      * @return bool
      */
     public function isProtected() {
@@ -44,6 +48,8 @@ class Property extends Node\Stmt
     }
 
     /**
+     * Whether the property is private.
+     *
      * @return bool
      */
     public function isPrivate() {
@@ -51,6 +57,8 @@ class Property extends Node\Stmt
     }
 
     /**
+     * Whether the property is static.
+     *
      * @return bool
      */
     public function isStatic() {
diff --git a/lib/PhpParser/NodeDumper.php b/lib/PhpParser/NodeDumper.php
index 090e57ce..c1e2674f 100644
--- a/lib/PhpParser/NodeDumper.php
+++ b/lib/PhpParser/NodeDumper.php
@@ -165,7 +165,11 @@ class NodeDumper
     }
 
     /**
-     * @return string|null
+     * Dump node position, if possible.
+     *
+     * @param Node $node Node for which to dump position
+     *
+     * @return string|null Dump of position, or null if position information not available
      */
     protected function dumpPosition(Node $node) {
         if (!$node->hasAttribute('startLine') || !$node->hasAttribute('endLine')) {
diff --git a/lib/PhpParser/NodeTraverser.php b/lib/PhpParser/NodeTraverser.php
index 03ad8935..a238e28a 100644
--- a/lib/PhpParser/NodeTraverser.php
+++ b/lib/PhpParser/NodeTraverser.php
@@ -58,8 +58,9 @@ class NodeTraverser implements NodeTraverserInterface
     /**
      * Traverses an array of nodes using the registered visitors.
      *
-     * @param  Node[] $nodes Array of nodes
-     * @return array
+     * @param Node[] $nodes Array of nodes
+     *
+     * @return Node[] Traversed array of nodes
      */
     public function traverse(array $nodes) {
         foreach ($this->visitors as $visitor) {
@@ -80,7 +81,11 @@ class NodeTraverser implements NodeTraverserInterface
     }
 
     /**
-     * @return \PhpParser\Node
+     * Recursively traverse a node.
+     *
+     * @param Node $node Node to traverse.
+     *
+     * @return Node Result of traversal (may be original node or new one)
      */
     protected function traverseNode(Node $node) {
         foreach ($node->getSubNodeNames() as $name) {
@@ -121,7 +126,11 @@ class NodeTraverser implements NodeTraverserInterface
     }
 
     /**
-     * @return array
+     * Recursively traverse array (usually of nodes).
+     *
+     * @param array $nodes Array to traverse
+     *
+     * @return array Result of traversal (may be original array or changed one)
      */
     protected function traverseArray(array $nodes) {
         $doNodes = array();
diff --git a/lib/PhpParser/NodeVisitor/NameResolver.php b/lib/PhpParser/NodeVisitor/NameResolver.php
index 0307ad8b..66391d7f 100644
--- a/lib/PhpParser/NodeVisitor/NameResolver.php
+++ b/lib/PhpParser/NodeVisitor/NameResolver.php
@@ -193,7 +193,11 @@ class NameResolver extends NodeVisitorAbstract
     }
 
     /**
-     * @return null|Name
+     * Resolve class name, according to name resolver options.
+     *
+     * @param Name $name Class ame to resolve
+     *
+     * @return Name Resolved name, or original name with attribute
      */
     protected function resolveClassName(Name $name) {
         if (!$this->replaceNodes) {
@@ -212,7 +216,12 @@ class NameResolver extends NodeVisitorAbstract
     }
 
     /**
-     * @return Name
+     * Resolve function or constant name, according to name resolver options.
+     *
+     * @param Name $name Function or constant name to resolve
+     * @param int  $type One of Stmt\Use_::TYPE_{FUNCTION|CONSTANT}
+     *
+     * @return Name Resolved name, or original name with attribute
      */
     protected function resolveOtherName(Name $name, $type) {
         if (!$this->replaceNodes) {
@@ -246,7 +255,11 @@ class NameResolver extends NodeVisitorAbstract
     }
 
     /**
-     * @return null|Name
+     * Get resolved class name.
+     *
+     * @param Name $name Class ame to resolve
+     *
+     * @return Name Resolved name
      */
     protected function getResolvedClassName(Name $name) {
         // don't resolve special class names
@@ -277,7 +290,12 @@ class NameResolver extends NodeVisitorAbstract
     }
 
     /**
-     * @return null|Name
+     * Get resolved function or constant name.
+     *
+     * @param Name $name Function or constant name to resolve
+     * @param int  $type One of Stmt\Use_::TYPE_{FUNCTION|CONSTANT}
+     *
+     * @return null|Name Resolved name, or null if static resolution is not possible
      */
     protected function getResolvedOtherName(Name $name, $type) {
         // fully qualified names are already resolved
diff --git a/lib/PhpParser/Parser/Multiple.php b/lib/PhpParser/Parser/Multiple.php
index 153cb69e..25296a4e 100644
--- a/lib/PhpParser/Parser/Multiple.php
+++ b/lib/PhpParser/Parser/Multiple.php
@@ -23,10 +23,6 @@ class Multiple implements Parser {
         $this->parsers = $parsers;
     }
 
-    /**
-     * @return       \PhpParser\Node\Stmt[]
-     * @psalm-return array<mixed, \PhpParser\Node\Stmt>
-     */
     public function parse($code, ErrorHandler $errorHandler = null) {
         if (null === $errorHandler) {
             $errorHandler = new ErrorHandler\Throwing;
diff --git a/lib/PhpParser/ParserAbstract.php b/lib/PhpParser/ParserAbstract.php
index 91b2c3d6..a088a892 100644
--- a/lib/PhpParser/ParserAbstract.php
+++ b/lib/PhpParser/ParserAbstract.php
@@ -47,40 +47,40 @@ abstract class ParserAbstract implements Parser
     protected $YY2TBLSTATE;
     protected $YYNLSTATES;
 
-    /** @var array Map of lexer tokens to internal symbols */
+    /** @var int[] Map of lexer tokens to internal symbols */
     protected $tokenToSymbol;
-    /** @var array Map of symbols to their names */
+    /** @var string[] Map of symbols to their names */
     protected $symbolToName;
     /** @var array Names of the production rules (only necessary for debugging) */
     protected $productions;
 
-    /** @var array Map of states to a displacement into the $action table. The corresponding action for this
+    /** @var int[] Map of states to a displacement into the $action table. The corresponding action for this
      *             state/symbol pair is $action[$actionBase[$state] + $symbol]. If $actionBase[$state] is 0, the
                    action is defaulted, i.e. $actionDefault[$state] should be used instead. */
     protected $actionBase;
-    /** @var array Table of actions. Indexed according to $actionBase comment. */
+    /** @var int[] Table of actions. Indexed according to $actionBase comment. */
     protected $action;
-    /** @var array Table indexed analogously to $action. If $actionCheck[$actionBase[$state] + $symbol] != $symbol
+    /** @var int[] Table indexed analogously to $action. If $actionCheck[$actionBase[$state] + $symbol] != $symbol
      *             then the action is defaulted, i.e. $actionDefault[$state] should be used instead. */
     protected $actionCheck;
-    /** @var array Map of states to their default action */
+    /** @var int[]Map of states to their default action */
     protected $actionDefault;
 
-    /** @var array Map of non-terminals to a displacement into the $goto table. The corresponding goto state for this
+    /** @var int[] Map of non-terminals to a displacement into the $goto table. The corresponding goto state for this
      *             non-terminal/state pair is $goto[$gotoBase[$nonTerminal] + $state] (unless defaulted) */
     protected $gotoBase;
-    /** @var array Table of states to goto after reduction. Indexed according to $gotoBase comment. */
+    /** @var int[] Table of states to goto after reduction. Indexed according to $gotoBase comment. */
     protected $goto;
-    /** @var array Table indexed analogously to $goto. If $gotoCheck[$gotoBase[$nonTerminal] + $state] != $nonTerminal
+    /** @var int[] Table indexed analogously to $goto. If $gotoCheck[$gotoBase[$nonTerminal] + $state] != $nonTerminal
      *             then the goto state is defaulted, i.e. $gotoDefault[$nonTerminal] should be used. */
     protected $gotoCheck;
-    /** @var array Map of non-terminals to the default state to goto after their reduction */
+    /** @var int[] Map of non-terminals to the default state to goto after their reduction */
     protected $gotoDefault;
 
-    /** @var array Map of rules to the non-terminal on their left-hand side, i.e. the non-terminal to use for
+    /** @var int[] Map of rules to the non-terminal on their left-hand side, i.e. the non-terminal to use for
      *             determining the state to goto after reduction. */
     protected $ruleToNonTerminal;
-    /** @var array Map of rules to the length of their right-hand side, which is the number of elements that have to
+    /** @var int[] Map of rules to the length of their right-hand side, which is the number of elements that have to
      *             be popped from the stack(s) on reduction. */
     protected $ruleToLength;
 
@@ -356,7 +356,12 @@ abstract class ParserAbstract implements Parser
     }
 
     /**
-     * @return string
+     * Format error message including expected tokens.
+     *
+     * @param int $symbol Unexpected symbol
+     * @param int $state  State at time of error
+     *
+     * @return string Formatted error message
      */
     protected function getErrorMessage($symbol, $state) {
         $expectedString = '';
@@ -368,8 +373,11 @@ abstract class ParserAbstract implements Parser
     }
 
     /**
-     * @return       array
-     * @psalm-return array<int, mixed>
+     * Get limited number of expected tokens in given state.
+     *
+     * @param int $state State
+     *
+     * @return string[] Expected tokens. If too many, an empty array is returned.
      */
     protected function getExpectedTokens($state) {
         $expected = array();
@@ -517,7 +525,11 @@ abstract class ParserAbstract implements Parser
     }
 
     /**
-     * @return null|string
+     * Determine namespacing style (semicolon or brace)
+     *
+     * @param Node[] $stmts Top-level statements.
+     *
+     * @return null|string One of "semicolon", "brace" or null (no namespaces)
      */
     private function getNamespacingStyle(array $stmts) {
         $style = null;
@@ -562,9 +574,6 @@ abstract class ParserAbstract implements Parser
         return $style;
     }
 
-    /**
-     * @return \PhpParser\Node\Expr\StaticCall
-     */
     protected function fixupPhp5StaticPropCall($prop, array $args, array $attributes) {
         if ($prop instanceof Node\Expr\StaticPropertyFetch) {
             // Preserve attributes if possible
@@ -649,15 +658,16 @@ abstract class ParserAbstract implements Parser
     );
 
     /**
-     * @return array
+     * Get combined start and end attributes at a stack location
+     *
+     * @param int $pos Stack location
+     *
+     * @return array Combined start and end attributes
      */
     protected function getAttributesAt($pos) {
         return $this->startAttributeStack[$pos] + $this->endAttributeStack[$pos];
     }
 
-    /**
-     * @return LNumber
-     */
     protected function parseLNumber($str, $attributes, $allowInvalidOctal = false) {
         try {
             return LNumber::fromString($str, $attributes, $allowInvalidOctal);
@@ -669,7 +679,12 @@ abstract class ParserAbstract implements Parser
     }
 
     /**
-     * @return LNumber|String_
+     * Parse a T_NUM_STRING token into either an integer or string node.
+     *
+     * @param string $str        Number string
+     * @param array  $attributes Attributes
+     *
+     * @return LNumber|String_ Integer or string node.
      */
     protected function parseNumString($str, $attributes) {
         if (!preg_match('/^(?:0|-?[1-9][0-9]*)$/', $str)) {
diff --git a/lib/PhpParser/PrettyPrinterAbstract.php b/lib/PhpParser/PrettyPrinterAbstract.php
index 1040d025..8ea70052 100644
--- a/lib/PhpParser/PrettyPrinterAbstract.php
+++ b/lib/PhpParser/PrettyPrinterAbstract.php
@@ -239,7 +239,14 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
-     * @return string
+     * Pretty-print an infix operation while taking precedence into account.
+     *
+     * @param string $type           Node type of operator
+     * @param Node   $leftNode       Left-hand side node
+     * @param string $operatorString String representation of the operator
+     * @param Node   $rightNode      Right-hand side node
+     *
+     * @return string Pretty printed infix operation
      */
     protected function pInfixOp($type, Node $leftNode, $operatorString, Node $rightNode) {
         list($precedence, $associativity) = $this->precedenceMap[$type];
@@ -250,7 +257,13 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
-     * @return string
+     * Pretty-print a prefix operation while taking precedence into account.
+     *
+     * @param string $type           Node type of operator
+     * @param string $operatorString String representation of the operator
+     * @param Node   $node           Node
+     *
+     * @return string Pretty printed prefix operation
      */
     protected function pPrefixOp($type, $operatorString, Node $node) {
         list($precedence, $associativity) = $this->precedenceMap[$type];
@@ -258,7 +271,13 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
-     * @return string
+     * Pretty-print a postfix operation while taking precedence into account.
+     *
+     * @param string $type           Node type of operator
+     * @param string $operatorString String representation of the operator
+     * @param Node   $node           Node
+     *
+     * @return string Pretty printed postfix operation
      */
     protected function pPostfixOp($type, Node $node, $operatorString) {
         list($precedence, $associativity) = $this->precedenceMap[$type];
@@ -735,6 +754,11 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
+     * Whether the fiven position is immediately surrounded by parenthesis.
+     *
+     * @param int $startPos Start position
+     * @param int $endPos   End position
+     *
      * @return bool
      */
     protected function haveParens($startPos, $endPos) {
@@ -743,6 +767,11 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
+     * Whether the fiven position is immediately surrounded by braces.
+     *
+     * @param int $startPos Start position
+     * @param int $endPos   End position
+     *
      * @return bool
      */
     protected function haveBraces($startPos, $endPos) {
diff --git a/lib/PhpParser/Unserializer/XML.php b/lib/PhpParser/Unserializer/XML.php
index 46b65956..3538804c 100644
--- a/lib/PhpParser/Unserializer/XML.php
+++ b/lib/PhpParser/Unserializer/XML.php
@@ -140,7 +140,11 @@ class XML implements Unserializer
     }
 
     /**
-     * @return string
+     * Reconstruct the class name from the node type.
+     *
+     * @param string $type Node type
+     *
+     * @return string Node class name
      */
     protected function getClassNameFromType($type) {
         $className = 'PhpParser\\Node\\' . strtr($type, '_', '\\');
diff --git a/test/PhpParser/Node/Stmt/ClassConstTest.php b/test/PhpParser/Node/Stmt/ClassConstTest.php
index 610972c6..877d67e1 100644
--- a/test/PhpParser/Node/Stmt/ClassConstTest.php
+++ b/test/PhpParser/Node/Stmt/ClassConstTest.php
@@ -22,7 +22,6 @@ class ClassConstTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue($node->isPublic());
         $this->assertFalse($node->isProtected());
         $this->assertFalse($node->isPrivate());
-        $this->assertFalse($node->isStatic());
     }
 
     public function provideModifiers() {