Properly handle static deref LHS

The rules for static and array/object deref are slightly different:
The former does not allow constants.

(cherry picked from commit 7b4a8c1ebd09fd6f6ccc33d7193df0f75e7e28d7)

lib/PhpParser/PrettyPrinter/Standard.php

@@ -529,7 +529,7 @@ class Standard extends PrettyPrinterAbstract
     }
 
     protected function pExpr_StaticCall(Expr\StaticCall $node) {
-        return $this->pDereferenceLhs($node->class) . '::'
+        return $this->pStaticDereferenceLhs($node->class) . '::'
              . ($node->name instanceof Expr
                 ? ($node->name instanceof Expr\Variable
                    ? $this->p($node->name)
@@ -606,7 +606,7 @@ class Standard extends PrettyPrinterAbstract
     }
 
     protected function pExpr_ClassConstFetch(Expr\ClassConstFetch $node) {
-        return $this->pDereferenceLhs($node->class) . '::' . $this->pObjectProperty($node->name);
+        return $this->pStaticDereferenceLhs($node->class) . '::' . $this->pObjectProperty($node->name);
     }
 
     protected function pExpr_PropertyFetch(Expr\PropertyFetch $node) {
@@ -618,7 +618,7 @@ class Standard extends PrettyPrinterAbstract
     }
 
     protected function pExpr_StaticPropertyFetch(Expr\StaticPropertyFetch $node) {
-        return $this->pDereferenceLhs($node->class) . '::$' . $this->pObjectProperty($node->name);
+        return $this->pStaticDereferenceLhs($node->class) . '::$' . $this->pObjectProperty($node->name);
     }
 
     protected function pExpr_ShellExec(Expr\ShellExec $node) {
@@ -1069,6 +1069,14 @@ class Standard extends PrettyPrinterAbstract
         }
     }
 
+    protected function pStaticDereferenceLhs(Node $node) {
+        if (!$this->staticDereferenceLhsRequiresParens($node)) {
+            return $this->p($node);
+        } else {
+            return '(' . $this->p($node) . ')';
+        }
+    }
+
     protected function pCallLhs(Node $node) {
         if (!$this->callLhsRequiresParens($node)) {
             return $this->p($node);

lib/PhpParser/PrettyPrinterAbstract.php

@@ -22,6 +22,7 @@ abstract class PrettyPrinterAbstract
     const FIXUP_VAR_BRACED_NAME = 5; // Name operand that may require ${} bracing
     const FIXUP_ENCAPSED        = 6; // Encapsed string part
     const FIXUP_NEW             = 7; // New/instanceof operand
+    const FIXUP_STATIC_DEREF_LHS = 8; // LHS of static dereferencing operation
 
     protected $precedenceMap = [
         // [precedence, associativity]
@@ -978,6 +979,13 @@ abstract class PrettyPrinterAbstract
                     return '(' . $this->p($subNode) . ')';
                 }
                 break;
+            case self::FIXUP_STATIC_DEREF_LHS:
+                if ($this->staticDereferenceLhsRequiresParens($subNode)
+                    && !$this->origTokens->haveParens($subStartPos, $subEndPos)
+                ) {
+                    return '(' . $this->p($subNode) . ')';
+                }
+                break;
             case self::FIXUP_NEW:
                 if ($this->newOperandRequiresParens($subNode)
                     && !$this->origTokens->haveParens($subStartPos, $subEndPos)) {
@@ -1054,13 +1062,26 @@ abstract class PrettyPrinterAbstract
     }
 
     /**
-     * Determines whether the LHS of a dereferencing operation must be wrapped in parenthesis.
+     * Determines whether the LHS of an array/object operation must be wrapped in parentheses.
      *
      * @param Node $node LHS of dereferencing operation
      *
      * @return bool Whether parentheses are required
      */
     protected function dereferenceLhsRequiresParens(Node $node) : bool {
+        // A constant can occur on the LHS of an array/object deref, but not a static deref.
+        return $this->staticDereferenceLhsRequiresParens($node)
+            && !$node instanceof Expr\ConstFetch;
+    }
+
+    /**
+     * Determines whether the LHS of a static operation must be wrapped in parentheses.
+     *
+     * @param Node $node LHS of dereferencing operation
+     *
+     * @return bool Whether parentheses are required
+     */
+    protected function staticDereferenceLhsRequiresParens(Node $node): bool {
         return !($node instanceof Expr\Variable
             || $node instanceof Node\Name
             || $node instanceof Expr\ArrayDimFetch
@@ -1073,7 +1094,6 @@ abstract class PrettyPrinterAbstract
             || $node instanceof Expr\StaticCall
             || $node instanceof Expr\Array_
             || $node instanceof Scalar\String_
-            || $node instanceof Expr\ConstFetch
             || $node instanceof Expr\ClassConstFetch);
     }
 
@@ -1208,9 +1228,9 @@ abstract class PrettyPrinterAbstract
             ],
 
             Expr\FuncCall::class => ['name' => self::FIXUP_CALL_LHS],
-            Expr\StaticCall::class => ['class' => self::FIXUP_DEREF_LHS],
+            Expr\StaticCall::class => ['class' => self::FIXUP_STATIC_DEREF_LHS],
             Expr\ArrayDimFetch::class => ['var' => self::FIXUP_DEREF_LHS],
-            Expr\ClassConstFetch::class => ['var' => self::FIXUP_DEREF_LHS],
+            Expr\ClassConstFetch::class => ['class' => self::FIXUP_STATIC_DEREF_LHS],
             Expr\New_::class => ['class' => self::FIXUP_NEW],
             Expr\MethodCall::class => [
                 'var' => self::FIXUP_DEREF_LHS,
@@ -1221,7 +1241,7 @@ abstract class PrettyPrinterAbstract
                 'name' => self::FIXUP_BRACED_NAME,
             ],
             Expr\StaticPropertyFetch::class => [
-                'class' => self::FIXUP_DEREF_LHS,
+                'class' => self::FIXUP_STATIC_DEREF_LHS,
                 'name' => self::FIXUP_VAR_BRACED_NAME,
             ],
             Expr\PropertyFetch::class => [

test/code/formatPreservation/fixup.test

@@ -44,6 +44,9 @@ self :: $foo;
 self :: $foo;
 new Foo();
 $x instanceof Foo;
+Foo :: bar;
+Foo :: $bar;
+Foo :: bar();
 -----
 $stmts[0]->expr->name = new Expr\Variable('a');
 $stmts[1]->expr->name = new Expr\BinaryOp\Concat(new Expr\Variable('a'), new Expr\Variable('b'));
@@ -58,6 +61,9 @@ $stmts[7]->expr->name = new Node\VarLikeIdentifier('bar');
 $stmts[8]->expr->name = new Expr\BinaryOp\Concat(new Expr\Variable('a'), new Expr\Variable('b'));
 $stmts[9]->expr->class = new Scalar\String_('Foo');
 $stmts[10]->expr->class = new Scalar\String_('Foo');
+$stmts[11]->expr->class = new Expr\ConstFetch(new Node\Name('FOO'));
+$stmts[12]->expr->class = new Expr\ConstFetch(new Node\Name('FOO'));
+$stmts[13]->expr->class = new Expr\ConstFetch(new Node\Name('FOO'));
 -----
 <?php
 $a ();
@@ -71,3 +77,6 @@ self :: $bar;
 self :: ${$a . $b};
 new ('Foo')();
 $x instanceof ('Foo');
+(FOO) :: bar;
+(FOO) :: $bar;
+(FOO) :: bar();

test/code/prettyPrinter/expr/newVariable.test

@@ -18,6 +18,6 @@ new (foo())();
 new ('foo')();
 new (x[0])();
 new (x->y)();
-new (x::$y)();
+new ((x)::$y)();
 $x instanceof ('a' . 'b');
 $x instanceof ($y++);

test/code/prettyPrinter/expr/uvs.test

@@ -11,6 +11,9 @@ A::$$b[$c]();
 ($a->b)();
 (A::$b)();
 ('a' . 'b')::X;
+(A)::X;
+(A)::$x;
+(A)::x();
 -----
 !!php7
 (function () {
@@ -22,4 +25,7 @@ $A::{$b[$c]}();
 A::${$b}[$c]();
 ($a->b)();
 (A::$b)();
-('a' . 'b')::X;
+('a' . 'b')::X;
+(A)::X;
+(A)::$x;
+(A)::x();