Warn about PHP 5.3 only functions and parameters

Test Plan:
Linted:

  json_decode('{}', true, 1, 1);
  gethostname();

Also linted all Phabricator repositories and found no occurrence.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1158

Differential Revision: https://secure.phabricator.com/D2806

scripts/update_compat_info.php

@@ -0,0 +1,63 @@
+#!/usr/bin/env php
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+require_once dirname(__FILE__).'/__init_script__.php';
+
+$target = 'resources/php_compat_info.json';
+echo "Purpose: Updates {$target} used by ArcanistXHPASTLinter.\n";
+
+$ok = include 'PHP/CompatInfo/Autoload.php';
+if (!$ok) {
+  echo "You need PHP_CompatInfo available in 'include_path'.\n";
+  echo "http://php5.laurent-laville.org/compatinfo/\n";
+  exit(1);
+}
+
+$required = '5.2.3';
+$reference = id(new PHP_CompatInfo_Reference_ALL())->getAll();
+
+$output = array();
+$output['@'.'generated'] = true;
+$output['params'] = array();
+
+foreach (array('functions', 'classes', 'interfaces') as $type) {
+  $output[$type] = array();
+  foreach ($reference[$type] as $name => $versions) {
+    $name = strtolower($name);
+    $versions = reset($versions);
+    list($min, $max) = $versions;
+    if (version_compare($min, $required) > 0) {
+      $output[$type][$name] = $min;
+    }
+    if ($type == 'functions' && isset($versions[2])) {
+      $params = explode(', ', $versions[2]);
+      foreach ($params as $i => $version) {
+        if (version_compare($version, $required) > 0) {
+          $output['params'][$name][$i] = $version;
+        }
+      }
+    }
+  }
+}
+
+file_put_contents(
+  dirname(__FILE__).'/../'.$target,
+  json_encode($output));
+
+echo "Done.\n";

src/lint/linter/ArcanistXHPASTLinter.php

@@ -302,6 +302,53 @@ final class ArcanistXHPASTLinter extends ArcanistLinter {
       }
     }
 
+    $this->lintPHP53Functions($root);
+  }
+
+  private function lintPHP53Functions($root) {
+    $target = dirname(__FILE__).'/../../../resources/php_compat_info.json';
+    $compat_info = json_decode(file_get_contents($target), true);
+
+    $calls = $root->selectDescendantsOfType('n_FUNCTION_CALL');
+    foreach ($calls as $call) {
+      $node = $call->getChildByIndex(0);
+      $name = strtolower($node->getConcreteString());
+      $version = idx($compat_info['functions'], $name);
+      if ($version) {
+        $this->raiseLintAtNode(
+          $node,
+          self::LINT_PHP_53_FEATURES,
+          "This codebase targets PHP 5.2.3, but `{$name}()` was not ".
+          "introduced until PHP {$version}.");
+      } else if (array_key_exists($name, $compat_info['params'])) {
+        $params = $call->getChildOfType(1, 'n_CALL_PARAMETER_LIST');
+        foreach (array_values($params->getChildren()) as $i => $param) {
+          $version = idx($compat_info['params'][$name], $i);
+          if ($version) {
+            $this->raiseLintAtNode(
+              $param,
+              self::LINT_PHP_53_FEATURES,
+              "This codebase targets PHP 5.2.3, but parameter ".($i + 1)." ".
+              "of `{$name}()` was not introduced until PHP {$version}.");
+          }
+        }
+      }
+    }
+
+    $classes = $root->selectDescendantsOfType('n_CLASS_NAME');
+    foreach ($classes as $node) {
+      $name = strtolower($node->getConcreteString());
+      $version = idx($compat_info['interfaces'], $name);
+      $version = idx($compat_info['classes'], $name, $version);
+      if ($version) {
+        $this->raiseLintAtNode(
+          $node,
+          self::LINT_PHP_53_FEATURES,
+          "This codebase targets PHP 5.2.3, but `{$name}` was not ".
+          "introduced until PHP {$version}.");
+      }
+    }
+
   }
 
   private function lintImplicitFallthrough($root) {