Move JDK version-dependent functions to orchard.java.compatibility

Author: alexander-yakushev

src/orchard/inspect.clj

@@ -12,6 +12,7 @@
    [clojure.core.protocols :refer [datafy nav]]
    [clojure.string :as str]
    [orchard.inspect.analytics :as analytics]
+   [orchard.java.compatibility :as compat]
    [orchard.pp :as pp]
    [orchard.print :as print])
   (:import
@@ -327,8 +328,8 @@
 ;; Rendering
 
 (defn render
-  ([{:keys [rendered] :as inspector} value]
-   (assoc inspector :rendered (conj! rendered value)))
+  ([inspector value]
+   (update inspector :rendered conj! value))
   ([inspector value & values]
    (reduce render (render inspector value) values)))
 
@@ -826,16 +827,6 @@
       (render-indent-str-lines obj)
       (unindent)))
 
-(defn- field-val [^Field f, obj]
-  (try
-    (.get f obj)
-    (catch Exception _
-      (try
-        (.setAccessible f true)
-        (.get f obj)
-        (catch Exception _
-          ::access-denied)))))
-
 (defn- shorten-member-string [member-string, ^Class class]
   ;; Ugly as hell, but easier than reimplementing all custom printing that
   ;; java.lang.reflect does.
@@ -855,8 +846,10 @@
                         res))
         all-fields (mapcat #(.getDeclaredFields ^Class %) class-chain)
         field-values (mapv (fn [^Field f]
-                             {:name (symbol (.getName f)), :value (field-val f obj)
-                              :static (Modifier/isStatic (.getModifiers f))})
+                             (let [static? (Modifier/isStatic (.getModifiers f))]
+                               {:name (symbol (.getName f))
+                                :value (compat/get-field-value f (when-not static? obj))
+                                :static static?}))
                            all-fields)
         {static-accessible        [true true]
          non-static-accessible    [false true]
@@ -865,7 +858,7 @@
         (group-by (fn [{:keys [static value]}]
                     ;; Be careful to use identical? instead of = because an
                     ;; object might not implement equiv().
-                    [static (not (identical? ::access-denied value))])
+                    [static (not (identical? ::compat/access-denied value))])
                   field-values)
         ;; This is fine like this for now. If this condp ever grows bigger,
         ;; consider refactoring it into something polymorphic.
@@ -891,7 +884,7 @@
                      (->> field-values
                           (map (fn [{:keys [name value]}]
                                  [name
-                                  (if (identical? value ::access-denied)
+                                  (if (identical? value ::compat/access-denied)
                                     ;; This is a special value that can be
                                     ;; detected client-side:
                                     (symbol "<non-inspectable value>")

src/orchard/java.clj

@@ -5,6 +5,7 @@
    [clojure.java.javadoc :as javadoc]
    [clojure.reflect :as reflect]
    [clojure.string :as str]
+   [orchard.java.compatibility :as compat]
    [orchard.java.resource :as resource]
    [orchard.java.source-files :as src-files]
    [orchard.misc :as misc]
@@ -61,21 +62,14 @@
    (when parser-next-source-info
      (parser-next-source-info klass source-url))))
 
-;; As of Java 11, Javadoc URLs begin with the module name.
-(defn module-name
-  "On JDK11+, return module name from the class if present; otherwise return nil"
-  [class-or-sym]
-  (when (>= misc/java-api-version 11)
-    ((requiring-resolve 'orchard.java.modules/module-name) class-or-sym)))
-
 (defn javadoc-url
   "Return the relative `.html` javadoc path and member fragment."
   ([class]
    (let [url (str (-> (str/replace (str class) "." "/")
                       (str/replace "$" "."))
                   ".html")
          ;; As of Java 11, Javadoc URLs begin with the module name.
-         module (module-name class)]
+         module (compat/module-name class)]
      (cond->> url
        module (format "%s/%s" module))))
   ([class member argtypes]

src/orchard/java/compatibility.clj

@@ -0,0 +1,33 @@
+(ns orchard.java.compatibility
+  "Small utilities that unify code to work between different Java versions."
+  (:require [orchard.misc :as misc])
+  (:import java.lang.reflect.Field))
+
+(defmacro ^:private module-name-macro [class-or-sym]
+  ;; On JDK8, always return nil.
+  (when (>= misc/java-api-version 11)
+    (let [klass (with-meta (gensym "klass") {:tag `Class})]
+      `(let [~klass (cond-> ~class-or-sym
+                      (symbol? ~class-or-sym) resolve)]
+         (some-> ~klass .getModule .getName)))))
+
+(defn module-name
+  "Return the module name for the class."
+  [class-or-sym]
+  (module-name-macro class-or-sym))
+
+(defmacro get-field-value-macro [field obj]
+  (if (>= misc/java-api-version 11)
+    `(try (if (or (.canAccess ~field ~obj)
+                  (.trySetAccessible ~field))
+            (.get ~field ~obj)
+            ::access-denied)
+          (catch Exception ~'_ ::access-denied))
+    ;; Fallback to deprecated try-catch based flow on JDK8.
+    `(try (when-not (.isAccessible ~field)
+            (.setAccessible ~field true))
+          (.get ~field ~obj)
+          (catch Exception ~'_ ::access-denied))))
+
+(defn get-field-value [^Field field, obj]
+  (get-field-value-macro field obj))

src/orchard/java/modules.clj

@@ -22,7 +22,7 @@
   (:require
    [clojure.java.io :as io]
    [clojure.string :as str]
-   [orchard.java.modules :as modules]
+   [orchard.java.compatibility :as compat]
    [orchard.java.source-files :as src-files]
    [orchard.misc :as misc])
   (:import
@@ -432,7 +432,7 @@
    {:pre [(class? klass)]}
    (misc/with-lock lock ;; the jdk.javadoc.doclet classes aren't meant for concurrent modification/access.
      (let [class-sym (symbol (.getName klass))
-           ^DocletEnvironment root (parse-java source-url (modules/module-name klass))]
+           ^DocletEnvironment root (parse-java source-url (compat/module-name klass))]
        (when root
          (try
            (some #(when (#{ElementKind/CLASS

src/orchard/java/parser_next.clj

@@ -5,7 +5,7 @@
    :added "0.29"}
   (:require [clojure.java.io :as io]
             [clojure.string :as str]
-            [orchard.misc :as misc])
+            [orchard.java.compatibility :as compat])
   (:import (java.io File IOException)
            (java.net URL)))
 
@@ -41,8 +41,7 @@
 (defn- class->classfile-path
   "Infer a relative path to the classfile of the given `klass`."
   [^Class klass]
-  (let [module (when (>= misc/java-api-version 11)
-                 ((requiring-resolve 'orchard.java.modules/module-name) klass))
+  (let [module (compat/module-name klass)
         classfile-name (-> (.getName klass)
                            (str/replace #"\$.*" "") ;; Drop internal class.
                            (str/replace "." "/")