compile-clj - add stream control args for compilation so out and err can be captured

Author: puredanger

CHANGELOG.md

@@ -2,6 +2,7 @@ Changelog
 ===========
 
 * next
+  * compile-clj - add stream control args for compilation so out and err can be captured
   * java-command - remove assert that :basis is required (that is no longer true)
 * v0.10.5 2a21b7a on July 12, 2024
   * compile-clj - fix ordering of namespaces not included in topo sort

src/main/clojure/clojure/tools/build/api.clj

@@ -307,8 +307,14 @@
                      :auto (default) - use only if os=windows && Java >= 9 && command length >= 8k
                      :always - always write classpath to temp file and include
                      :never - never write classpath to temp file (pass on command line)
+    :out - one of :inherit :capture :write :append :ignore
+    :err - one of :inherit :capture :write :append :ignore
+    :out-file - file path to write if :out is :write or :append
+    :err-file - file path to write if :err is :write or :append
 
-  Returns nil."
+  Returns nil, or if needed a map with keys:
+    :out captured-out
+    :err captured-err"
   [params]
   (assert-required "compile-clj" params [:basis :class-dir])
   (assert-specs "compile-clj" params

src/main/clojure/clojure/tools/build/tasks/compile_clj.clj

@@ -96,19 +96,25 @@
 
         ;; java-command will run in context of *project-dir* - basis, classpaths, etc
         ;; should all be relative to that (or absolute like working-compile-dir)
-        process-args (process/java-command (merge
-                                             (select-keys params [:java-cmd :java-opts :use-cp-file])
-                                             {:cp [(.getPath working-compile-dir) class-dir]
-                                              :basis basis
-                                              :main 'clojure.main
-                                              :main-args [(.getCanonicalPath compile-script)]}))
+        process-args (merge
+                       (process/java-command
+                         (merge
+                           (select-keys params [:java-cmd :java-opts :use-cp-file])
+                           {:cp [(.getPath working-compile-dir) class-dir]
+                            :basis basis
+                            :main 'clojure.main
+                            :main-args [(.getCanonicalPath compile-script)]}))
+                       (select-keys params [:out :err :out-file :err-file]))
         _ (spit (jio/file working-dir "compile.args") (str/join " " (:command-args process-args)))
-        exit (:exit (process/process process-args))]
+        {exit :exit, ps-out :out, ps-err :err} (process/process process-args)]
     (if (zero? exit)
       (do
         (if (seq filter-nses)
           (file/copy-contents working-compile-dir compile-dir-file (map ns->path filter-nses))
           (file/copy-contents working-compile-dir compile-dir-file))
         ;; only delete on success, otherwise leave the evidence!
-        (file/delete working-dir))
+        (file/delete working-dir)
+        (cond-> nil
+          ps-out (assoc :out ps-out)
+          ps-err (assoc :err ps-err)))
       (throw (ex-info (str "Clojure compilation failed, working dir preserved: " (.toString working-dir)) {})))))

src/test/clojure/clojure/tools/build/tasks/test_compile_clj.clj

@@ -83,6 +83,27 @@
       (api/compile-clj (assoc compile-params :bindings {#'clojure.core/*assert* false})) ;; turn off asserts
       (is (= {:exit 0, :out (str "100" (System/lineSeparator))} (invoke))))))
 
+(deftest test-capture-reflection
+  (with-test-dir "test-data/reflecting"
+    (api/set-project-root! (.getAbsolutePath *test-dir*))
+    (let [basis (api/create-basis nil)
+          compile-params {:class-dir "target/classes"
+                          :src-dirs ["src"]
+                          :basis basis
+                          :ns-compile ['foo.bar]}]
+
+      ;; by default, reflection does not warn
+      (is (nil? (api/compile-clj compile-params))) ;; no :bindings set
+
+      ;; compile with reflection warnings and capture the error output
+      (api/delete {:path "target/classes"})
+      (is (str/starts-with?
+            (:err
+              (api/compile-clj (merge compile-params
+                                 {:bindings {#'clojure.core/*warn-on-reflection* true}
+                                  :err :capture})))
+            "Reflection warning")))))
+
 (deftest test-accidental-basis-delay
   (with-test-dir "test-data/p1"
     (api/set-project-root! (.getAbsolutePath *test-dir*))

test-data/reflecting/deps.edn

@@ -0,0 +1,4 @@
+{:paths ["src"]
+ :deps
+ {org.clojure/clojure {:mvn/version "1.12.0"}}
+}

test-data/reflecting/src/foo/bar.clj

@@ -0,0 +1,7 @@
+(ns foo.bar
+  (:gen-class))
+
+(defn foo [s] (.length s))
+
+(defn -main [& args]
+  (println (foo "abc")))