Implement BindgenReportingSpec

tests/src/test/scala/org/scalanative/bindgen/BindgenReportingSpec.scala

@@ -0,0 +1,62 @@
+package org.scalanative.bindgen
+
+import java.io.{File, PrintWriter}
+
+import org.scalatest.FunSpec
+
+class BindgenReportingSpec extends FunSpec {
+  describe("Bindgen") {
+
+    val bindgenPath = System.getProperty("bindgen.path")
+
+    def writeToFile(file: File, input: String): Unit = {
+      new PrintWriter(file) {
+        try {
+          write(input)
+        } finally {
+          close()
+        }
+      }
+    }
+
+    def bindgen(input: String): Bindings = {
+      val tempFile = File.createTempFile("scala-native-bindgen-tests", ".h")
+      try {
+        writeToFile(tempFile, input)
+
+        Bindgen()
+          .bindgenExecutable(new File(bindgenPath))
+          .header(tempFile)
+          .name("BindgenTests")
+          .link("bindgentests")
+          .packageName("org.scalanative.bindgen.samples")
+          .excludePrefix("__")
+          .generate()
+
+      } finally {
+        tempFile.delete()
+      }
+    }
+
+    it("Skips functions that pass struct or union by value") {
+      val bindings =
+        bindgen(input = """struct s { int a; };
+                          |void useStruct(struct s);
+                          |typedef struct s s;
+                          |s returnStruct();
+                          |
+                          |union u { int a; };
+                          |void useUnion(union u);
+                          |typedef union u u;
+                          |u returnUnion();
+                          |""".stripMargin)
+      assert(
+        bindings.errs ==
+          """Warning: Function useStruct is skipped because Scala Native does not support passing structs and arrays by value.
+            |Warning: Function returnStruct is skipped because Scala Native does not support passing structs and arrays by value.
+            |Warning: Function useUnion is skipped because Scala Native does not support passing structs and arrays by value.
+            |Warning: Function returnUnion is skipped because Scala Native does not support passing structs and arrays by value.""".stripMargin
+      )
+    }
+  }
+}

tools/src/main/scala/org/scalanative/bindgen/Bindgen.scala

@@ -3,7 +3,7 @@ package org.scalanative.bindgen
 import java.io.File
 
 import scala.collection.immutable.Seq
-import scala.sys.process.Process
+import scala.sys.process.{Process, ProcessLogger}
 
 sealed trait Bindgen {
 
@@ -129,9 +129,13 @@ object Bindgen {
         withArgs("--extra-arg-before", extraArgBefore) ++
         Seq(header.get.getAbsolutePath, "--")
 
-      val output = Process(cmd).!!
+      var errs = Seq[String]()
 
-      new Bindings(output)
+      val output = Process(cmd).!!(ProcessLogger { err: String =>
+        errs :+= err
+      })
+
+      new Bindings(output, errs.mkString("\n"))
     }
   }
 }

tools/src/main/scala/org/scalanative/bindgen/Bindings.scala

@@ -2,7 +2,7 @@ package org.scalanative.bindgen
 
 import java.io.{File, PrintWriter}
 
-class Bindings(private val bindings: String) {
+class Bindings(private val bindings: String, val errs: String) {
   def writeToFile(file: File): Unit = {
     file.getParentFile.mkdirs()
     new PrintWriter(file) {