Merge pull request scala#3894 from adriaanm/depmsg

Better error message than 'bad symbolic reference'.

src/reflect/scala/reflect/internal/pickling/UnPickler.scala

@@ -254,12 +254,13 @@ abstract class UnPickler {
               // (4) Call the mirror's "missing" hook.
               adjust(mirrorThatLoaded(owner).missingHook(owner, name)) orElse {
                 // (5) Create a stub symbol to defer hard failure a little longer.
-                val fullName = s"${owner.fullName}.$name"
+                val advice = moduleAdvice(s"${owner.fullName}.$name")
                 val missingMessage =
-                  s"""|bad symbolic reference to $fullName encountered in class file '$filename'.
-                      |Cannot access ${name.longString} in ${owner.kindString} ${owner.fullName}. The current classpath may be
-                      |missing a definition for $fullName, or $filename may have been compiled against a version that's
-                      |incompatible with the one found on the current classpath.${moduleAdvice(fullName)}""".stripMargin
+                  s"""|missing or invalid dependency detected while loading class file '$filename'.
+                      |Could not access ${name.longString} in ${owner.kindString} ${owner.fullName},
+                      |because it (or its dependencies) are missing. Check your build definition for
+                      |missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
+                      |A full rebuild may help if '$filename' was compiled against an incompatible version of ${owner.fullName}.$advice""".stripMargin
                 owner.newStubSymbol(name, missingMessage)
               }
             }

test/files/neg/t5148.check

@@ -1,5 +1,6 @@
-error: bad symbolic reference to scala.tools.nsc.interpreter.IMain.Request encountered in class file 'Imports.class'.
-Cannot access type Request in class scala.tools.nsc.interpreter.IMain. The current classpath may be
-missing a definition for scala.tools.nsc.interpreter.IMain.Request, or Imports.class may have been compiled against a version that's
-incompatible with the one found on the current classpath.
+error: missing or invalid dependency detected while loading class file 'Imports.class'.
+Could not access type Request in class scala.tools.nsc.interpreter.IMain,
+because it (or its dependencies) are missing. Check your build definition for
+missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
+A full rebuild may help if 'Imports.class' was compiled against an incompatible version of scala.tools.nsc.interpreter.IMain.
 one error found

test/files/run/t6440.check

@@ -1,4 +1,5 @@
-pos: source-newSource1.scala,line-9,offset=109 bad symbolic reference to <root>.pack1 encountered in class file 'U.class'.
-Cannot access term pack1 in package <root>. The current classpath may be
-missing a definition for <root>.pack1, or U.class may have been compiled against a version that's
-incompatible with the one found on the current classpath. ERROR
+pos: source-newSource1.scala,line-9,offset=109 missing or invalid dependency detected while loading class file 'U.class'.
+Could not access term pack1 in package <root>,
+because it (or its dependencies) are missing. Check your build definition for
+missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
+A full rebuild may help if 'U.class' was compiled against an incompatible version of <root>. ERROR

test/files/run/t6440b.check

@@ -1,4 +1,5 @@
-pos: NoPosition bad symbolic reference to pack1.T encountered in class file 'U.class'.
-Cannot access type T in package pack1. The current classpath may be
-missing a definition for pack1.T, or U.class may have been compiled against a version that's
-incompatible with the one found on the current classpath. ERROR
+pos: NoPosition missing or invalid dependency detected while loading class file 'U.class'.
+Could not access type T in package pack1,
+because it (or its dependencies) are missing. Check your build definition for
+missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
+A full rebuild may help if 'U.class' was compiled against an incompatible version of pack1. ERROR

test/files/run/typetags_without_scala_reflect_typetag_lookup.scala

@@ -36,8 +36,8 @@ object Test extends StoreReporterDirectTest {
     println(filteredInfos.mkString("\n"))
     storeReporter.infos.clear()
     compileApp();
-    // we should get bad symbolic reference errors, because we're trying to use an implicit that can't be unpickled
+    // we should get "missing or invalid dependency detected" errors, because we're trying to use an implicit that can't be unpickled
     // but we don't know the number of these errors and their order, so I just ignore them all
-    println(filteredInfos.filterNot(_.msg.contains("bad symbolic reference")).mkString("\n"))
+    println(filteredInfos.filterNot(_.msg.contains("missing or invalid dependency detected")).mkString("\n"))
   }
 }

test/files/run/typetags_without_scala_reflect_typetag_manifest_interop.scala

@@ -40,8 +40,8 @@ object Test extends StoreReporterDirectTest {
     println(filteredInfos.mkString("\n"))
     storeReporter.infos.clear()
     compileApp();
-    // we should get bad symbolic reference errors, because we're trying to use an implicit that can't be unpickled
+    // we should get "missing or invalid dependency detected" errors, because we're trying to use an implicit that can't be unpickled
     // but we don't know the number of these errors and their order, so I just ignore them all
-    println(filteredInfos.filterNot (_.msg.contains("bad symbolic reference")).mkString("\n"))
+    println(filteredInfos.filterNot (_.msg.contains("missing or invalid dependency detected")).mkString("\n"))
   }
 }