From be53c7910a0ccfad38664b9d63f70357f6867643 Mon Sep 17 00:00:00 2001
From: Liu Fengyun <liu@fengy.me>
Date: Sun, 29 Nov 2020 23:39:23 +0100
Subject: [PATCH] Fix #9176: Handle parent call argument effects in full mode

---
 .../tools/dotc/transform/init/Checking.scala  | 28 +++++++++++--------
 .../dotty/tools/dotc/CompilationTests.scala   |  1 -
 tests/init/full/neg/global-cycle1.scala       | 10 +++++++
 tests/init/{ => full}/neg/hybrid2.scala       |  0
 tests/init/full/neg/i9176.scala               |  9 ++++++
 5 files changed, 36 insertions(+), 12 deletions(-)
 create mode 100644 tests/init/full/neg/global-cycle1.scala
 rename tests/init/{ => full}/neg/hybrid2.scala (100%)
 create mode 100644 tests/init/full/neg/i9176.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/init/Checking.scala b/compiler/src/dotty/tools/dotc/transform/init/Checking.scala
index e52a283a7702..d5287d6612f4 100644
--- a/compiler/src/dotty/tools/dotc/transform/init/Checking.scala
+++ b/compiler/src/dotty/tools/dotc/transform/init/Checking.scala
@@ -141,11 +141,14 @@ object Checking {
           checkSecondaryConstructor(ctor)
       }
 
-      (stats :+ expr).foreach { stat =>
-        val summary = Summarization.analyze(stat)(theEnv.withOwner(ctor))
+      checkStats(stats :+ expr, ctor)
+    }
+
+    def checkStats(stats: List[Tree], owner: Symbol)(using state: State): Unit =
+      stats.foreach { stat =>
+        val summary = Summarization.analyze(stat)(theEnv.withOwner(owner))
         checkEffects(summary.effs)
       }
-    }
 
     cls.paramAccessors.foreach { acc =>
       if (!acc.is(Flags.Method)) {
@@ -155,16 +158,19 @@ object Checking {
     }
 
     tpl.parents.foreach {
-      case tree @ Block(_, parent) =>
-        val (ctor, _, _) = decomposeCall(parent)
+      case tree @ Block(stats, parent) =>
+        val (ctor, _, argss) = decomposeCall(parent)
+        if theEnv.isFullMode then checkStats((stats :: argss).flatten, cls)
         checkConstructor(ctor.symbol, parent.tpe, tree)
 
-      case tree @ Apply(Block(_, parent), _) =>
-        val (ctor, _, _) = decomposeCall(parent)
+      case tree @ Apply(Block(stats, parent), args) =>
+        val (ctor, _, argss) = decomposeCall(parent)
+        if theEnv.isFullMode then checkStats((stats :: argss).flatten, cls)
         checkConstructor(ctor.symbol, tree.tpe, tree)
 
       case parent : Apply =>
         val (ctor, _, argss) = decomposeCall(parent)
+        if theEnv.isFullMode then checkStats(argss.flatten, cls)
         checkConstructor(ctor.symbol, parent.tpe, parent)
 
       case ref =>
@@ -203,13 +209,13 @@ object Checking {
         val errors = state.check(MethodCall(pot, sym)(source))
         if errors.nonEmpty then return errors
 
-      // if sym.name.isTermName && !sym.isOneOf(Flags.Method | Flags.Private) && sym.hasSource then
-      //   val errors = state.check(Promote(FieldReturn(pot, sym)(source))(source))
-      //   if errors.nonEmpty then return errors
+      if sym.name.isTermName && !sym.isOneOf(Flags.Method | Flags.Private) && sym.hasSource then
+        val errors = state.check(Promote(FieldReturn(pot, sym)(source))(source))
+        if errors.nonEmpty then return errors
     }
 
     // best-effort in fast mode
-    // if !theEnv.isFullMode then return Errors.empty
+    if !theEnv.isFullMode then return Errors.empty
 
     val excludedFlags = Flags.Deferred | Flags.Private | Flags.Protected
 
diff --git a/compiler/test/dotty/tools/dotc/CompilationTests.scala b/compiler/test/dotty/tools/dotc/CompilationTests.scala
index cb8a2347b323..9af6e664bf19 100644
--- a/compiler/test/dotty/tools/dotc/CompilationTests.scala
+++ b/compiler/test/dotty/tools/dotc/CompilationTests.scala
@@ -321,7 +321,6 @@ class CompilationTests {
     compileFilesInDir("tests/init/neg", options).checkExpectedErrors()
     compileFilesInDir("tests/init/full/neg", options).checkExpectedErrors()
     compileFilesInDir("tests/init/pos", options).checkCompile()
-    compileFilesInDir("tests/init/crash", options.without("-Xfatal-warnings")).checkCompile()
   }
 }
 
diff --git a/tests/init/full/neg/global-cycle1.scala b/tests/init/full/neg/global-cycle1.scala
new file mode 100644
index 000000000000..ebd667c51ba0
--- /dev/null
+++ b/tests/init/full/neg/global-cycle1.scala
@@ -0,0 +1,10 @@
+object A {
+  val a: Int = B.b     // error
+}
+
+object B {
+  val b: Int = A.a     // error
+}
+
+@main
+def Test = print(A.a)
\ No newline at end of file
diff --git a/tests/init/neg/hybrid2.scala b/tests/init/full/neg/hybrid2.scala
similarity index 100%
rename from tests/init/neg/hybrid2.scala
rename to tests/init/full/neg/hybrid2.scala
diff --git a/tests/init/full/neg/i9176.scala b/tests/init/full/neg/i9176.scala
new file mode 100644
index 000000000000..abb8a6394dd2
--- /dev/null
+++ b/tests/init/full/neg/i9176.scala
@@ -0,0 +1,9 @@
+class Foo(val opposite: Foo)
+case object A extends Foo(B) // error
+case object B extends Foo(A) // error
+object Test {
+  def main(args: Array[String]): Unit = {
+    println(A.opposite)
+    println(B.opposite)
+  }
+}
\ No newline at end of file