Make all numeric coercions explicit.

Optimistically, this is preparation for a day when we don't
let numeric types drift with the winds. Even without the optimism
it's a good idea. It flushed out an undocumented change in
the math package object relative to the methods being forwarded (a
type is widened from what is returned in java) so I documented
the intentionality of it.

Managing type coercions manually is a bit tedious, no doubt,
but it's not tedious enough to warrant abandoning type safety
just because java did it.

7 files changed, 14 insertions, 11 deletions

diff --git a/src/reflect/scala/reflect/internal/Constants.scala b/src/reflect/scala/reflect/internal/Constants.scala
index aa95db546f..511b39b8c6 100644
--- a/src/reflect/scala/reflect/internal/Constants.scala
+++ b/src/reflect/scala/reflect/internal/Constants.scala
@@ -212,7 +212,7 @@ trait Constants extends api.Constants {
       case '"'  => "\\\""
       case '\'' => "\\\'"
       case '\\' => "\\\\"
-      case _    => if (ch.isControl) "\\0" + toOctalString(ch) else String.valueOf(ch)
+      case _    => if (ch.isControl) "\\0" + toOctalString(ch.toInt) else String.valueOf(ch)
     }
 
     def escapedStringValue: String = {
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 1db9c5c78f..f3cea1fd00 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -269,7 +269,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       val newName  = nme.moduleVarName(accessor.name.toTermName)
       val newFlags = MODULEVAR | ( if (this.isClass) PrivateLocal | SYNTHETIC else 0 )
       val newInfo  = accessor.tpe.finalResultType
-      val mval     = newVariable(newName, accessor.pos.focus, newFlags) addAnnotation VolatileAttr
+      val mval     = newVariable(newName, accessor.pos.focus, newFlags.toLong) addAnnotation VolatileAttr
 
       if (this.isClass)
         mval setInfoAndEnter newInfo
@@ -627,6 +627,8 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       if (!isCompilerUniverse && needsInitialize(isFlagRelated = true, mask = mask)) initialize
       (flags & mask) != 0
     }
+    def hasFlag(mask: Int): Boolean = hasFlag(mask.toLong)
+
     /** Does symbol have ALL the flags in `mask` set? */
     final def hasAllFlags(mask: Long): Boolean = {
       if (!isCompilerUniverse && needsInitialize(isFlagRelated = true, mask = mask)) initialize
@@ -2967,7 +2969,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     // a type symbol bound by an existential type, for instance the T in
     // List[T] forSome { type T }
     override def isExistentialSkolem = this hasFlag EXISTENTIAL
-    override def isGADTSkolem        = this hasAllFlags GADT_SKOLEM_FLAGS
+    override def isGADTSkolem        = this hasAllFlags GADT_SKOLEM_FLAGS.toLong
     override def isTypeSkolem        = this hasFlag PARAM
     override def isAbstractType      = this hasFlag DEFERRED
 
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala
index de0b4e8247..833adb99c7 100644
--- a/src/reflect/scala/reflect/internal/Trees.scala
+++ b/src/reflect/scala/reflect/internal/Trees.scala
@@ -944,6 +944,7 @@ trait Trees extends api.Trees { self: SymbolTable =>
       if (flags1 == flags) this
       else Modifiers(flags1, privateWithin, annotations) setPositions positions
     }
+    def | (flag: Int): Modifiers = this | flag.toLong
     def | (flag: Long): Modifiers = {
       val flags1 = flags | flag
       if (flags1 == flags) this
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index 09cd5d591f..00a929003e 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -961,7 +961,7 @@ trait Types
       var sym: Symbol = NoSymbol
       var e: ScopeEntry = decls.lookupEntry(name)
       while (e ne null) {
-        if (!e.sym.hasFlag(excludedFlags)) {
+        if (!e.sym.hasFlag(excludedFlags.toLong)) {
           if (sym == NoSymbol) sym = e.sym
           else {
             if (alts.isEmpty) alts = sym :: Nil
diff --git a/src/reflect/scala/reflect/internal/pickling/ByteCodecs.scala b/src/reflect/scala/reflect/internal/pickling/ByteCodecs.scala
index 18d7e05c4c..eb266e8125 100644
--- a/src/reflect/scala/reflect/internal/pickling/ByteCodecs.scala
+++ b/src/reflect/scala/reflect/internal/pickling/ByteCodecs.scala
@@ -128,7 +128,7 @@ object ByteCodecs {
     var j = 0
     val dstlen = (srclen * 7 + 7) / 8
     while (i + 7 < srclen) {
-      var out: Int = src(i)
+      var out: Int = src(i).toInt
       var in: Byte = src(i + 1)
       src(j) = (out | (in & 0x01) << 7).toByte
       out = in >>> 1
@@ -153,7 +153,7 @@ object ByteCodecs {
       j += 7
     }
     if (i < srclen) {
-      var out: Int = src(i)
+      var out: Int = src(i).toInt
       if (i + 1 < srclen) {
         var in: Byte = src(i + 1)
         src(j) = (out | (in & 0x01) << 7).toByte; j += 1
diff --git a/src/reflect/scala/reflect/internal/pickling/PickleBuffer.scala b/src/reflect/scala/reflect/internal/pickling/PickleBuffer.scala
index c953b5df22..a814256f8e 100644
--- a/src/reflect/scala/reflect/internal/pickling/PickleBuffer.scala
+++ b/src/reflect/scala/reflect/internal/pickling/PickleBuffer.scala
@@ -94,7 +94,7 @@ class PickleBuffer(data: Array[Byte], from: Int, to: Int) {
 
   /** Read a byte */
   def readByte(): Int = {
-    val x = bytes(readIndex); readIndex += 1; x
+    val x = bytes(readIndex).toInt; readIndex += 1; x
   }
 
   /** Read a natural number in big endian format, base 128.
@@ -105,7 +105,7 @@ class PickleBuffer(data: Array[Byte], from: Int, to: Int) {
     var b = 0L
     var x = 0L
     do {
-      b = readByte()
+      b = readByte().toLong
       x = (x << 7) + (b & 0x7f)
     } while ((b & 0x80) != 0L)
     x
diff --git a/src/reflect/scala/reflect/internal/util/Statistics.scala b/src/reflect/scala/reflect/internal/util/Statistics.scala
index 9c19159657..b583137059 100644
--- a/src/reflect/scala/reflect/internal/util/Statistics.scala
+++ b/src/reflect/scala/reflect/internal/util/Statistics.scala
@@ -103,8 +103,8 @@ quant)
     for ((_, q) <- qs if q.underlying == q;
          r <- q :: q.children.toList if r.prefix.nonEmpty) yield r
 
-  private def showPercent(x: Double, base: Double) =
-    if (base == 0) "" else f" (${x / base * 100}%2.1f%%)"
+  private def showPercent(x: Long, base: Long) =
+    if (base == 0) "" else f" (${x.toDouble / base.toDouble * 100}%2.1f%%)"
 
   /** The base trait for quantities.
    *  Quantities with non-empty prefix are printed in the statistics info.
@@ -156,7 +156,7 @@ quant)
       value = value0 + underlying.value - uvalue0
     }
     override def toString =
-      value + showPercent(value, underlying.value)
+      value + showPercent(value.toLong, underlying.value.toLong)
   }
 
   class Timer(val prefix: String, val phases: Seq[String]) extends Quantity {