scala-wasm · tanishiking · May 25, 2025 · Apr 16, 2025 · May 25, 2025
diff --git a/javalib/src/main/scala/java/lang/Character.scala b/javalib/src/main/scala/java/lang/Character.scala
@@ -128,15 +128,16 @@ object Character {
     if (!isValidCodePoint(codePoint))
       throw new IllegalArgumentException()
 
-    if (LinkingInfo.targetPureWasm) {
+    LinkingInfo.linkTimeIf (LinkingInfo.targetPureWasm) {
       if (isBmpCodePoint(codePoint)) {
         Character.toString(codePoint.toChar)
       } else {
         val dst = new Array[Char](2)
         toSurrogate(codePoint, dst, 0)
         new String(dst)
       }
-    } else if (LinkingInfo.esVersion >= ESVersion.ES2015) {
+    } {
+    if (LinkingInfo.esVersion >= ESVersion.ES2015) {
       js.Dynamic.global.String.fromCodePoint(codePoint).asInstanceOf[String]
     } else {
       if (codePoint < MIN_SUPPLEMENTARY_CODE_POINT) {
@@ -148,7 +149,7 @@ object Character {
           .fromCharCode(highSurrogate(codePoint).toInt, lowSurrogate(codePoint).toInt)
           .asInstanceOf[String]
       }
-    }
+    }}
   }
 
   // Low-level code point and code unit manipulations -------------------------
@@ -706,10 +707,10 @@ object Character {
       case _ =>
         // In WASI implementation, we cannot use String#toUpperCase
         // since it uses Character#toUpperCase.
-        if (LinkingInfo.targetPureWasm) {
+        LinkingInfo.linkTimeIf(LinkingInfo.targetPureWasm) {
           import CaseUtil._
           toCase(codePoint, a, z, lowerBeta, lowerRanges, lowerDeltas, lowerSteps)
-        } else {
+        } {
           val upperChars = toString(codePoint).toUpperCase()
           upperChars.length match {
             case 1 =>
@@ -735,12 +736,12 @@ object Character {
       case 0x0130 =>
         0x0069 // İ => i
       case _ =>
-        if (LinkingInfo.targetPureWasm) {
+        LinkingInfo.linkTimeIf(LinkingInfo.targetPureWasm) {
           // in pure Wasm implementation, we cannot use String#toLowerCase
           // since it uses Character$toLowerCase
           import CaseUtil._
           toCase(codePoint, A, Z, upperMu, upperRanges, upperDeltas, upperSteps)
-        } else {
+        } {
           val lowerChars = toString(codePoint).toLowerCase()
           lowerChars.length match {
             case 1 =>

diff --git a/javalib/src/main/scala/java/lang/Double.scala b/javalib/src/main/scala/java/lang/Double.scala
@@ -16,6 +16,7 @@ import java.lang.constant.{Constable, ConstantDesc}
 
 import scala.scalajs.js
 import scala.scalajs.LinkingInfo
+import scala.scalajs.LinkingInfo.linkTimeIf
 
 import Utils._
 
@@ -380,10 +381,11 @@ object Double {
    *  The two implementations compute the same results.
    */
   @inline def hashCode(value: scala.Double): Int = {
-    if (LinkingInfo.isWebAssembly)
+    linkTimeIf(LinkingInfo.isWebAssembly) {
       hashCodeForWasm(value)
-    else
+    } {
       hashCodeForJS(value)
+    }
   }
 
   @inline

diff --git a/javalib/src/main/scala/java/lang/Integer.scala b/javalib/src/main/scala/java/lang/Integer.scala
@@ -17,7 +17,7 @@ import java.util.function._
 
 import scala.scalajs.js
 import scala.scalajs.LinkingInfo
-import scala.scalajs.LinkingInfo.ESVersion
+import scala.scalajs.LinkingInfo.{ESVersion, linkTimeIf}
 
 /* This is a hijacked class. Its instances are primitive numbers.
  * Constructors are not emitted.
@@ -103,7 +103,7 @@ object Integer {
     if (i >= s.length)
       fail()
 
-    if (LinkingInfo.targetPureWasm) {
+    linkTimeIf(LinkingInfo.targetPureWasm) {
       val maxAbsValue: scala.Long = {
         if (!signed) 0xffffffffL
         else if (negative) 0x80000000L
@@ -123,7 +123,7 @@ object Integer {
         -result.toInt
       else
         result.toInt
-    } else {
+    } {
       val maxAbsValue: scala.Double = {
         if (!signed) 0xffffffffL.toDouble
         else if (negative) 0x80000000L.toDouble
@@ -298,29 +298,42 @@ object Integer {
 
   // Intrinsic, fallback on actual code for non-literal in JS
   @inline def numberOfLeadingZeros(i: scala.Int): scala.Int = {
-    if (LinkingInfo.esVersion >= ESVersion.ES2015) js.Math.clz32(i)
-    else clz32Dynamic(i)
+    linkTimeIf(LinkingInfo.targetPureWasm) {
+      clz32Dynamic(i)
+    } {
+      if (LinkingInfo.esVersion >= ESVersion.ES2015) js.Math.clz32(i)
+      else clz32Dynamic(i)
+    }
+
   }
 
   private def clz32Dynamic(i: scala.Int) = {
-    if (js.typeOf(js.Dynamic.global.Math.clz32) == "function") {
-      js.Math.clz32(i)
-    } else {
-      // See Hacker's Delight, Section 5-3
-      var x = i
-      if (x == 0) {
-        32
+    linkTimeIf(LinkingInfo.targetPureWasm) {
+      clz32Dynamic0(i)
+    } {
+      if (js.typeOf(js.Dynamic.global.Math.clz32) == "function") {
+        js.Math.clz32(i)
       } else {
-        var r = 1
-        if ((x & 0xffff0000) == 0) { x <<= 16; r += 16 }
-        if ((x & 0xff000000) == 0) { x <<= 8; r += 8 }
-        if ((x & 0xf0000000) == 0) { x <<= 4; r += 4 }
-        if ((x & 0xc0000000) == 0) { x <<= 2; r += 2 }
-        r + (x >> 31)
+        clz32Dynamic0(i)
       }
     }
   }
 
+  @inline private def clz32Dynamic0(i: scala.Int) = {
+    // See Hacker's Delight, Section 5-3
+    var x = i
+    if (x == 0) {
+      32
+    } else {
+      var r = 1
+      if ((x & 0xffff0000) == 0) { x <<= 16; r += 16 }
+      if ((x & 0xff000000) == 0) { x <<= 8; r += 8 }
+      if ((x & 0xf0000000) == 0) { x <<= 4; r += 4 }
+      if ((x & 0xc0000000) == 0) { x <<= 2; r += 2 }
+      r + (x >> 31)
+    }
+  }
+
   // Wasm intrinsic
   @inline def numberOfTrailingZeros(i: scala.Int): scala.Int =
     if (i == 0) 32

diff --git a/javalib/src/main/scala/java/lang/Math.scala b/javalib/src/main/scala/java/lang/Math.scala
@@ -17,7 +17,7 @@ import scala.scalajs.js
 import js.Dynamic.{ global => g }
 
 import scala.scalajs.LinkingInfo
-import scala.scalajs.LinkingInfo.ESVersion
+import scala.scalajs.LinkingInfo.{ESVersion, linkTimeIf}
 
 object Math {
   final val E  = 2.718281828459045
@@ -30,8 +30,19 @@ object Math {
   @inline def abs(a: scala.Long): scala.Long = if (a < 0) -a else a
 
   // Wasm intrinsics
-  @inline def abs(a: scala.Float): scala.Float = js.Math.abs(a).toFloat
-  @inline def abs(a: scala.Double): scala.Double = js.Math.abs(a)
+  @inline def abs(a: scala.Float): scala.Float =
+    linkTimeIf(LinkingInfo.targetPureWasm) {
+      Float.intBitsToFloat(Float.floatToIntBits(a) & ~Int.MinValue)
+    } {
+      js.Math.abs(a).toFloat
+    }
+
+  @inline def abs(a: scala.Double): scala.Double =
+    linkTimeIf(LinkingInfo.targetPureWasm) {
+      Double.longBitsToDouble(Double.doubleToLongBits(a) & ~scala.Long.MinValue)
+    } {
+      js.Math.abs(a)
+    }
 
   @inline def max(a: scala.Int, b: scala.Int): scala.Int = if (a > b) a else b
   @inline def max(a: scala.Long, b: scala.Long): scala.Long = if (a > b) a else b
@@ -154,8 +165,11 @@ object Math {
   @inline def atan2(y: scala.Double, x: scala.Double): scala.Double = js.Math.atan2(y, x)
 
   @inline def random(): scala.Double =
-    if (LinkingInfo.targetPureWasm) WasmSystem.random()
-    else js.Math.random()
+    linkTimeIf(LinkingInfo.targetPureWasm) {
+      WasmSystem.random()
+    } {
+      js.Math.random()
+    }
 
   @inline def toDegrees(a: scala.Double): scala.Double = a * 180.0 / PI
   @inline def toRadians(a: scala.Double): scala.Double = a / 180.0 * PI

diff --git a/javalib/src/main/scala/java/lang/System.scala b/javalib/src/main/scala/java/lang/System.scala
@@ -68,8 +68,11 @@ object System {
 
   @inline
   def currentTimeMillis(): scala.Long =
-    if (LinkingInfo.targetPureWasm) WasmSystem.currentTimeMillis()
-    else js.Date.now().toLong
+    LinkingInfo.linkTimeIf(LinkingInfo.targetPureWasm) {
+      WasmSystem.currentTimeMillis()
+    } {
+      js.Date.now().toLong
+    }
 
   private object NanoTime {
     val getHighPrecisionTime: js.Function0[scala.Double] = {
@@ -91,8 +94,11 @@ object System {
 
   @inline
   def nanoTime(): scala.Long =
-    if (LinkingInfo.targetPureWasm) WasmSystem.nanoTime()
-    else (NanoTime.getHighPrecisionTime() * 1000000).toLong
+    LinkingInfo.linkTimeIf(LinkingInfo.targetPureWasm) {
+      WasmSystem.nanoTime()
+    } {
+      (NanoTime.getHighPrecisionTime() * 1000000).toLong
+    }
 
   // arraycopy ----------------------------------------------------------------
 
@@ -385,9 +391,9 @@ private final class JSConsoleBasedPrintStream(isErr: scala.Boolean)
   override def close(): Unit = ()
 
   private def doWriteLine(line: String): Unit = {
-    if (LinkingInfo.targetPureWasm) {
+    LinkingInfo.linkTimeIf (LinkingInfo.targetPureWasm) {
       WasmSystem.print(line)
-    } else {
+    } {
       import js.DynamicImplicits.truthValue
 
       if (js.typeOf(global.console) != "undefined") {

diff --git a/javalib/src/main/scala/java/lang/Throwables.scala b/javalib/src/main/scala/java/lang/Throwables.scala
@@ -35,7 +35,7 @@ class Throwable protected (s: String, private var e: Throwable,
    */
   private[this] var suppressed: Array[Throwable] = _
 
-  if (writableStackTrace && !LinkingInfo.targetPureWasm)
+  if (writableStackTrace)
     fillInStackTrace()
 
   def initCause(cause: Throwable): Throwable = {
@@ -48,30 +48,41 @@ class Throwable protected (s: String, private var e: Throwable,
   def getLocalizedMessage(): String = getMessage()
 
   def fillInStackTrace(): Throwable = {
-    if (!LinkingInfo.targetPureWasm) jsErrorForStackTrace = StackTrace.captureJSError(this)
-    this
+    LinkingInfo.linkTimeIf(!LinkingInfo.targetPureWasm) {
+      jsErrorForStackTrace = StackTrace.captureJSError(this)
+      this
+    } {
+      this
+    }
   }
 
   def getStackTrace(): Array[StackTraceElement] = {
     if (stackTrace eq null) {
-      if (!LinkingInfo.targetPureWasm && writableStackTrace)
-        stackTrace = StackTrace.extract(jsErrorForStackTrace)
-      else
+      LinkingInfo.linkTimeIf(LinkingInfo.targetPureWasm) {
         stackTrace = new Array[StackTraceElement](0)
+      } {
+        if (writableStackTrace)
+          stackTrace = StackTrace.extract(jsErrorForStackTrace)
+        else
+          stackTrace = new Array[StackTraceElement](0)
+      }
     }
     stackTrace
   }
 
   def setStackTrace(stackTrace: Array[StackTraceElement]): Unit = {
-    if (writableStackTrace && !LinkingInfo.targetPureWasm) {
-      var i = 0
-      while (i < stackTrace.length) {
-        if (stackTrace(i) eq null)
-          throw new NullPointerException()
-        i += 1
-      }
+    LinkingInfo.linkTimeIf(!LinkingInfo.targetPureWasm) {
+      if (writableStackTrace) {
+        var i = 0
+        while (i < stackTrace.length) {
+          if (stackTrace(i) eq null)
+            throw new NullPointerException()
+          i += 1
+        }
 
-      this.stackTrace = stackTrace.clone()
+        this.stackTrace = stackTrace.clone()
+      }
+    } {
     }
   }