Deprecate implicit .U() and .S() syntax for literal bit extracts (backport #2534) (#2559)

* Deprecate .U() and .S() syntax for literal bit extracts (#2534)

(cherry picked from commit cadaf33a650ef898fdab2f81244e4ad6a07a9ea8)

# Conflicts:
#	macros/src/main/scala/chisel3/internal/sourceinfo/SourceInfoTransform.scala

* Fix backport conflict (#2560)

Co-authored-by: Jared Barocsi <82000041+jared-barocsi@users.noreply.github.com>

2 files changed, 18 insertions, 12 deletions

diff --git a/core/src/main/scala/chisel3/Bits.scala b/core/src/main/scala/chisel3/Bits.scala
index a135a8e5..c914e88c 100644
--- a/core/src/main/scala/chisel3/Bits.scala
+++ b/core/src/main/scala/chisel3/Bits.scala
@@ -8,7 +8,13 @@ import chisel3.experimental.{FixedPoint, Interval}
 import chisel3.internal._
 import chisel3.internal.Builder.pushOp
 import chisel3.internal.firrtl._
-import chisel3.internal.sourceinfo.{SourceInfo, SourceInfoTransform, SourceInfoWhiteboxTransform, UIntTransform}
+import chisel3.internal.sourceinfo.{
+  IntLiteralApplyTransform,
+  SourceInfo,
+  SourceInfoTransform,
+  SourceInfoWhiteboxTransform,
+  UIntTransform
+}
 import chisel3.internal.firrtl.PrimOp._
 import _root_.firrtl.{ir => firrtlir}
 import _root_.firrtl.{constraint => firrtlconstraint}
@@ -94,7 +100,7 @@ sealed abstract class Bits(private[chisel3] val width: Width) extends Element wi
     * @param x an index
     * @return the specified bit
     */
-  final def apply(x: BigInt): Bool = macro SourceInfoTransform.xArg
+  final def apply(x: BigInt): Bool = macro IntLiteralApplyTransform.safeApply
 
   /** @group SourceInfoTransformMacro */
   final def do_apply(x: BigInt)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): Bool = {
@@ -121,12 +127,12 @@ sealed abstract class Bits(private[chisel3] val width: Width) extends Element wi
     *
     * @param x an index
     * @return the specified bit
-    * @note convenience method allowing direct use of [[scala.Int]] without implicits
     */
-  final def apply(x: Int): Bool = macro SourceInfoTransform.xArg
+  final def apply(x: Int): Bool = macro IntLiteralApplyTransform.safeApply
 
   /** @group SourceInfoTransformMacro */
-  final def do_apply(x: Int)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): Bool = apply(BigInt(x))
+  final def do_apply(x: Int)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): Bool =
+    do_apply(BigInt(x))
 
   /** Returns the specified bit on this wire as a [[Bool]], dynamically addressed.
     *
@@ -193,7 +199,7 @@ sealed abstract class Bits(private[chisel3] val width: Width) extends Element wi
 
   /** @group SourceInfoTransformMacro */
   final def do_apply(x: BigInt, y: BigInt)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): UInt =
-    apply(castToInt(x, "High index"), castToInt(y, "Low index"))
+    do_apply(castToInt(x, "High index"), castToInt(y, "Low index"))
 
   private[chisel3] def unop[T <: Data](sourceInfo: SourceInfo, dest: T, op: PrimOp): T = {
     requireIsHardware(this, "bits operated on")
diff --git a/core/src/main/scala/chisel3/package.scala b/core/src/main/scala/chisel3/package.scala
index 5521c51e..87024683 100644
--- a/core/src/main/scala/chisel3/package.scala
+++ b/core/src/main/scala/chisel3/package.scala
@@ -7,6 +7,8 @@ import scala.collection.mutable
 /** This package contains the main chisel3 API.
   */
 package object chisel3 {
+  import internal.chiselRuntimeDeprecated
+  import internal.sourceinfo.DeprecatedSourceInfo
   import internal.firrtl.{Port, Width}
   import internal.Builder
 
@@ -39,13 +41,11 @@ package object chisel3 {
       case bigint                => Builder.error(s"Cannot convert $bigint to Bool, must be 0 or 1"); Bool.Lit(false)
     }
 
-    /** Int to UInt conversion, recommended style for constants.
-      */
-    def U: UInt = UInt.Lit(bigint, Width())
+    /** Int to UInt conversion, recommended style for constants. */
+    def U: UInt = UInt.Lit(bigint, Width()) // scalastyle:ignore method.name
 
-    /** Int to SInt conversion, recommended style for constants.
-      */
-    def S: SInt = SInt.Lit(bigint, Width())
+    /** Int to SInt conversion, recommended style for constants. */
+    def S: SInt = SInt.Lit(bigint, Width()) // scalastyle:ignore method.name
 
     /** Int to UInt conversion with specified width, recommended style for constants.
       */