Swift SIL: add the possibility to pass a custom location to Builder initializers.

And add the static property `Location.autoGeneratedLocation`

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/PassManager/PassContext.swift

@@ -157,20 +157,31 @@ extension Builder {
     self.init(insertAt: .before(insPnt), location: insPnt.location, passContext: context._bridged)
   }
 
-  /// Creates a builder which inserts _after_ `insPnt`, using the location of `insPnt`.
-  init(after insPnt: Instruction, _ context: PassContext) {
+  /// Creates a builder which inserts _after_ `insPnt`, using a custom `location`.
+  init(after insPnt: Instruction, location: Location, _ context: PassContext) {
     if let nextInst = insPnt.next {
-      self.init(insertAt: .before(nextInst), location: insPnt.location, passContext: context._bridged)
+      self.init(insertAt: .before(nextInst), location: location, passContext: context._bridged)
     } else {
-      self.init(insertAt: .atEndOf(insPnt.block), location: insPnt.location, passContext: context._bridged)
+      self.init(insertAt: .atEndOf(insPnt.block), location: location, passContext: context._bridged)
     }
   }
 
+  /// Creates a builder which inserts _after_ `insPnt`, using the location of `insPnt`.
+  init(after insPnt: Instruction, _ context: PassContext) {
+    self.init(after: insPnt, location: insPnt.location, context)
+  }
+
   /// Creates a builder which inserts at the end of `block`, using a custom `location`.
   init(atEndOf block: BasicBlock, location: Location, _ context: PassContext) {
     self.init(insertAt: .atEndOf(block), location: location, passContext: context._bridged)
   }
 
+  /// Creates a builder which inserts at the begin of `block`, using a custom `location`.
+  init(atBeginOf block: BasicBlock, location: Location, _ context: PassContext) {
+    let firstInst = block.instructions.first!
+    self.init(insertAt: .before(firstInst), location: location, passContext: context._bridged)
+  }
+
   /// Creates a builder which inserts at the begin of `block`, using the location of the first
   /// instruction of `block`.
   init(atBeginOf block: BasicBlock, _ context: PassContext) {

SwiftCompilerSources/Sources/SIL/Location.swift

@@ -14,4 +14,8 @@ import SILBridging
 
 public struct Location {
   let bridged: BridgedLocation
+  
+  public static var autoGeneratedLocation: Location {
+    Location(bridged: SILLocation_getAutogeneratedLocation())
+  }
 }

include/swift/SIL/SILBridging.h

@@ -334,6 +334,8 @@ SwiftInt SILType_getCaseIdxOfEnumType(BridgedType type,
 
 BridgedSubstitutionMap SubstitutionMap_getEmpty();
 
+BridgedLocation SILLocation_getAutogeneratedLocation();
+
 BridgedBasicBlock SILArgument_getParent(BridgedArgument argument);
 SwiftInt SILArgument_isExclusiveIndirectParameter(BridgedArgument argument);
 

lib/SIL/Utils/SILBridging.cpp

@@ -529,6 +529,15 @@ BridgedSubstitutionMap SubstitutionMap_getEmpty() {
   return {SubstitutionMap().getOpaqueValue()};
 }
 
+//===----------------------------------------------------------------------===//
+//                                SILLocation
+//===----------------------------------------------------------------------===//
+
+BridgedLocation SILLocation_getAutogeneratedLocation() {
+  SILDebugLocation loc;
+  return *reinterpret_cast<BridgedLocation *>(&loc);
+}
+
 //===----------------------------------------------------------------------===//
 //                            SILGlobalVariable
 //===----------------------------------------------------------------------===//