[DebugInfo] Use Stmt EndLoc if SILLocation passed in is the Stmt EndLoc.

When creating an ExtendedASTNodeLoc from a SILLocation, if the
SILLocation passed in belongs to a swift::Stmt, we only ever use the
Stmt's StartLoc for the SourceLocation. If the SILLocation passed in,
has a SourceLocation that matches the EndLoc of the Stmt, we should
correctly set the primary ASTNodeTy PointerUnion's integer to 1, to
denote that the SourceLocation dervied from the Stmt points to the
EndLoc.

Author: rastogishubham

lib/SIL/IR/SILLocation.cpp

@@ -290,8 +290,14 @@ RegularLocation::getDebugOnlyExtendedASTNodeLoc(SILLocation L,
     return new (Module) ExtendedASTNodeLoc(Empty, {D, 0});
   if (auto E = L.getAsASTNode<Expr>())
     return new (Module) ExtendedASTNodeLoc(Empty, {E, 0});
-  if (auto S = L.getAsASTNode<Stmt>())
+  if (auto S = L.getAsASTNode<Stmt>()) {
+    // If the source locatuon of the SILLocation passed in matches the EndLoc of
+    // the Stmt, set the primary ASTNodeTy integer to 1, therefore
+    // SILLocation::getSourceLoc returns the EndLoc when queried.
+    if (L.getSourceLocForDebugging() == S->getEndLoc())
+      Empty.setInt(1);
     return new (Module) ExtendedASTNodeLoc(Empty, {S, 0});
+  }
   auto P = L.getAsASTNode<Pattern>();
   return new (Module) ExtendedASTNodeLoc(Empty, {P, 0});
 }

test/DebugInfo/hop_to_executor.swift

@@ -0,0 +1,26 @@
+// RUN: %target-swiftc_driver %s -c -g -Onone -o - -Xllvm -sil-print-debuginfo -emit-sil -parse-as-library -module-name m |  %FileCheck %s
+
+// This test ensures that the hop_to_executor source location matches the end of the do block
+
+// CHECK: %35 = function_ref @swift_asyncLet_finish : $@convention(thin) @async (Builtin.RawPointer, Builtin.RawPointer) -> (), loc {{.*}}:19:3, scope 8
+// CHECK-NEXT: %36 = apply %35(%10, %5) : $@convention(thin) @async (Builtin.RawPointer, Builtin.RawPointer) -> (), loc{{.*}}:19:3
+// CHECK-NEXT: hop_to_executor %0, loc * {{.*}}:19:3, scope 8 
+
+
+func getTimestamp(x: Int) async -> Int {
+  return 40 + x
+}
+func work() {}
+func foo() async {
+  do {
+    work()
+    async let timestamp2 = getTimestamp(x:2)
+    print(await timestamp2)
+  }
+  work()
+}
+@main enum entry {
+  static func main() async {
+    await foo()
+  }
+}