Merge pull request #31873 from nathawes/default-arg-location-sourceloc-5.3

[5.3][AST] Restore getSourceRange() on DefaultArgumentExpr

Author: tkremenek

include/swift/AST/Expr.h

@@ -4214,9 +4214,7 @@ class DefaultArgumentExpr final : public Expr {
       DefaultArgsOwner(defaultArgsOwner), ParamIndex(paramIndex), Loc(loc),
       ContextOrCallerSideExpr(dc) { }
 
-  SourceRange getSourceRange() const { return {}; }
-
-  SourceLoc getArgumentListLoc() const { return Loc; }
+  SourceRange getSourceRange() const { return Loc; }
 
   ConcreteDeclRef getDefaultArgsOwner() const {
     return DefaultArgsOwner;

lib/AST/Expr.cpp

@@ -1272,6 +1272,10 @@ SourceRange TupleExpr::getSourceRange() const {
     } else {
       // Scan backwards for a valid source loc.
       for (Expr *expr : llvm::reverse(getElements())) {
+        // Default arguments are located at the start of their parent tuple, so
+        // skip over them.
+        if (isa<DefaultArgumentExpr>(expr))
+          continue;
         end = expr->getEndLoc();
         if (end.isValid()) {
           break;

lib/Sema/TypeCheckExpr.cpp

@@ -789,7 +789,7 @@ Expr *CallerSideDefaultArgExprRequest::evaluate(
 
   // Re-create the default argument using the location info of the call site.
   auto *initExpr =
-      synthesizeCallerSideDefault(param, defaultExpr->getArgumentListLoc());
+      synthesizeCallerSideDefault(param, defaultExpr->getLoc());
   auto *dc = defaultExpr->ContextOrCallerSideExpr.get<DeclContext *>();
   assert(dc && "Expected a DeclContext before type-checking caller-side arg");
 

test/DebugInfo/callexpr.swift

@@ -1,4 +1,5 @@
 // RUN: %target-swift-frontend %s -g -emit-ir -o - | %FileCheck %s
+// RUN: %target-swift-frontend %s -g -emit-ir -o - | %FileCheck --check-prefix=CHECK2 %s
 
 func markUsed<T>(_ t: T) {}
 
@@ -15,3 +16,11 @@ let r = foo(
            )            // CHECK: ![[OUTER]] = !DILocation(line: [[@LINE-3]],
 markUsed(r)
 
+struct MyType {}
+func bar(x: MyType = MyType()) {}
+
+// CHECK2: call {{.*}}MyType{{.*}}, !dbg ![[DEFAULTARG:.*]]
+// CHECK2: call {{.*}}bar{{.*}}, !dbg ![[BARCALL:.*]]
+bar() // CHECK2: ![[DEFAULTARG]] = !DILocation(line: [[@LINE]], column: 4
+      // CHECK2: ![[BARCALL]] = !DILocation(line: [[@LINE-1]], column: 1
+