[clang] Make CXXDefaultArgExpr inherit dependence from the inner Expr

Before this change, CXXDefaultArgExpr would always have
ExprDependence::None. This can lead to issues when, for example, the
inner expression is RecoveryExpr and yet containsErrors() on the default
expression is false.

Differential Revision: https://reviews.llvm.org/D103982

diff --git a/clang/include/clang/AST/ComputeDependence.h b/clang/include/clang/AST/ComputeDependence.h
index 7dde42e..8db09e6 100644 (file)
--- a/clang/include/clang/AST/ComputeDependence.h
+++ b/clang/include/clang/AST/ComputeDependence.h
@@ -71,6 +71,7 @@ class OverloadExpr;
 class DependentScopeDeclRefExpr;
 class CXXConstructExpr;
 class CXXDefaultInitExpr;
+class CXXDefaultArgExpr;
 class LambdaExpr;
 class CXXUnresolvedConstructExpr;
 class CXXDependentScopeMemberExpr;
@@ -156,6 +157,7 @@ ExprDependence computeDependence(OverloadExpr *E, bool KnownDependent,
 ExprDependence computeDependence(DependentScopeDeclRefExpr *E);
 ExprDependence computeDependence(CXXConstructExpr *E);
 ExprDependence computeDependence(CXXDefaultInitExpr *E);
+ExprDependence computeDependence(CXXDefaultArgExpr *E);
 ExprDependence computeDependence(LambdaExpr *E,
                                  bool ContainsUnexpandedParameterPack);
 ExprDependence computeDependence(CXXUnresolvedConstructExpr *E);

diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
index c46f9bd..2626f9b 100644 (file)
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -1257,7 +1257,7 @@ class CXXDefaultArgExpr final : public Expr {
              Param->getDefaultArg()->getObjectKind()),
         Param(Param), UsedContext(UsedContext) {
     CXXDefaultArgExprBits.Loc = Loc;
-    setDependence(ExprDependence::None);
+    setDependence(computeDependence(this));
   }
 
 public:

diff --git a/clang/lib/AST/ComputeDependence.cpp b/clang/lib/AST/ComputeDependence.cpp
index 1a5d2f7..5648cf2 100644 (file)
--- a/clang/lib/AST/ComputeDependence.cpp
+++ b/clang/lib/AST/ComputeDependence.cpp
@@ -748,6 +748,10 @@ ExprDependence clang::computeDependence(CXXDefaultInitExpr *E) {
   return E->getExpr()->getDependence();
 }
 
+ExprDependence clang::computeDependence(CXXDefaultArgExpr *E) {
+  return E->getExpr()->getDependence();
+}
+
 ExprDependence clang::computeDependence(LambdaExpr *E,
                                         bool ContainsUnexpandedParameterPack) {
   auto D = toExprDependence(E->getType()->getDependence());

diff --git a/clang/test/AST/ast-dump-default-arg-dep.cpp b/clang/test/AST/ast-dump-default-arg-dep.cpp
new file mode 100644 (file)
index 0000000..a804ac1
--- /dev/null
+++ b/clang/test/AST/ast-dump-default-arg-dep.cpp
@@ -0,0 +1,10 @@
+// RUN: not %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -ast-dump -frecovery-ast %s | FileCheck %s
+
+// CXXDefaultArgExpr should inherit dependence from the inner Expr, in this case
+// RecoveryExpr.
+void fun(int arg = foo());
+
+void test() {
+  fun();
+}
+// CHECK: -CXXDefaultArgExpr 0x{{[^ ]*}} <<invalid sloc>> '<dependent type>' contains-errors lvalue