From: John McCall <rjmccall@apple.com>
Date: Fri, 11 Dec 2015 01:56:36 +0000 (+0000)
Subject: Correctly type-check the default arguments of local functions
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=40ef2b7531472c41212c4719a9294aeb7bddebbc;p=clang

Correctly type-check the default arguments of local functions
when eagerly instantiating them.

rdar://23721638

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@255325 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 3a3f6323d4..ac99a25470 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1680,8 +1680,11 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
       Sema::ContextRAII SavedContext(*this, OwningFunc);
       LocalInstantiationScope Local(*this);
       ExprResult NewArg = SubstExpr(Arg, TemplateArgs);
-      if (NewArg.isUsable())
-        NewParm->setDefaultArg(NewArg.get());
+      if (NewArg.isUsable()) {
+        // It would be nice if we still had this.
+        SourceLocation EqualLoc = NewArg.get()->getLocStart();
+        SetParamDefaultArgument(NewParm, NewArg.get(), EqualLoc);
+      }
     } else {
       // FIXME: if we non-lazily instantiated non-dependent default args for
       // non-dependent parameter types we could remove a bunch of duplicate
diff --git a/test/SemaTemplate/instantiate-local-class.cpp b/test/SemaTemplate/instantiate-local-class.cpp
index c0ea6a0bc8..a61af7a5af 100644
--- a/test/SemaTemplate/instantiate-local-class.cpp
+++ b/test/SemaTemplate/instantiate-local-class.cpp
@@ -448,3 +448,30 @@ namespace PR21332 {
   }
   template void f7<int>();
 }
+
+// rdar://23721638: Ensure that we correctly perform implicit
+// conversions when instantiating the default arguments of local functions.
+namespace rdar23721638 {
+  struct A {
+    A(const char *) = delete;  // expected-note 2 {{explicitly marked deleted here}}
+  };
+
+  template <typename T> void foo() {
+    struct Inner { // expected-note {{in instantiation}}
+      void operator()(T a = "") {} // expected-error {{conversion function from 'const char [1]' to 'rdar23721638::A' invokes a deleted function}}
+      // expected-note@-1 {{passing argument to parameter 'a' here}}
+      // expected-note@-2 {{candidate function not viable}}
+    };
+    Inner()(); // expected-error {{no matching function}}
+  }
+  template void foo<A>(); // expected-note 2 {{in instantiation}}
+
+  template <typename T> void bar() {
+    auto lambda = [](T a = "") {}; // expected-error {{conversion function from 'const char [1]' to 'rdar23721638::A' invokes a deleted function}}
+      // expected-note@-1 {{passing argument to parameter 'a' here}}
+      // expected-note@-2 {{candidate function not viable}}
+      // expected-note@-3 {{conversion candidate of type}}
+    lambda(); // expected-error {{no matching function}}
+  }
+  template void bar<A>(); // expected-note {{in instantiation}}
+}