From: Richard Trieu <rtrieu@google.com>
Date: Sat, 5 Mar 2016 04:04:57 +0000 (+0000)
Subject: Add null check to diagnostic path for lambda captures.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1585d71ce11df5799d519a6af26ae256dff633c1;p=clang

Add null check to diagnostic path for lambda captures.

Previously, the failed capture of a variable in nested lambdas may crash when
the lambda pointer is null.  Only give the note if a location can be retreived
from the lambda pointer.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@262765 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index a90fda8bfc..4071acd906 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -13509,8 +13509,9 @@ bool Sema::tryCaptureVariable(
         Diag(ExprLoc, diag::err_lambda_impcap) << Var->getDeclName();
         Diag(Var->getLocation(), diag::note_previous_decl) 
           << Var->getDeclName();
-        Diag(cast<LambdaScopeInfo>(CSI)->Lambda->getLocStart(),
-             diag::note_lambda_decl);
+        if (cast<LambdaScopeInfo>(CSI)->Lambda)
+          Diag(cast<LambdaScopeInfo>(CSI)->Lambda->getLocStart(),
+               diag::note_lambda_decl);
         // FIXME: If we error out because an outer lambda can not implicitly
         // capture a variable that an inner lambda explicitly captures, we
         // should have the inner lambda do the explicit capture - because
diff --git a/test/SemaCXX/lambda-expressions.cpp b/test/SemaCXX/lambda-expressions.cpp
index 08446a0ee4..17808cef36 100644
--- a/test/SemaCXX/lambda-expressions.cpp
+++ b/test/SemaCXX/lambda-expressions.cpp
@@ -487,3 +487,15 @@ void foo() {
   };
 }
 }
+
+namespace nested_lambda {
+template <int N>
+class S {};
+
+void foo() {
+  const int num = 18;  // expected-note {{'num' declared here}}
+  auto outer = []() {
+    auto inner = [](S<num> &X) {};  // expected-error {{variable 'num' cannot be implicitly captured in a lambda with no capture-default specified}}
+  };
+}
+}