r262765 - Add null check to diagnostic path for lambda captures.

[Richard Trieu via cfe-commits]

Author: rtrieu
Date: Fri Mar  4 22:04:57 2016
New Revision: 262765

URL: http://llvm.org/viewvc/llvm-project?rev=262765&view=rev
Log:
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.

Modified:
    cfe/trunk/lib/Sema/SemaExpr.cpp
    cfe/trunk/test/SemaCXX/lambda-expressions.cpp

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=262765&r1=262764&r2=262765&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Mar  4 22:04:57 2016
@@ -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

Modified: cfe/trunk/test/SemaCXX/lambda-expressions.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/lambda-expressions.cpp?rev=262765&r1=262764&r2=262765&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/lambda-expressions.cpp (original)
+++ cfe/trunk/test/SemaCXX/lambda-expressions.cpp Fri Mar  4 22:04:57 2016
@@ -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}}
+  };
+}
+}