[ExpressionParser] Fix evaluation failures due to mismatch in C++ versions.
Clang recently switched to C++14 (with GNU extensions) as the default
dialect, but LLDB didn't catch up. This causes failures as LLDB still
evaluates ObjectiveC expressions as Objective C++ using C++98 as standard.
There are things not available in C++98, including, e.g. nullptr.
In some cases Objective-C `nil` is defined as `nullptr` so this causes
an evaluation failure. Switch the default to overcome this issue
(actually, currently lldb evaluates both C++11 and C++14 as C++11,
but that seems a larger change and definitely could be re-evaluated
in the future).
No test as this is currently failing on the LLDB bots after the clang
switch (so, de facto, there's a test already for it).
This is a recommit, with a thinko fixed (the code was previously
placed incorrectly).
<rdar://problem/36011995>
llvm-svn: 320778
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
index 6c6e4fd..d9e5307 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
@@ -389,6 +389,14 @@
// FIXME: the following language option is a temporary workaround,
// to "ask for ObjC, get ObjC++" (see comment above).
m_compiler->getLangOpts().CPlusPlus = true;
+
+ // Clang now sets as default C++14 as the default standard (with
+ // GNU extensions), so we do the same here to avoid mismatches that
+ // cause compiler error when evaluating expressions (e.g. nullptr
+ // not found as it's a C++11 feature). Currently lldb evaluates
+ // C++14 as C++11 (see two lines below) so we decide to be consistent
+ // with that, but this could be re-evaluated in the future.
+ m_compiler->getLangOpts().CPlusPlus11 = true;
break;
case lldb::eLanguageTypeC_plus_plus:
case lldb::eLanguageTypeC_plus_plus_11: