Fix a couple of bugs, add some new cool stuff.
1. Fix a todo in Parser::ParseTag, to recover better. On code like
that in test/Sema/decl-invalid.c it causes us to return a single
error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
declarator didn't have an identifier. Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
by a declspec or declarator. This is mostly implemented for declspec,
but could be improved, it is missing for declarator.
Thanks to Neil for pointing out this crash.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/expr_liveness.c b/test/Preprocessor/expr_liveness.c
new file mode 100644
index 0000000..f14ac0a
--- /dev/null
+++ b/test/Preprocessor/expr_liveness.c
@@ -0,0 +1,32 @@
+/* RUN: clang -E %s -DNO_ERRORS &&
+ RUN: not clang -E %s
+ */
+
+#ifdef NO_ERRORS
+/* None of these divisions by zero are in live parts of the expression, do not
+ emit any diagnostics. */
+
+#define MACRO_0 0
+#define MACRO_1 1
+
+#if MACRO_0 && 10 / MACRO_0
+foo
+#endif
+
+#if MACRO_1 || 10 / MACRO_0
+bar
+#endif
+
+#if 0 ? 124/0 : 42
+#endif
+
+#else
+
+
+/* The 1/0 is live, it should error out. */
+#if 0 && 1 ? 4 : 1 / 0
+baz
+#endif
+
+
+#endif