Rejigger how -pedantic and -pedantic-errors work and their interaction
with other diagnostic mapping.  In the new scheme, -Wfoo or -Wno-foo or 
-Werror=foo all override the -pedantic options, and __extension__ 
robustly silences all extension diagnostics in their scope.

An added bonus of this change is that MAP_DEFAULT goes away, meaning that
per-diagnostic mapping information can now be stored in 2 bits, doubling
the density of the Diagnostic::DiagMapping array.  This also 
substantially simplifies Diagnostic::getDiagnosticLevel.

OTOH, this temporarily introduces some "macro intensive" code in 
Diagnostic.cpp.  This will be addressed in a later patch.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69154 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Misc/diag-mapping.c b/test/Misc/diag-mapping.c
new file mode 100644
index 0000000..f6ace02
--- /dev/null
+++ b/test/Misc/diag-mapping.c
@@ -0,0 +1,27 @@
+// This should warn by default.
+// RUN: clang-cc %s 2>&1 | grep "warning:" &&
+// This should not emit anything.
+// RUN: clang-cc %s -Wno-extra-tokens 2>&1 | not grep diagnostic
+
+// -Werror can map all warnings to error.
+// RUN: clang-cc %s -Werror 2>&1 | grep "error:" &&
+
+// -Werror can map this one warning to error.
+// RUN: clang-cc %s -Werror=extra-tokens 2>&1 | grep "error:" &&
+
+// This should stay a warning with -pedantic.
+// RUN: clang-cc %s -pedantic 2>&1 | grep "warning:" &&
+
+// This should emit an error with -pedantic-errors.
+// RUN: clang-cc %s -pedantic-errors 2>&1 | grep "error:" &&
+
+// This should emit a warning, because -Wfoo overrides -pedantic*.
+// RUN: clang-cc %s -pedantic-errors -Wextra_tokens 2>&1 | grep "error:" &&
+
+// This should emit nothing, because -Wno-extra-tokens overrides -pedantic*
+// RUN: clang-cc %s -pedantic-errors -Wno-extra-tokens 2>&1 | not grep diagnostic
+
+#ifdef foo
+#endif bad // extension!
+
+int x;