[cfe-commits] [PATCH] Emit error for unknown warning options

[Eli Friedman]

See PR9701.  Essentially, the issue is that if we don't emit an error
for unknown warning options, there isn't any supported way for
configure scripts to check whether clang supports a given warning
option, which leads to a bunch of useless warnings about unknown
warning options.  Given that gcc emits an error for unknown warning
options,  and we've at least stubbed out all the common warning
options, I think changing the default behavior like this makes sense.

-Eli
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Index: test/Driver/cc-log-diagnostics.c
===================================================================
--- test/Driver/cc-log-diagnostics.c	(revision 131176)
+++ test/Driver/cc-log-diagnostics.c	(working copy)
@@ -1,7 +1,7 @@
 // RUN: rm -f %t.log
 // RUN: env RC_DEBUG_OPTIONS=1 \
 // RUN:     CC_LOG_DIAGNOSTICS=1 CC_LOG_DIAGNOSTICS_FILE=%t.log \
-// RUN: %clang -Wfoobar -no-canonical-prefixes -ccc-host-triple x86_64-apple-darwin10 -fsyntax-only %s
+// RUN: %clang -Wno-error=unknown-warning-option -Wfoobar -no-canonical-prefixes -ccc-host-triple x86_64-apple-darwin10 -fsyntax-only %s
 // RUN: FileCheck %s < %t.log
 
 int f0() {}
Index: include/clang/Basic/DiagnosticFrontendKinds.td
===================================================================
--- include/clang/Basic/DiagnosticFrontendKinds.td	(revision 131176)
+++ include/clang/Basic/DiagnosticFrontendKinds.td	(working copy)
@@ -280,10 +280,10 @@
     "'%0' does not appear to be a precompiled header file">, DefaultFatal;
 def warn_unknown_warning_option : Warning<
     "unknown warning option '%0'">,
-    InGroup<DiagGroup<"unknown-warning-option"> >;
+    InGroup<DiagGroup<"unknown-warning-option"> >, DefaultError;
 def warn_unknown_warning_specifier : Warning<
     "unknown %0 warning specifier: '%1'">,
-    InGroup<DiagGroup<"unknown-warning-option"> >;
+    InGroup<DiagGroup<"unknown-warning-option"> >, DefaultError;
 
 def warn_unkwown_analyzer_checker : Warning<
     "no analyzer checkers are associated with '%0'">;