[CFI] Diagnose when we CFI in diagnostic mode is unavailable on a toolchain.
Summary:
Namely, we must have proper C++ABI support in UBSan runtime. We don't
have a good way to check for that, so just assume that C++ABI support is
there whenever -fsanitize=vptr is supported (i.e. only on handful of
platforms).
Exact diagnostic is also tricky. It's not "cfi" that is unsupported,
just the diagnostic mode. So, I suggest to report that
"-fno-sanitize-trap=cfi-foobar" is incompatible with a given target
toolchain.
Test Plan: regression test suite
Reviewers: pcc
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D10751
llvm-svn: 240716
diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index 14c3702..e203aac 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -26,6 +26,7 @@
enum : SanitizerMask {
NeedsUbsanRt = Undefined | Integer | CFI,
+ NeedsUbsanCxxRt = Vptr | CFI,
NotAllowedWithTrap = Vptr,
RequiresPIE = Memory | DataFlow,
NeedsUnwindTables = Address | Thread | Memory | DataFlow,
@@ -194,7 +195,7 @@
SanitizerMask DiagnosedKinds = 0; // All Kinds we have diagnosed up to now.
// Used to deduplicate diagnostics.
SanitizerMask Kinds = 0;
- SanitizerMask Supported = setGroupBits(TC.getSupportedSanitizers());
+ const SanitizerMask Supported = setGroupBits(TC.getSupportedSanitizers());
ToolChain::RTTIMode RTTIMode = TC.getRTTIMode();
const Driver &D = TC.getDriver();
@@ -282,6 +283,21 @@
<< lastArgumentForMask(D, Args, Kinds & NeedsLTO) << "-flto";
}
+ // Report error if there are non-trapping sanitizers that require
+ // c++abi-specific parts of UBSan runtime, and they are not provided by the
+ // toolchain. We don't have a good way to check the latter, so we just
+ // check if the toolchan supports vptr.
+ if (~Supported & Vptr) {
+ if (SanitizerMask KindsToDiagnose =
+ Kinds & ~TrappingKinds & NeedsUbsanCxxRt) {
+ SanitizerSet S;
+ S.Mask = KindsToDiagnose;
+ D.Diag(diag::err_drv_unsupported_opt_for_target)
+ << ("-fno-sanitize-trap=" + toString(S)) << TC.getTriple().str();
+ Kinds &= ~KindsToDiagnose;
+ }
+ }
+
// Warn about incompatible groups of sanitizers.
std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
std::make_pair(Address, Thread), std::make_pair(Address, Memory),