2 files changed, 45 insertions, 5 deletions

diff --git a/lib/Driver/SanitizerArgs.h b/lib/Driver/SanitizerArgs.h
index a281959891..bc3aa58331 100644
--- a/lib/Driver/SanitizerArgs.h
+++ b/lib/Driver/SanitizerArgs.h
@@ -36,25 +36,32 @@ class SanitizerArgs {
     NeedsAsanRt = Address,
     NeedsTsanRt = Thread,
     NeedsMsanRt = Memory,
-    NeedsUbsanRt = (Undefined & ~Bounds) | Integer
+    NeedsUbsanRt = (Undefined & ~Bounds) | Integer,
+    NotAllowedWithTrap = Vptr
   };
   unsigned Kind;
   std::string BlacklistFile;
   bool MsanTrackOrigins;
   bool AsanZeroBaseShadow;
+  bool UbsanTrapOnError;
 
  public:
   SanitizerArgs() : Kind(0), BlacklistFile(""), MsanTrackOrigins(false),
-                    AsanZeroBaseShadow(false) {}
+                    AsanZeroBaseShadow(false), UbsanTrapOnError(false) {}
   /// Parses the sanitizer arguments from an argument list.
   SanitizerArgs(const Driver &D, const ArgList &Args);
 
   bool needsAsanRt() const { return Kind & NeedsAsanRt; }
   bool needsTsanRt() const { return Kind & NeedsTsanRt; }
   bool needsMsanRt() const { return Kind & NeedsMsanRt; }
-  bool needsUbsanRt() const { return Kind & NeedsUbsanRt; }
+  bool needsUbsanRt() const {
+    if (UbsanTrapOnError)
+      return false;
+    return Kind & NeedsUbsanRt;
+  }
 
   bool sanitizesVptr() const { return Kind & Vptr; }
+  bool notAllowedWithTrap() const { return Kind & NotAllowedWithTrap; }
 
   void addArgs(const ArgList &Args, ArgStringList &CmdArgs) const {
     if (!Kind)
@@ -127,8 +134,9 @@ class SanitizerArgs {
       Remove = Thread;
       DeprecatedReplacement = "-fno-sanitize=thread";
     } else if (A->getOption().matches(options::OPT_fcatch_undefined_behavior)) {
-      Add = Undefined;
-      DeprecatedReplacement = "-fsanitize=undefined";
+      Add = UndefinedTrap;
+      DeprecatedReplacement = 
+        "-fsanitize=undefined-trap -fsanitize-undefined-trap-on-error";
     } else if (A->getOption().matches(options::OPT_fbounds_checking) ||
                A->getOption().matches(options::OPT_fbounds_checking_EQ)) {
       Add = Bounds;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index e4be6935ea..f925f762e5 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1459,6 +1459,33 @@ SanitizerArgs::SanitizerArgs(const Driver &D, const ArgList &Args)
     AllKinds |= Add;
   }
 
+  UbsanTrapOnError =
+    Args.hasArg(options::OPT_fcatch_undefined_behavior) ||
+    Args.hasFlag(options::OPT_fsanitize_undefined_trap_on_error,
+                 options::OPT_fno_sanitize_undefined_trap_on_error, false);
+
+  if (Args.hasArg(options::OPT_fcatch_undefined_behavior) &&
+      !Args.hasFlag(options::OPT_fsanitize_undefined_trap_on_error,
+                    options::OPT_fno_sanitize_undefined_trap_on_error, true)) {
+    D.Diag(diag::err_drv_argument_not_allowed_with)
+      << "-fcatch-undefined-behavior"
+      << "-fno-sanitize-undefined-trap-on-error";
+  }
+
+  // Warn about undefined sanitizer options that require runtime support.
+  if (UbsanTrapOnError && notAllowedWithTrap()) {
+    if (Args.hasArg(options::OPT_fcatch_undefined_behavior))
+      D.Diag(diag::err_drv_argument_not_allowed_with)
+        << lastArgumentForKind(D, Args, NotAllowedWithTrap)
+        << "-fcatch-undefined-behavior";
+    else if (Args.hasFlag(options::OPT_fsanitize_undefined_trap_on_error,
+                          options::OPT_fno_sanitize_undefined_trap_on_error,
+                          false))
+      D.Diag(diag::err_drv_argument_not_allowed_with)
+        << lastArgumentForKind(D, Args, NotAllowedWithTrap)
+        << "-fsanitize-undefined-trap-on-error";
+  }
+
   // Only one runtime library can be used at once.
   bool NeedsAsan = needsAsanRt();
   bool NeedsTsan = needsTsanRt();
@@ -2501,6 +2528,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     true))
     CmdArgs.push_back("-fno-sanitize-recover");
 
+  if (Args.hasArg(options::OPT_fcatch_undefined_behavior) ||
+      Args.hasFlag(options::OPT_fsanitize_undefined_trap_on_error,
+                   options::OPT_fno_sanitize_undefined_trap_on_error, false))
+    CmdArgs.push_back("-fsanitize-undefined-trap-on-error");
+
   // Report and error for -faltivec on anything other then PowerPC.
   if (const Arg *A = Args.getLastArg(options::OPT_faltivec))
     if (!(getToolChain().getTriple().getArch() == llvm::Triple::ppc ||