Index: compiler-rt/trunk/lib/asan/asan_win.cc
===================================================================
--- compiler-rt/trunk/lib/asan/asan_win.cc
+++ compiler-rt/trunk/lib/asan/asan_win.cc
@@ -247,16 +247,44 @@
 
 static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
 
+// Check based on flags if we should report this exception.
+static bool ShouldReportDeadlyException(unsigned code) {
+  switch (code) {
+    case EXCEPTION_ACCESS_VIOLATION:
+    case EXCEPTION_IN_PAGE_ERROR:
+      return common_flags()->handle_segv;
+    case EXCEPTION_BREAKPOINT:
+    case EXCEPTION_ILLEGAL_INSTRUCTION: {
+      return common_flags()->handle_sigill;
+    }
+  }
+  return false;
+}
+
+// Return the textual name for this exception.
+static const char *DescribeDeadlyException(unsigned code) {
+  switch (code) {
+    case EXCEPTION_ACCESS_VIOLATION:
+      return "access-violation";
+    case EXCEPTION_IN_PAGE_ERROR:
+      return "in-page-error";
+    case EXCEPTION_BREAKPOINT:
+      return "breakpoint";
+    case EXCEPTION_ILLEGAL_INSTRUCTION:
+      return "illegal-instruction";
+  }
+  return nullptr;
+}
+
 static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) {
   EXCEPTION_RECORD *exception_record = info->ExceptionRecord;
   CONTEXT *context = info->ContextRecord;
 
-  if (exception_record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
-      exception_record->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) {
+  if (ShouldReportDeadlyException(exception_record->ExceptionCode)) {
+    // Get the string description of the exception if this is a known deadly
+    // exception.
     const char *description =
-        (exception_record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION)
-            ? "access-violation"
-            : "in-page-error";
+        DescribeDeadlyException(exception_record->ExceptionCode);
     SignalContext sig = SignalContext::Create(exception_record, context);
     ReportDeadlySignal(description, sig);
   }
Index: compiler-rt/trunk/lib/sanitizer_common/CMakeLists.txt
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/CMakeLists.txt
+++ compiler-rt/trunk/lib/sanitizer_common/CMakeLists.txt
@@ -126,14 +126,6 @@
 
 set(SANITIZER_COMMON_DEFINITIONS)
 
-if(MSVC)
-  list(APPEND SANITIZER_COMMON_DEFINITIONS
-    SANITIZER_NEEDS_SEGV=0)
-else()
-  list(APPEND SANITIZER_COMMON_DEFINITIONS
-    SANITIZER_NEEDS_SEGV=1)
-endif()
-
 include(CheckIncludeFile)
 append_have_file_definition(rpc/xdr.h HAVE_RPC_XDR_H SANITIZER_COMMON_DEFINITIONS)
 append_have_file_definition(tirpc/rpc/xdr.h HAVE_TIRPC_RPC_XDR_H SANITIZER_COMMON_DEFINITIONS)
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc
@@ -30,11 +30,6 @@
 
 IntrusiveList<FlagDescription> flag_descriptions;
 
-// If set, the tool will install its own SEGV signal handler by default.
-#ifndef SANITIZER_NEEDS_SEGV
-# define SANITIZER_NEEDS_SEGV 1
-#endif
-
 void CommonFlags::SetDefaults() {
 #define COMMON_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
 #include "sanitizer_flags.inc"
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc
@@ -75,7 +75,7 @@
             "If false, disable printing error summaries in addition to error "
             "reports.")
 COMMON_FLAG(bool, check_printf, true, "Check printf arguments.")
-COMMON_FLAG(bool, handle_segv, SANITIZER_NEEDS_SEGV,
+COMMON_FLAG(bool, handle_segv, true,
             "If set, registers the tool's custom SIGSEGV/SIGBUS handler.")
 COMMON_FLAG(bool, handle_abort, false,
             "If set, registers the tool's custom SIGABRT handler.")
Index: compiler-rt/trunk/test/asan/TestCases/ill.cc
===================================================================
--- compiler-rt/trunk/test/asan/TestCases/ill.cc
+++ compiler-rt/trunk/test/asan/TestCases/ill.cc
@@ -0,0 +1,25 @@
+// Test the handle_sigill option.
+//
+// RUN: %clangxx_asan %s -o %t && %env_asan_opts=handle_sigill=0 not --crash %run %t 2>&1 | FileCheck %s --check-prefix=CHECK0
+// RUN: %clangxx_asan %s -o %t && %env_asan_opts=handle_sigill=1 not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK1
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+int main() {
+#ifdef _WIN32
+  // Sometimes on Windows this test generates a WER fault dialog. Suppress that.
+  UINT new_flags = SEM_FAILCRITICALERRORS |
+                   SEM_NOGPFAULTERRORBOX |
+                   SEM_NOOPENFILEERRORBOX;
+  // Preserve existing error mode, as discussed at
+  // http://blogs.msdn.com/oldnewthing/archive/2004/07/27/198410.aspx
+  UINT existing_flags = SetErrorMode(new_flags);
+  SetErrorMode(existing_flags | new_flags);
+#endif
+
+  __builtin_trap();
+}
+// CHECK0-NOT: ERROR: AddressSanitizer
+// CHECK1: ERROR: AddressSanitizer: {{ILL|illegal-instruction}} on unknown address {{0x0*}}