[ubsan] Add support for reporting diagnostics to a monitor process

Add support to the ubsan runtime for reporting diagnostics to a monitor
process (e.g a debugger).

The Xcode IDE uses this by setting a breakpoint on __ubsan_on_report and
collecting diagnostic information via __ubsan_get_current_report_data,
which it then surfaces to users in the editor UI.

Testing for this functionality already exists in upstream lldb, here:
lldb/packages/Python/lldbsuite/test/functionalities/ubsan

Apart from that, this is `ninja check-{a,ub}san` clean.

Differential Revision: https://reviews.llvm.org/D48446

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@335371 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 0 deletions

diff --git a/test/ubsan/TestCases/Misc/monitor.cpp b/test/ubsan/TestCases/Misc/monitor.cpp
new file mode 100644
index 000000000..78187019c
--- /dev/null
+++ b/test/ubsan/TestCases/Misc/monitor.cpp
@@ -0,0 +1,37 @@
+// RUN: %clangxx -w -fsanitize=bool %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#include <iostream>
+
+extern "C" {
+void __ubsan_get_current_report_data(const char **OutIssueKind,
+                                     const char **OutMessage,
+                                     const char **OutFilename,
+                                     unsigned *OutLine, unsigned *OutCol,
+                                     char **OutMemoryAddr);
+
+// Override the weak definition of __ubsan_on_report from the runtime, just
+// for testing purposes.
+void __ubsan_on_report(void) {
+  const char *IssueKind, *Message, *Filename;
+  unsigned Line, Col;
+  char *Addr;
+  __ubsan_get_current_report_data(&IssueKind, &Message, &Filename, &Line, &Col,
+                                  &Addr);
+
+  std::cout << "Issue: " << IssueKind << "\n"
+            << "Location: " << Filename << ":" << Line << ":" << Col << "\n"
+            << "Message: " << Message << std::endl;
+
+  (void)Addr;
+}
+}
+
+int main() {
+  char C = 3;
+  bool B = *(bool *)&C;
+  // CHECK: Issue: invalid-bool-load
+  // CHECK-NEXT: Location: {{.*}}monitor.cpp:[[@LINE-2]]:12
+  // CHECK-NEXT: Message: Load of value 3, which is not a valid value for type 'bool'
+  return 0;
+}