[asan] Add a "dump_registers" flag to print out CPU registers after a SIGSEGV

This patch prints out all CPU registers after a SIGSEGV. These are available in the signal handler context. Only implemented for Darwin. Can be turned off with the dump_registers flag.

Differential Revision: https://reviews.llvm.org/D11365



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@287957 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/test/asan/TestCases/Darwin/dump_registers.cc b/test/asan/TestCases/Darwin/dump_registers.cc
new file mode 100644
index 000000000..884ad2ed4
--- /dev/null
+++ b/test/asan/TestCases/Darwin/dump_registers.cc
@@ -0,0 +1,26 @@
+// Check that ASan dumps the CPU registers on a SIGSEGV.
+
+// RUN: %clangxx_asan %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s
+
+#include <assert.h>
+#include <stdio.h>
+
+int main() {
+  fprintf(stderr, "Hello\n");
+  char *ptr;
+
+  if (sizeof(void *) == 8)
+    ptr = (char *)0x6666666666666666;
+  else if (sizeof(void *) == 4)
+    ptr = (char *)0x55555555;
+  else
+    assert(0 && "Your computer is weird.");
+
+  char c = *ptr;  // BOOM
+  // CHECK: ERROR: AddressSanitizer: SEGV
+  // CHECK: Register values:
+  // CHECK: {{0x55555555|0x6666666666666666}}
+  fprintf(stderr, "World\n");
+  return c;
+}