Reapply: [asan] On OS X, log reports to syslog and os_trace

        When ASan currently detects a bug, by default it will only print out the text
        of the report to stderr. This patch changes this behavior and writes the full
        text of the report to syslog before we terminate the process. It also calls
        os_trace (Activity Tracing available on OS X and iOS) with a message saying
        that the report is available in syslog. This is useful, because this message
        will be shown in the crash log.

        For this to work, the patch makes sure we store the full report into
        error_message_buffer unconditionally, and it also strips out ANSI escape
        sequences from the report (they are used when producing colored reports).

        I've initially tried to log to syslog during printing, which is done on Android
        right now. The advantage is that if we crash during error reporting or the
        produced error does not go through ScopedInErrorReport, we would still get a
        (partial) message in the syslog. However, that solution is very problematic on
        OS X. One issue is that the logging routine uses GCD, which may spawn a new
        thread on its behalf. In many cases, the reporting logic locks threadRegistry,
        which leads to deadlocks.

        Reviewed at http://reviews.llvm.org/D13452

        (In addition, add sanitizer_common_libcdep.cc to buildgo.sh to avoid
         build failures on Linux.)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@251577 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_common.cc b/lib/sanitizer_common/sanitizer_common.cc
index 2fb88688d..db734d628 100644
--- a/lib/sanitizer_common/sanitizer_common.cc
+++ b/lib/sanitizer_common/sanitizer_common.cc
@@ -295,6 +295,40 @@ void ReportErrorSummary(const char *error_type, const AddressInfo &info) {
 }
 #endif
 
+// Removes the ANSI escape sequences from the input string (in-place).
+void RemoveANSIEscapeSequencesFromString(char *str) {
+  if (!str)
+    return;
+
+  // We are going to remove the escape sequences in place.
+  char *s = str;
+  char *z = str;
+  while (*s != '\0') {
+    CHECK_GE(s, z);
+    // Skip over ANSI escape sequences with pointer 's'.
+    if (*s == '\033' && *(s + 1) == '[') {
+      s = internal_strchrnul(s, 'm');
+      if (*s == '\0') {
+        break;
+      }
+      s++;
+      continue;
+    }
+    // 's' now points at a character we want to keep. Copy over the buffer
+    // content if the escape sequence has been perviously skipped andadvance
+    // both pointers.
+    if (s != z)
+      *z = *s;
+
+    // If we have not seen an escape sequence, just advance both pointers.
+    z++;
+    s++;
+  }
+
+  // Null terminate the string.
+  *z = '\0';
+}
+
 void LoadedModule::set(const char *module_name, uptr base_address) {
   clear();
   full_name_ = internal_strdup(module_name);