[libsymbolized] If we can't find an address in the list of shared libraries, try to reload it.

Add a regression test for the case where such behavior helps TSan:
  1. race is reported in the main module
  2. new shared library is loaded
  3. race is reported in the shared library

llvm-svn: 179032

3 files changed, 70 insertions, 0 deletions

diff --git a/compiler-rt/lib/tsan/lit_tests/SharedLibs/lit.local.cfg b/compiler-rt/lib/tsan/lit_tests/SharedLibs/lit.local.cfg
new file mode 100644
index 00000000000..b3677c17a0f
--- /dev/null
+++ b/compiler-rt/lib/tsan/lit_tests/SharedLibs/lit.local.cfg
@@ -0,0 +1,4 @@
+# Sources in this directory are compiled as shared libraries and used by
+# tests in parent directory.
+
+config.suffixes = []
diff --git a/compiler-rt/lib/tsan/lit_tests/SharedLibs/load_shared_lib-so.cc b/compiler-rt/lib/tsan/lit_tests/SharedLibs/load_shared_lib-so.cc
new file mode 100644
index 00000000000..d05aa6a40d1
--- /dev/null
+++ b/compiler-rt/lib/tsan/lit_tests/SharedLibs/load_shared_lib-so.cc
@@ -0,0 +1,22 @@
+//===----------- load_shared_lib-so.cc --------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+//===----------------------------------------------------------------------===//
+
+#include <stddef.h>
+
+int GLOB_SHARED = 0;
+
+extern "C"
+void *write_from_so(void *unused) {
+  GLOB_SHARED++;
+  return NULL;
+}
diff --git a/compiler-rt/lib/tsan/lit_tests/load_shared_lib.cc b/compiler-rt/lib/tsan/lit_tests/load_shared_lib.cc
new file mode 100644
index 00000000000..598b4ca3109
--- /dev/null
+++ b/compiler-rt/lib/tsan/lit_tests/load_shared_lib.cc
@@ -0,0 +1,44 @@
+// Check that if the list of shared libraries changes between the two race
+// reports, the second report occurring in a new shared library is still
+// symbolized correctly.
+
+// RUN: %clangxx_tsan -O1 %p/SharedLibs/load_shared_lib-so.cc \
+// RUN:     -fPIC -shared -o %t-so.so
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdio.h>
+
+#include <string>
+
+int GLOB = 0;
+
+void *write_glob(void *unused) {
+  GLOB++;
+  return NULL;
+}
+
+void race_two_threads(void *(*access_callback)(void *)) {
+  pthread_t t1, t2;
+  pthread_create(&t1, NULL, access_callback, NULL);
+  pthread_create(&t2, NULL, access_callback, NULL);
+  pthread_join(t1, NULL);
+  pthread_join(t2, NULL);
+}
+
+int main(int argc, char *argv[]) {
+  std::string path = std::string(argv[0]) + std::string("-so.so");
+  race_two_threads(write_glob);
+  // CHECK: write_glob
+  void *lib = dlopen(path.c_str(), RTLD_NOW);
+    if (!lib) {
+    printf("error in dlopen(): %s\n", dlerror());
+    return 1;
+  }
+  void *(*write_from_so)(void *);
+  *(void **)&write_from_so = dlsym(lib, "write_from_so");
+  race_two_threads(write_from_so);
+  // CHECK: write_from_so
+  return 0;
+}