linux: reenable symbols in backtraces in debug builds

base/debug_util_unittest.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sstream>
 #include <string>
 
 #include "base/debug_util.h"
 #include "base/logging.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+// Note: this test currently only fully works on Linux Debug builds.
+// See comments in the #ifdef soup if you intend to change this.
 TEST(StackTrace, OutputToStream) {
   StackTrace trace;
 
   // Dump the trace into a string.
   std::ostringstream os;
   trace.OutputToStream(&os);
   std::string backtrace_message = os.str();
 
 #if defined(OS_LINUX) && NDEBUG
   // Stack traces require an extra data table that bloats our binaries,
   // so they're turned off for release builds.  We stop the test here,
   // at least letting us verify that the calls don't crash.
   return;
 #endif  // defined(OS_LINUX) && NDEBUG
 
   size_t frames_found = 0;
   trace.Addresses(&frames_found);
   ASSERT_GE(frames_found, 5u) <<
       "No stack frames found.  Skipping rest of test.";
 
   // Check if the output has symbol initialization warning.  If it does, fail.
   ASSERT_EQ(backtrace_message.find("Dumping unresolved backtrace"),
             std::string::npos) <<
       "Unable to resolve symbols.  Skipping rest of test.";
 
-#if 0
-// TODO(ajwong): Disabling checking of symbol resolution since it depends
-//  on whether or not symbols are present, and there are too many
-//  configurations to reliably ensure that symbols are findable.
-#if defined(OS_MACOSX)
+#if defined(OS_MACOSX) && 0
+  // Disabled due to -fvisibility=hidden in build config.
 
-  // Symbol resolution via the backtrace_symbol funciton does not work well
-  // in OsX.
+  // Symbol resolution via the backtrace_symbol function does not work well
+  // in OS X.
   // See this thread:
   //
   //    http://lists.apple.com/archives/darwin-dev/2009/Mar/msg00111.html
   //
   // Just check instead that we find our way back to the "start" symbol
   // which should be the first symbol in the trace.
   //
   // TODO(port): Find a more reliable way to resolve symbols.
 
   // Expect to at least find main.
   EXPECT_TRUE(backtrace_message.find("start") != std::string::npos)
       << "Expected to find start in backtrace:\n"
       << backtrace_message;
 
 #elif defined(__GLIBCXX__)
 
   // Expect a demangled symbol.
   EXPECT_TRUE(backtrace_message.find("testing::Test::Run()") !=
               std::string::npos)
       << "Expected a demangled symbol in backtrace:\n"
       << backtrace_message;
-#else  // defined(__GLIBCXX__)
+
+#elif 0
+  // Disabled on other platforms because of varying buildbot configs;
+  // some lack symbols.
 
   // Expect to at least find main.
   EXPECT_TRUE(backtrace_message.find("main") != std::string::npos)
       << "Expected to find main in backtrace:\n"
       << backtrace_message;
 
 #if defined(OS_WIN)
 // MSVC doesn't allow the use of C99's __func__ within C++, so we fake it with
 // MSVC's __FUNCTION__ macro.
 #define __func__ __FUNCTION__
 #endif
 
   // Expect to find this function as well.
   // Note: This will fail if not linked with -rdynamic (aka -export_dynamic)
   EXPECT_TRUE(backtrace_message.find(__func__) != std::string::npos)
       << "Expected to find " << __func__ << " in backtrace:\n"
       << backtrace_message;
 
 #endif  // define(OS_MACOSX)
-#endif
 }