Debug exit code

base/debug/debugger_posix.cc

 // Copyright (c) 2012 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 "base/debug/debugger.h"
 
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <memory>
 #include <vector>
@@ skipping 33 matching lines @@
 #endif
 
 namespace base {
 namespace debug {
 
 #if defined(OS_MACOSX) || defined(OS_BSD)
 
 // Based on Apple's recommended method as described in
 // http://developer.apple.com/qa/qa2004/qa1361.html
 bool BeingDebugged() {
+  LOG(ERROR) << "In BeingDebugged()";
   // NOTE: This code MUST be async-signal safe (it's used by in-process
   // stack dumping signal handler). NO malloc or stdio is allowed here.
   //
   // While some code used below may be async-signal unsafe, note how
   // the result is cached (see |is_set| and |being_debugged| static variables
   // right below). If this code is properly warmed-up early
   // in the start-up process, it should be safe to use later.
 
   // If the process is sandboxed then we can't use the sysctl, so cache the
   // value.
   static bool is_set = false;
   static bool being_debugged = false;
 
-  if (is_set)
+  if (is_set) {
+    LOG(ERROR) << "is_set=true, being_debugged=" << being_debugged;
     return being_debugged;
+  }
 
   // Initialize mib, which tells sysctl what info we want.  In this case,
   // we're looking for information about a specific process ID.
   int mib[] = {
     CTL_KERN,
     KERN_PROC,
     KERN_PROC_PID,
     getpid()
 #if defined(OS_OPENBSD)
     , sizeof(struct kinfo_proc),
@@ skipping 11 matching lines @@
     return -1;
 
   mib[5] = (info_size / sizeof(struct kinfo_proc));
 #endif
 
   int sysctl_result = sysctl(mib, arraysize(mib), &info, &info_size, NULL, 0);
   DCHECK_EQ(sysctl_result, 0);
   if (sysctl_result != 0) {
     is_set = true;
     being_debugged = false;
+    LOG(ERROR) << "sysctl_result=" << sysctl_result << " being_debugged=" << being_debugged;
     return being_debugged;
   }
 
   // This process is being debugged if the P_TRACED flag is set.
   is_set = true;
 #if defined(OS_FREEBSD)
   being_debugged = (info.ki_flag & P_TRACED) != 0;
 #elif defined(OS_BSD)
   being_debugged = (info.p_flag & P_TRACED) != 0;
 #else
   being_debugged = (info.kp_proc.p_flag & P_TRACED) != 0;
 #endif
+  LOG(ERROR) << "being_debugged=" << being_debugged;
   return being_debugged;
 }
 
 #elif defined(OS_LINUX) || defined(OS_ANDROID)
 
 // We can look in /proc/self/status for TracerPid.  We are likely used in crash
 // handling, so we are careful not to use the heap or have side effects.
 // Another option that is common is to try to ptrace yourself, but then we
 // can't detach without forking(), and that's not so great.
 // static
@@ skipping 47 matching lines @@
 // | Linux |       N         |        Y        |
 // | Mac   |       Y         |        N        |
 // +-------+-----------------+-----------------+
 //
 // Thus we do the following:
 // Linux: Debug mode if a debugger is attached, send SIGTRAP; otherwise send
 //        SIGABRT
 // Mac: Always send SIGTRAP.
 
 #if defined(ARCH_CPU_ARMEL)
-#define DEBUG_BREAK_ASM() asm("bkpt 0")
+#define DEBUG_BREAK_ASM() do { LOG(ERROR) << "DEBUG_BREAK_ASM brpt 0"; asm("bkpt 0"); } while (0)
 #elif defined(ARCH_CPU_ARM64)
-#define DEBUG_BREAK_ASM() asm("brk 0")
+#define DEBUG_BREAK_ASM() do { LOG(ERROR) << "DEBUG_BREAK_ASM brk 0"; asm("brk 0"); } while (0)
 #elif defined(ARCH_CPU_MIPS_FAMILY)
-#define DEBUG_BREAK_ASM() asm("break 2")
+#define DEBUG_BREAK_ASM() do { LOG(ERROR) << "DEBUG_BREAK_ASM break 2"; asm("break 2"); } while (0)
 #elif defined(ARCH_CPU_X86_FAMILY)
-#define DEBUG_BREAK_ASM() asm("int3")
+#define DEBUG_BREAK_ASM() do { LOG(ERROR) << "DEBUG_BREAK_ASM abort"; abort(); asm("int3"); } while (0)
 #endif
 
 #if defined(NDEBUG) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
-#define DEBUG_BREAK() abort()
+#define DEBUG_BREAK() do { LOG(ERROR) << "DEBUG_BREAK abort()"; abort(); } while (0)
 #elif defined(OS_NACL)
 // The NaCl verifier doesn't let use use int3.  For now, we call abort().  We
 // should ask for advice from some NaCl experts about the optimum thing here.
 // http://code.google.com/p/nativeclient/issues/detail?id=645
-#define DEBUG_BREAK() abort()
+#define DEBUG_BREAK() do { LOG(ERROR) << "DEBUG_BREAK abort()"; abort(); } while (0)
 #elif !defined(OS_MACOSX)
 // Though Android has a "helpful" process called debuggerd to catch native
 // signals on the general assumption that they are fatal errors. If no debugger
 // is attached, we call abort since Breakpad needs SIGABRT to create a dump.
 // When debugger is attached, for ARM platform the bkpt instruction appears
 // to cause SIGBUS which is trapped by debuggerd, and we've had great
 // difficulty continuing in a debugger once we stop from SIG triggered by native
 // code, use GDB to set |go| to 1 to resume execution; for X86 platform, use
 // "int3" to setup breakpiont and raise SIGTRAP.
 //
 // On other POSIX architectures, except Mac OS X, we use the same logic to
 // ensure that breakpad creates a dump on crashes while it is still possible to
 // use a debugger.
 namespace {
 void DebugBreak() {
+  LOG(ERROR) << "DebugBreak function";
   if (!BeingDebugged()) {
+    LOG(ERROR) << "Not being debugged. abort()";
     abort();
   } else {
 #if defined(DEBUG_BREAK_ASM)
     DEBUG_BREAK_ASM();
 #else
     volatile int go = 0;
     while (!go) {
+      LOG(ERROR) << "In loop waiting for debugger";
       base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(100));
     }
 #endif
   }
 }
 }  // namespace
 #define DEBUG_BREAK() DebugBreak()
 #elif defined(DEBUG_BREAK_ASM)
 #define DEBUG_BREAK() DEBUG_BREAK_ASM()
 #else
 #error "Don't know how to debug break on this architecture/OS"
 #endif
 
+typedef void (*handlert)(int);
+handlert oldhandlers[32];
+void newhandler(int sig) {
+  LOG(ERROR) << "handler: " << sig;
+  oldhandlers[sig](sig);
+}
+
 void BreakDebugger() {
   // NOTE: This code MUST be async-signal safe (it's used by in-process
   // stack dumping signal handler). NO malloc or stdio is allowed here.
 
   // Linker's ICF feature may merge this function with other functions with the
   // same definition (e.g. any function whose sole job is to call abort()) and
   // it may confuse the crash report processing system. http://crbug.com/508489
   static int static_variable_to_make_this_function_unique = 0;
   base::debug::Alias(&static_variable_to_make_this_function_unique);
 
+  LOG(ERROR) << "DEBUG_BREAK";
+  
+  //for (int i = 1; i < 32; ++i)
+  //  oldhandlers[i] = signal(i, newhandler);
+
   DEBUG_BREAK();
+
+  LOG(ERROR) << "After DEBUG_BREAK";
+
 #if defined(OS_ANDROID) && !defined(OFFICIAL_BUILD)
   // For Android development we always build release (debug builds are
   // unmanageably large), so the unofficial build is used for debugging. It is
   // helpful to be able to insert BreakDebugger() statements in the source,
   // attach the debugger, inspect the state of the program and then resume it by
   // setting the 'go' variable above.
 #elif defined(NDEBUG)
   // Terminate the program after signaling the debug break.
   _exit(1);
 #endif
 }
 
 }  // namespace debug
 }  // namespace base