Merge pull request #835 from Devsh-Graphics-Programming/yas_is_debugger_attached

nbl::system::isDebuggerAttached

Author: AnastaZIuk

include/nbl/system/CSystemLinux.h

@@ -16,6 +16,7 @@ class CSystemLinux final : public ISystemPOSIX
 
 		NBL_API2 SystemInfo getSystemInfo() const override;
 };
+
 #endif
 }
 

include/nbl/system/CSystemWin32.h

@@ -120,7 +120,6 @@ class NBL_API2 CSystemWin32 : public ISystem
             return true;
         }
 };
-
 }
 #endif
 

include/nbl/system/ISystem.h

@@ -167,6 +167,7 @@ class NBL_API2 ISystem : public core::IReferenceCounted
         };
         virtual SystemInfo getSystemInfo() const = 0;
 
+        static bool isDebuggerAttached();
 
     protected:
         // all file operations take place serially on a dedicated thread (to make fibers possible in the future)

src/nbl/system/CSystemLinux.cpp

@@ -6,6 +6,9 @@ using namespace nbl::system;
 #ifdef _NBL_PLATFORM_LINUX_
 
 #include <sys/sysinfo.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
 ISystem::SystemInfo CSystemLinux::getSystemInfo() const
 {
     SystemInfo info;
@@ -26,4 +29,37 @@ ISystem::SystemInfo CSystemLinux::getSystemInfo() const
 
     return info;
 }
+
+bool isDebuggerAttached()
+{
+   constexpr char tracerPidStr[] = "TracerPid:";
+   char buf[4096];
+
+   const int status = open("/proc/self/status");
+   if (status == -1)
+      return false;
+
+   const size_t numRead = read(status, static_cast<void*>(buf), sizeof(buf) - 1);
+   close(status);
+
+   buf[numRead] = '\0';
+   const auto offset = strstr(buf, tracerPidStr);
+   if (not offset)
+      return false;
+
+   // few helper lambdas
+   auto isSpace = [](char c) { return c == ' '; };
+   auto isDigit = [](char c) { return c >= '0' && c <= '9'; };
+
+   for (const char* cPtr = offset + sizeof(tracerPidStr) - 1; cPtr <= buf + numRead; cPtr++)
+   {
+      if (isSpace(*cPtr))
+         continue;
+      else
+         return isDigit(*cPtr) && *cPtr != '0';
+   }
+
+   return false;
+}
+
 #endif

src/nbl/system/CSystemWin32.cpp

@@ -101,4 +101,10 @@ core::smart_refctd_ptr<ISystemFile> CSystemWin32::CCaller::createFile(const std:
     }
     return core::make_smart_refctd_ptr<CFileWin32>(core::smart_refctd_ptr<ISystem>(m_system),path(filename),flags,_mappedPtr,_native,_fileMappingObj);
 }
+
+bool isDebuggerAttached()
+{
+   return IsDebuggerPresent();
+}
+
 #endif

src/nbl/system/ISystem.cpp

@@ -349,4 +349,49 @@ bool ISystem::areBuiltinsMounted() const
 			return false;
 
     return true;
-}
+}
+
+#ifdef _NBL_PLATFORM_WINDOWS_
+bool ISystem::isDebuggerAttached() 
+{
+    return IsDebuggerPresent();
+}
+#elif defined(_NBL_PLATFORM_LINUX_)
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <cstring>
+
+bool ISystem::isDebuggerAttached()
+{
+    constexpr char debuggerPidStr[] = "TracerPid:";
+    constexpr size_t bufSize = 4096;
+
+    const int status = open("/proc/self/status", O_RDONLY);
+    if (status == -1)
+        return false;
+
+    char buf[bufSize];
+    const size_t numRead = read(status, static_cast<void*>(buf), bufSize - 1);
+    close(status);
+
+    buf[numRead] = '\0';
+    const auto offset = strstr(buf, debuggerPidStr);
+    if (not offset)
+        return false;
+
+
+    auto isSpace = [](const char c) { return c == ' ' || c == '\t'; };
+    auto isDigit = [](const char c) { return c >= '0' && c <= '9'; };
+
+    for (const char* cPtr = offset + sizeof(debuggerPidStr) - 1; cPtr <= buf + numRead; cPtr++)
+    {
+        if (isSpace(*cPtr))
+            continue;
+        else
+            return isDigit(*cPtr) && *cPtr != '0';
+    }
+
+    return false;
+}
+#endif