From db7bf2b3b7012cafee486c06e7fb905f3c08eed3 Mon Sep 17 00:00:00 2001
From: Darryl Pogue <darryl@dpogue.ca>
Date: Sat, 6 Jun 2015 18:04:20 -0700
Subject: [PATCH] Added Linux check for debugger presence.

---
 CMakeLists.txt                      |  7 +++++++
 Sources/Plasma/CoreLib/HeadSpin.cpp | 28 +++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e0d9d164..e38406e2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,12 +22,19 @@ include(cmake/CompilerChecks.cmake)
 if(WIN32 AND NOT CYGWIN)
     add_definitions(-DHS_BUILD_FOR_WIN32)
 endif(WIN32 AND NOT CYGWIN)
+
 if(UNIX)
+    # This is set for both Linux and Mac builds
     add_definitions(-DHS_BUILD_FOR_UNIX)
 endif(UNIX)
+
 if(APPLE AND ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     add_definitions(-DHS_BUILD_FOR_OSX)
 endif(APPLE AND ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+
+if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+    add_definitions(-DHS_BUILD_FOR_LINUX)
+endif(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 # End HeadSpin Configuration
 
 set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
diff --git a/Sources/Plasma/CoreLib/HeadSpin.cpp b/Sources/Plasma/CoreLib/HeadSpin.cpp
index ecac79fb..2be9e794 100644
--- a/Sources/Plasma/CoreLib/HeadSpin.cpp
+++ b/Sources/Plasma/CoreLib/HeadSpin.cpp
@@ -46,6 +46,13 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #ifdef _MSC_VER
 #   include <crtdbg.h>
 #endif
+
+#if defined(HS_DEBUGGING) && defined(HS_BUILD_FOR_LINUX)
+#   include <cstring>
+#   include <sys/stat.h>
+#   include <fcntl.h>
+#   include <unistd.h>
+#endif
 #pragma hdrstop
 
 #include "hsTemplates.h"
@@ -139,8 +146,27 @@ void ErrorAssert(int line, const char* file, const char* fmt, ...)
 
 bool DebugIsDebuggerPresent()
 {
-#ifdef _MSC_VER
+#if defined(HS_BUILD_FOR_WIN32)
     return IsDebuggerPresent();
+#elif defined(HS_BUILD_FOR_LINUX)
+    // From http://google-perftools.googlecode.com/svn/trunk/src/heap-checker.cc
+    char buf[256];   // TracerPid comes relatively earlier in status output
+    int fd = open("/proc/self/status", O_RDONLY);
+    if (fd == -1) {
+        return false;  // Can't tell for sure.
+    }
+    const int len = read(fd, buf, sizeof(buf));
+    bool rc = false;
+    if (len > 0) {
+        const char* const kTracerPid = "TracerPid:\t";
+        buf[len - 1] = '\0';
+        const char* p = strstr(buf, kTracerPid);
+        if (p) {
+            rc = (strncmp(p + strlen(kTracerPid), "0\n", 2) != 0);
+        }
+    }
+    close(fd);
+    return rc;
 #else
     // FIXME
     return false;