Clang/GCC compiler settings update [SECURITY] (#7358)

- Add the following compilation flags for clang
  -fpie
  -fstack-protector-all
  -fstack-check (non-release)

- Add the following compilation flags for gcc
  -fpie
  -fstack-protector-all

- Fix -Wunused-result errors from above compilation flag updates

- Add _FORTIFY_SOURCE=2 to GCC DEFINES

Signed-off-by: Steve Pham <82231385+spham-amzn@users.noreply.github.com>

Code/Framework/AzCore/Tests/Platform/Android/Tests/UtilsTests_Android.cpp

@@ -69,9 +69,11 @@ namespace UnitTest
         // Note that ConvertToAbsolutePath will perform a realpath on the result. The result of AZ::Utils::GetExecutableDirectory
         // uses AZ::Android::AndroidEnv::Get()->GetAppPrivateStoragePath() which will retrieve the storage path, but that path could
         // be symlinked, so we need to perform a real path on it before comparison
-        char realExecutableDirectory[AZ::IO::MaxPathLength];
-        ASSERT_TRUE(realpath(executableDirectory, realExecutableDirectory));
-
+        char* realExecutableDirectory = realpath(executableDirectory, nullptr);
+        ASSERT_NE(realExecutableDirectory, nullptr);
+        
         EXPECT_STRCASEEQ(realExecutableDirectory, absolutePath->c_str());
+
+        free(realExecutableDirectory);
     }
 }

Code/Framework/AzFramework/AzFramework/Archive/ZipDirCache.cpp

@@ -383,7 +383,7 @@ namespace AZ::IO::ZipDir
             if (!AZ::IO::FileIOBase::GetDirectInstance()->Write(m_fileHandle, ptr, sizeToWrite))
             {
                 char error[1024];
-                azstrerror_s(error, AZ_ARRAY_SIZE(error), errno);
+                [[maybe_unused]] auto azStrErrorResult = azstrerror_s(error, AZ_ARRAY_SIZE(error), errno);
                 AZ_Warning("Archive", false, "Cannot write to zip file!! error = (%d): %s", errno, error);
                 return ZD_ERROR_IO_FAILED;
             }
@@ -531,7 +531,7 @@ namespace AZ::IO::ZipDir
         if (!WriteCompressedData((uint8_t*)pUncompressed, nSegmentSize, encrypt))
         {
             char error[1024];
-            azstrerror_s(error, AZ_ARRAY_SIZE(error), errno);
+            [[maybe_unused]] auto azStrErrorResult = azstrerror_s(error, AZ_ARRAY_SIZE(error), errno);
             AZ_Warning("Archive", false, "Cannot write to zip file!! error = (%d): %s", errno, error);
             return ZD_ERROR_IO_FAILED;
         }

Code/Framework/AzFramework/Platform/Linux/AzFramework/Process/ProcessWatcher_Linux.cpp

@@ -120,7 +120,7 @@ namespace AzFramework
                 int res = chdir(processLaunchInfo.m_workingDirectory.c_str());
                 if (res != 0)
                 {
-                    write(errorPipe[1], &errno, sizeof(int));
+                    [[maybe_unused]] auto writeResult = write(errorPipe[1], &errno, sizeof(int));
                     // We *have* to _exit as we are the child process and simply
                     // returning at this point would mean we would start running
                     // the code from our parent process and that will just wreck
@@ -132,15 +132,19 @@ namespace AzFramework
             switch (processLaunchInfo.m_processPriority)
             {
                 case PROCESSPRIORITY_BELOWNORMAL:
-                    nice(1);
+                {
+                    [[maybe_unused]] auto niceResult = nice(1);
                     // also reduce disk impact:
                     // setiopolicy_np(IOPOL_TYPE_DISK, IOPOL_SCOPE_PROCESS, IOPOL_UTILITY);
                     break;
+                }
                 case PROCESSPRIORITY_IDLE:
-                    nice(20);
+                {
+                    [[maybe_unused]] auto niceResult = nice(20);
                     // also reduce disk impact:
                     // setiopolicy_np(IOPOL_TYPE_DISK, IOPOL_SCOPE_PROCESS, IOPOL_THROTTLE);
                     break;
+                }
             }
 
             startupInfo.SetupHandlesForChildProcess();
@@ -153,7 +157,7 @@ namespace AzFramework
             // to stop it from continuing to run as a clone of the parent.
             // Communicate the error code back to the parent via a pipe for the
             // parent to read.
-            write(errorPipe[1], &errval, sizeof(errval));
+            [[maybe_unused]] auto writeResult = write(errorPipe[1], &errval, sizeof(errval));
 
             _exit(0);
         }
@@ -317,7 +321,7 @@ namespace AzFramework
 
         // Set up a pipe to communicate the error code from the subprocess's execvpe call
         AZStd::array<int, 2> childErrorPipeFds{};
-        pipe(childErrorPipeFds.data());
+        [[maybe_unused]] auto pipeResult = pipe(childErrorPipeFds.data());
 
         // This configures the write end of the pipe to close on calls to `exec`
         fcntl(childErrorPipeFds[1], F_SETFD, fcntl(childErrorPipeFds[1], F_GETFD) | FD_CLOEXEC);

Code/Framework/AzNetworking/Platform/Common/UnixLike/AzNetworking/Utilities/NetworkCommon_UnixLike.cpp

@@ -71,7 +71,7 @@ namespace AzNetworking
         const char* GetNetworkErrorDesc(int32_t errorCode)
         {
             static AZ_THREAD_LOCAL char buffer[1024];
-            strerror_r(errorCode, buffer, sizeof(buffer));
+            [[maybe_unused]] auto strErrorResult = strerror_r(errorCode, buffer, sizeof(buffer));
             return buffer;
         }
     }