[GPUJIT] Improved temporary file handling.

[PhilippSchaad]

Summary

Imporved the way the GPUJIT handles temporary files for Intel's Beignet.

[grosser]

Typo: "improve"

Otherwise, LGTM.

[philip.pfaffe]

Instead of POSIX, you should use the OS-independent abstractions for interfacing with the system in the llvm::sys and llvm::sys::fs namespaces.

[grosser]

This is a run-time library, we do not (yet) link with LLVM libraries.

[philip.pfaffe]

My bad, didn't realize this was in GPUJIT and assumed it was related to D37429.

[grosser]

No worries. Thank you for reviewing!

[PhilippSchaad]

Thank you both for the review!

tools/GPURuntime/GPUJIT.c

static PollyGPUFunction *getKernelCL(const char *BinaryBuffer,
   if (!GlobalDeviceID) {
     fprintf(stderr, "GPGPU-code generation not initialized correctly.\n");
     exit(-1);
   }
 
   cl_int Ret;
 
   if (HandleOpenCLBeignet) {
-    // TODO: This is a workaround, since clCreateProgramWithLLVMIntel only
+    // This is a workaround, since clCreateProgramWithLLVMIntel only
     // accepts a filename to a valid llvm-ir file as an argument, instead
     // of accepting the BinaryBuffer directly.
-    FILE *fp = fopen("kernel.ll", "wb");
-    if (fp != NULL) {
-      fputs(BinaryBuffer, fp);
-      fclose(fp);
-    }
+    char FileName[] = "/tmp/polly_kernelXXXXXX";
+    int File = mkstemp(FileName);
+    write(File, BinaryBuffer, strlen(BinaryBuffer));
 
     ((OpenCLKernel *)Function->Kernel)->Program =
         clCreateProgramWithLLVMIntelFcnPtr(
             ((OpenCLContext *)GlobalContext->Context)->Context, 1,
-            &GlobalDeviceID, "kernel.ll", &Ret);
+            &GlobalDeviceID, FileName, &Ret);
     checkOpenCLError(Ret, "Failed to create program from llvm.\n");
-    unlink("kernel.ll");
+    close(File);
+    unlink(FileName);
   } else {
     size_t BinarySize = strlen(BinaryBuffer);
     ((OpenCLKernel *)Function->Kernel)->Program =
         clCreateProgramWithBinaryFcnPtr(
             ((OpenCLContext *)GlobalContext->Context)->Context, 1,
             &GlobalDeviceID, (const size_t *)&BinarySize,
             (const unsigned char **)&BinaryBuffer, NULL, &Ret);
     checkOpenCLError(Ret, "Failed to create program from binary.\n");