Automatically pre-include CUDA headers just like NVCC.

tools/amd_build/pyHIPIFY/hipify-python.py

@@ -487,6 +487,34 @@ def replace_math_functions(input_string):
     return output_string
 
 
+def hip_header_magic(input_string):
+    """If the file makes kernel builtin calls and does not include the cuda_runtime.h header,
+    then automatically add an #include to match the "magic" includes provided by NVCC.
+    TODO:
+        Update logic to ignore cases where the cuda_runtime.h is included by another file.
+    """
+
+    # Copy the input.
+    output_string = input_string
+
+    # Check if one of the following headers is already included.
+    headers = ["hip/hip_runtime.h", "hip/hip_runtime_api.h"]
+    if any(re.search(r'#include ("{0}"|<{0}>)'.format(ext), output_string) for ext in headers):
+        return output_string
+
+    # Rough logic to detect if we're inside device code
+    hasDeviceLogic = "hipLaunchKernelGGL" in output_string
+    hasDeviceLogic += "__global__" in output_string
+    hasDeviceLogic += "__shared__" in output_string
+    hasDeviceLogic += re.search(r"[:]?[:]?\b(__syncthreads)\b(\w*\()", output_string) is not None
+
+    # If device logic found, provide the necessary header.
+    if hasDeviceLogic:
+        output_string = '#include "hip/hip_runtime.h"\n' + input_string
+
+    return output_string
+
+
 def replace_extern_shared(input_string):
     """Match extern __shared__ type foo[]; syntax and use HIP_DYNAMIC_SHARED() MACRO instead.
        https://github.com/ROCm-Developer-Tools/HIP/blob/master/docs/markdown/hip_kernel_language.md#__shared__
@@ -715,6 +743,9 @@ def preprocessor(filepath, stats, hipify_caffe2):
         # Replace __forceinline__ with inline
         output_source = replace_forceinline(output_source)
 
+        # Include header if device code is contained.
+        output_source = hip_header_magic(output_source)
+
         # Replace the extern __shared__
         output_source = replace_extern_shared(output_source)