[ROCm][Windows] Add hipcc compatibility flags to cpp_extension.py. (#159790)

ScottTodd · pytorchmergebot · commit b7ca502f2915 · 2025-08-16T02:20:49.000Z
This is a similar change to #153986, this time adding flags to the hipcc command under `cpp_extension.py`. The `-Wno-ignored-attributes` flag in particular avoids about 200MB of warning spam when building torchvision, like these: ``` In file included from D:\b\vision_main\torchvision\csrc\ops\hip\deform_conv2d_kernel.hip:72: In file included from D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\ATen/ATen.h:13: In file included from D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\ATen/Functions.h:386: In file included from D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\ATen/ops/_sparse_softmax.h:21: D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\ATen/ops/_sparse_softmax_ops.h:18:8: warning: __declspec attribute 'dllimport' is not supported [-Wignored-attributes] 18 | struct TORCH_API _sparse_softmax_int { | ^~~~~~~~~ D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\torch/headeronly/macros/Export.h:100:19: note: expanded from macro 'TORCH_API' 100 | #define TORCH_API C10_IMPORT | ^~~~~~~~~~ D:\projects\TheRock\external-builds\pytorch\.venv\Lib\site-packages\torch\include\torch/headeronly/macros/Export.h:53:31: note: expanded from macro 'C10_IMPORT' 53 | #define C10_IMPORT __declspec(dllimport) | ^~~~~~~~~ ``` The `-fms-extensions` flag just seems beneficial to include: https://clang.llvm.org/docs/MSVCCompatibility.html. See also this downstream issue where these changes were tested: ROCm/TheRock#910. Pull Request resolved: #159790 Approved by: https://github.com/jeffdaily
diff --git a/torch/utils/cpp_extension.py b/torch/utils/cpp_extension.py
@@ -275,6 +275,11 @@ def _join_sycl_home(*paths) -> str:
     '-DHIP_ENABLE_WARP_SYNC_BUILTINS=1'
 ]
 
+if IS_WINDOWS:
+    # Compatibility flags, similar to those set in cmake/Dependencies.cmake.
+    COMMON_HIPCC_FLAGS.append('-fms-extensions')
+    # Suppress warnings about dllexport.
+    COMMON_HIPCC_FLAGS.append('-Wno-ignored-attributes')
 
 
 def _get_sycl_arch_list():

Original file line number	Diff line number	Diff line change
`@@ -275,6 +275,11 @@ def _join_sycl_home(*paths) -> str:`
`275`	`275`	`'-DHIP_ENABLE_WARP_SYNC_BUILTINS=1'`
`276`	`276`	`]`
`277`	`277`
	`278`	`+if IS_WINDOWS:`
	`279`	`+ # Compatibility flags, similar to those set in cmake/Dependencies.cmake.`
	`280`	`+ COMMON_HIPCC_FLAGS.append('-fms-extensions')`
	`281`	`+ # Suppress warnings about dllexport.`
	`282`	`+ COMMON_HIPCC_FLAGS.append('-Wno-ignored-attributes')`
`278`	`283`
`279`	`284`
`280`	`285`	`def _get_sycl_arch_list():`