Support discovery of nvrtc libraries at run time

CTK installations distribute their libraries using personal packages:
- nvidia-cuda-nvrtc-cuXX

The relative path of their libraries to cuda-bindings is consistent,
and allows us to use relative paths to discover them when loading
at run time.

Author: vzhurba01

cuda_bindings/cuda/bindings/_bindings/cynvrtc.pyx.in

@@ -6,8 +6,10 @@
 # this software and related documentation outside the terms of the EULA
 # is strictly prohibited.
 {{if 'Windows' == platform.system()}}
-import win32api
+import os
+import site
 import struct
+import win32api
 from pywintypes import error
 {{else}}
 cimport cuda.bindings._lib.dlfcn as dlfcn
@@ -40,8 +42,8 @@ cdef int cuPythonInit() except -1 nogil:
 
     # Load library
     {{if 'Windows' == platform.system()}}
-    LOAD_LIBRARY_SAFE_CURRENT_DIRS = 0x00002000
     with gil:
+        # First check if the DLL has been loaded by 3rd parties
         try:
             handle = win32api.LoadLibraryEx("nvrtc64_112_0.dll", 0, LOAD_LIBRARY_SAFE_CURRENT_DIRS)
         except:
@@ -51,7 +53,53 @@ cdef int cuPythonInit() except -1 nogil:
                 try:
                     handle = win32api.LoadLibraryEx("nvrtc64_110_0.dll", 0, LOAD_LIBRARY_SAFE_CURRENT_DIRS)
                 except:
-                    raise RuntimeError('Failed to LoadLibraryEx nvrtc64_112_0.dll, or nvrtc64_111_0.dll, or nvrtc64_110_0.dll')
+                    handle = None
+
+        # Else try default search
+        if not handle:
+            LOAD_LIBRARY_SAFE_CURRENT_DIRS = 0x00002000
+            try:
+                handle = win32api.LoadLibraryEx("nvrtc64_120_0.dll", 0, LOAD_LIBRARY_SAFE_CURRENT_DIRS)
+            except:
+                pass
+
+        # Final check if DLLs can be found within pip installations
+        if not handle:
+            site_packages = [site.getusersitepackages()] + site.getsitepackages()
+            for sp in site_packages:
+                mod_path = os.path.join(sp, "nvidia", "cuda_nvrtc", "bin")
+                if not os.path.isdir(mod_path):
+                    continue
+                os.add_dll_directory(mod_path)
+            LOAD_LIBRARY_SEARCH_DEFAULT_DIRS = 0x00001000
+            LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR = 0x00000100
+            try:
+                handle = win32api.LoadLibraryEx(
+                # Note: LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR needs an abs path...
+                    os.path.join(mod_path, "nvrtc64_112_0.dll"),
+                    0, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR)
+
+                # Note: nvrtc64_120_0.dll calls into nvrtc-builtins64_*.dll which is
+                # located in the same mod_path.
+                # Update PATH environ so that the two dlls can find each other
+                os.environ["PATH"] = os.pathsep.join((os.environ.get("PATH", ""), mod_path))
+            except:
+                try:
+                    handle = win32api.LoadLibraryEx(
+                        os.path.join(mod_path, "nvrtc64_111_0.dll"),
+                        0, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR)
+                    os.environ["PATH"] = os.pathsep.join((os.environ.get("PATH", ""), mod_path))
+                except:
+                    try:
+                        handle = win32api.LoadLibraryEx(
+                            os.path.join(mod_path, "nvrtc64_110_0.dll"),
+                            0, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR)
+                        os.environ["PATH"] = os.pathsep.join((os.environ.get("PATH", ""), mod_path))
+                    except:
+                        pass
+
+        if not handle:
+            raise RuntimeError('Failed to LoadLibraryEx nvrtc64_112_0.dll, or nvrtc64_111_0.dll, or nvrtc64_110_0.dll')
     {{else}}
     handle = NULL
     if handle == NULL:

cuda_bindings/pyproject.toml

@@ -32,6 +32,11 @@ dependencies = [
   "pywin32; sys_platform == 'win32'",
 ]
 
+[project.optional-dependencies]
+all = [
+    "nvidia-cuda-nvrtc-cu11"
+]
+
 [project.urls]
 Repository = "https://github.com/NVIDIA/cuda-python"
 Documentation = "https://nvidia.github.io/cuda-python/"

cuda_bindings/setup.py

@@ -17,16 +17,15 @@
 from pyclibrary import CParser
 from setuptools import find_packages, setup
 from setuptools.extension import Extension
+from setuptools.command.bdist_wheel import bdist_wheel
 from setuptools.command.build_ext import build_ext
 import versioneer
 
 
 # ----------------------------------------------------------------------
 # Fetch configuration options
 
-CUDA_HOME = os.environ.get("CUDA_HOME")
-if not CUDA_HOME:
-    CUDA_HOME = os.environ.get("CUDA_PATH")
+CUDA_HOME = os.environ.get("CUDA_HOME", os.environ.get("CUDA_PATH", None))
 if not CUDA_HOME:
     raise RuntimeError('Environment variable CUDA_HOME or CUDA_PATH is not set')
 
@@ -236,20 +235,52 @@ def do_cythonize(extensions):
     extensions += prep_extensions(sources)
 
 # ---------------------------------------------------------------------
-# Custom build_ext command
-# Files are build in two steps:
-# 1) Cythonized (in the do_cythonize() command)
-# 2) Compiled to .o files as part of build_ext
-# This class is solely for passing the value of nthreads to build_ext
+# Custom cmdclass extensions
+
+building_wheel = False
+
+
+class WheelsBuildExtensions(bdist_wheel):
+    def run(self):
+        global building_wheel
+        building_wheel = True
+        super().run()
+
 
 class ParallelBuildExtensions(build_ext):
     def initialize_options(self):
-        build_ext.initialize_options(self)
+        super().initialize_options()
         if nthreads > 0:
             self.parallel = nthreads
 
-    def finalize_options(self):
-        build_ext.finalize_options(self)
+    def build_extension(self, ext):
+        if building_wheel and sys.platform == "linux":
+            # Strip binaries to remove debug symbols
+            extra_linker_flags = ["-Wl,--strip-all"]
+
+            # Allow extensions to discover libraries at runtime
+            # relative their wheels installation.
+            if ext.name == "cuda.bindings._bindings.cynvrtc":
+                ldflag = f"-Wl,--disable-new-dtags,-rpath,$ORIGIN/../../../nvidia/cuda_nvrtc/lib"
+            elif ext.name == "cuda.bindings._internal.nvjitlink":
+                ldflag = f"-Wl,--disable-new-dtags,-rpath,$ORIGIN/../../../nvidia/nvjitlink/lib"
+            else:
+                ldflag = None
+
+            if ldflag:
+                extra_linker_flags.append(ldflag)
+        else:
+            extra_linker_flags = []
+
+        ext.extra_link_args += extra_linker_flags
+        super().build_extension(ext)
+
+
+cmdclass = {
+    "bdist_wheel": WheelsBuildExtensions,
+    "build_ext": ParallelBuildExtensions,
+    }
+
 
 cmdclass = {"build_ext": ParallelBuildExtensions}
 cmdclass = versioneer.get_cmdclass(cmdclass)