Detect CUDA version from CUDA_PATH on Windows, unify helper

Author: andriiryzhkov

src/ai/ort_install.c

@@ -35,7 +35,10 @@
 #endif
 
 // forward declarations
+#ifndef _WIN32
 static gchar *_get_rocm_version(void);
+#endif
+static gchar *_get_cuda_version(void);
 
 // ---------------------------------------------------------------------------
 // Manifest-driven package metadata (loaded from data/ort_gpu.json)
@@ -186,32 +189,17 @@ static _ort_package_t *_find_package(GList *packages, dt_ort_gpu_vendor_t vendor
 #endif
 
   gchar *rocm_mm = NULL;
+#ifndef _WIN32
   if(vendor == DT_ORT_GPU_AMD)
   {
     gchar *rocm_ver = _get_rocm_version();
     rocm_mm = _version_major_minor(rocm_ver);
     g_free(rocm_ver);
   }
+#endif
 
-  // detect CUDA toolkit version via nvcc
-  gchar *cuda_mm = NULL;
-  if(vendor == DT_ORT_GPU_NVIDIA)
-  {
-    gchar *nvcc_out = NULL;
-    if(g_spawn_command_line_sync("nvcc --version", &nvcc_out,
-                                 NULL, NULL, NULL)
-       && nvcc_out)
-    {
-      // parse "Cuda compilation tools, release X.Y, VX.Y.Z"
-      gchar *v = g_strstr_len(nvcc_out, -1, ", V");
-      if(v)
-      {
-        v += 3; // skip ", V"
-        cuda_mm = _version_major_minor(v);
-      }
-      g_free(nvcc_out);
-    }
-  }
+  // detect CUDA toolkit version (nvcc on Linux, CUDA_PATH on Windows)
+  gchar *cuda_mm = (vendor == DT_ORT_GPU_NVIDIA) ? _get_cuda_version() : NULL;
 
   _ort_package_t *best = NULL;
   for(GList *l = packages; l; l = g_list_next(l))
@@ -246,18 +234,14 @@ static _ort_package_t *_find_package(GList *packages, dt_ort_gpu_vendor_t vendor
 // Helpers
 // ---------------------------------------------------------------------------
 
-// run a command via shell and capture stdout. Returns TRUE on success
-// on Linux uses sh -c to support pipes and redirections
-// on Windows uses cmd /c since /bin/sh is not available
+#ifndef _WIN32
+// run a command via sh -c and capture stdout.  Use for commands that
+// need shell features like pipes or redirections.
 static gboolean _run_cmd(const char *cmd, char **out)
 {
   gchar *stdout_buf = NULL;
   gint exit_status = 0;
-#ifdef _WIN32
-  const gchar *argv[] = { "cmd.exe", "/c", cmd, NULL };
-#else
   const gchar *argv[] = { "/bin/sh", "-c", cmd, NULL };
-#endif
   gboolean ok = g_spawn_sync(NULL, (gchar **)argv, NULL,
                               G_SPAWN_SEARCH_PATH | G_SPAWN_STDERR_TO_DEV_NULL,
                               NULL, NULL, &stdout_buf, NULL, &exit_status, NULL);
@@ -272,10 +256,11 @@ static gboolean _run_cmd(const char *cmd, char **out)
   if(out) *out = NULL;
   return FALSE;
 }
+#endif
 
+#ifndef _WIN32
 // run a command directly (no shell) and capture stdout. Use this for
-// commands that don't need shell features — avoids cmd.exe quoting
-// issues and console-window flicker on Windows GUI apps
+// commands that don't need shell features
 static gboolean _run_argv(const gchar * const *argv, char **out)
 {
   gchar *stdout_buf = NULL;
@@ -294,6 +279,7 @@ static gboolean _run_argv(const gchar * const *argv, char **out)
   if(out) *out = NULL;
   return FALSE;
 }
+#endif
 
 #ifdef _WIN32
 // recursively search a directory for a file whose name starts with prefix.
@@ -319,6 +305,7 @@ static gboolean _find_file_recursive(const char *dir, const char *prefix)
 }
 #endif
 
+#ifndef _WIN32
 // check if a library is in /etc/ld.so.cache — fast but only works
 // when the distro package registered a SONAME (Debian's libcudnn9
 // package does not, so this misses cuDNN there)
@@ -377,16 +364,28 @@ static gchar *_get_rocm_version(void)
   }
   return NULL;
 }
+#endif // !_WIN32
 
 
 // ---------------------------------------------------------------------------
 // GPU detection
 // ---------------------------------------------------------------------------
 
-// Get CUDA toolkit version (major.minor) from nvcc, e.g. "13.2".
-// Returns NULL if nvcc is not available.
+// Get CUDA toolkit version (major.minor), e.g. "13.2".
+// On Windows: parse CUDA_PATH (e.g. ".../CUDA/v13.2"), which is set by
+// the CUDA installer and is always present regardless of PATH.
+// On Linux: run nvcc --version.  Returns NULL if not found.
 static gchar *_get_cuda_version(void)
 {
+#ifdef _WIN32
+  const char *cuda_path = g_getenv("CUDA_PATH");
+  if(!cuda_path) return NULL;
+  const char *sep = strrchr(cuda_path, '\\');
+  if(!sep) sep = strrchr(cuda_path, '/');
+  const char *ver = sep ? sep + 1 : cuda_path;
+  if(ver[0] == 'v' || ver[0] == 'V') ver++;
+  return _version_major_minor(ver);
+#else
   gchar *nvcc_out = NULL;
   if(!g_spawn_command_line_sync("nvcc --version", &nvcc_out, NULL, NULL, NULL)
      || !nvcc_out)
@@ -397,6 +396,7 @@ static gchar *_get_cuda_version(void)
     result = _version_major_minor(v + 3);  // skip ", V"
   g_free(nvcc_out);
   return result;
+#endif
 }
 
 static dt_ort_gpu_info_t *_detect_nvidia(void)