nproc: port to WIN32 and enable by default

Use the WIN32 API GetProcessAffinityMask() to obtain the number
of processors configured and the number available to the current
process.  This only works for up to 64 processors.

3 files changed, 34 insertions, 4 deletions

diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index 772f7fdb9..7108c2dda 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.34.0.git
-# Sat Feb 13 10:29:16 2021
+# Wed Feb 17 13:34:38 2021
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -295,7 +295,7 @@ CONFIG_MV=y
 # CONFIG_NICE is not set
 CONFIG_NL=y
 # CONFIG_NOHUP is not set
-# CONFIG_NPROC is not set
+CONFIG_NPROC=y
 CONFIG_OD=y
 CONFIG_PASTE=y
 CONFIG_PRINTENV=y
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index f73f23fa3..0cb4f4a3e 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.34.0.git
-# Sat Feb 13 10:37:01 2021
+# Wed Feb 17 13:34:38 2021
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -295,7 +295,7 @@ CONFIG_MV=y
 # CONFIG_NICE is not set
 CONFIG_NL=y
 # CONFIG_NOHUP is not set
-# CONFIG_NPROC is not set
+CONFIG_NPROC=y
 CONFIG_OD=y
 CONFIG_PASTE=y
 CONFIG_PRINTENV=y
diff --git a/coreutils/nproc.c b/coreutils/nproc.c
index 31e452bc4..7025765c5 100644
--- a/coreutils/nproc.c
+++ b/coreutils/nproc.c
@@ -29,6 +29,7 @@
 int nproc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int nproc_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
+#if !ENABLE_PLATFORM_MINGW32
         unsigned long mask[1024];
         int count = 0;
 #if ENABLE_LONG_OPTS
@@ -63,6 +64,35 @@ int nproc_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                         }
                 }
         }
+#else /* ENABLE_PLATFORM_MINGW32 */
+        int count = 0;
+        DWORD_PTR process_affinity, system_affinity;
+#if ENABLE_LONG_OPTS
+        int ignore = 0;
+        int opts = getopt32long(argv, "\xfe:+",
+                        "ignore\0" Required_argument "\xfe"
+                        "all\0"    No_argument       "\xff"
+                        , &ignore
+        );
+#endif
+        if (!GetProcessAffinityMask(GetCurrentProcess(), &process_affinity,
+                                        &system_affinity)) {
+                process_affinity = system_affinity = 0;
+        }
+
+#if ENABLE_LONG_OPTS
+        if (opts & (1 << 1)) {
+                for (count = 0; system_affinity; system_affinity >>= 1) {
+                        count += system_affinity & 1;
+                }
+        } else
+#endif
+        {
+                for (count = 0; process_affinity; process_affinity >>= 1) {
+                        count += process_affinity & 1;
+                }
+        }
+#endif /* ENABLE_PLATFORM_MINGW32 */
 
         IF_LONG_OPTS(count -= ignore;)
         if (count <= 0)