From 50d69741cb35db1a535282060c51e536a863ce99 Mon Sep 17 00:00:00 2001
From: Kevin Sheppard <kevin.k.sheppard@gmail.com>
Date: Thu, 20 Jan 2022 18:12:14 +0000
Subject: [PATCH] ENH: Add changes that allow NumPy to compile with clang-cl

Port over changes needed to compile NumPy using clang-cl
from #13816. Desirable to retain these even though distutils is
effectively deprecated and so not worth the effort to alter.
---
 numpy/core/include/numpy/ndarraytypes.h            | 2 +-
 numpy/core/include/numpy/npy_common.h              | 7 ++++---
 numpy/core/src/common/simd/intdiv.h                | 2 +-
 numpy/core/src/multiarray/common_dtype.c           | 2 +-
 numpy/core/src/umath/loops_unary_fp.dispatch.c.src | 3 +++
 5 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/numpy/core/include/numpy/ndarraytypes.h b/numpy/core/include/numpy/ndarraytypes.h
index 47d063178d15..35d82ec036bd 100644
--- a/numpy/core/include/numpy/ndarraytypes.h
+++ b/numpy/core/include/numpy/ndarraytypes.h
@@ -87,7 +87,7 @@ enum NPY_TYPES {    NPY_BOOL=0,
                     /* The number of types not including the new 1.6 types */
                     NPY_NTYPES_ABI_COMPATIBLE=21
 };
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 #pragma deprecated(NPY_CHAR)
 #endif
 
diff --git a/numpy/core/include/numpy/npy_common.h b/numpy/core/include/numpy/npy_common.h
index 1d6234e20e0f..2bcc45e4f677 100644
--- a/numpy/core/include/numpy/npy_common.h
+++ b/numpy/core/include/numpy/npy_common.h
@@ -131,9 +131,10 @@
 #endif
 #endif
 
-#if defined(_MSC_VER)
-        #define NPY_INLINE __inline
-#elif defined(__GNUC__)
+#if defined(_MSC_VER) && !defined(__clang__)
+    #define NPY_INLINE __inline
+/* clang included here to handle clang-cl on Windows */
+#elif defined(__GNUC__) || defined(__clang__)
     #if defined(__STRICT_ANSI__)
          #define NPY_INLINE __inline__
     #else
diff --git a/numpy/core/src/common/simd/intdiv.h b/numpy/core/src/common/simd/intdiv.h
index a7a461721dba..42f022c551a7 100644
--- a/numpy/core/src/common/simd/intdiv.h
+++ b/numpy/core/src/common/simd/intdiv.h
@@ -136,7 +136,7 @@ NPY_FINLINE npy_uint64 npyv__divh128_u64(npy_uint64 high, npy_uint64 divisor)
 {
     assert(divisor > 1);
     npy_uint64 quotient;
-#if defined(_M_X64) && defined(_MSC_VER) && _MSC_VER >= 1920
+#if defined(_M_X64) && defined(_MSC_VER) && _MSC_VER >= 1920 && !defined(__clang__)
     npy_uint64 remainder;
     quotient = _udiv128(high, 0, divisor, &remainder);
     (void)remainder;
diff --git a/numpy/core/src/multiarray/common_dtype.c b/numpy/core/src/multiarray/common_dtype.c
index ca80b1ed7002..3561a905aa7a 100644
--- a/numpy/core/src/multiarray/common_dtype.c
+++ b/numpy/core/src/multiarray/common_dtype.c
@@ -41,7 +41,7 @@
  * @param dtype2 Second DType class.
  * @return The common DType or NULL with an error set
  */
-NPY_NO_EXPORT NPY_INLINE PyArray_DTypeMeta *
+NPY_NO_EXPORT PyArray_DTypeMeta *
 PyArray_CommonDType(PyArray_DTypeMeta *dtype1, PyArray_DTypeMeta *dtype2)
 {
     if (dtype1 == dtype2) {
diff --git a/numpy/core/src/umath/loops_unary_fp.dispatch.c.src b/numpy/core/src/umath/loops_unary_fp.dispatch.c.src
index 5817cf500b40..78e231965bca 100644
--- a/numpy/core/src/umath/loops_unary_fp.dispatch.c.src
+++ b/numpy/core/src/umath/loops_unary_fp.dispatch.c.src
@@ -128,6 +128,9 @@ NPY_FINLINE double c_square_f64(double a)
         #if __clang_major__ < 10
         // Clang before v10
         #define WORKAROUND_CLANG_RECIPROCAL_BUG 1
+        #elif defined(_MSC_VER)
+        // clang-cl has the same bug
+        #define WORKAROUND_CLANG_RECIPROCAL_BUG 1
         #elif defined(NPY_CPU_X86) || defined(NPY_CPU_AMD64)
         // Clang v10+, targeting i386 or x86_64
         #define WORKAROUND_CLANG_RECIPROCAL_BUG 0