From 63ef585d4b80a960087e016badde1e14460e235f Mon Sep 17 00:00:00 2001
From: Benjamin Hall <bhall@ctr-electronics.com>
Date: Tue, 24 Oct 2023 00:35:13 -0400
Subject: [PATCH] [wpiutil] Fix compilation of MathExtras.h on Windows with
 /sdl (#5809)

Fix copied from the LLVM main branch.
---
 ...-of-MathExtras.h-on-Windows-with-sdl.patch | 26 +++++++++++++++++++
 upstream_utils/update_llvm.py                 |  1 +
 .../thirdparty/llvm/include/wpi/MathExtras.h  |  5 +++-
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 upstream_utils/llvm_patches/0032-Fix-compilation-of-MathExtras.h-on-Windows-with-sdl.patch

diff --git a/upstream_utils/llvm_patches/0032-Fix-compilation-of-MathExtras.h-on-Windows-with-sdl.patch b/upstream_utils/llvm_patches/0032-Fix-compilation-of-MathExtras.h-on-Windows-with-sdl.patch
new file mode 100644
index 0000000000..52956f95ba
--- /dev/null
+++ b/upstream_utils/llvm_patches/0032-Fix-compilation-of-MathExtras.h-on-Windows-with-sdl.patch
@@ -0,0 +1,26 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Benjamin Hall <bhallctre@gmail.com>
+Date: Mon, 23 Oct 2023 21:36:40 -0400
+Subject: [PATCH 32/32] Fix compilation of MathExtras.h on Windows with /sdl
+
+See https://github.com/llvm/llvm-project/pull/68978
+---
+ llvm/include/llvm/Support/MathExtras.h | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/llvm/include/llvm/Support/MathExtras.h b/llvm/include/llvm/Support/MathExtras.h
+index 5f034b694989d8ef24e0b249abd12a5c20146b97..03db6e4d92cb3b62ac3d8b3cbd97783817c6326b 100644
+--- a/llvm/include/llvm/Support/MathExtras.h
++++ b/llvm/include/llvm/Support/MathExtras.h
+@@ -356,7 +356,10 @@ inline uint64_t alignTo(uint64_t Value, uint64_t Align) {
+ inline uint64_t alignToPowerOf2(uint64_t Value, uint64_t Align) {
+   assert(Align != 0 && (Align & (Align - 1)) == 0 &&
+          "Align must be a power of 2");
+-  return (Value + Align - 1) & -Align;
++  // Replace unary minus to avoid compilation error on Windows:
++  // "unary minus operator applied to unsigned type, result still unsigned"
++  uint64_t negAlign = (~Align) + 1;
++  return (Value + Align - 1) & negAlign;
+ }
+ 
+ /// If non-zero \p Skew is specified, the return value will be a minimal integer
diff --git a/upstream_utils/update_llvm.py b/upstream_utils/update_llvm.py
index 3414ec4deb..edbd3df716 100755
--- a/upstream_utils/update_llvm.py
+++ b/upstream_utils/update_llvm.py
@@ -209,6 +209,7 @@ def main():
         "0029-Use-C-20-bit-header.patch",
         "0030-Remove-DenseMap-GTest-printer-test.patch",
         "0031-Replace-deprecated-std-aligned_storage_t.patch",
+        "0032-Fix-compilation-of-MathExtras.h-on-Windows-with-sdl.patch",
     ]:
         git_am(
             os.path.join(wpilib_root, "upstream_utils/llvm_patches", f),
diff --git a/wpiutil/src/main/native/thirdparty/llvm/include/wpi/MathExtras.h b/wpiutil/src/main/native/thirdparty/llvm/include/wpi/MathExtras.h
index b77cce7bd9..ed3b2b1efc 100644
--- a/wpiutil/src/main/native/thirdparty/llvm/include/wpi/MathExtras.h
+++ b/wpiutil/src/main/native/thirdparty/llvm/include/wpi/MathExtras.h
@@ -356,7 +356,10 @@ inline uint64_t alignTo(uint64_t Value, uint64_t Align) {
 inline uint64_t alignToPowerOf2(uint64_t Value, uint64_t Align) {
   assert(Align != 0 && (Align & (Align - 1)) == 0 &&
          "Align must be a power of 2");
-  return (Value + Align - 1) & -Align;
+  // Replace unary minus to avoid compilation error on Windows:
+  // "unary minus operator applied to unsigned type, result still unsigned"
+  uint64_t negAlign = (~Align) + 1;
+  return (Value + Align - 1) & negAlign;
 }
 
 /// If non-zero \p Skew is specified, the return value will be a minimal integer