[upstream_utils] Fix compilation failures on constexpr matrices with …

…GCC 14 (wpilibsuite#6626)

upstream_utils/eigen_patches/0001-Disable-warnings.patch

@@ -1,7 +1,7 @@
 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
 From: Tyler Veness <[email protected]>
 Date: Wed, 18 May 2022 09:14:24 -0700
-Subject: [PATCH 1/3] Disable warnings
+Subject: [PATCH 1/4] Disable warnings
 
 ---
  Eigen/src/Core/util/DisableStupidWarnings.h | 9 +++++++++

upstream_utils/eigen_patches/0002-Intellisense-fix.patch

@@ -1,7 +1,7 @@
 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
 From: Peter Johnson <[email protected]>
 Date: Fri, 20 Jan 2023 23:41:56 -0800
-Subject: [PATCH 2/3] Intellisense fix
+Subject: [PATCH 2/4] Intellisense fix
 
 ---
  Eigen/src/Core/util/ConfigureVectorization.h | 7 +++++++

upstream_utils/eigen_patches/0003-Suppress-C-23-deprecation-warnings-for-std-has_denor.patch

@@ -1,7 +1,7 @@
 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
 From: Tyler Veness <[email protected]>
 Date: Mon, 13 May 2024 12:46:15 -0700
-Subject: [PATCH 3/3] Suppress C++23 deprecation warnings for std::has_denorm
+Subject: [PATCH 3/4] Suppress C++23 deprecation warnings for std::has_denorm
  and std::has_denorm_loss
 
 ---

upstream_utils/eigen_patches/0004-Fix-compilation-failures-on-constexpr-matrices-with-.patch

@@ -0,0 +1,48 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Tyler Veness <[email protected]>
+Date: Tue, 14 May 2024 14:53:02 -0700
+Subject: [PATCH 4/4] Fix compilation failures on constexpr matrices with GCC
+ 14
+
+DenseBase must have a trivial default constructor.
+`constexpr DenseBase() {}` is not sufficient.
+---
+ Eigen/src/Core/DenseBase.h | 22 +++++++++++-----------
+ 1 file changed, 11 insertions(+), 11 deletions(-)
+
+diff --git a/Eigen/src/Core/DenseBase.h b/Eigen/src/Core/DenseBase.h
+index 5ab54efa3d8d454b2d5e02cb9d6145a723683b91..297c42679d978c36388ccba5831dab6624b6cb92 100644
+--- a/Eigen/src/Core/DenseBase.h
++++ b/Eigen/src/Core/DenseBase.h
+@@ -621,20 +621,20 @@ class DenseBase
+  protected:
+   EIGEN_DEFAULT_COPY_CONSTRUCTOR(DenseBase)
+   /** Default constructor. Do nothing. */
+-  EIGEN_DEVICE_FUNC constexpr DenseBase() {
+-    /* Just checks for self-consistency of the flags.
+-     * Only do it when debugging Eigen, as this borders on paranoia and could slow compilation down
+-     */
+ #ifdef EIGEN_INTERNAL_DEBUGGING
+-    EIGEN_STATIC_ASSERT(
+-        (internal::check_implication(MaxRowsAtCompileTime == 1 && MaxColsAtCompileTime != 1, int(IsRowMajor)) &&
+-         internal::check_implication(MaxColsAtCompileTime == 1 && MaxRowsAtCompileTime != 1, int(!IsRowMajor))),
+-        INVALID_STORAGE_ORDER_FOR_THIS_VECTOR_EXPRESSION)
++  EIGEN_DEVICE_FUNC constexpr DenseBase(){
++      /* Just checks for self-consistency of the flags.
++       * Only do it when debugging Eigen, as this borders on paranoia and could slow compilation down
++       */
++      EIGEN_STATIC_ASSERT(
++          (internal::check_implication(MaxRowsAtCompileTime == 1 && MaxColsAtCompileTime != 1, int(IsRowMajor)) &&
++           internal::check_implication(MaxColsAtCompileTime == 1 && MaxRowsAtCompileTime != 1, int(!IsRowMajor))),
++          INVALID_STORAGE_ORDER_FOR_THIS_VECTOR_EXPRESSION)}
++#else
++  EIGEN_DEVICE_FUNC constexpr DenseBase() = default;
+ #endif
+-  }
+
+- private:
+-  EIGEN_DEVICE_FUNC explicit DenseBase(int);
++  private : EIGEN_DEVICE_FUNC explicit DenseBase(int);
+   EIGEN_DEVICE_FUNC DenseBase(int, int);
+   template <typename OtherDerived>
+   EIGEN_DEVICE_FUNC explicit DenseBase(const DenseBase<OtherDerived>&);

upstream_utils/update_eigen.py

@@ -110,6 +110,7 @@ def main():
         "0001-Disable-warnings.patch",
         "0002-Intellisense-fix.patch",
         "0003-Suppress-C-23-deprecation-warnings-for-std-has_denor.patch",
+        "0004-Fix-compilation-failures-on-constexpr-matrices-with-.patch",
     ]:
         git_am(os.path.join(wpilib_root, "upstream_utils/eigen_patches", f))
 

wpimath/src/main/native/thirdparty/eigen/include/Eigen/src/Core/DenseBase.h

@@ -621,20 +621,20 @@ class DenseBase
  protected:
   EIGEN_DEFAULT_COPY_CONSTRUCTOR(DenseBase)
   /** Default constructor. Do nothing. */
-  EIGEN_DEVICE_FUNC constexpr DenseBase() {
-    /* Just checks for self-consistency of the flags.
-     * Only do it when debugging Eigen, as this borders on paranoia and could slow compilation down
-     */
 #ifdef EIGEN_INTERNAL_DEBUGGING
-    EIGEN_STATIC_ASSERT(
-        (internal::check_implication(MaxRowsAtCompileTime == 1 && MaxColsAtCompileTime != 1, int(IsRowMajor)) &&
-         internal::check_implication(MaxColsAtCompileTime == 1 && MaxRowsAtCompileTime != 1, int(!IsRowMajor))),
-        INVALID_STORAGE_ORDER_FOR_THIS_VECTOR_EXPRESSION)
+  EIGEN_DEVICE_FUNC constexpr DenseBase(){
+      /* Just checks for self-consistency of the flags.
+       * Only do it when debugging Eigen, as this borders on paranoia and could slow compilation down
+       */
+      EIGEN_STATIC_ASSERT(
+          (internal::check_implication(MaxRowsAtCompileTime == 1 && MaxColsAtCompileTime != 1, int(IsRowMajor)) &&
+           internal::check_implication(MaxColsAtCompileTime == 1 && MaxRowsAtCompileTime != 1, int(!IsRowMajor))),
+          INVALID_STORAGE_ORDER_FOR_THIS_VECTOR_EXPRESSION)}
+#else
+  EIGEN_DEVICE_FUNC constexpr DenseBase() = default;
 #endif
-  }
 
- private:
-  EIGEN_DEVICE_FUNC explicit DenseBase(int);
+  private : EIGEN_DEVICE_FUNC explicit DenseBase(int);
   EIGEN_DEVICE_FUNC DenseBase(int, int);
   template <typename OtherDerived>
   EIGEN_DEVICE_FUNC explicit DenseBase(const DenseBase<OtherDerived>&);