3 files changed, 239 insertions, 0 deletions
diff --git a/libsupport/src/corelib/math/MathExtras.cc b/libsupport/src/corelib/math/MathExtras.cc
new file mode 100644
index 0000000..99d7ba7
--- /dev/null
+++ b/libsupport/src/corelib/math/MathExtras.cc
@@ -0,0 +1,97 @@
+/*
+ RCC-Project
+
+ Copyright (C) 2026 Richard Qin
+
+ This file is part of RCC-Project.
+
+ RCC-Project is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your option) any
+ later version.
+
+ RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ RCC-Project; see the file COPYING.  If not see
+ <http://www.gnu.org/licenses/>.
+*/
+
+//===-- MathExtras.cpp - Implement the MathExtras header --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the MathExtras.h header
+//
+//===----------------------------------------------------------------------===//
+
+#include "CoreLib/Math/MathExtras.h"
+
+#ifdef _MSC_VER
+#include <limits>
+#else
+#include <cmath>
+#endif
+
+namespace rcc
+{
+
+#if defined(_MSC_VER)
+// Visual Studio defines the HUGE_VAL class of macros using purposeful
+// constant arithmetic overflow, which it then warns on when encountered.
+const float huge_valf = std::numeric_limits<float>::infinity ();
+#else
+const float huge_valf = HUGE_VALF;
+#endif
+
+/// Returns the number of digits in the given integer.
+int
+NumDigitsBase10 (uint64_t X)
+{
+  static constexpr struct ConstexprData
+  {
+    uint8_t AtLeast[65] = {};
+    uint64_t Boundaries[20] = {};
+    static constexpr int
+    NumDigitsConstexpr (uint64_t N)
+    {
+      int res = 1;
+      while (N >= 10)
+      {
+        res++;
+        N /= 10;
+      }
+      return res;
+    }
+    constexpr ConstexprData ()
+    {
+      uint64_t Val = ~0ull;
+      for (uint64_t i = 0; i <= 64; i++)
+      {
+        uint64_t Digits = NumDigitsConstexpr (Val) - 1;
+        AtLeast[i] = Digits;
+        Val >>= 1;
+      }
+      // Special case because X=0 should return 1 and not 0
+      Boundaries[0] = 0;
+      Val = 10;
+      for (uint64_t i = 1; i < 20; i++)
+      {
+        Boundaries[i] = Val;
+        Val *= 10;
+      }
+    }
+  } Data;
+
+  uint64_t Base2 = X ? std::countl_zero (X) : 64;
+  uint64_t Digits = Data.AtLeast[Base2];
+  return Digits + (X >= Data.Boundaries[Digits]);
+}
+
+} // namespace rcc
diff --git a/libsupport/src/corelib/memory/MemAlloc.cpp b/libsupport/src/corelib/memory/MemAlloc.cpp
new file mode 100644
index 0000000..9413922
--- /dev/null
+++ b/libsupport/src/corelib/memory/MemAlloc.cpp
@@ -0,0 +1,63 @@
+/*
+ RCC-Project
+
+ Copyright (C) 2026 Richard Qin
+
+ This file is part of RCC-Project.
+
+ RCC-Project is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your option) any
+ later version.
+
+ RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ RCC-Project; see the file COPYING.  If not see
+ <http://www.gnu.org/licenses/>.
+ */
+
+//===- MemAlloc.cpp - Memory allocation functions -------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CoreLib/Memory/MemAlloc.h"
+#include <new>
+
+// These are out of line to have __cpp_aligned_new not affect ABI.
+
+RCC_ATTRIBUTE_RETURNS_NONNULL RCC_ATTRIBUTE_RETURNS_NOALIAS void *
+rcc::allocate_buffer (size_t Size, size_t Alignment)
+{
+  void *Result = ::operator new (Size,
+#ifdef __cpp_aligned_new
+                                 std::align_val_t (Alignment),
+#endif
+                                 std::nothrow);
+  if (Result == nullptr)
+  {
+    report_bad_alloc_error ("Buffer allocation failed");
+  }
+  return Result;
+}
+
+void
+rcc::deallocate_buffer (void *Ptr, size_t Size, size_t Alignment)
+{
+  ::operator delete (Ptr
+#ifdef __cpp_sized_deallocation
+                     ,
+                     Size
+#endif
+#ifdef __cpp_aligned_new
+                     ,
+                     std::align_val_t (Alignment)
+#endif
+  );
+}
diff --git a/libsupport/src/corelib/system/Errno.cc b/libsupport/src/corelib/system/Errno.cc
new file mode 100644
index 0000000..66ced94
--- /dev/null
+++ b/libsupport/src/corelib/system/Errno.cc
@@ -0,0 +1,79 @@
+/*
+ RCC-Project
+
+ Copyright (C) 2026 Richard Qin
+
+ This file is part of RCC-Project.
+
+ RCC-Project is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your option) any
+ later version.
+
+ RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ RCC-Project; see the file COPYING.  If not see
+ <http://www.gnu.org/licenses/>.
+*/
+
+// This implementation is based on llvm/lib/Support/Errno.cpp.
+
+#include "CoreLib/System/Errno.h"
+#include "rcc/Config/config.h"
+
+#include <cstring>
+#include <errno.h>
+
+namespace rcc
+{
+namespace sys
+{
+
+std::string
+StrError ()
+{
+  return StrError (errno);
+}
+
+std::string
+StrError (int errnum)
+{
+  std::string str;
+  if (errnum == 0)
+  {
+    return str;
+  }
+
+#if defined(HAVE_STRERROR_R) || HAVE_DECL_STRERROR_S
+  const int maxErrStrLen = 2000;
+  char buffer[maxErrStrLen];
+  buffer[0] = '\0';
+#endif
+
+#ifdef HAVE_STRERROR_R
+  // strerror_r is thread-safe.
+#if defined(__GLIBC__) && defined(_GNU_SOURCE)
+  // glibc defines its own incompatible version of strerror_r which may not
+  // use the buffer supplied.
+  str = strerror_r (errnum, buffer, maxErrStrLen - 1);
+#else
+  strerror_r (errnum, buffer, maxErrStrLen - 1);
+  str = buffer;
+#endif
+#elif HAVE_DECL_STRERROR_S
+  // Windows Secure API.
+  strerror_s (buffer, maxErrStrLen - 1, errnum);
+  str = buffer;
+#else
+  // Copy the thread-unsafe result of strerror into the buffer as fast as
+  // possible to minimize the impact of collisions in multiple threads.
+  str = strerror (errnum);
+#endif
+  return str;
+}
+
+} // namespace sys
+} // namespace rcc