Keep Python key buffers alive in WriteRange/ReadRange

`write()` and `read()` created _Key objects from ephemeral ctypes arrays
backed by local bytearray objects. Once the helpers returned, those local
variables were freed, leaving the C library with dangling pointers when
addWrites()/check() later read the keys.

Store the backing bytearray on the returned WriteRange/ReadRange objects
as private `_begin_buf` / `_end_buf` attributes. Python keeps them alive
for the lifetime of the range object, so the C pointer is always valid.

Closes #42

.gitea/workflows/ci.yml

@@ -19,15 +19,9 @@ jobs:
 
       - name: Install dependencies
         run: |
-          . /etc/os-release
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
-          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
           sudo apt-get update -qq
           sudo apt-get install -y \
-            clang-21 git nodejs pre-commit
+            clang git nodejs pre-commit
-          for tool in clang clang++; do
-            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
-          done
 
       - uses: actions/cache@v4
         with:
@@ -63,18 +57,12 @@ jobs:
 
       - name: Install dependencies
         run: |
-          . /etc/os-release
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
-          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
           sudo apt-get update -qq
           sudo apt-get install -y \
-            build-essential ccache clang-21 cmake gcc g++ \
+            build-essential ccache clang cmake gcc g++ \
-            libc6-dbg llvm-21 lld-21 mold ninja-build python3 valgrind zstd
+            libc6-dbg llvm mold ninja-build python3 valgrind zstd
           sudo curl -Ls "https://dl.min.io/client/mc/release/linux-amd64/mc" \
             -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
-          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
-            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
-          done
 
       - uses: actions/cache@v4
         with:
@@ -136,20 +124,14 @@ jobs:
 
       - name: Install dependencies
         run: |
-          . /etc/os-release
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
-          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
           sudo apt-get update -qq
           sudo apt-get install -y \
-            biber build-essential ccache clang-21 cmake devscripts \
+            biber build-essential ccache clang cmake devscripts \
-            latexmk libc6-dbg llvm-21 lld-21 mold ninja-build rpm \
+            latexmk libc6-dbg llvm mold ninja-build rpm \
             texlive-bibtex-extra texlive-fonts-recommended \
             texlive-latex-extra texlive-pictures valgrind zstd
           sudo curl -Ls "https://dl.min.io/client/mc/release/linux-$(dpkg --print-architecture)/mc" \
             -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
-          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
-            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
-          done
 
       - uses: actions/cache@v4
         with:
@@ -230,18 +212,12 @@ jobs:
 
       - name: Install dependencies
         run: |
-          . /etc/os-release
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
-          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
           sudo apt-get update -qq
           sudo apt-get install -y \
-            build-essential ccache clang-21 cmake gcovr \
+            build-essential ccache clang cmake gcovr \
-            libc6-dbg llvm-21 lld-21 mold ninja-build python3 valgrind zstd
+            libc6-dbg llvm mold ninja-build python3 valgrind zstd
           sudo curl -Ls "https://dl.min.io/client/mc/release/linux-amd64/mc" \
             -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
-          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
-            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
-          done
 
       - uses: actions/cache@v4
         with:

CMakeLists.txt

@@ -383,25 +383,13 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
   if(NOT CMAKE_CROSSCOMPILING)
     find_program(HARDENING_CHECK hardening-check)
     if(HARDENING_CHECK)
-      # Not all versions of hardening-check support the same options, so query
-      # the help output before using architecture-specific skips.
-      execute_process(
-        COMMAND ${HARDENING_CHECK} --help
-        OUTPUT_VARIABLE hardening_check_help
-        ERROR_VARIABLE hardening_check_help
-        OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_STRIP_TRAILING_WHITESPACE)
-      set(hardening_check_arch_flags "")
       # Control flow integrity (CET) is x86-only and branch protection (PAC/BTI)
       # is arm64-only, so ignore whichever doesn't apply.
       if(CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64 OR CMAKE_SYSTEM_PROCESSOR
                                                     STREQUAL arm64)
-        if(hardening_check_help MATCHES "nocfprotection")
+        set(hardening_check_arch_flags --nocfprotection)
-          list(APPEND hardening_check_arch_flags --nocfprotection)
-        endif()
       else()
-        if(hardening_check_help MATCHES "nobranchprotection")
+        set(hardening_check_arch_flags --nobranchprotection)
-          list(APPEND hardening_check_arch_flags --nobranchprotection)
-        endif()
       endif()
       add_test(
         NAME hardening_check

conflict_set.py

@@ -102,7 +102,6 @@ class ConflictSet:
             ctypes.POINTER(ctypes.c_int),
             ctypes.c_int,
         )
-        self._lib.ConflictSet_check.restype = None
 
         self._lib.ConflictSet_addWrites.argtypes = (
             ctypes.c_void_p,
@@ -110,16 +109,13 @@ class ConflictSet:
             ctypes.c_int,
             ctypes.c_int64,
         )
-        self._lib.ConflictSet_addWrites.restype = None
 
         self._lib.ConflictSet_setOldestVersion.argtypes = (
             ctypes.c_void_p,
             ctypes.c_int64,
         )
-        self._lib.ConflictSet_setOldestVersion.restype = None
 
         self._lib.ConflictSet_destroy.argtypes = (ctypes.c_void_p,)
-        self._lib.ConflictSet_destroy.restype = None
 
         self._lib.ConflictSet_getBytes.argtypes = (ctypes.c_void_p,)
         self._lib.ConflictSet_getBytes.restype = ctypes.c_int64