build: patch nix cpp toolchain compatibility

Author: darwin67

CMakeLists.txt

@@ -42,6 +42,9 @@ endif()
 
 include(limit_jobs)
 # Configure Seastar compile options to align with Scylla
+if(DEFINED ENV{NIX_CC})
+  add_compile_definitions(FMT_USE_CONSTEVAL=0)
+endif()
 set(CMAKE_CXX_STANDARD "23" CACHE INTERNAL "")
 set(CMAKE_CXX_EXTENSIONS ON CACHE INTERNAL "")
 set(CMAKE_CXX_SCAN_FOR_MODULES OFF CACHE INTERNAL "")

cmake/mode.common.cmake

@@ -6,6 +6,7 @@ set(disabled_warnings
   overloaded-virtual
   unsupported-friend
   enum-constexpr-conversion
+  unnecessary-virtual-specifier
   unused-parameter)
 include(CheckCXXCompilerFlag)
 foreach(warning ${disabled_warnings})

configure.py

@@ -1548,6 +1548,7 @@ def get_warning_options(cxx):
         '-Wno-unsupported-friend',
         '-Wno-missing-field-initializers',
         '-Wno-deprecated-copy',
+        '-Wno-unnecessary-virtual-specifier',
         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
         '-Wno-psabi',
         '-Wno-enum-constexpr-conversion',
@@ -1675,6 +1676,9 @@ def dynamic_linker_option():
 if args.target != '':
     user_cflags += ' -march=' + args.target
 
+if os.environ.get('NIX_CC'):
+    user_cflags += ' -DFMT_USE_CONSTEVAL=0'
+
 for mode in modes:
     # Those flags are passed not only to Scylla objects, but also to libraries
     # that we compile ourselves.

flake.nix

@@ -39,6 +39,21 @@
         lib = pkgs.lib;
         llvm = pkgs.llvmPackages;
 
+        antlr3Cpp = pkgs.antlr3.overrideAttrs (old: {
+          postInstall = (old.postInstall or "") + ''
+            sed -i \
+              -e 's/const ANTLR_INT32[[:space:]]*m_decisionNumber;/ANTLR_INT32 m_decisionNumber;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_eot;/const ANTLR_INT32* m_eot;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_eof;/const ANTLR_INT32* m_eof;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_min;/const ANTLR_INT32* m_min;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_max;/const ANTLR_INT32* m_max;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_accept;/const ANTLR_INT32* m_accept;/' \
+              -e 's/const ANTLR_INT32\* const[[:space:]]*m_special;/const ANTLR_INT32* m_special;/' \
+              -e 's/const ANTLR_INT32\* const \*const[[:space:]]*m_transition;/const ANTLR_INT32* const * m_transition;/' \
+              "$out/include/antlr3cyclicdfa.hpp"
+          '';
+        });
+
         pythonEnv = pkgs.python3.withPackages (
           ps: with ps; [
             aiohttp
@@ -107,7 +122,7 @@
               flake = true;
               shell = true;
               srcPath = self;
-              antlr3Package = pkgs.antlr3;
+              antlr3Package = antlr3Cpp;
               fmtPackage = pkgs.fmt_10.overrideAttrs (old: {
                 cmakeFlags = (old.cmakeFlags or [ ]) ++ [
                   "-DFMT_TEST=OFF"