config: disable C++ support by default

Introduces a FD_HAS_CXX flag that re-enables it

Author: riptl

config/base.mk

@@ -35,6 +35,9 @@ LD?=$(CXX)
 LLVM_COV?=llvm-cov
 LLVM_PROFDATA?=llvm-profdata
 
+# C++ support (libstdc++ and default exception handler)
+#FD_HAS_CXX:=1
+
 # Rust
 RUST_PROFILE=debug
 

config/extra/with-clang.mk

@@ -36,7 +36,3 @@ CPPFLAGS+=-DFD_USING_CLANG=1
 # itself doesn't matter ... only that the variable is defined).
 
 FD_USING_CLANG:=1
-
-# Using clang++ doesn't always bring in this library
-
-LDFLAGS+=-lstdc++

config/extra/with-libcxx.mk

@@ -13,6 +13,7 @@ ifndef LIBCXX
 $(error LIBCXX is not set)
 endif
 
+FD_HAS_CXX:=1
 CXXFLAGS+=-nostdinc++ -nostdlib++
 CXXFLAGS+=-isystem $(LIBCXX)/include/c++/v1
 LDFLAGS+=$(LIBCXX)/lib/libc++.a $(LIBCXX)/lib/libc++abi.a

config/extra/with-rocksdb.mk

@@ -2,8 +2,12 @@ ifneq (,$(wildcard $(OPT)/lib/librocksdb.a))
 ifneq (,$(wildcard $(OPT)/lib/libsnappy.a))
 ifneq (,$(wildcard $(OPT)/lib/libzstd.a))
 FD_HAS_ROCKSDB:=1
+FD_HAS_CXX:=1
 CFLAGS+=-DFD_HAS_ROCKSDB=1 -DROCKSDB_LITE=1
 ROCKSDB_LIBS:=$(OPT)/lib/librocksdb.a $(OPT)/lib/libsnappy.a
+ifndef LIBCXX
+ROCKSDB_LIBS+=-lstdc++
+endif
 
 # RocksDB enables io_uring support opportunistically; only link liburing when
 # the static archive actually references its symbols (e.g. Arch Linux builds).

contrib/quic/agave_compat/build.rs

@@ -29,7 +29,6 @@ fn main() {
             lib
         );
     }
-    println!("cargo:rustc-link-lib=static=stdc++"); // fd_tile_threads.cxx
 
     let mut include_path = build_path.clone();
     include_path.push("include");

contrib/quic/go_compat/main.go

@@ -8,7 +8,6 @@ package main
 // #cgo LDFLAGS: -lfd_tango
 // #cgo LDFLAGS: -lfd_ballet
 // #cgo LDFLAGS: -lfd_util
-// #cgo LDFLAGS: -lstdc++
 // #include <stdlib.h>
 // #include <stdio.h>
 // #include <firedancer/waltz/quic/fd_quic.h>

contrib/quic/rust_compat/build.rs

@@ -29,7 +29,6 @@ fn main() {
             lib
         );
     }
-    println!("cargo:rustc-link-lib=static=stdc++"); // fd_tile_threads.cxx
 
     let mut include_path = build_path.clone();
     include_path.push("include");

src/util/tile/Local.mk

@@ -3,7 +3,11 @@ $(call add-objs,fd_tile,fd_util)
 ifdef FD_HAS_THREADS
 $(call make-unit-test,test_cpuset,test_cpuset,fd_util)
 $(call run-unit-test,test_cpuset)
+ifdef FD_HAS_CXX
+$(call add-objs,fd_tile_threads_cxx,fd_util)
+else
 $(call add-objs,fd_tile_threads,fd_util)
+endif
 else
 $(call add-objs,fd_tile_nothreads,fd_util)
 endif

src/util/tile/fd_tile_threads.c

@@ -0,0 +1 @@
+#include "fd_tile_threads.inc"

src/util/tile/fd_tile_threads.cxx src/util/tile/fd_tile_threads.incsrc/util/tile/fd_tile_threads.cxx renamed to src/util/tile/fd_tile_threads.inc

@@ -339,12 +339,16 @@ fd_tile_private_manager( void * _args ) {
     int            argc = FD_VOLATILE_CONST( tile->argc );
     char **        argv = FD_VOLATILE_CONST( tile->argv );
     fd_tile_task_t task = FD_VOLATILE_CONST( tile->task );
+#   ifdef __cplusplus
     try {
+#   endif
       FD_VOLATILE( tile->ret  ) = task( argc, argv );
       FD_VOLATILE( tile->fail ) = NULL;
+#   ifdef __cplusplus
     } catch( ... ) {
       FD_VOLATILE( tile->fail ) = "uncaught exception";
     }
+#   endif
 
     FD_COMPILER_MFENCE();
     FD_VOLATILE( tile->state ) = FD_TILE_PRIVATE_STATE_IDLE;