fix: make static C++ linking opt-in for cross-platform app embedding

cpp-cli/CMakeLists.txt

@@ -5,50 +5,48 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-# ── Release Optimization Flags ────────────────────────────────────────────
-# Full static binary, size-optimized, no debug symbols in release mode.
-if(CMAKE_BUILD_TYPE STREQUAL "Release")
-    # Strip all debug symbols from the final binary
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffunction-sections -fdata-sections")
-    set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -s -Wl,--gc-sections -Wl,--strip-all")
-    # Optimize for size
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Os")
-endif()
+# ── Build Options ───────────────────────────────────────────────────────
+# Fully static linking is NOT safe as a default for arbitrary apps/platforms.
+# glibc, Wasmtime, TLS stacks, and system libraries can make static builds
+# brittle or impossible depending on the target. Keep it opt-in.
+option(BEX_FORCE_STATIC_EXE "Force fully static bexcli executable on Unix" OFF)
 
 # ── Build Configuration ──────────────────────────────────────────────────
 if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release)
 endif()
 
+# ── Release Optimization Flags ────────────────────────────────────────────
+if(CMAKE_BUILD_TYPE STREQUAL "Release")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffunction-sections -fdata-sections -Os")
+    if(NOT WIN32)
+        set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -Wl,--gc-sections")
+    endif()
+endif()
+
 # ── Bex Engine Integration ───────────────────────────────────────────────
-# This CMake is designed to be self-contained and reusable.
-# Copy this directory into any C++ project and it will automatically
-# find and link the Rust Bex Engine static library.
+# Reusable CMake integration for any C/C++ app.
 #
 # Requirements:
-#   1. Build the Rust library first: cargo build -p bex-runtime --release
-#   2. Set BEX_ENGINE_ROOT if this directory is not inside the bex-engine repo
+#   1. Build Rust library first: cargo build -p bex-runtime --release
+#   2. Set BEX_ENGINE_ROOT if cpp-cli/ is copied outside the repo.
 #
-# The Rust library exports a pure C ABI via bex_engine.h — no bridge crate needed.
+# The Rust library exports a pure C ABI via bex_engine.h — no cxx bridge.
 
-# Find the Bex Engine root directory
 if(NOT BEX_ENGINE_ROOT)
-    # Default: assume we're inside bex-engine/cpp-cli/
     get_filename_component(_BEX_ROOT "${CMAKE_SOURCE_DIR}/.." ABSOLUTE)
     if(EXISTS "${_BEX_ROOT}/Cargo.toml")
         set(BEX_ENGINE_ROOT "${_BEX_ROOT}")
     else()
         message(FATAL_ERROR
             "Cannot find Bex Engine root. Set -DBEX_ENGINE_ROOT=/path/to/bex-engine\n"
-            "The bex-engine directory should contain Cargo.toml and the crates/ directory."
+            "The bex-engine directory should contain Cargo.toml and crates/."
         )
     endif()
 endif()
 
 message(STATUS "Bex Engine root: ${BEX_ENGINE_ROOT}")
 
-# ── Rust Target Directory ────────────────────────────────────────────────
-# CMake uses "Release" / "Debug", but Rust uses "release" / "debug"
 if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo" OR CMAKE_BUILD_TYPE STREQUAL "MinSizeRel")
     set(RUST_PROFILE "release")
 else()
@@ -57,25 +55,25 @@ endif()
 
 set(RUST_TARGET_DIR "${BEX_ENGINE_ROOT}/target/${RUST_PROFILE}")
 
-# ── Detect the Rust library name ─────────────────────────────────────────
-# bex-runtime compiles as both cdylib and staticlib. The produced filename
-# differs by platform/toolchain: Windows (MSVC) -> "bex_runtime.lib"/.dll,
-# GNU toolchain -> "libbex_runtime.a"/.so. Prefer static when available.
-
+# ── Detect Rust library name ────────────────────────────────────────────
 if(WIN32)
     set(RUST_STATIC_LIB "${RUST_TARGET_DIR}/bex_runtime.lib")
     set(RUST_SHARED_LIB "${RUST_TARGET_DIR}/bex_runtime.dll")
+elseif(APPLE)
+    set(RUST_STATIC_LIB "${RUST_TARGET_DIR}/libbex_runtime.a")
+    set(RUST_SHARED_LIB "${RUST_TARGET_DIR}/libbex_runtime.dylib")
 else()
     set(RUST_STATIC_LIB "${RUST_TARGET_DIR}/libbex_runtime.a")
     set(RUST_SHARED_LIB "${RUST_TARGET_DIR}/libbex_runtime.so")
 endif()
 
+# Prefer static Rust archive when present, but do not force a fully static executable.
 if(EXISTS "${RUST_STATIC_LIB}")
-    set(BEX_LINK_MODE "static")
+    set(BEX_LINK_MODE "static-rustlib")
     set(BEX_LIB_PATH "${RUST_STATIC_LIB}")
     message(STATUS "Found Rust static library: ${BEX_LIB_PATH}")
 elseif(EXISTS "${RUST_SHARED_LIB}")
-    set(BEX_LINK_MODE "shared")
+    set(BEX_LINK_MODE "shared-rustlib")
     set(BEX_LIB_PATH "${RUST_SHARED_LIB}")
     message(STATUS "Found Rust shared library: ${BEX_LIB_PATH}")
 else()
@@ -83,70 +81,43 @@ else()
         "Rust library not found at ${RUST_STATIC_LIB} or ${RUST_SHARED_LIB}\n"
         "Build it first: cd ${BEX_ENGINE_ROOT} && cargo build -p bex-runtime --release"
     )
-    set(BEX_LINK_MODE "static")
+    set(BEX_LINK_MODE "static-rustlib")
     set(BEX_LIB_PATH "${RUST_STATIC_LIB}")
 endif()
 
-if(WIN32)
-    set(BEX_WINDOWS_SYS_LIBS bcrypt userenv ntdll advapi32)
-endif()
-
-# ── C Header Location ────────────────────────────────────────────────────
+# ── C Header Location ───────────────────────────────────────────────────
 set(BEX_INCLUDE_DIR "${CMAKE_SOURCE_DIR}")
 
-# ── Bex Engine Library (Imported Target) ─────────────────────────────────
-# Create an INTERFACE library target so other projects can simply do:
-#   target_link_libraries(myapp PRIVATE bex::engine)
-#   target_include_directories(myapp PRIVATE ${BEX_INCLUDE_DIR})
 add_library(bex_engine_lib INTERFACE)
 add_library(bex::engine ALIAS bex_engine_lib)
 
 target_include_directories(bex_engine_lib INTERFACE "${BEX_INCLUDE_DIR}")
 
-if(BEX_LINK_MODE STREQUAL "static")
-    if(WIN32)
-        target_link_libraries(bex_engine_lib INTERFACE
-            "${BEX_LIB_PATH}"
-            ${BEX_WINDOWS_SYS_LIBS}
-        )
-    else()
-        target_link_libraries(bex_engine_lib INTERFACE
-            "${BEX_LIB_PATH}"
-            dl
-            pthread
-            m
-        )
-        target_link_directories(bex_engine_lib INTERFACE "${RUST_TARGET_DIR}/deps")
-    endif()
+target_link_libraries(bex_engine_lib INTERFACE "${BEX_LIB_PATH}")
+
+if(WIN32)
+    target_link_libraries(bex_engine_lib INTERFACE bcrypt userenv ntdll advapi32 ws2_32 user32)
+elseif(APPLE)
+    target_link_libraries(bex_engine_lib INTERFACE
+        "-framework Security"
+        "-framework CoreFoundation"
+        pthread
+        m
+    )
 else()
-    if(WIN32)
-        target_link_libraries(bex_engine_lib INTERFACE
-            "${BEX_LIB_PATH}"
-        )
-    else()
-        target_link_libraries(bex_engine_lib INTERFACE
-            "${BEX_LIB_PATH}"
-            dl
-            pthread
-            m
-        )
-    endif()
+    target_link_libraries(bex_engine_lib INTERFACE dl pthread m)
+    target_link_directories(bex_engine_lib INTERFACE "${RUST_TARGET_DIR}/deps")
 endif()
 
-# ── Executable: bexcli ───────────────────────────────────────────────────
 add_executable(bexcli bexcli.cpp)
-
 target_include_directories(bexcli PRIVATE "${BEX_INCLUDE_DIR}")
-
 target_link_libraries(bexcli PRIVATE bex_engine_lib)
 
-# ── Static Linking for Release ────────────────────────────────────────────
-# Produce a fully static binary in release mode (no runtime dependencies).
-if(CMAKE_BUILD_TYPE STREQUAL "Release" AND NOT WIN32)
+# Optional fully-static Unix executable for environments that explicitly want it.
+if(BEX_FORCE_STATIC_EXE AND NOT WIN32 AND NOT APPLE)
     target_link_options(bexcli PRIVATE -static)
 endif()
 
-# ── Helper Target: Build Rust Library ────────────────────────────────────
 add_custom_target(rustlib
     COMMAND ${CMAKE_COMMAND} -E env cargo build -p bex-runtime --release
     WORKING_DIRECTORY ${BEX_ENGINE_ROOT}
@@ -154,19 +125,13 @@ add_custom_target(rustlib
     VERBATIM
 )
 
-# Make bexcli depend on rustlib if the library file doesn't exist yet
 if(NOT EXISTS "${BEX_LIB_PATH}")
     add_dependencies(bexcli rustlib)
 endif()
 
-# ── Install Rules (for integration into other projects) ──────────────────
 install(TARGETS bexcli RUNTIME DESTINATION bin)
-install(FILES
-    "${CMAKE_SOURCE_DIR}/bex_engine.h"
-    DESTINATION include/bex
-)
+install(FILES "${CMAKE_SOURCE_DIR}/bex_engine.h" DESTINATION include/bex)
 
-# ── Print Configuration Summary ──────────────────────────────────────────
 message(STATUS "")
 message(STATUS "=== Bex CLI Configuration (Pure C ABI) ===")
 message(STATUS "  Build type:       ${CMAKE_BUILD_TYPE}")
@@ -176,6 +141,7 @@ message(STATUS "  Rust target dir:  ${RUST_TARGET_DIR}")
 message(STATUS "  Link mode:        ${BEX_LINK_MODE}")
 message(STATUS "  Library path:     ${BEX_LIB_PATH}")
 message(STATUS "  Include dir:      ${BEX_INCLUDE_DIR}")
+message(STATUS "  Force static exe: ${BEX_FORCE_STATIC_EXE}")
 message(STATUS "  FFI:              Pure C ABI (bex_engine.h)")
 message(STATUS "==========================================")
 message(STATUS "")