CMake: gate -nostdlib for executables via GITLEDGER_USE_NOSTDLIB (OFF); keep -nostdlib on library (non‑MSVC)

Author: flyingrobots

CMakeLists.txt

@@ -26,6 +26,7 @@ if(MSVC)
 else()
 
 include(CheckCCompilerFlag)
+option(GITLEDGER_USE_NOSTDLIB "Link executables with -nostdlib (non-MSVC)" OFF)
 # Project policy: strict warnings, C99, no fun, visibility hidden.
 set(PROJECT_WARNING_FLAGS -Wall -Wextra -Werror -pedantic -Wshadow -Wconversion -fvisibility=hidden -std=c99)
 check_c_compiler_flag("-Wno-fun" COMPILER_SUPPORTS_WNOFUN)
@@ -54,10 +55,14 @@ add_library(gitledger STATIC ${LIBGITLEDGER_SOURCES} ${LIBGITLEDGER_HEADERS})
 target_compile_options(gitledger PRIVATE ${PROJECT_WARNING_FLAGS})
 target_compile_definitions(gitledger PRIVATE GITLEDGER_BUILD=1)
 function(add_nostdlib target)
-  if(NOT MSVC)
+  if(GITLEDGER_USE_NOSTDLIB AND NOT MSVC)
     target_link_options(${target} PRIVATE -nostdlib)
   endif()
 endfunction()
+if(NOT MSVC)
+  # Keep library pure/freestanding from the linker perspective.
+  target_link_options(gitledger PRIVATE -nostdlib)
+endif()
 
 if(GITLEDGER_VENDOR_LIBGIT2)
     message(FATAL_ERROR "Vendored libgit2 support is not implemented yet.\n"
@@ -130,7 +135,6 @@ if(BUILD_TESTING)
     add_test(NAME gitledger_cli_smoke COMMAND gitledger_tests)
     add_test(NAME error COMMAND gitledger_error_test)
 endif()
-add_nostdlib(gitledger)
 add_nostdlib(gitledger_version_test)
 add_nostdlib(gitledger_tests)
 add_nostdlib(mg-ledger)