Class: FFI::Clang::MswinArgs

Inherits:
Args
  • Object
show all
Defined in:
lib/ffi/clang/args/mswin.rb

Overview

MSVC-specific clang configuration. Discovers libclang and system include paths from the Visual Studio installation:

  1. Find the VS installation path via vswhere.exe

  2. Call vcvarsall.bat to set up the MSVC developer environment

  3. Run clang-cl -v -E -x c++ NUL in that environment

  4. Parse the “#include <…> search starts here:” block from the output

  5. Inject each discovered path as -I into parse_translation_unit

Constant Summary collapse

VSWHERE = 
"C:/Program Files (x86)/Microsoft Visual Studio/Installer/vswhere.exe"

Instance Attribute Summary

Attributes inherited from Args

#libclang_loaded_path

Instance Method Summary collapse

Methods inherited from Args

#command_line_args, create, #libclang_paths, #resource_dir

Instance Method Details

#post_load(library) ⇒ Object

Pin libclang in memory so Windows will not unload it at exit.

LLVM’s rpmalloc allocator registers Fiber Local Storage (FLS) callbacks via FlsAlloc but does not call FlsFree on DLL_PROCESS_DETACH (LLVM bug #154361, fixed in LLVM 22.1.0 by github.com/llvm/llvm-project/pull/171465). Pinning with GET_MODULE_HANDLE_EX_FLAG_PIN prevents the unload so the FLS callbacks remain valid through process shutdown.



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# File 'lib/ffi/clang/args/mswin.rb', line 29

def post_load(library)
	symbol = library.find_symbol("clang_getClangVersion")
	return unless symbol
	
	kernel32 = FFI::DynamicLibrary.open("kernel32", 0)
	get_module_handle_ex_w = kernel32.find_function("GetModuleHandleExW")
	return unless get_module_handle_ex_w
	
	get_module_handle_ex_flag_from_address = 0x4
	get_module_handle_ex_flag_pin = 0x1
	flags = get_module_handle_ex_flag_from_address | get_module_handle_ex_flag_pin
	handle_out = FFI::MemoryPointer.new(:pointer)
	pin = FFI::Function.new(:bool, [:uint, :pointer, :pointer], get_module_handle_ex_w)
	pin.call(flags, symbol, handle_out)
end