Skip to contents

Make FFI function call

Source: R/01-functions.R
ffi_call.Rd

Call a C function through the FFI interface.

Usage

ffi_call(cif, symbol, ...)

Arguments

cif

CIF object defining the call interface

symbol

NativeSymbol or character name of function

...

Arguments to pass to the function (including na_check)

Value

The return value from the C function, converted to an R type

Details

The method implementations accept an additional na_check argument (logical, default TRUE). When TRUE, the function checks for NA values in arguments and errors if found. Set to FALSE to skip NA checking for better performance (at your own risk).

Error Handling Limitations

Important: libffi provides no error handling for the actual C function call. If the called C function crashes (segmentation fault, illegal instruction, abort, etc.), R itself will crash. This is a fundamental limitation of FFI

  • there is no portable way to catch such errors in C code.

Before making FFI calls, ensure:

  • The function pointer is valid (not NULL, points to executable code)

  • All pointer arguments are valid (use ffi_is_null to check)

  • Array/buffer sizes are correct - buffer overruns cause undefined behavior

  • The CIF signature exactly matches the C function's signature

  • Struct layouts match between R types and C (check alignment/padding)

For debugging crashes:

  • Run R under a debugger: R -d gdb

  • Enable core dumps: ulimit -c unlimited

  • Use address sanitizers when building the library being called

See also

ffi_is_null for checking pointer validity