tcc_call_symbol: Call a symbol from a TinyCC state

In Rtinycc: Builds the 'TinyCC' Command-Line Interface and Library for 'C' Scripting in 'R'

Call a symbol from a TinyCC state

Description

The memory state must first be successfully finalized with tcc_relocate().

Usage

tcc_call_symbol(
  .state,
  .NAME,
  ...,
  return = c("int", "double", "void"),
  NAOK = FALSE
)

Arguments

.state	A tcc_state. Named ⁠state =⁠ is also accepted for compatibility with earlier releases.
.NAME	Symbol name to call. Named ⁠name =⁠ is also accepted for compatibility with earlier releases.
...	Optional arguments for .C()-style pointer calls.
return	One of "int", "double", or "void". If ... is present, the only supported value is "void"; when omitted with ..., it defaults to "void".
NAOK	If FALSE, integer/logical NA and non-finite numeric/complex values are rejected before the call, matching .C()'s default safety check. If TRUE, those values are passed through.

Details

With no additional arguments, tcc_call_symbol() preserves its historical quick-test behavior: call a zero-argument symbol and box an int, double, or void return value.

With additional arguments, it uses an R .C()-style calling convention: the target C function must be void, each atomic or character R argument is copied to guarded mutable call storage and passed by pointer, and the result is a list of the modified argument values. Supported argument mappings follow R's .C() interface: raw as ⁠unsigned char *⁠, integer/logical as ⁠int *⁠, numeric as ⁠double *⁠ or ⁠float *⁠ when attr(x, "Csingle") is true, complex as ⁠Rcomplex *⁠, character as ⁠char **⁠, lists as read-only ⁠SEXP *⁠, and functions/environments/other R objects as read-only SEXP. Up to 65 arguments are supported. Guard bytes around copied buffers are checked after the call to catch simple native underwrites and overwrites; character code may edit string contents in place but must not replace ⁠char *⁠ elements in the ⁠char **⁠ array.

Non-atomic R objects are borrowed for the duration of the call only. C code must not mutate them through this interface, and must call R_PreserveObject() if it deliberately stores a SEXP beyond the call. This is a low-level convenience interface; for typed scalar returns, explicit zero-copy arrays, ownership metadata, and clearer signatures, prefer tcc_ffi().

Value

For zero-argument scalar calls, the boxed return value (NULL for void). For .C()-style calls, a list mirroring ... with any C-side modifications copied back.

Rtinycc documentation built on July 26, 2026, 1:06 a.m.