Type conflict with mp_digit and mp_int when building against Tcl with bundled libtommath

[Sublime1]

Hello!

thank you for this wonderful library. I recent upgraded from 0.15.3 to 0.15.7 and ran into some problems. I'm building a Docker container that runs Naviserver. I got my LLM to help write up this issue - hope that's OK to do.

When building RL_JSON against a Tcl installation that exposes its own copy of libtommath (e.g., via tcl.h), the build fails due to conflicting type definitions for mp_digit and mp_int. RL_JSON vendors its own copy of libtommath, while Tcl also exposes these types, but with potentially different definitions.

Error output

local/include/tommath.h:59:18: error: conflicting types for 'mp_digit'; have 'uint64_t' {aka 'long unsigned int'}
/usr/local/ns/include/tcl.h:2258:22: note: previous declaration of 'mp_digit' with type 'mp_digit' {aka 'unsigned int'}
local/include/tommath.h:179:3: error: conflicting types for 'mp_int'; have 'struct '
/usr/local/ns/include/tcl.h:2256:23: note: previous declaration of 'mp_int' with type 'mp_int'

Environment

Ubuntu 24.04.2 LTS Docker container running on WSL on Windows 11
Tcl version: 8.6.17
RL_JSON version: 0.15.7

[ngc1399-tech]

I also have the same issue building the extension on RHEL 8.10 with gcc 15.2.0.

[fgaz]

I had the same problem while updating the NixOS package (NixOS/nixpkgs#497128) for rl_json. Switching back to tclTomMath didn't seem to cause any issue so I did just that. Maybe I'm wrong though. It'd be nice to know if/why "proper bignum handling" (according to 9294d53) requires upstream libtommath.

[fgaz]

Seems to be fixed in 0.16