Problem

n_atof.c uses a K&R (pre-ANSI C) style function definition for JAtoN, separating parameter types from the parameter list:

JNUMBER
JAtoN(string, endPtr)
const char *string;
char **endPtr;
{

GCC 15 (shipping with Debian Forky / Ubuntu 25.04 and later) now emits -Wold-style-definition for this pattern. Downstream projects that compile note-c sources with -Werror will fail to build.

This was discovered while validating note-posix, a POSIX platform SDK for the Notecard that compiles note-c sources directly with -Wall -Wextra -Wpedantic -Werror.

Fix

Convert to a standard ANSI C prototype-style definition, preserving all original inline parameter documentation:

JNUMBER
JAtoN(
    const char *string, /* A decimal ASCII floating-point number, ... */
    char **endPtr       /* If non-NULL, store terminating character's address here. */
)
{

Validation

Compiled cleanly with:

gcc -std=c11 -Wall -Wextra -Wpedantic -Werror -c n_atof.c

No functional changes — this is a purely syntactic fix.