Reorder comments, function attributes, and macro def args

Some changes I've wanted for a while. Still a bit of a WIP.

reorder comments to convert C-style / Doxygen prefixed comments to Nim-style postfixed comments
- currently only tested on proc defs, and struct bodies
add in __attribute__ to list of declarations for functions to help with parsing function attributes
add --def arg to allow defining a macro from the command line
add --stdints pre-defined mangle to convert C stdint to Nim ints

Example usage:

c2nim \
  --strict --header \
  --stdints # gives: --mangle:'{u?}int{\d+}_t=$1int$2' \
  --reordercomments \
  --def:RCL_PUBLIC='__attribute__ ()' \
  --def:RCL_WARN_UNUSED='__attribute__ ()' \
    testsuite/tests/rcl_arguments.h

Example re-order comments:

  /** * allocator objects.  */
  void * state;

becomes:

  void * state; ##\
      ## allocator objects.

Parsing __attributes__ and --def: makes it posible to handle the GCC C function pragmas style. For example --def:RCL_WARN_UNUSED='__attribute__ ()' and --def:RCL_PUBLIC='__attribute__ ()' will make the below parse:

// function defined with macros attributes:
RCL_PUBLIC RCL_WARN_UNUSED int rcl_arguments_get_count_unparsed(const rcl_arguments_t * args);
// expands to:
__attribute__(public) __attribute__(...) int rcl_arguments_get_count_unparsed(const rcl_arguments_t * args);

That last change is responsible for a good portion of C files not parsing properly. Eventually it'd be nice to add pragmas to the Nim procs so people could define them, but that's a project for another day.

nim-lang / c2nim

Reorder comments, function attributes, and macro def args #251