the Scheme variable *struct-printer*. This variable can be set by
Scheme code to override the printing of structures.
(scm_print_struct): If struct_printer is set, call it. If it is
not set, or returns #f, print the structure in the old fashion.
Include "eval.h" for scm_apply.
scm_struct_i_n_words to get the number of fields, not
-scm_struct_n_extra_words.
On the route to fancier struct printing:
* struct.c (scm_print_struct): New function to print a structure.
Include "genio.h" to support it. This function doesn't do
anything interesting right now, but I think it should be here
anyway.
* struct.h: Include "print.h" and add prototype for
scm_print_struct.
* print.c (scm_iprin1): Call scm_print_struct instead of trying to
print structures ourself.
variables aren't used uninitialized.
* error.h (scm_error, scm_syserror, scm_syserror_msg,
scm_sysmissing, scm_num_overflow, scm_out_of_range,
scm_wrong_num_args, scm_wrong_type_arg, scm_memory_error,
scm_misc_error): Tell GCC that these functions never return.
* struct.c (scm_struct_ref, scm_struct_set_x): If we can't figure
out the field type, call abort if SCM_ASSERT returns, to placate
the optimizer.
* stacks.c (scm_make_stack, scm_last_stack_frame): abort if
scm_wta ever returns. We can't handle this case anyway, and this
gives the optimizer more information.
* unif.c (scm_uniform_vector_ref, scm_array_set_x): Abort if
scm_wta ever returns.
In some cases, the code is fine, but GCC isn't smart enough to
figure that out; this usually happens when one variable is only
initialized and used when a particular condition holds true, and
we know that condition will never change within a given invocation
of the function. In this case, we simply initialize the variables
to placate the compiler, hopefully to a value which will cause a
crash if it is ever actually used.
* print.c (scm_iprin1): Initialize mw_pos.
* read.c (scm_lreadrecparen): Initialize tl2, ans2.
* throw.c (scm_ithrow): Initialize dynpair.
* unif.c (scm_uniform_vector_ref): Initialize cra.
* struct.c (init_struct): Initialize prot.
* mbstrings.c (scm_print_mb_symbol): Initialize mw_pos and inc.
required by the tagging system.
* struct.c (alloc_struct): New function.
(scm_make_struct, scm_make_vtable_vtable): Call it.
* struct.h (scm_struct_n_extra_words): Bump to 3.
(scm_struct_i_ptr): New "field".
* gc.c (scm_gc_sweep): When we need to free the data, use the
information stored by alloc_struct to find the beginning of the
block allocated to the structure, so we can free it.
scm_struct_set_x), struct.h, gc.c (scm_gc_mark): Completed Tom
Lord's implementation of structs, allowing for tail arrays as
described in the manual. Also fixed some bugs. (Both the interface
and the implementation should be improved.)
