2012-07-30 18:38:15 -07:00

289 lines
11 KiB
Rust

/*
* The compiler code necessary to support the #fmt extension. Eventually this
* should all get sucked into either the standard library extfmt module or the
* compiler syntax extension plugin interface.
*/
import extfmt::ct::*;
import base::*;
import codemap::span;
import ext::build::*;
export expand_syntax_ext;
fn expand_syntax_ext(cx: ext_ctxt, sp: span, arg: ast::mac_arg,
_body: ast::mac_body) -> @ast::expr {
let args = get_mac_args_no_max(cx, sp, arg, 1u, ~"fmt");
let fmt =
expr_to_str(cx, args[0],
~"first argument to #fmt must be a string literal.");
let fmtspan = args[0].span;
debug!{"Format string:"};
log(debug, fmt);
fn parse_fmt_err_(cx: ext_ctxt, sp: span, msg: ~str) -> ! {
cx.span_fatal(sp, msg);
}
let parse_fmt_err = fn@(s: ~str) -> ! {
parse_fmt_err_(cx, fmtspan, s)
};
let pieces = parse_fmt_string(fmt, parse_fmt_err);
ret pieces_to_expr(cx, sp, pieces, args);
}
// FIXME (#2249): A lot of these functions for producing expressions can
// probably be factored out in common with other code that builds
// expressions. Also: Cleanup the naming of these functions.
// NOTE: Moved many of the common ones to build.rs --kevina
fn pieces_to_expr(cx: ext_ctxt, sp: span,
pieces: ~[piece], args: ~[@ast::expr])
-> @ast::expr {
fn make_path_vec(_cx: ext_ctxt, ident: ast::ident) -> ~[ast::ident] {
ret ~[@~"extfmt", @~"rt", ident];
}
fn make_rt_path_expr(cx: ext_ctxt, sp: span,
ident: ast::ident) -> @ast::expr {
let path = make_path_vec(cx, ident);
ret mk_path(cx, sp, path);
}
// Produces an AST expression that represents a RT::conv record,
// which tells the RT::conv* functions how to perform the conversion
fn make_rt_conv_expr(cx: ext_ctxt, sp: span, cnv: conv) -> @ast::expr {
fn make_flags(cx: ext_ctxt, sp: span, flags: ~[flag]) -> @ast::expr {
let mut tmp_expr = make_rt_path_expr(cx, sp, @~"flag_none");
for flags.each |f| {
let fstr = alt f {
flag_left_justify { ~"flag_left_justify" }
flag_left_zero_pad { ~"flag_left_zero_pad" }
flag_space_for_sign { ~"flag_space_for_sign" }
flag_sign_always { ~"flag_sign_always" }
flag_alternate { ~"flag_alternate" }
};
tmp_expr = mk_binary(cx, sp, ast::bitor, tmp_expr,
make_rt_path_expr(cx, sp, @fstr));
}
ret tmp_expr;
}
fn make_count(cx: ext_ctxt, sp: span, cnt: count) -> @ast::expr {
alt cnt {
count_implied {
ret make_rt_path_expr(cx, sp, @~"count_implied");
}
count_is(c) {
let count_lit = mk_int(cx, sp, c);
let count_is_path = make_path_vec(cx, @~"count_is");
let count_is_args = ~[count_lit];
ret mk_call(cx, sp, count_is_path, count_is_args);
}
_ { cx.span_unimpl(sp, ~"unimplemented #fmt conversion"); }
}
}
fn make_ty(cx: ext_ctxt, sp: span, t: ty) -> @ast::expr {
let mut rt_type;
alt t {
ty_hex(c) {
alt c {
case_upper { rt_type = ~"ty_hex_upper"; }
case_lower { rt_type = ~"ty_hex_lower"; }
}
}
ty_bits { rt_type = ~"ty_bits"; }
ty_octal { rt_type = ~"ty_octal"; }
_ { rt_type = ~"ty_default"; }
}
ret make_rt_path_expr(cx, sp, @rt_type);
}
fn make_conv_rec(cx: ext_ctxt, sp: span, flags_expr: @ast::expr,
width_expr: @ast::expr, precision_expr: @ast::expr,
ty_expr: @ast::expr) -> @ast::expr {
ret mk_rec_e(cx, sp,
~[{ident: @~"flags", ex: flags_expr},
{ident: @~"width", ex: width_expr},
{ident: @~"precision", ex: precision_expr},
{ident: @~"ty", ex: ty_expr}]);
}
let rt_conv_flags = make_flags(cx, sp, cnv.flags);
let rt_conv_width = make_count(cx, sp, cnv.width);
let rt_conv_precision = make_count(cx, sp, cnv.precision);
let rt_conv_ty = make_ty(cx, sp, cnv.ty);
ret make_conv_rec(cx, sp, rt_conv_flags, rt_conv_width,
rt_conv_precision, rt_conv_ty);
}
fn make_conv_call(cx: ext_ctxt, sp: span, conv_type: ~str, cnv: conv,
arg: @ast::expr) -> @ast::expr {
let fname = ~"conv_" + conv_type;
let path = make_path_vec(cx, @fname);
let cnv_expr = make_rt_conv_expr(cx, sp, cnv);
let args = ~[cnv_expr, arg];
ret mk_call(cx, arg.span, path, args);
}
fn make_new_conv(cx: ext_ctxt, sp: span, cnv: conv, arg: @ast::expr) ->
@ast::expr {
// FIXME: Move validation code into core::extfmt (Issue #2249)
fn is_signed_type(cnv: conv) -> bool {
alt cnv.ty {
ty_int(s) {
alt s { signed { ret true; } unsigned { ret false; } }
}
ty_float { ret true; }
_ { ret false; }
}
}
let unsupported = ~"conversion not supported in #fmt string";
alt cnv.param {
option::none { }
_ { cx.span_unimpl(sp, unsupported); }
}
for cnv.flags.each |f| {
alt f {
flag_left_justify { }
flag_sign_always {
if !is_signed_type(cnv) {
cx.span_fatal(sp,
~"+ flag only valid in " +
~"signed #fmt conversion");
}
}
flag_space_for_sign {
if !is_signed_type(cnv) {
cx.span_fatal(sp,
~"space flag only valid in " +
~"signed #fmt conversions");
}
}
flag_left_zero_pad { }
_ { cx.span_unimpl(sp, unsupported); }
}
}
alt cnv.width {
count_implied { }
count_is(_) { }
_ { cx.span_unimpl(sp, unsupported); }
}
alt cnv.precision {
count_implied { }
count_is(_) { }
_ { cx.span_unimpl(sp, unsupported); }
}
alt cnv.ty {
ty_str { ret make_conv_call(cx, arg.span, ~"str", cnv, arg); }
ty_int(sign) {
alt sign {
signed { ret make_conv_call(cx, arg.span, ~"int", cnv, arg); }
unsigned {
ret make_conv_call(cx, arg.span, ~"uint", cnv, arg);
}
}
}
ty_bool { ret make_conv_call(cx, arg.span, ~"bool", cnv, arg); }
ty_char { ret make_conv_call(cx, arg.span, ~"char", cnv, arg); }
ty_hex(_) { ret make_conv_call(cx, arg.span, ~"uint", cnv, arg); }
ty_bits { ret make_conv_call(cx, arg.span, ~"uint", cnv, arg); }
ty_octal { ret make_conv_call(cx, arg.span, ~"uint", cnv, arg); }
ty_float { ret make_conv_call(cx, arg.span, ~"float", cnv, arg); }
ty_poly { ret make_conv_call(cx, arg.span, ~"poly", cnv, arg); }
}
}
fn log_conv(c: conv) {
alt c.param {
some(p) { log(debug, ~"param: " + int::to_str(p, 10u)); }
_ { debug!{"param: none"}; }
}
for c.flags.each |f| {
alt f {
flag_left_justify { debug!{"flag: left justify"}; }
flag_left_zero_pad { debug!{"flag: left zero pad"}; }
flag_space_for_sign { debug!{"flag: left space pad"}; }
flag_sign_always { debug!{"flag: sign always"}; }
flag_alternate { debug!{"flag: alternate"}; }
}
}
alt c.width {
count_is(i) { log(debug,
~"width: count is " + int::to_str(i, 10u)); }
count_is_param(i) {
log(debug,
~"width: count is param " + int::to_str(i, 10u));
}
count_is_next_param { debug!{"width: count is next param"}; }
count_implied { debug!{"width: count is implied"}; }
}
alt c.precision {
count_is(i) { log(debug,
~"prec: count is " + int::to_str(i, 10u)); }
count_is_param(i) {
log(debug,
~"prec: count is param " + int::to_str(i, 10u));
}
count_is_next_param { debug!{"prec: count is next param"}; }
count_implied { debug!{"prec: count is implied"}; }
}
alt c.ty {
ty_bool { debug!{"type: bool"}; }
ty_str { debug!{"type: str"}; }
ty_char { debug!{"type: char"}; }
ty_int(s) {
alt s {
signed { debug!{"type: signed"}; }
unsigned { debug!{"type: unsigned"}; }
}
}
ty_bits { debug!{"type: bits"}; }
ty_hex(cs) {
alt cs {
case_upper { debug!{"type: uhex"}; }
case_lower { debug!{"type: lhex"}; }
}
}
ty_octal { debug!{"type: octal"}; }
ty_float { debug!{"type: float"}; }
ty_poly { debug!{"type: poly"}; }
}
}
let fmt_sp = args[0].span;
let mut n = 0u;
let mut piece_exprs = ~[];
let nargs = args.len();
for pieces.each |pc| {
alt pc {
piece_string(s) {
vec::push(piece_exprs, mk_uniq_str(cx, fmt_sp, s));
}
piece_conv(conv) {
n += 1u;
if n >= nargs {
cx.span_fatal(sp,
~"not enough arguments to #fmt " +
~"for the given format string");
}
debug!{"Building conversion:"};
log_conv(conv);
let arg_expr = args[n];
let c_expr = make_new_conv(cx, fmt_sp, conv, arg_expr);
vec::push(piece_exprs, c_expr);
}
}
}
let expected_nargs = n + 1u; // n conversions + the fmt string
if expected_nargs < nargs {
cx.span_fatal
(sp, fmt!{"too many arguments to #fmt. found %u, expected %u",
nargs, expected_nargs});
}
let arg_vec = mk_fixed_vec_e(cx, fmt_sp, piece_exprs);
ret mk_call(cx, fmt_sp, ~[@~"str", @~"concat"], ~[arg_vec]);
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//