user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

auto merge of #14874 : pcwalton/rust/enum-to-float-casts-part-deux, r=alexcrichton

Browse source 
Closes #14794.

If you're casting from an enum to a float, cast through an integer
first.

[breaking-change]

r? @alexcrichton
This commit is contained in:
bors 2014-06-14 08:46:48 +00:00
commit dbd29ea96e
7 changed files with 32 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

3
src/librustc/middle/trans/consts.rs
View file

@ -503,9 +503,8 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr,
let s = ty::type_is_signed(ety) as Bool;
llvm::LLVMConstIntCast(iv, llty.to_ref(), s)
}
expr::cast_float => llvm::LLVMConstSIToFP(iv, llty.to_ref()),
_ => cx.sess().bug("enum cast destination is not \
integral or float")
integral")
}
}
(expr::cast_pointer, expr::cast_pointer) => {

8
src/librustc/middle/ty.rs
View file

@ -1685,6 +1685,14 @@ pub fn type_is_scalar(ty: t) -> bool {
}
}
/// Returns true if this type is a floating point type and false otherwise.
pub fn type_is_floating_point(ty: t) -> bool {
match get(ty).sty {
ty_float(_) => true,
_ => false,
}
}
pub fn type_needs_drop(cx: &ctxt, ty: t) -> bool {
type_contents(cx, ty).needs_drop(cx)
}

19
src/librustc/middle/typeck/check/mod.rs
View file

@ -3042,12 +3042,24 @@ fn check_expr_with_unifier(fcx: &FnCtxt,
let t_1_is_scalar = type_is_scalar(fcx, expr.span, t_1);
let t_1_is_char = type_is_char(fcx, expr.span, t_1);
let t_1_is_bare_fn = type_is_bare_fn(fcx, expr.span, t_1);
let t_1_is_float = type_is_floating_point(fcx,
expr.span,
t_1);
// casts to scalars other than `char` and `bare fn` are trivial
let t_1_is_trivial = t_1_is_scalar &&
!t_1_is_char && !t_1_is_bare_fn;
if type_is_c_like_enum(fcx, expr.span, t_e) && t_1_is_trivial {
if type_is_c_like_enum(fcx, expr.span, t_e) &&
t_1_is_trivial {
if t_1_is_float {
fcx.type_error_message(expr.span, |actual| {
format!("illegal cast; cast through an \
integer first: `{}` as `{}`",
actual,
fcx.infcx().ty_to_str(t_1))
}, t_e, None);
}
// casts from C-like enums are allowed
} else if t_1_is_char {
let te = fcx.infcx().resolve_type_vars_if_possible(te);
@ -4206,6 +4218,11 @@ pub fn type_is_bare_fn(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool {
return ty::type_is_bare_fn(typ_s);
}
pub fn type_is_floating_point(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool {
let typ_s = structurally_resolved_type(fcx, sp, typ);
return ty::type_is_floating_point(typ_s);
}
pub fn type_is_unsafe_ptr(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool {
let typ_s = structurally_resolved_type(fcx, sp, typ);
return ty::type_is_unsafe_ptr(typ_s);