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Support for casts in macros with smaller integers #15

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Support for casts in macros with smaller integers #15

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62 changes: 60 additions & 2 deletions src/expr.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,8 @@
use std::collections::HashMap;
use std::ops::{AddAssign,BitAndAssign,BitOrAssign,BitXorAssign,DivAssign,MulAssign,RemAssign,ShlAssign,ShrAssign,SubAssign};
use std::num::Wrapping;
use std::mem::size_of;
use std::os::raw::*;

use literal::{self,CChar};
use token::{Token,Kind as TokenKind};
Expand Down Expand Up @@ -65,7 +67,7 @@ impl EvalResult {
result_opt!(fn as_float: Float -> f64);
result_opt!(fn as_char: Char -> CChar);
result_opt!(fn as_str: Str -> Vec<u8>);

fn as_numeric(self) -> Option<EvalResult> {
match self {
EvalResult::Int(_) | EvalResult::Float(_) => Some(self),
Expand Down Expand Up @@ -130,6 +132,14 @@ macro_rules! p (
($i:expr, $c:expr) => (exact_token!($i,Punctuation,$c.as_bytes()))
);

macro_rules! k (
($i:expr, $c:expr) => (exact_token!($i,Keyword,$c.as_bytes()))
);

macro_rules! i (
($i:expr, $c:expr) => (exact_token!($i,Identifier,$c.as_bytes()))
);

macro_rules! one_of_punctuation (
($i:expr, $c:expr) => ({
if $i.is_empty() {
Expand Down Expand Up @@ -298,9 +308,57 @@ macro_rules! numeric (
($i:expr, $f:expr ) => (map_opt!($i,call!($f),EvalResult::as_numeric));
);

enum TypeCast {
SignedInt(usize),
UnsignedInt(usize),
}

impl EvalResult {
fn cast(self, ctype: TypeCast) -> Self {
use self::TypeCast::*;
let round = |bits| 2i64.pow((bits) as u32);
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Unnecessary parentheses around bits

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I will remove it.

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I think this doesn't implement rounding, maybe give it another name?

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Is pow2 a proper name?

let unsigned_mask = |i, b| (i+round(b*8)) % round(b*8);
let signed_mask = |i, b| {
let rounded = unsigned_mask(i, b);
let half = round(8*b-1);
if rounded >= half {rounded - half * 2} else { rounded }
};
match self {
EvalResult::Float(f) => match ctype {
SignedInt(b) => EvalResult::Int(Wrapping(signed_mask(f as i64, b))),
UnsignedInt(b) => EvalResult::Int(Wrapping(unsigned_mask(f as i64, b))),
},
EvalResult::Int(Wrapping(i)) => match ctype {
SignedInt(b) => EvalResult::Int(Wrapping(signed_mask(i, b))),
UnsignedInt(b) => EvalResult::Int(Wrapping(unsigned_mask(i, b))),
},
_ => self
}
}
}


impl<'a> PRef<'a> {
method!(cast<PRef<'a>,&[Token],TypeCast,::Error>, mut self,
delimited!(p!("("), alt!(
do_parse!(k!("unsigned") >> k!("int") >> (TypeCast::UnsignedInt(size_of::<c_uint>()))) |
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This will choose the size based on the platform that bindgen runs on (generally the compilation host), that seems incorrect.

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Should we handle cross compilation? unsigned int may be different size on different architectures.

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Yes we should, but I don't have a good idea for how.

do_parse!(k!("unsigned") >> k!("short") >> (TypeCast::UnsignedInt(size_of::<c_ushort>()))) |
do_parse!(k!("unsigned") >> k!("char") >> (TypeCast::UnsignedInt(size_of::<c_uchar>()))) |
do_parse!(opt!(k!("signed")) >> k!("int") >> (TypeCast::SignedInt(size_of::<c_int>()))) |
do_parse!(opt!(k!("signed")) >> k!("short") >> (TypeCast::SignedInt(size_of::<c_short>()))) |
do_parse!(opt!(k!("signed")) >> k!("char") >> (TypeCast::SignedInt(size_of::<c_char>()))) |
do_parse!(i!("uint8_t") >> (TypeCast::UnsignedInt(1))) |
do_parse!(i!("uint16_t") >> (TypeCast::UnsignedInt(2))) |
do_parse!(i!("uint32_t") >> (TypeCast::UnsignedInt(4))) |
do_parse!(i!("int8_t") >> (TypeCast::SignedInt(1))) |
do_parse!(i!("int16_t") >> (TypeCast::SignedInt(2))) |
do_parse!(i!("int32_t") >> (TypeCast::SignedInt(4)))
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What about long, long long, and 64-bit types? In general, it may be useful to handle unknown types here in some graceful manner.

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Any integer type longer than 32 bits(size_t, uint64_t, long) is not supported since EvalResult::Int can not hold it. We need change the API to support 64-bit types.

) ,p!(")"))
);

method!(unary<PRef<'a>,&[Token],EvalResult,::Error>, mut self,
alt!(
map!(pair!(call_m!(self.cast), call_m!(self.unary)), |(c, r)| r.cast(c) ) |
delimited!(p!("("),call_m!(self.numeric_expr),p!(")")) |
numeric!(call_m!(self.literal)) |
numeric!(call_m!(self.identifier)) |
Expand Down Expand Up @@ -489,7 +547,7 @@ impl<'ident> IdentifierParser<'ident> {
fn as_ref(&self) -> PRef {
PRef(self)
}

/// Create a new `IdentifierParser` with a set of known identifiers. When
/// a known identifier is encountered during parsing, it is substituted
/// for the value specified.
Expand Down
1 change: 1 addition & 0 deletions tests/clang.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -254,3 +254,4 @@ test_file!(strings);
test_file!(int_signed);
test_file!(int_unsigned);
test_file!(fail);
test_file!(casts);
8 changes: 8 additions & 0 deletions tests/input/casts.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
#define Int_n2 (int)-2
#define Int_254 (uint8_t)-2
#define Float_236p3 (int)233.3 + 3.3
#define Int_255 (uint8_t)255.6
#define Int_n128 (int8_t)128
#define Int_n121 (int8_t)1234567
#define Int_111 (unsigned int)111.111
#define Int_4294967295 (unsigned int)-1
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Missing newline

2 changes: 1 addition & 1 deletion tests/input/int_unsigned.h
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
#define Int_124 124u
#define Int_125 125uL
#define Int_126 126LuL
#define Int_16 (((1)<<4ULL))/*comment*/
#define Int_16 (((1)<<4ULL))/*comment*/
#define Int_13 1|8^6&2<<1

#define Int_47 32|15
Expand Down