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29967ef6 XL |
1 | use rustc_apfloat::ieee::{Double, Single}; |
2 | use rustc_apfloat::Float; | |
3 | use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; | |
4 | use rustc_target::abi::{Size, TargetDataLayout}; | |
5 | use std::convert::{TryFrom, TryInto}; | |
6 | use std::fmt; | |
3dfed10e | 7 | |
6a06907d XL |
8 | use crate::ty::TyCtxt; |
9 | ||
3dfed10e XL |
10 | #[derive(Copy, Clone)] |
11 | /// A type for representing any integer. Only used for printing. | |
3dfed10e | 12 | pub struct ConstInt { |
29967ef6 XL |
13 | /// The "untyped" variant of `ConstInt`. |
14 | int: ScalarInt, | |
3dfed10e XL |
15 | /// Whether the value is of a signed integer type. |
16 | signed: bool, | |
17 | /// Whether the value is a `usize` or `isize` type. | |
18 | is_ptr_sized_integral: bool, | |
3dfed10e XL |
19 | } |
20 | ||
21 | impl ConstInt { | |
29967ef6 XL |
22 | pub fn new(int: ScalarInt, signed: bool, is_ptr_sized_integral: bool) -> Self { |
23 | Self { int, signed, is_ptr_sized_integral } | |
3dfed10e XL |
24 | } |
25 | } | |
26 | ||
27 | impl std::fmt::Debug for ConstInt { | |
28 | fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { | |
29967ef6 XL |
29 | let Self { int, signed, is_ptr_sized_integral } = *self; |
30 | let size = int.size().bytes(); | |
31 | let raw = int.data; | |
3dfed10e XL |
32 | if signed { |
33 | let bit_size = size * 8; | |
34 | let min = 1u128 << (bit_size - 1); | |
35 | let max = min - 1; | |
36 | if raw == min { | |
37 | match (size, is_ptr_sized_integral) { | |
38 | (_, true) => write!(fmt, "isize::MIN"), | |
39 | (1, _) => write!(fmt, "i8::MIN"), | |
40 | (2, _) => write!(fmt, "i16::MIN"), | |
41 | (4, _) => write!(fmt, "i32::MIN"), | |
42 | (8, _) => write!(fmt, "i64::MIN"), | |
43 | (16, _) => write!(fmt, "i128::MIN"), | |
44 | _ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed), | |
45 | } | |
46 | } else if raw == max { | |
47 | match (size, is_ptr_sized_integral) { | |
48 | (_, true) => write!(fmt, "isize::MAX"), | |
49 | (1, _) => write!(fmt, "i8::MAX"), | |
50 | (2, _) => write!(fmt, "i16::MAX"), | |
51 | (4, _) => write!(fmt, "i32::MAX"), | |
52 | (8, _) => write!(fmt, "i64::MAX"), | |
53 | (16, _) => write!(fmt, "i128::MAX"), | |
54 | _ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed), | |
55 | } | |
56 | } else { | |
57 | match size { | |
58 | 1 => write!(fmt, "{}", raw as i8)?, | |
59 | 2 => write!(fmt, "{}", raw as i16)?, | |
60 | 4 => write!(fmt, "{}", raw as i32)?, | |
61 | 8 => write!(fmt, "{}", raw as i64)?, | |
62 | 16 => write!(fmt, "{}", raw as i128)?, | |
63 | _ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed), | |
64 | } | |
65 | if fmt.alternate() { | |
66 | match (size, is_ptr_sized_integral) { | |
67 | (_, true) => write!(fmt, "_isize")?, | |
68 | (1, _) => write!(fmt, "_i8")?, | |
69 | (2, _) => write!(fmt, "_i16")?, | |
70 | (4, _) => write!(fmt, "_i32")?, | |
71 | (8, _) => write!(fmt, "_i64")?, | |
72 | (16, _) => write!(fmt, "_i128")?, | |
73 | _ => bug!(), | |
74 | } | |
75 | } | |
76 | Ok(()) | |
77 | } | |
78 | } else { | |
29967ef6 | 79 | let max = Size::from_bytes(size).truncate(u128::MAX); |
3dfed10e XL |
80 | if raw == max { |
81 | match (size, is_ptr_sized_integral) { | |
82 | (_, true) => write!(fmt, "usize::MAX"), | |
83 | (1, _) => write!(fmt, "u8::MAX"), | |
84 | (2, _) => write!(fmt, "u16::MAX"), | |
85 | (4, _) => write!(fmt, "u32::MAX"), | |
86 | (8, _) => write!(fmt, "u64::MAX"), | |
87 | (16, _) => write!(fmt, "u128::MAX"), | |
88 | _ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed), | |
89 | } | |
90 | } else { | |
91 | match size { | |
92 | 1 => write!(fmt, "{}", raw as u8)?, | |
93 | 2 => write!(fmt, "{}", raw as u16)?, | |
94 | 4 => write!(fmt, "{}", raw as u32)?, | |
95 | 8 => write!(fmt, "{}", raw as u64)?, | |
96 | 16 => write!(fmt, "{}", raw as u128)?, | |
97 | _ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed), | |
98 | } | |
99 | if fmt.alternate() { | |
100 | match (size, is_ptr_sized_integral) { | |
101 | (_, true) => write!(fmt, "_usize")?, | |
102 | (1, _) => write!(fmt, "_u8")?, | |
103 | (2, _) => write!(fmt, "_u16")?, | |
104 | (4, _) => write!(fmt, "_u32")?, | |
105 | (8, _) => write!(fmt, "_u64")?, | |
106 | (16, _) => write!(fmt, "_u128")?, | |
107 | _ => bug!(), | |
108 | } | |
109 | } | |
110 | Ok(()) | |
111 | } | |
112 | } | |
113 | } | |
114 | } | |
29967ef6 XL |
115 | |
116 | /// The raw bytes of a simple value. | |
117 | /// | |
118 | /// This is a packed struct in order to allow this type to be optimally embedded in enums | |
119 | /// (like Scalar). | |
120 | #[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)] | |
121 | #[repr(packed)] | |
122 | pub struct ScalarInt { | |
123 | /// The first `size` bytes of `data` are the value. | |
124 | /// Do not try to read less or more bytes than that. The remaining bytes must be 0. | |
125 | data: u128, | |
126 | size: u8, | |
127 | } | |
128 | ||
129 | // Cannot derive these, as the derives take references to the fields, and we | |
130 | // can't take references to fields of packed structs. | |
131 | impl<CTX> crate::ty::HashStable<CTX> for ScalarInt { | |
132 | fn hash_stable(&self, hcx: &mut CTX, hasher: &mut crate::ty::StableHasher) { | |
133 | // Using a block `{self.data}` here to force a copy instead of using `self.data` | |
134 | // directly, because `hash_stable` takes `&self` and would thus borrow `self.data`. | |
135 | // Since `Self` is a packed struct, that would create a possibly unaligned reference, | |
136 | // which is UB. | |
137 | { self.data }.hash_stable(hcx, hasher); | |
138 | self.size.hash_stable(hcx, hasher); | |
139 | } | |
140 | } | |
141 | ||
142 | impl<S: Encoder> Encodable<S> for ScalarInt { | |
143 | fn encode(&self, s: &mut S) -> Result<(), S::Error> { | |
144 | s.emit_u128(self.data)?; | |
145 | s.emit_u8(self.size) | |
146 | } | |
147 | } | |
148 | ||
149 | impl<D: Decoder> Decodable<D> for ScalarInt { | |
150 | fn decode(d: &mut D) -> Result<ScalarInt, D::Error> { | |
151 | Ok(ScalarInt { data: d.read_u128()?, size: d.read_u8()? }) | |
152 | } | |
153 | } | |
154 | ||
155 | impl ScalarInt { | |
156 | pub const TRUE: ScalarInt = ScalarInt { data: 1_u128, size: 1 }; | |
157 | ||
158 | pub const FALSE: ScalarInt = ScalarInt { data: 0_u128, size: 1 }; | |
159 | ||
160 | pub const ZST: ScalarInt = ScalarInt { data: 0_u128, size: 0 }; | |
161 | ||
162 | #[inline] | |
163 | pub fn size(self) -> Size { | |
164 | Size::from_bytes(self.size) | |
165 | } | |
166 | ||
167 | /// Make sure the `data` fits in `size`. | |
168 | /// This is guaranteed by all constructors here, but having had this check saved us from | |
169 | /// bugs many times in the past, so keeping it around is definitely worth it. | |
170 | #[inline(always)] | |
171 | fn check_data(self) { | |
172 | // Using a block `{self.data}` here to force a copy instead of using `self.data` | |
173 | // directly, because `debug_assert_eq` takes references to its arguments and formatting | |
174 | // arguments and would thus borrow `self.data`. Since `Self` | |
175 | // is a packed struct, that would create a possibly unaligned reference, which | |
176 | // is UB. | |
177 | debug_assert_eq!( | |
178 | self.size().truncate(self.data), | |
179 | { self.data }, | |
180 | "Scalar value {:#x} exceeds size of {} bytes", | |
181 | { self.data }, | |
182 | self.size | |
183 | ); | |
184 | } | |
185 | ||
186 | #[inline] | |
187 | pub fn null(size: Size) -> Self { | |
188 | Self { data: 0, size: size.bytes() as u8 } | |
189 | } | |
190 | ||
191 | #[inline] | |
192 | pub fn is_null(self) -> bool { | |
193 | self.data == 0 | |
194 | } | |
195 | ||
196 | pub(crate) fn ptr_sized_op<E>( | |
197 | self, | |
198 | dl: &TargetDataLayout, | |
199 | f_int: impl FnOnce(u64) -> Result<u64, E>, | |
200 | ) -> Result<Self, E> { | |
201 | assert_eq!(u64::from(self.size), dl.pointer_size.bytes()); | |
202 | Ok(Self::try_from_uint(f_int(u64::try_from(self.data).unwrap())?, self.size()).unwrap()) | |
203 | } | |
204 | ||
205 | #[inline] | |
206 | pub fn try_from_uint(i: impl Into<u128>, size: Size) -> Option<Self> { | |
207 | let data = i.into(); | |
208 | if size.truncate(data) == data { | |
209 | Some(Self { data, size: size.bytes() as u8 }) | |
210 | } else { | |
211 | None | |
212 | } | |
213 | } | |
214 | ||
215 | #[inline] | |
216 | pub fn try_from_int(i: impl Into<i128>, size: Size) -> Option<Self> { | |
217 | let i = i.into(); | |
218 | // `into` performed sign extension, we have to truncate | |
219 | let truncated = size.truncate(i as u128); | |
220 | if size.sign_extend(truncated) as i128 == i { | |
221 | Some(Self { data: truncated, size: size.bytes() as u8 }) | |
222 | } else { | |
223 | None | |
224 | } | |
225 | } | |
226 | ||
227 | #[inline] | |
228 | pub fn assert_bits(self, target_size: Size) -> u128 { | |
229 | self.to_bits(target_size).unwrap_or_else(|size| { | |
230 | bug!("expected int of size {}, but got size {}", target_size.bytes(), size.bytes()) | |
231 | }) | |
232 | } | |
233 | ||
234 | #[inline] | |
235 | pub fn to_bits(self, target_size: Size) -> Result<u128, Size> { | |
236 | assert_ne!(target_size.bytes(), 0, "you should never look at the bits of a ZST"); | |
237 | if target_size.bytes() == u64::from(self.size) { | |
238 | self.check_data(); | |
239 | Ok(self.data) | |
240 | } else { | |
241 | Err(self.size()) | |
242 | } | |
243 | } | |
6a06907d XL |
244 | |
245 | #[inline] | |
246 | pub fn try_to_machine_usize(&self, tcx: TyCtxt<'tcx>) -> Result<u64, Size> { | |
247 | Ok(self.to_bits(tcx.data_layout.pointer_size)? as u64) | |
248 | } | |
29967ef6 XL |
249 | } |
250 | ||
251 | macro_rules! from { | |
252 | ($($ty:ty),*) => { | |
253 | $( | |
254 | impl From<$ty> for ScalarInt { | |
255 | #[inline] | |
256 | fn from(u: $ty) -> Self { | |
257 | Self { | |
258 | data: u128::from(u), | |
259 | size: std::mem::size_of::<$ty>() as u8, | |
260 | } | |
261 | } | |
262 | } | |
263 | )* | |
264 | } | |
265 | } | |
266 | ||
267 | macro_rules! try_from { | |
268 | ($($ty:ty),*) => { | |
269 | $( | |
270 | impl TryFrom<ScalarInt> for $ty { | |
271 | type Error = Size; | |
272 | #[inline] | |
273 | fn try_from(int: ScalarInt) -> Result<Self, Size> { | |
274 | // The `unwrap` cannot fail because to_bits (if it succeeds) | |
275 | // is guaranteed to return a value that fits into the size. | |
276 | int.to_bits(Size::from_bytes(std::mem::size_of::<$ty>())) | |
277 | .map(|u| u.try_into().unwrap()) | |
278 | } | |
279 | } | |
280 | )* | |
281 | } | |
282 | } | |
283 | ||
284 | from!(u8, u16, u32, u64, u128, bool); | |
285 | try_from!(u8, u16, u32, u64, u128); | |
286 | ||
6a06907d XL |
287 | impl TryFrom<ScalarInt> for bool { |
288 | type Error = Size; | |
289 | #[inline] | |
290 | fn try_from(int: ScalarInt) -> Result<Self, Size> { | |
291 | int.to_bits(Size::from_bytes(1)).and_then(|u| match u { | |
292 | 0 => Ok(false), | |
293 | 1 => Ok(true), | |
294 | _ => Err(Size::from_bytes(1)), | |
295 | }) | |
296 | } | |
297 | } | |
298 | ||
29967ef6 XL |
299 | impl From<char> for ScalarInt { |
300 | #[inline] | |
301 | fn from(c: char) -> Self { | |
302 | Self { data: c as u128, size: std::mem::size_of::<char>() as u8 } | |
303 | } | |
304 | } | |
305 | ||
306 | impl TryFrom<ScalarInt> for char { | |
307 | type Error = Size; | |
308 | #[inline] | |
309 | fn try_from(int: ScalarInt) -> Result<Self, Size> { | |
310 | int.to_bits(Size::from_bytes(std::mem::size_of::<char>())) | |
311 | .map(|u| char::from_u32(u.try_into().unwrap()).unwrap()) | |
312 | } | |
313 | } | |
314 | ||
315 | impl From<Single> for ScalarInt { | |
316 | #[inline] | |
317 | fn from(f: Single) -> Self { | |
318 | // We trust apfloat to give us properly truncated data. | |
319 | Self { data: f.to_bits(), size: 4 } | |
320 | } | |
321 | } | |
322 | ||
323 | impl TryFrom<ScalarInt> for Single { | |
324 | type Error = Size; | |
325 | #[inline] | |
326 | fn try_from(int: ScalarInt) -> Result<Self, Size> { | |
327 | int.to_bits(Size::from_bytes(4)).map(Self::from_bits) | |
328 | } | |
329 | } | |
330 | ||
331 | impl From<Double> for ScalarInt { | |
332 | #[inline] | |
333 | fn from(f: Double) -> Self { | |
334 | // We trust apfloat to give us properly truncated data. | |
335 | Self { data: f.to_bits(), size: 8 } | |
336 | } | |
337 | } | |
338 | ||
339 | impl TryFrom<ScalarInt> for Double { | |
340 | type Error = Size; | |
341 | #[inline] | |
342 | fn try_from(int: ScalarInt) -> Result<Self, Size> { | |
343 | int.to_bits(Size::from_bytes(8)).map(Self::from_bits) | |
344 | } | |
345 | } | |
346 | ||
347 | impl fmt::Debug for ScalarInt { | |
348 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
349 | if self.size == 0 { | |
350 | self.check_data(); | |
351 | write!(f, "<ZST>") | |
352 | } else { | |
353 | // Dispatch to LowerHex below. | |
354 | write!(f, "0x{:x}", self) | |
355 | } | |
356 | } | |
357 | } | |
358 | ||
359 | impl fmt::LowerHex for ScalarInt { | |
360 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
361 | self.check_data(); | |
362 | // Format as hex number wide enough to fit any value of the given `size`. | |
363 | // So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014". | |
364 | // Using a block `{self.data}` here to force a copy instead of using `self.data` | |
365 | // directly, because `write!` takes references to its formatting arguments and | |
366 | // would thus borrow `self.data`. Since `Self` | |
367 | // is a packed struct, that would create a possibly unaligned reference, which | |
368 | // is UB. | |
369 | write!(f, "{:01$x}", { self.data }, self.size as usize * 2) | |
370 | } | |
371 | } | |
372 | ||
373 | impl fmt::UpperHex for ScalarInt { | |
374 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
375 | self.check_data(); | |
376 | // Format as hex number wide enough to fit any value of the given `size`. | |
377 | // So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014". | |
378 | // Using a block `{self.data}` here to force a copy instead of using `self.data` | |
379 | // directly, because `write!` takes references to its formatting arguments and | |
380 | // would thus borrow `self.data`. Since `Self` | |
381 | // is a packed struct, that would create a possibly unaligned reference, which | |
382 | // is UB. | |
383 | write!(f, "{:01$X}", { self.data }, self.size as usize * 2) | |
384 | } | |
385 | } |