cranelift_codegen/ir/
sourceloc.rs

1//! Source locations.
2//!
3//! Cranelift tracks the original source location of each instruction, and preserves the source
4//! location when instructions are transformed.
5
6use core::fmt;
7#[cfg(feature = "enable-serde")]
8use serde_derive::{Deserialize, Serialize};
9
10/// A source location.
11///
12/// This is an opaque 32-bit number attached to each Cranelift IR instruction. Cranelift does not
13/// interpret source locations in any way, they are simply preserved from the input to the output.
14///
15/// The default source location uses the all-ones bit pattern `!0`. It is used for instructions
16/// that can't be given a real source location.
17#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
18#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
19pub struct SourceLoc(u32);
20
21impl SourceLoc {
22    /// Create a new source location with the given bits.
23    pub fn new(bits: u32) -> Self {
24        Self(bits)
25    }
26
27    /// Is this the default source location?
28    pub fn is_default(self) -> bool {
29        self == Default::default()
30    }
31
32    /// Read the bits of this source location.
33    pub fn bits(self) -> u32 {
34        self.0
35    }
36}
37
38impl Default for SourceLoc {
39    fn default() -> Self {
40        Self(!0)
41    }
42}
43
44impl fmt::Display for SourceLoc {
45    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
46        if self.is_default() {
47            write!(f, "@-")
48        } else {
49            write!(f, "@{:04x}", self.0)
50        }
51    }
52}
53
54/// Source location relative to another base source location.
55#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
56#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
57pub struct RelSourceLoc(u32);
58
59impl RelSourceLoc {
60    /// Create a new relative source location with the given bits.
61    pub fn new(bits: u32) -> Self {
62        Self(bits)
63    }
64
65    /// Creates a new `RelSourceLoc` based on the given base and offset.
66    pub fn from_base_offset(base: SourceLoc, offset: SourceLoc) -> Self {
67        if base.is_default() || offset.is_default() {
68            Self::default()
69        } else {
70            Self(offset.bits().wrapping_sub(base.bits()))
71        }
72    }
73
74    /// Expands the relative source location into an absolute one, using the given base.
75    pub fn expand(&self, base: SourceLoc) -> SourceLoc {
76        if self.is_default() || base.is_default() {
77            Default::default()
78        } else {
79            SourceLoc::new(self.0.wrapping_add(base.bits()))
80        }
81    }
82
83    /// Is this the default relative source location?
84    pub fn is_default(self) -> bool {
85        self == Default::default()
86    }
87}
88
89impl Default for RelSourceLoc {
90    fn default() -> Self {
91        Self(!0)
92    }
93}
94
95impl fmt::Display for RelSourceLoc {
96    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
97        if self.is_default() {
98            write!(f, "@-")
99        } else {
100            write!(f, "@+{:04x}", self.0)
101        }
102    }
103}
104
105#[cfg(test)]
106mod tests {
107    use crate::ir::SourceLoc;
108    use alloc::string::ToString;
109
110    #[test]
111    fn display() {
112        assert_eq!(SourceLoc::default().to_string(), "@-");
113        assert_eq!(SourceLoc::new(0).to_string(), "@0000");
114        assert_eq!(SourceLoc::new(16).to_string(), "@0010");
115        assert_eq!(SourceLoc::new(0xabcdef).to_string(), "@abcdef");
116    }
117}
cranelift_codegen/ir/sourceloc.rs

cranelift_codegen/ir/
sourceloc.rs
