blob: 6704574d0d09b0c414faf9d38f970e577aba10fb [file] [log] [blame]
//! Source locations.
//!
//! Cranelift tracks the original source location of each instruction, and preserves the source
//! location when instructions are transformed.
use core::fmt;
#[cfg(feature = "enable-serde")]
use serde_derive::{Deserialize, Serialize};
/// A source location.
///
/// This is an opaque 32-bit number attached to each Cranelift IR instruction. Cranelift does not
/// interpret source locations in any way, they are simply preserved from the input to the output.
///
/// The default source location uses the all-ones bit pattern `!0`. It is used for instructions
/// that can't be given a real source location.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
pub struct SourceLoc(u32);
impl SourceLoc {
/// Create a new source location with the given bits.
pub fn new(bits: u32) -> Self {
Self(bits)
}
/// Is this the default source location?
pub fn is_default(self) -> bool {
self == Default::default()
}
/// Read the bits of this source location.
pub fn bits(self) -> u32 {
self.0
}
}
impl Default for SourceLoc {
fn default() -> Self {
Self(!0)
}
}
impl fmt::Display for SourceLoc {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.is_default() {
write!(f, "@-")
} else {
write!(f, "@{:04x}", self.0)
}
}
}
/// Source location relative to another base source location.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
pub struct RelSourceLoc(u32);
impl RelSourceLoc {
/// Create a new relative source location with the given bits.
pub fn new(bits: u32) -> Self {
Self(bits)
}
/// Creates a new `RelSourceLoc` based on the given base and offset.
pub fn from_base_offset(base: SourceLoc, offset: SourceLoc) -> Self {
if base.is_default() || offset.is_default() {
Self::default()
} else {
Self(offset.bits().wrapping_sub(base.bits()))
}
}
/// Expands the relative source location into an absolute one, using the given base.
pub fn expand(&self, base: SourceLoc) -> SourceLoc {
if self.is_default() || base.is_default() {
Default::default()
} else {
SourceLoc::new(self.0.wrapping_add(base.bits()))
}
}
/// Is this the default relative source location?
pub fn is_default(self) -> bool {
self == Default::default()
}
}
impl Default for RelSourceLoc {
fn default() -> Self {
Self(!0)
}
}
impl fmt::Display for RelSourceLoc {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.is_default() {
write!(f, "@-")
} else {
write!(f, "@+{:04x}", self.0)
}
}
}
#[cfg(test)]
mod tests {
use crate::ir::SourceLoc;
use alloc::string::ToString;
#[test]
fn display() {
assert_eq!(SourceLoc::default().to_string(), "@-");
assert_eq!(SourceLoc::new(0).to_string(), "@0000");
assert_eq!(SourceLoc::new(16).to_string(), "@0010");
assert_eq!(SourceLoc::new(0xabcdef).to_string(), "@abcdef");
}
}