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use alloc::vec::Vec;
use indexmap::IndexSet;
use std::ops::{Deref, DerefMut};
use crate::common::{DebugAbbrevOffset, SectionId};
use crate::constants;
use crate::write::{Result, Section, Writer};
/// A table of abbreviations that will be stored in a `.debug_abbrev` section.
// Requirements:
// - values are `Abbreviation`
// - insertion returns an abbreviation code for use in writing a DIE
// - inserting a duplicate returns the code of the existing value
#[derive(Debug, Default)]
pub(crate) struct AbbreviationTable {
abbrevs: IndexSet<Abbreviation>,
}
impl AbbreviationTable {
/// Add an abbreviation to the table and return its code.
pub fn add(&mut self, abbrev: Abbreviation) -> u64 {
let (code, _) = self.abbrevs.insert_full(abbrev);
// Code must be non-zero
(code + 1) as u64
}
/// Write the abbreviation table to the `.debug_abbrev` section.
pub fn write<W: Writer>(&self, w: &mut DebugAbbrev<W>) -> Result<()> {
for (code, abbrev) in self.abbrevs.iter().enumerate() {
w.write_uleb128((code + 1) as u64)?;
abbrev.write(w)?;
}
// Null abbreviation code
w.write_u8(0)
}
}
/// An abbreviation describes the shape of a `DebuggingInformationEntry`'s type:
/// its tag type, whether it has children, and its set of attributes.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub(crate) struct Abbreviation {
tag: constants::DwTag,
has_children: bool,
attributes: Vec<AttributeSpecification>,
}
impl Abbreviation {
/// Construct a new `Abbreviation`.
#[inline]
pub fn new(
tag: constants::DwTag,
has_children: bool,
attributes: Vec<AttributeSpecification>,
) -> Abbreviation {
Abbreviation {
tag,
has_children,
attributes,
}
}
/// Write the abbreviation to the `.debug_abbrev` section.
pub fn write<W: Writer>(&self, w: &mut DebugAbbrev<W>) -> Result<()> {
w.write_uleb128(self.tag.0.into())?;
w.write_u8(if self.has_children {
constants::DW_CHILDREN_yes.0
} else {
constants::DW_CHILDREN_no.0
})?;
for attr in &self.attributes {
attr.write(w)?;
}
// Null name and form
w.write_u8(0)?;
w.write_u8(0)
}
}
/// The description of an attribute in an abbreviated type.
// TODO: support implicit const
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub(crate) struct AttributeSpecification {
name: constants::DwAt,
form: constants::DwForm,
}
impl AttributeSpecification {
/// Construct a new `AttributeSpecification`.
#[inline]
pub fn new(name: constants::DwAt, form: constants::DwForm) -> AttributeSpecification {
AttributeSpecification { name, form }
}
/// Write the attribute specification to the `.debug_abbrev` section.
#[inline]
pub fn write<W: Writer>(&self, w: &mut DebugAbbrev<W>) -> Result<()> {
w.write_uleb128(self.name.0.into())?;
w.write_uleb128(self.form.0.into())
}
}
define_section!(
DebugAbbrev,
DebugAbbrevOffset,
"A writable `.debug_abbrev` section."
);
#[cfg(test)]
#[cfg(feature = "read")]
mod tests {
use super::*;
use crate::constants;
use crate::read;
use crate::write::EndianVec;
use crate::LittleEndian;
#[test]
fn test_abbreviation_table() {
let mut abbrevs = AbbreviationTable::default();
let abbrev1 = Abbreviation::new(
constants::DW_TAG_subprogram,
false,
vec![AttributeSpecification::new(
constants::DW_AT_name,
constants::DW_FORM_string,
)],
);
let abbrev2 = Abbreviation::new(
constants::DW_TAG_compile_unit,
true,
vec![
AttributeSpecification::new(constants::DW_AT_producer, constants::DW_FORM_strp),
AttributeSpecification::new(constants::DW_AT_language, constants::DW_FORM_data2),
],
);
let code1 = abbrevs.add(abbrev1.clone());
assert_eq!(code1, 1);
let code2 = abbrevs.add(abbrev2.clone());
assert_eq!(code2, 2);
assert_eq!(abbrevs.add(abbrev1.clone()), code1);
assert_eq!(abbrevs.add(abbrev2.clone()), code2);
let mut debug_abbrev = DebugAbbrev::from(EndianVec::new(LittleEndian));
let debug_abbrev_offset = debug_abbrev.offset();
assert_eq!(debug_abbrev_offset, DebugAbbrevOffset(0));
abbrevs.write(&mut debug_abbrev).unwrap();
assert_eq!(debug_abbrev.offset(), DebugAbbrevOffset(17));
let read_debug_abbrev = read::DebugAbbrev::new(debug_abbrev.slice(), LittleEndian);
let read_abbrevs = read_debug_abbrev
.abbreviations(debug_abbrev_offset)
.unwrap();
let read_abbrev1 = read_abbrevs.get(code1).unwrap();
assert_eq!(abbrev1.tag, read_abbrev1.tag());
assert_eq!(abbrev1.has_children, read_abbrev1.has_children());
assert_eq!(abbrev1.attributes.len(), read_abbrev1.attributes().len());
assert_eq!(
abbrev1.attributes[0].name,
read_abbrev1.attributes()[0].name()
);
assert_eq!(
abbrev1.attributes[0].form,
read_abbrev1.attributes()[0].form()
);
let read_abbrev2 = read_abbrevs.get(code2).unwrap();
assert_eq!(abbrev2.tag, read_abbrev2.tag());
assert_eq!(abbrev2.has_children, read_abbrev2.has_children());
assert_eq!(abbrev2.attributes.len(), read_abbrev2.attributes().len());
assert_eq!(
abbrev2.attributes[0].name,
read_abbrev2.attributes()[0].name()
);
assert_eq!(
abbrev2.attributes[0].form,
read_abbrev2.attributes()[0].form()
);
assert_eq!(
abbrev2.attributes[1].name,
read_abbrev2.attributes()[1].name()
);
assert_eq!(
abbrev2.attributes[1].form,
read_abbrev2.attributes()[1].form()
);
}
}