diff options
Diffstat (limited to 'compiler/rustc_codegen_cranelift/src/debuginfo/emit.rs')
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/debuginfo/emit.rs | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/debuginfo/emit.rs b/compiler/rustc_codegen_cranelift/src/debuginfo/emit.rs new file mode 100644 index 000000000..589910ede --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/debuginfo/emit.rs @@ -0,0 +1,190 @@ +//! Write the debuginfo into an object file. + +use cranelift_object::ObjectProduct; +use rustc_data_structures::fx::FxHashMap; + +use gimli::write::{Address, AttributeValue, EndianVec, Result, Sections, Writer}; +use gimli::{RunTimeEndian, SectionId}; + +use super::object::WriteDebugInfo; +use super::DebugContext; + +impl DebugContext<'_> { + pub(crate) fn emit(&mut self, product: &mut ObjectProduct) { + let unit_range_list_id = self.dwarf.unit.ranges.add(self.unit_range_list.clone()); + let root = self.dwarf.unit.root(); + let root = self.dwarf.unit.get_mut(root); + root.set(gimli::DW_AT_ranges, AttributeValue::RangeListRef(unit_range_list_id)); + + let mut sections = Sections::new(WriterRelocate::new(self.endian)); + self.dwarf.write(&mut sections).unwrap(); + + let mut section_map = FxHashMap::default(); + let _: Result<()> = sections.for_each_mut(|id, section| { + if !section.writer.slice().is_empty() { + let section_id = product.add_debug_section(id, section.writer.take()); + section_map.insert(id, section_id); + } + Ok(()) + }); + + let _: Result<()> = sections.for_each(|id, section| { + if let Some(section_id) = section_map.get(&id) { + for reloc in §ion.relocs { + product.add_debug_reloc(§ion_map, section_id, reloc); + } + } + Ok(()) + }); + } +} + +#[derive(Clone)] +pub(crate) struct DebugReloc { + pub(crate) offset: u32, + pub(crate) size: u8, + pub(crate) name: DebugRelocName, + pub(crate) addend: i64, + pub(crate) kind: object::RelocationKind, +} + +#[derive(Clone)] +pub(crate) enum DebugRelocName { + Section(SectionId), + Symbol(usize), +} + +/// A [`Writer`] that collects all necessary relocations. +#[derive(Clone)] +pub(super) struct WriterRelocate { + pub(super) relocs: Vec<DebugReloc>, + pub(super) writer: EndianVec<RunTimeEndian>, +} + +impl WriterRelocate { + pub(super) fn new(endian: RunTimeEndian) -> Self { + WriterRelocate { relocs: Vec::new(), writer: EndianVec::new(endian) } + } + + /// Perform the collected relocations to be usable for JIT usage. + #[cfg(all(feature = "jit", not(windows)))] + pub(super) fn relocate_for_jit(mut self, jit_module: &cranelift_jit::JITModule) -> Vec<u8> { + for reloc in self.relocs.drain(..) { + match reloc.name { + super::DebugRelocName::Section(_) => unreachable!(), + super::DebugRelocName::Symbol(sym) => { + let addr = jit_module.get_finalized_function( + cranelift_module::FuncId::from_u32(sym.try_into().unwrap()), + ); + let val = (addr as u64 as i64 + reloc.addend) as u64; + self.writer.write_udata_at(reloc.offset as usize, val, reloc.size).unwrap(); + } + } + } + self.writer.into_vec() + } +} + +impl Writer for WriterRelocate { + type Endian = RunTimeEndian; + + fn endian(&self) -> Self::Endian { + self.writer.endian() + } + + fn len(&self) -> usize { + self.writer.len() + } + + fn write(&mut self, bytes: &[u8]) -> Result<()> { + self.writer.write(bytes) + } + + fn write_at(&mut self, offset: usize, bytes: &[u8]) -> Result<()> { + self.writer.write_at(offset, bytes) + } + + fn write_address(&mut self, address: Address, size: u8) -> Result<()> { + match address { + Address::Constant(val) => self.write_udata(val, size), + Address::Symbol { symbol, addend } => { + let offset = self.len() as u64; + self.relocs.push(DebugReloc { + offset: offset as u32, + size, + name: DebugRelocName::Symbol(symbol), + addend: addend as i64, + kind: object::RelocationKind::Absolute, + }); + self.write_udata(0, size) + } + } + } + + fn write_offset(&mut self, val: usize, section: SectionId, size: u8) -> Result<()> { + let offset = self.len() as u32; + self.relocs.push(DebugReloc { + offset, + size, + name: DebugRelocName::Section(section), + addend: val as i64, + kind: object::RelocationKind::Absolute, + }); + self.write_udata(0, size) + } + + fn write_offset_at( + &mut self, + offset: usize, + val: usize, + section: SectionId, + size: u8, + ) -> Result<()> { + self.relocs.push(DebugReloc { + offset: offset as u32, + size, + name: DebugRelocName::Section(section), + addend: val as i64, + kind: object::RelocationKind::Absolute, + }); + self.write_udata_at(offset, 0, size) + } + + fn write_eh_pointer(&mut self, address: Address, eh_pe: gimli::DwEhPe, size: u8) -> Result<()> { + match address { + // Address::Constant arm copied from gimli + Address::Constant(val) => { + // Indirect doesn't matter here. + let val = match eh_pe.application() { + gimli::DW_EH_PE_absptr => val, + gimli::DW_EH_PE_pcrel => { + // FIXME better handling of sign + let offset = self.len() as u64; + offset.wrapping_sub(val) + } + _ => { + return Err(gimli::write::Error::UnsupportedPointerEncoding(eh_pe)); + } + }; + self.write_eh_pointer_data(val, eh_pe.format(), size) + } + Address::Symbol { symbol, addend } => match eh_pe.application() { + gimli::DW_EH_PE_pcrel => { + let size = match eh_pe.format() { + gimli::DW_EH_PE_sdata4 => 4, + _ => return Err(gimli::write::Error::UnsupportedPointerEncoding(eh_pe)), + }; + self.relocs.push(DebugReloc { + offset: self.len() as u32, + size, + name: DebugRelocName::Symbol(symbol), + addend, + kind: object::RelocationKind::Relative, + }); + self.write_udata(0, size) + } + _ => Err(gimli::write::Error::UnsupportedPointerEncoding(eh_pe)), + }, + } + } +} |