-pub trait Product {
- fn add_rustc_section(&mut self, symbol_name: String, data: Vec<u8>, is_like_osx: bool);
-}
+//! Abstraction around the object writing crate
-impl Product for faerie::Artifact {
- fn add_rustc_section(&mut self, symbol_name: String, data: Vec<u8>, is_like_osx: bool) {
- self
- .declare(".rustc", faerie::Decl::section(faerie::SectionKind::Data))
- .unwrap();
- self
- .define_with_symbols(".rustc", data, {
- let mut map = std::collections::BTreeMap::new();
- // FIXME implement faerie elf backend section custom symbols
- // For MachO this is necessary to prevent the linker from throwing away the .rustc section,
- // but for ELF it isn't.
- if is_like_osx {
- map.insert(
- symbol_name,
- 0,
- );
- }
- map
- })
- .unwrap();
- }
+use std::convert::{TryFrom, TryInto};
+
+use rustc_data_structures::fx::FxHashMap;
+use rustc_session::Session;
+
+use cranelift_codegen::isa::TargetIsa;
+use cranelift_module::FuncId;
+use cranelift_object::{ObjectBuilder, ObjectModule, ObjectProduct};
+
+use object::write::*;
+use object::{RelocationEncoding, SectionKind, SymbolFlags};
+
+use gimli::SectionId;
+
+use crate::debuginfo::{DebugReloc, DebugRelocName};
+
+pub(crate) trait WriteMetadata {
+ fn add_rustc_section(&mut self, symbol_name: String, data: Vec<u8>);
}
-impl Product for object::write::Object {
- fn add_rustc_section(&mut self, symbol_name: String, data: Vec<u8>, is_like_osx: bool) {
+impl WriteMetadata for object::write::Object {
+ fn add_rustc_section(&mut self, symbol_name: String, data: Vec<u8>) {
let segment = self.segment_name(object::write::StandardSegment::Data).to_vec();
let section_id = self.add_section(segment, b".rustc".to_vec(), object::SectionKind::Data);
let offset = self.append_section_data(section_id, &data, 1);
- // FIXME implement faerie elf backend section custom symbols
- // For MachO this is necessary to prevent the linker from throwing away the .rustc section,
- // but for ELF it isn't.
- if is_like_osx {
- self.add_symbol(object::write::Symbol {
- name: symbol_name.into_bytes(),
- value: offset,
- size: data.len() as u64,
- kind: object::SymbolKind::Data,
- scope: object::SymbolScope::Compilation,
- weak: false,
- section: Some(section_id),
- });
+ // For MachO and probably PE this is necessary to prevent the linker from throwing away the
+ // .rustc section. For ELF this isn't necessary, but it also doesn't harm.
+ self.add_symbol(object::write::Symbol {
+ name: symbol_name.into_bytes(),
+ value: offset,
+ size: data.len() as u64,
+ kind: object::SymbolKind::Data,
+ scope: object::SymbolScope::Dynamic,
+ weak: false,
+ section: SymbolSection::Section(section_id),
+ flags: SymbolFlags::None,
+ });
+ }
+}
+
+pub(crate) trait WriteDebugInfo {
+ type SectionId: Copy;
+
+ fn add_debug_section(&mut self, name: SectionId, data: Vec<u8>) -> Self::SectionId;
+ fn add_debug_reloc(
+ &mut self,
+ section_map: &FxHashMap<SectionId, Self::SectionId>,
+ from: &Self::SectionId,
+ reloc: &DebugReloc,
+ );
+}
+
+impl WriteDebugInfo for ObjectProduct {
+ type SectionId = (object::write::SectionId, object::write::SymbolId);
+
+ fn add_debug_section(
+ &mut self,
+ id: SectionId,
+ data: Vec<u8>,
+ ) -> (object::write::SectionId, object::write::SymbolId) {
+ let name = if self.object.format() == object::BinaryFormat::MachO {
+ id.name().replace('.', "__") // machO expects __debug_info instead of .debug_info
+ } else {
+ id.name().to_string()
}
+ .into_bytes();
+
+ let segment = self.object.segment_name(StandardSegment::Debug).to_vec();
+ // FIXME use SHT_X86_64_UNWIND for .eh_frame
+ let section_id = self.object.add_section(
+ segment,
+ name,
+ if id == SectionId::EhFrame { SectionKind::ReadOnlyData } else { SectionKind::Debug },
+ );
+ self.object
+ .section_mut(section_id)
+ .set_data(data, if id == SectionId::EhFrame { 8 } else { 1 });
+ let symbol_id = self.object.section_symbol(section_id);
+ (section_id, symbol_id)
+ }
+
+ fn add_debug_reloc(
+ &mut self,
+ section_map: &FxHashMap<SectionId, Self::SectionId>,
+ from: &Self::SectionId,
+ reloc: &DebugReloc,
+ ) {
+ let (symbol, symbol_offset) = match reloc.name {
+ DebugRelocName::Section(id) => (section_map.get(&id).unwrap().1, 0),
+ DebugRelocName::Symbol(id) => {
+ let symbol_id = self.function_symbol(FuncId::from_u32(id.try_into().unwrap()));
+ self.object
+ .symbol_section_and_offset(symbol_id)
+ .expect("Debug reloc for undef sym???")
+ }
+ };
+ self.object
+ .add_relocation(
+ from.0,
+ Relocation {
+ offset: u64::from(reloc.offset),
+ symbol,
+ kind: reloc.kind,
+ encoding: RelocationEncoding::Generic,
+ size: reloc.size * 8,
+ addend: i64::try_from(symbol_offset).unwrap() + reloc.addend,
+ },
+ )
+ .unwrap();
}
}
+
+pub(crate) fn with_object(sess: &Session, name: &str, f: impl FnOnce(&mut Object)) -> Vec<u8> {
+ let triple = crate::target_triple(sess);
+
+ let binary_format = match triple.binary_format {
+ target_lexicon::BinaryFormat::Elf => object::BinaryFormat::Elf,
+ target_lexicon::BinaryFormat::Coff => object::BinaryFormat::Coff,
+ target_lexicon::BinaryFormat::Macho => object::BinaryFormat::MachO,
+ binary_format => sess.fatal(&format!("binary format {} is unsupported", binary_format)),
+ };
+ let architecture = match triple.architecture {
+ target_lexicon::Architecture::X86_32(_) => object::Architecture::I386,
+ target_lexicon::Architecture::X86_64 => object::Architecture::X86_64,
+ target_lexicon::Architecture::Arm(_) => object::Architecture::Arm,
+ target_lexicon::Architecture::Aarch64(_) => object::Architecture::Aarch64,
+ architecture => {
+ sess.fatal(&format!("target architecture {:?} is unsupported", architecture,))
+ }
+ };
+ let endian = match triple.endianness().unwrap() {
+ target_lexicon::Endianness::Little => object::Endianness::Little,
+ target_lexicon::Endianness::Big => object::Endianness::Big,
+ };
+
+ let mut metadata_object = object::write::Object::new(binary_format, architecture, endian);
+ metadata_object.add_file_symbol(name.as_bytes().to_vec());
+ f(&mut metadata_object);
+ metadata_object.write().unwrap()
+}
+
+pub(crate) fn make_module(sess: &Session, isa: Box<dyn TargetIsa>, name: String) -> ObjectModule {
+ let mut builder =
+ ObjectBuilder::new(isa, name + ".o", cranelift_module::default_libcall_names()).unwrap();
+ // Unlike cg_llvm, cg_clif defaults to disabling -Zfunction-sections. For cg_llvm binary size
+ // is important, while cg_clif cares more about compilation times. Enabling -Zfunction-sections
+ // can easily double the amount of time necessary to perform linking.
+ builder.per_function_section(sess.opts.debugging_opts.function_sections.unwrap_or(false));
+ ObjectModule::new(builder)
+}
projects / rust.git / blobdiff