authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2024-08-19 08:17:28+02:00
committergravatar for jacobly@ziglang.orgJacob Young <jacobly@ziglang.org> 2024-08-21 01:43:21-04:00
logd3d5ed992c339ef114115fb621e0659ce121e027
tree397782fb0131dc932f53db662d080c3ab673c024
parent517721bbccbbbe571c90226197948a9ae2430d8f

elf: emit .rela.debug* sections for relocatable if required

4 files changed, 69 insertions(+), 46 deletions(-)

src/arch/riscv64/Emit.zig+12-12
......@@ -56,17 +56,17 @@ pub fn emitMir(emit: *Emit) Error!void {
5656 const hi_r_type: u32 = @intFromEnum(std.elf.R_RISCV.HI20);
5757 const lo_r_type: u32 = @intFromEnum(std.elf.R_RISCV.LO12_I);
5858
59 try atom_ptr.addReloc(elf_file, .{
59 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
6060 .r_offset = start_offset,
6161 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | hi_r_type,
6262 .r_addend = 0,
63 });
63 }, zo);
6464
65 try atom_ptr.addReloc(elf_file, .{
65 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
6666 .r_offset = start_offset + 4,
6767 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | lo_r_type,
6868 .r_addend = 0,
69 });
69 }, zo);
7070 },
7171 .load_tlv_reloc => |symbol| {
7272 const elf_file = emit.bin_file.cast(.elf).?;
......@@ -76,23 +76,23 @@ pub fn emitMir(emit: *Emit) Error!void {
7676
7777 const R_RISCV = std.elf.R_RISCV;
7878
79 try atom_ptr.addReloc(elf_file, .{
79 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
8080 .r_offset = start_offset,
8181 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | @intFromEnum(R_RISCV.TPREL_HI20),
8282 .r_addend = 0,
83 });
83 }, zo);
8484
85 try atom_ptr.addReloc(elf_file, .{
85 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
8686 .r_offset = start_offset + 4,
8787 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | @intFromEnum(R_RISCV.TPREL_ADD),
8888 .r_addend = 0,
89 });
89 }, zo);
9090
91 try atom_ptr.addReloc(elf_file, .{
91 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
9292 .r_offset = start_offset + 8,
9393 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | @intFromEnum(R_RISCV.TPREL_LO12_I),
9494 .r_addend = 0,
95 });
95 }, zo);
9696 },
9797 .call_extern_fn_reloc => |symbol| {
9898 const elf_file = emit.bin_file.cast(.elf).?;
......@@ -101,11 +101,11 @@ pub fn emitMir(emit: *Emit) Error!void {
101101
102102 const r_type: u32 = @intFromEnum(std.elf.R_RISCV.CALL_PLT);
103103
104 try atom_ptr.addReloc(elf_file, .{
104 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
105105 .r_offset = start_offset,
106106 .r_info = (@as(u64, @intCast(symbol.sym_index)) << 32) | r_type,
107107 .r_addend = 0,
108 });
108 }, zo);
109109 },
110110 };
111111 }
src/arch/x86_64/Emit.zig+10-10
......@@ -48,11 +48,11 @@ pub fn emitMir(emit: *Emit) Error!void {
4848 const zo = elf_file.zigObjectPtr().?;
4949 const atom_ptr = zo.symbol(emit.atom_index).atom(elf_file).?;
5050 const r_type = @intFromEnum(std.elf.R_X86_64.PLT32);
51 try atom_ptr.addReloc(elf_file, .{
51 try atom_ptr.addReloc(elf_file.base.comp.gpa, .{
5252 .r_offset = end_offset - 4,
5353 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
5454 .r_addend = lowered_relocs[0].off - 4,
55 });
55 }, zo);
5656 } else if (emit.lower.bin_file.cast(.macho)) |macho_file| {
5757 // Add relocation to the decl.
5858 const zo = macho_file.getZigObject().?;
......@@ -95,22 +95,22 @@ pub fn emitMir(emit: *Emit) Error!void {
9595 const zo = elf_file.zigObjectPtr().?;
9696 const atom = zo.symbol(emit.atom_index).atom(elf_file).?;
9797 const r_type = @intFromEnum(std.elf.R_X86_64.TLSLD);
98 try atom.addReloc(elf_file, .{
98 try atom.addReloc(elf_file.base.comp.gpa, .{
9999 .r_offset = end_offset - 4,
100100 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
101101 .r_addend = lowered_relocs[0].off - 4,
102 });
102 }, zo);
103103 },
104104 .linker_dtpoff => |sym_index| {
105105 const elf_file = emit.lower.bin_file.cast(.elf).?;
106106 const zo = elf_file.zigObjectPtr().?;
107107 const atom = zo.symbol(emit.atom_index).atom(elf_file).?;
108108 const r_type = @intFromEnum(std.elf.R_X86_64.DTPOFF32);
109 try atom.addReloc(elf_file, .{
109 try atom.addReloc(elf_file.base.comp.gpa, .{
110110 .r_offset = end_offset - 4,
111111 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
112112 .r_addend = lowered_relocs[0].off,
113 });
113 }, zo);
114114 },
115115 .linker_reloc => |sym_index| if (emit.lower.bin_file.cast(.elf)) |elf_file| {
116116 const zo = elf_file.zigObjectPtr().?;
......@@ -121,21 +121,21 @@ pub fn emitMir(emit: *Emit) Error!void {
121121 @intFromEnum(std.elf.R_X86_64.GOTPCREL)
122122 else
123123 @intFromEnum(std.elf.R_X86_64.PC32);
124 try atom.addReloc(elf_file, .{
124 try atom.addReloc(elf_file.base.comp.gpa, .{
125125 .r_offset = end_offset - 4,
126126 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
127127 .r_addend = lowered_relocs[0].off - 4,
128 });
128 }, zo);
129129 } else {
130130 const r_type: u32 = if (sym.flags.is_tls)
131131 @intFromEnum(std.elf.R_X86_64.TPOFF32)
132132 else
133133 @intFromEnum(std.elf.R_X86_64.@"32");
134 try atom.addReloc(elf_file, .{
134 try atom.addReloc(elf_file.base.comp.gpa, .{
135135 .r_offset = end_offset - 4,
136136 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
137137 .r_addend = lowered_relocs[0].off,
138 });
138 }, zo);
139139 }
140140 } else if (emit.lower.bin_file.cast(.macho)) |macho_file| {
141141 const zo = macho_file.getZigObject().?;
src/link/Elf/Atom.zig+12-14
......@@ -302,7 +302,7 @@ pub fn free(self: *Atom, elf_file: *Elf) void {
302302 }
303303
304304 // TODO create relocs free list
305 self.freeRelocs(elf_file);
305 self.freeRelocs(zo);
306306 // TODO figure out how to free input section mappind in ZigModule
307307 // const zig_object = elf_file.zigObjectPtr().?
308308 // assert(zig_object.atoms.swapRemove(self.atom_index));
......@@ -377,21 +377,19 @@ pub fn markFdesDead(self: Atom, elf_file: *Elf) void {
377377 }
378378}
379379
380pub fn addReloc(self: Atom, elf_file: *Elf, reloc: elf.Elf64_Rela) !void {
381 const comp = elf_file.base.comp;
382 const gpa = comp.gpa;
383 const file_ptr = self.file(elf_file).?;
384 assert(file_ptr == .zig_object);
385 const zig_object = file_ptr.zig_object;
386 const rels = &zig_object.relocs.items[self.relocs_section_index];
387 try rels.append(gpa, reloc);
380pub fn addReloc(self: Atom, alloc: Allocator, reloc: elf.Elf64_Rela, zo: *ZigObject) !void {
381 const rels = &zo.relocs.items[self.relocs_section_index];
382 try rels.ensureUnusedCapacity(alloc, 1);
383 self.addRelocAssumeCapacity(reloc, zo);
388384}
389385
390pub fn freeRelocs(self: Atom, elf_file: *Elf) void {
391 const file_ptr = self.file(elf_file).?;
392 assert(file_ptr == .zig_object);
393 const zig_object = file_ptr.zig_object;
394 zig_object.relocs.items[self.relocs_section_index].clearRetainingCapacity();
386pub fn addRelocAssumeCapacity(self: Atom, reloc: elf.Elf64_Rela, zo: *ZigObject) void {
387 const rels = &zo.relocs.items[self.relocs_section_index];
388 rels.appendAssumeCapacity(reloc);
389}
390
391pub fn freeRelocs(self: Atom, zo: *ZigObject) void {
392 zo.relocs.items[self.relocs_section_index].clearRetainingCapacity();
395393}
396394
397395pub fn scanRelocsRequiresCode(self: Atom, elf_file: *Elf) bool {
src/link/Elf/ZigObject.zig+35-10
......@@ -182,6 +182,8 @@ pub fn flushModule(self: *ZigObject, elf_file: *Elf, tid: Zcu.PerThread.Id) !voi
182182 try dwarf.flushModule(pt);
183183 try dwarf.resolveRelocs();
184184
185 const gpa = elf_file.base.comp.gpa;
186
185187 // TODO invert this logic so that we manage the output section with the atom, not the
186188 // other way around
187189 for ([_]u32{
......@@ -206,24 +208,47 @@ pub fn flushModule(self: *ZigObject, elf_file: *Elf, tid: Zcu.PerThread.Id) !voi
206208 const sym = self.symbol(sym_index);
207209 const atom_ptr = self.atom(sym.ref.index).?;
208210 if (!atom_ptr.alive) continue;
209 const shdr = elf_file.shdrs.items[sym.outputShndx(elf_file).?];
211 const shndx = sym.outputShndx(elf_file).?;
212 const shdr = elf_file.shdrs.items[shndx];
210213 const esym = &self.symtab.items(.elf_sym)[sym.esym_index];
211214 esym.st_size = shdr.sh_size;
212215 atom_ptr.size = shdr.sh_size;
213216 atom_ptr.alignment = Atom.Alignment.fromNonzeroByteUnits(shdr.sh_addralign);
214217
215218 const relocs = &self.relocs.items[atom_ptr.relocsShndx().?];
216 _ = relocs;
217219 for (sect.units.items) |*unit| {
220 try relocs.ensureUnusedCapacity(gpa, unit.external_relocs.items.len);
218221 for (unit.external_relocs.items) |reloc| {
219222 const tsym = self.symbol(reloc.target_sym);
220223 const r_offset = unit.off + unit.header_len + unit.getEntry(reloc.source_entry).off + reloc.source_off;
221 const r_addend = reloc.target_off;
222 std.debug.print("{s} <- r_off={x}, r_add={x}\n", .{
224 const r_addend: i64 = @intCast(reloc.target_off);
225 const r_type: elf.R_X86_64 = switch (dwarf.address_size) {
226 .@"32" => .@"32",
227 .@"64" => .@"64",
228 else => unreachable,
229 };
230 log.debug("{s} <- r_off={x}, r_add={x}, r_type={s}\n", .{
223231 tsym.name(elf_file),
224232 r_offset,
225233 r_addend,
234 @tagName(r_type),
226235 });
236 atom_ptr.addRelocAssumeCapacity(.{
237 .r_offset = r_offset,
238 .r_addend = r_addend,
239 .r_info = (@as(u64, @intCast(reloc.target_sym)) << 32) | @intFromEnum(r_type),
240 }, self);
241 }
242 }
243
244 if (elf_file.base.isRelocatable() and relocs.items.len > 0) {
245 const gop = try elf_file.output_rela_sections.getOrPut(gpa, shndx);
246 if (!gop.found_existing) {
247 const rela_sect_name = try std.fmt.allocPrintZ(gpa, ".rela{s}", .{elf_file.getShString(shdr.sh_name)});
248 defer gpa.free(rela_sect_name);
249 const rela_sh_name = try elf_file.insertShString(rela_sect_name);
250 const rela_shndx = try elf_file.addRelaShdr(rela_sh_name, shndx);
251 gop.value_ptr.* = .{ .shndx = rela_shndx };
227252 }
228253 }
229254 }
......@@ -698,11 +723,11 @@ pub fn getNavVAddr(
698723 const vaddr = this_sym.address(.{}, elf_file);
699724 const parent_atom = self.symbol(reloc_info.parent_atom_index).atom(elf_file).?;
700725 const r_type = relocation.encode(.abs, elf_file.getTarget().cpu.arch);
701 try parent_atom.addReloc(elf_file, .{
726 try parent_atom.addReloc(elf_file.base.comp.gpa, .{
702727 .r_offset = reloc_info.offset,
703728 .r_info = (@as(u64, @intCast(this_sym_index)) << 32) | r_type,
704729 .r_addend = reloc_info.addend,
705 });
730 }, self);
706731 return @intCast(vaddr);
707732}
708733
......@@ -717,11 +742,11 @@ pub fn getUavVAddr(
717742 const vaddr = sym.address(.{}, elf_file);
718743 const parent_atom = self.symbol(reloc_info.parent_atom_index).atom(elf_file).?;
719744 const r_type = relocation.encode(.abs, elf_file.getTarget().cpu.arch);
720 try parent_atom.addReloc(elf_file, .{
745 try parent_atom.addReloc(elf_file.base.comp.gpa, .{
721746 .r_offset = reloc_info.offset,
722747 .r_info = (@as(u64, @intCast(sym_index)) << 32) | r_type,
723748 .r_addend = reloc_info.addend,
724 });
749 }, self);
725750 return @intCast(vaddr);
726751}
727752
......@@ -1068,7 +1093,7 @@ pub fn updateFunc(
10681093 log.debug("updateFunc {}({d})", .{ ip.getNav(func.owner_nav).fqn.fmt(ip), func.owner_nav });
10691094
10701095 const sym_index = try self.getOrCreateMetadataForNav(elf_file, func.owner_nav);
1071 self.symbol(sym_index).atom(elf_file).?.freeRelocs(elf_file);
1096 self.symbol(sym_index).atom(elf_file).?.freeRelocs(self);
10721097
10731098 var code_buffer = std.ArrayList(u8).init(gpa);
10741099 defer code_buffer.deinit();
......@@ -1196,7 +1221,7 @@ pub fn updateNav(
11961221
11971222 if (nav_init != .none and Value.fromInterned(nav_init).typeOf(zcu).hasRuntimeBits(pt)) {
11981223 const sym_index = try self.getOrCreateMetadataForNav(elf_file, nav_index);
1199 self.symbol(sym_index).atom(elf_file).?.freeRelocs(elf_file);
1224 self.symbol(sym_index).atom(elf_file).?.freeRelocs(self);
12001225
12011226 var code_buffer = std.ArrayList(u8).init(zcu.gpa);
12021227 defer code_buffer.deinit();