authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2022-12-08 14:13:37+01:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2022-12-09 09:24:25+01:00
log9ade4f6d8c410eea63ad71569b5cf7813337659d
treed33bd6170d88cce565577b1df3ecfbbf94913246
parentd7e42014caadeb726d19243995365a573b6a9d06

elf: hint linker when file range copy is not necessary

2 files changed, 33 insertions(+), 47 deletions(-)

src/link/Dwarf.zig+5-5
......@@ -1151,7 +1151,7 @@ pub fn commitDeclState(
11511151 .elf => {
11521152 const elf_file = self.bin_file.cast(File.Elf).?;
11531153 const shdr_index = elf_file.debug_line_section_index.?;
1154 try elf_file.growNonAllocSection(shdr_index, needed_size, 1);
1154 try elf_file.growNonAllocSection(shdr_index, needed_size, 1, true);
11551155 const debug_line_sect = elf_file.sections.items[shdr_index];
11561156 const file_pos = debug_line_sect.sh_offset + src_fn.off;
11571157 try pwriteDbgLineNops(
......@@ -1398,7 +1398,7 @@ fn writeDeclDebugInfo(self: *Dwarf, atom: *Atom, dbg_info_buf: []const u8) !void
13981398 .elf => {
13991399 const elf_file = self.bin_file.cast(File.Elf).?;
14001400 const shdr_index = elf_file.debug_info_section_index.?;
1401 try elf_file.growNonAllocSection(shdr_index, needed_size, 1);
1401 try elf_file.growNonAllocSection(shdr_index, needed_size, 1, true);
14021402 const debug_info_sect = elf_file.sections.items[shdr_index];
14031403 const file_pos = debug_info_sect.sh_offset + atom.off;
14041404 try pwriteDbgInfoNops(
......@@ -1689,7 +1689,7 @@ pub fn writeDbgAbbrev(self: *Dwarf) !void {
16891689 .elf => {
16901690 const elf_file = self.bin_file.cast(File.Elf).?;
16911691 const shdr_index = elf_file.debug_abbrev_section_index.?;
1692 try elf_file.growNonAllocSection(shdr_index, needed_size, 1);
1692 try elf_file.growNonAllocSection(shdr_index, needed_size, 1, false);
16931693 const debug_abbrev_sect = elf_file.sections.items[shdr_index];
16941694 const file_pos = debug_abbrev_sect.sh_offset + abbrev_offset;
16951695 try elf_file.base.file.?.pwriteAll(&abbrev_buf, file_pos);
......@@ -2126,7 +2126,7 @@ pub fn writeDbgAranges(self: *Dwarf, addr: u64, size: u64) !void {
21262126 .elf => {
21272127 const elf_file = self.bin_file.cast(File.Elf).?;
21282128 const shdr_index = elf_file.debug_aranges_section_index.?;
2129 try elf_file.growNonAllocSection(shdr_index, needed_size, 16);
2129 try elf_file.growNonAllocSection(shdr_index, needed_size, 16, false);
21302130 const debug_aranges_sect = elf_file.sections.items[shdr_index];
21312131 const file_pos = debug_aranges_sect.sh_offset;
21322132 try elf_file.base.file.?.pwriteAll(di_buf.items, file_pos);
......@@ -2289,7 +2289,7 @@ pub fn writeDbgLineHeader(self: *Dwarf, module: *Module) !void {
22892289 const elf_file = self.bin_file.cast(File.Elf).?;
22902290 const shdr_index = elf_file.debug_line_section_index.?;
22912291 const needed_size = elf_file.sections.items[shdr_index].sh_size + delta;
2292 try elf_file.growNonAllocSection(shdr_index, needed_size, 1);
2292 try elf_file.growNonAllocSection(shdr_index, needed_size, 1, true);
22932293 const file_pos = elf_file.sections.items[shdr_index].sh_offset + src_fn.off;
22942294
22952295 const amt = try elf_file.base.file.?.preadAll(buffer, file_pos);
src/link/Elf.zig+28-42
......@@ -967,7 +967,13 @@ fn growAllocSection(self: *Elf, shdr_index: u16, phdr_index: u16, needed_size: u
967967 self.markDirty(shdr_index, phdr_index);
968968}
969969
970pub fn growNonAllocSection(self: *Elf, shdr_index: u16, needed_size: u64, min_alignment: u32) !void {
970pub fn growNonAllocSection(
971 self: *Elf,
972 shdr_index: u16,
973 needed_size: u64,
974 min_alignment: u32,
975 requires_file_copy: bool,
976) !void {
971977 const shdr = &self.sections.items[shdr_index];
972978
973979 if (needed_size > self.allocatedSize(shdr.sh_offset)) {
......@@ -982,13 +988,17 @@ pub fn growNonAllocSection(self: *Elf, shdr_index: u16, needed_size: u64, min_al
982988 // Move all the symbols to a new file location.
983989 const new_offset = self.findFreeSpace(needed_size, min_alignment);
984990 log.debug("moving '{s}' from 0x{x} to 0x{x}", .{ self.getString(shdr.sh_name), shdr.sh_offset, new_offset });
985 const amt = try self.base.file.?.copyRangeAll(
986 shdr.sh_offset,
987 self.base.file.?,
988 new_offset,
989 existing_size,
990 );
991 if (amt != existing_size) return error.InputOutput;
991
992 if (requires_file_copy) {
993 const amt = try self.base.file.?.copyRangeAll(
994 shdr.sh_offset,
995 self.base.file.?,
996 new_offset,
997 existing_size,
998 );
999 if (amt != existing_size) return error.InputOutput;
1000 }
1001
9921002 shdr.sh_offset = new_offset;
9931003 }
9941004
......@@ -1191,45 +1201,21 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
11911201 }
11921202
11931203 {
1194 const shstrtab_sect = &self.sections.items[self.shstrtab_index.?];
1195 if (self.shstrtab_dirty or self.shstrtab.items.len != shstrtab_sect.sh_size) {
1196 const allocated_size = self.allocatedSize(shstrtab_sect.sh_offset);
1197 const needed_size = self.shstrtab.items.len;
1198
1199 if (needed_size > allocated_size) {
1200 shstrtab_sect.sh_size = 0; // free the space
1201 shstrtab_sect.sh_offset = self.findFreeSpace(needed_size, 1);
1202 }
1203 shstrtab_sect.sh_size = needed_size;
1204 log.debug("writing shstrtab start=0x{x} end=0x{x}", .{ shstrtab_sect.sh_offset, shstrtab_sect.sh_offset + needed_size });
1205
1204 const shdr_index = self.shstrtab_index.?;
1205 if (self.shstrtab_dirty or self.shstrtab.items.len != self.sections.items[shdr_index].sh_size) {
1206 try self.growNonAllocSection(shdr_index, self.shstrtab.items.len, 1, false);
1207 const shstrtab_sect = self.sections.items[shdr_index];
12061208 try self.base.file.?.pwriteAll(self.shstrtab.items, shstrtab_sect.sh_offset);
1207 if (!self.shdr_table_dirty) {
1208 // Then it won't get written with the others and we need to do it.
1209 try self.writeSectHeader(self.shstrtab_index.?);
1210 }
12111209 self.shstrtab_dirty = false;
12121210 }
12131211 }
12141212
12151213 if (self.dwarf) |dwarf| {
1216 const debug_strtab_sect = &self.sections.items[self.debug_str_section_index.?];
1217 if (self.debug_strtab_dirty or dwarf.strtab.items.len != debug_strtab_sect.sh_size) {
1218 const allocated_size = self.allocatedSize(debug_strtab_sect.sh_offset);
1219 const needed_size = dwarf.strtab.items.len;
1220
1221 if (needed_size > allocated_size) {
1222 debug_strtab_sect.sh_size = 0; // free the space
1223 debug_strtab_sect.sh_offset = self.findFreeSpace(needed_size, 1);
1224 }
1225 debug_strtab_sect.sh_size = needed_size;
1226 log.debug("debug_strtab start=0x{x} end=0x{x}", .{ debug_strtab_sect.sh_offset, debug_strtab_sect.sh_offset + needed_size });
1227
1214 const shdr_index = self.debug_str_section_index.?;
1215 if (self.debug_strtab_dirty or dwarf.strtab.items.len != self.sections.items[shdr_index].sh_size) {
1216 try self.growNonAllocSection(shdr_index, dwarf.strtab.items.len, 1, false);
1217 const debug_strtab_sect = self.sections.items[shdr_index];
12281218 try self.base.file.?.pwriteAll(dwarf.strtab.items, debug_strtab_sect.sh_offset);
1229 if (!self.shdr_table_dirty) {
1230 // Then it won't get written with the others and we need to do it.
1231 try self.writeSectHeader(self.debug_str_section_index.?);
1232 }
12331219 self.debug_strtab_dirty = false;
12341220 }
12351221 }
......@@ -2861,7 +2847,7 @@ fn writeSymbol(self: *Elf, index: usize) !void {
28612847 .p64 => @alignOf(elf.Elf64_Sym),
28622848 };
28632849 const needed_size = (self.local_symbols.items.len + self.global_symbols.items.len) * sym_size;
2864 try self.growNonAllocSection(self.symtab_section_index.?, needed_size, sym_align);
2850 try self.growNonAllocSection(self.symtab_section_index.?, needed_size, sym_align, true);
28652851 syms_sect.sh_info = @intCast(u32, self.local_symbols.items.len);
28662852 }
28672853 const foreign_endian = self.base.options.target.cpu.arch.endian() != builtin.cpu.arch.endian();
......@@ -2910,7 +2896,7 @@ fn writeAllGlobalSymbols(self: *Elf) !void {
29102896 .p64 => @alignOf(elf.Elf64_Sym),
29112897 };
29122898 const needed_size = (self.local_symbols.items.len + self.global_symbols.items.len) * sym_size;
2913 try self.growNonAllocSection(self.symtab_section_index.?, needed_size, sym_align);
2899 try self.growNonAllocSection(self.symtab_section_index.?, needed_size, sym_align, true);
29142900
29152901 const foreign_endian = self.base.options.target.cpu.arch.endian() != builtin.cpu.arch.endian();
29162902 const global_syms_off = syms_sect.sh_offset + self.local_symbols.items.len * sym_size;