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elf: allow expanding segments in virtual memory

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This commit is contained in:
Jakub Konka
2023-09-26 11:12:31 +02:00
parent de4d1ea250
commit 1200a5a240
6 changed files with 177 additions and 79 deletions
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148
src/link/Elf.zig
View File

@@ -1,4 +1,5 @@
base: link.File,
dwarf: ?Dwarf = null,
ptr_width: PtrWidth,
@@ -103,6 +104,7 @@ phdr_table_dirty: bool = false,
shdr_table_dirty: bool = false,
shstrtab_dirty: bool = false,
strtab_dirty: bool = false,
got_dirty: bool = false,
debug_strtab_dirty: bool = false,
debug_abbrev_section_dirty: bool = false,
@@ -411,7 +413,6 @@ fn findFreeSpace(self: *Elf, object_size: u64, min_alignment: u64) u64 {
const AllocateSegmentOpts = struct {
size: u64,
alignment: u64,
addr: ?u64 = null, // TODO find free VM space
flags: u32 = elf.PF_R,
};
@@ -422,7 +423,7 @@ pub fn allocateSegment(self: *Elf, opts: AllocateSegmentOpts) error{OutOfMemory}
// Memory is always allocated in sequence.
// TODO is this correct? Or should we implement something similar to `findFreeSpace`?
// How would that impact HCS?
const addr = opts.addr orelse blk: {
const addr = blk: {
assert(self.phdr_table_load_index != null);
const phdr = &self.phdrs.items[index - 1];
break :blk mem.alignForward(u64, phdr.p_vaddr + phdr.p_memsz, opts.alignment);
@@ -568,7 +569,6 @@ pub fn populateMissingMetadata(self: *Elf) !void {
if (self.phdr_load_re_index == null) {
self.phdr_load_re_index = try self.allocateSegment(.{
.addr = self.defaultEntryAddress(),
.size = self.base.options.program_code_size_hint,
.alignment = self.page_size,
.flags = elf.PF_X | elf.PF_R | elf.PF_W,
@@ -577,15 +577,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {
}
if (self.phdr_got_index == null) {
// TODO instead of hard coding the vaddr, make a function to find a vaddr to put things at.
// we'll need to re-use that function anyway, in case the GOT grows and overlaps something
// else in virtual memory.
const addr: u64 = if (self.base.options.target.ptrBitWidth() >= 32) 0x4000000 else 0x8000;
// We really only need ptr alignment but since we are using PROGBITS, linux requires
// page align.
const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);
self.phdr_got_index = try self.allocateSegment(.{
.addr = addr,
.size = @as(u64, ptr_size) * self.base.options.symbol_count_hint,
.alignment = alignment,
.flags = elf.PF_R | elf.PF_W,
@@ -593,12 +588,9 @@ pub fn populateMissingMetadata(self: *Elf) !void {
}
if (self.phdr_load_ro_index == null) {
// TODO Same as for GOT
const addr: u64 = if (self.base.options.target.ptrBitWidth() >= 32) 0xc000000 else 0xa000;
// Same reason as for GOT
const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);
self.phdr_load_ro_index = try self.allocateSegment(.{
.addr = addr,
.size = 1024,
.alignment = alignment,
.flags = elf.PF_R | elf.PF_W,
@@ -606,12 +598,9 @@ pub fn populateMissingMetadata(self: *Elf) !void {
}
if (self.phdr_load_rw_index == null) {
// TODO Same as for GOT
const addr: u64 = if (self.base.options.target.ptrBitWidth() >= 32) 0x10000000 else 0xc000;
// Same reason as for GOT
const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);
self.phdr_load_rw_index = try self.allocateSegment(.{
.addr = addr,
.size = 1024,
.alignment = alignment,
.flags = elf.PF_R | elf.PF_W,
@@ -619,11 +608,8 @@ pub fn populateMissingMetadata(self: *Elf) !void {
}
if (self.phdr_load_zerofill_index == null) {
// TODO Same as for GOT
const addr: u64 = if (self.base.options.target.ptrBitWidth() >= 32) 0x14000000 else 0xf000;
const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);
self.phdr_load_zerofill_index = try self.allocateSegment(.{
.addr = addr,
.size = 0,
.alignment = alignment,
.flags = elf.PF_R | elf.PF_W,
@@ -858,7 +844,19 @@ pub fn growAllocSection(self: *Elf, shdr_index: u16, needed_size: u64) !void {
}
const mem_capacity = self.allocatedVirtualSize(phdr.p_vaddr);
assert(needed_size <= mem_capacity); // TODO grow section in virtual memory
if (needed_size > mem_capacity) {
// We are exceeding our allocated VM capacity so we need to shift everything in memory
// and grow.
{
const dirty_addr = phdr.p_vaddr + phdr.p_memsz;
self.got_dirty = for (self.got.entries.items) |entry| {
if (self.symbol(entry.symbol_index).value >= dirty_addr) break true;
} else false;
// TODO mark relocs dirty
}
try self.growSegment(shdr_index, needed_size);
}
shdr.sh_size = needed_size;
phdr.p_memsz = needed_size;
@@ -870,6 +868,61 @@ pub fn growAllocSection(self: *Elf, shdr_index: u16, needed_size: u64) !void {
self.markDirty(shdr_index, phdr_index);
}
fn growSegment(self: *Elf, shndx: u16, needed_size: u64) !void {
const phdr_index = self.phdr_to_shdr_table.get(shndx).?;
const phdr = &self.phdrs.items[phdr_index];
const increased_size = padToIdeal(needed_size);
const end_addr = phdr.p_vaddr + phdr.p_memsz;
const old_aligned_end = phdr.p_vaddr + mem.alignForward(u64, phdr.p_memsz, phdr.p_align);
const new_aligned_end = phdr.p_vaddr + mem.alignForward(u64, increased_size, phdr.p_align);
const diff = new_aligned_end - old_aligned_end;
log.debug("growing phdr({d}) in memory by {x}", .{ phdr_index, diff });
// Update symbols and atoms.
var files = std.ArrayList(File.Index).init(self.base.allocator);
defer files.deinit();
try files.ensureTotalCapacityPrecise(self.objects.items.len + 1);
if (self.zig_module_index) |index| files.appendAssumeCapacity(index);
files.appendSliceAssumeCapacity(self.objects.items);
for (files.items) |index| {
const file_ptr = self.file(index).?;
for (file_ptr.locals()) |sym_index| {
const sym = self.symbol(sym_index);
const atom_ptr = sym.atom(self) orelse continue;
if (!atom_ptr.flags.alive or !atom_ptr.flags.allocated) continue;
if (atom_ptr.value >= end_addr) sym.value += diff;
}
for (file_ptr.globals()) |sym_index| {
const sym = self.symbol(sym_index);
const atom_ptr = sym.atom(self) orelse continue;
if (!atom_ptr.flags.alive or !atom_ptr.flags.allocated) continue;
if (atom_ptr.value >= end_addr) sym.value += diff;
}
for (file_ptr.atoms()) |atom_index| {
const atom_ptr = self.atom(atom_index) orelse continue;
if (!atom_ptr.flags.alive or !atom_ptr.flags.allocated) continue;
if (atom_ptr.value >= end_addr) atom_ptr.value += diff;
}
}
// Finally, update section headers.
for (self.shdrs.items, 0..) |*other_shdr, other_shndx| {
if (other_shdr.sh_flags & elf.SHF_ALLOC == 0) continue;
if (other_shndx == shndx) continue;
const other_phdr_index = self.phdr_to_shdr_table.get(@intCast(other_shndx)) orelse continue;
const other_phdr = &self.phdrs.items[other_phdr_index];
if (other_phdr.p_vaddr < end_addr) continue;
other_shdr.sh_addr += diff;
other_phdr.p_vaddr += diff;
other_phdr.p_paddr += diff;
}
}
pub fn growNonAllocSection(
self: *Elf,
shdr_index: u16,
@@ -1133,6 +1186,10 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
// Scan and create missing synthetic entries such as GOT indirection.
try self.scanRelocs();
if (build_options.enable_logging) {
state_log.debug("{}", .{self.dumpState()});
}
// Allocate atoms parsed from input object files, followed by allocating
// linker-defined synthetic symbols.
try self.allocateObjects();
@@ -1143,7 +1200,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
if (self.zig_module_index) |index| {
for (self.file(index).?.zig_module.atoms.keys()) |atom_index| {
const atom_ptr = self.atom(atom_index).?;
if (!atom_ptr.alive) continue;
if (!atom_ptr.flags.alive) continue;
const shdr = &self.shdrs.items[atom_ptr.outputShndx().?];
const file_offset = shdr.sh_offset + atom_ptr.value - shdr.sh_addr;
const size = math.cast(usize, atom_ptr.size) orelse return error.Overflow;
@@ -1157,6 +1214,15 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
}
try self.writeObjects();
if (self.got_dirty) {
const shdr = &self.shdrs.items[self.got_section_index.?];
var buffer = try std.ArrayList(u8).initCapacity(gpa, self.got.size(self));
defer buffer.deinit();
try self.got.writeAllEntries(self, buffer.writer());
try self.base.file.?.pwriteAll(buffer.items, shdr.sh_offset);
self.got_dirty = false;
}
// Look for entry address in objects if not set by the incremental compiler.
if (self.entry_addr == null) {
const entry: ?[]const u8 = entry: {
@@ -1537,7 +1603,7 @@ fn resolveSymbols(self: *Elf) error{Overflow}!void {
for (try object.comdatGroupMembers(cg.shndx)) |shndx| {
const atom_index = object.atoms.items[shndx];
if (self.atom(atom_index)) |atom_ptr| {
atom_ptr.alive = false;
atom_ptr.flags.alive = false;
// atom_ptr.markFdesDead(self);
}
}
@@ -1645,25 +1711,26 @@ fn scanRelocs(self: *Elf) !void {
fn allocateObjects(self: *Elf) !void {
for (self.objects.items) |index| {
const object = self.file(index).?.object;
for (object.atoms.items) |atom_index| {
const atom_ptr = self.atom(atom_index) orelse continue;
if (!atom_ptr.alive) continue;
if (!atom_ptr.flags.alive or atom_ptr.flags.allocated) continue;
try atom_ptr.allocate(self);
}
for (object.locals()) |local_index| {
const local = self.symbol(local_index);
const atom_ptr = local.atom(self) orelse continue;
if (!atom_ptr.alive) continue;
local.value += atom_ptr.value;
if (!atom_ptr.flags.alive) continue;
local.value = local.elfSym(self).st_value + atom_ptr.value;
}
for (object.globals()) |global_index| {
const global = self.symbol(global_index);
const atom_ptr = global.atom(self) orelse continue;
if (!atom_ptr.alive) continue;
if (!atom_ptr.flags.alive) continue;
if (global.file_index == index) {
global.value += atom_ptr.value;
global.value = global.elfSym(self).st_value + atom_ptr.value;
}
}
}
@@ -1676,7 +1743,7 @@ fn writeObjects(self: *Elf) !void {
const object = self.file(index).?.object;
for (object.atoms.items) |atom_index| {
const atom_ptr = self.atom(atom_index) orelse continue;
if (!atom_ptr.alive) continue;
if (!atom_ptr.flags.alive) continue;
const shdr = &self.shdrs.items[atom_ptr.outputShndx().?];
if (shdr.sh_type == elf.SHT_NOBITS) continue;
@@ -2650,7 +2717,7 @@ fn updateDeclCode(
atom_ptr.output_section_index = shdr_index;
sym.name_offset = try self.strtab.insert(gpa, decl_name);
atom_ptr.alive = true;
atom_ptr.flags.alive = true;
atom_ptr.name_offset = sym.name_offset;
esym.st_name = sym.name_offset;
esym.st_info |= stt_bits;
@@ -2681,11 +2748,6 @@ fn updateDeclCode(
} else {
try atom_ptr.allocate(self);
errdefer self.freeDeclMetadata(sym_index);
log.debug("allocated atom for {s} at 0x{x} to 0x{x}", .{
decl_name,
atom_ptr.value,
atom_ptr.value + atom_ptr.size,
});
sym.value = atom_ptr.value;
esym.st_value = atom_ptr.value;
@@ -2873,7 +2935,6 @@ fn updateLazySymbol(self: *Elf, sym: link.File.LazySymbol, symbol_index: Symbol.
defer gpa.free(name);
break :blk try self.strtab.insert(gpa, name);
};
const name = self.strtab.get(name_str_index).?;
const src = if (sym.ty.getOwnerDeclOrNull(mod)) |owner_decl|
mod.declPtr(owner_decl).srcLoc(mod)
@@ -2913,7 +2974,7 @@ fn updateLazySymbol(self: *Elf, sym: link.File.LazySymbol, symbol_index: Symbol.
local_esym.st_info |= elf.STT_OBJECT;
local_esym.st_size = code.len;
const atom_ptr = local_sym.atom(self).?;
atom_ptr.alive = true;
atom_ptr.flags.alive = true;
atom_ptr.name_offset = name_str_index;
atom_ptr.alignment = required_alignment;
atom_ptr.size = code.len;
@@ -2922,12 +2983,6 @@ fn updateLazySymbol(self: *Elf, sym: link.File.LazySymbol, symbol_index: Symbol.
try atom_ptr.allocate(self);
errdefer self.freeDeclMetadata(symbol_index);
log.debug("allocated atom for {s} at 0x{x} to 0x{x}", .{
name,
atom_ptr.value,
atom_ptr.value + atom_ptr.size,
});
local_sym.value = atom_ptr.value;
local_esym.st_value = atom_ptr.value;
@@ -2961,7 +3016,6 @@ pub fn lowerUnnamedConst(self: *Elf, typed_value: TypedValue, decl_index: Module
defer gpa.free(name);
break :blk try self.strtab.insert(gpa, name);
};
const name = self.strtab.get(name_str_index).?;
const zig_module = self.file(self.zig_module_index.?).?.zig_module;
const sym_index = try zig_module.addAtom(self);
@@ -2992,7 +3046,7 @@ pub fn lowerUnnamedConst(self: *Elf, typed_value: TypedValue, decl_index: Module
local_esym.st_info |= elf.STT_OBJECT;
local_esym.st_size = code.len;
const atom_ptr = local_sym.atom(self).?;
atom_ptr.alive = true;
atom_ptr.flags.alive = true;
atom_ptr.name_offset = name_str_index;
atom_ptr.alignment = required_alignment;
atom_ptr.size = code.len;
@@ -3001,8 +3055,6 @@ pub fn lowerUnnamedConst(self: *Elf, typed_value: TypedValue, decl_index: Module
try atom_ptr.allocate(self);
errdefer self.freeDeclMetadata(sym_index);
log.debug("allocated atom for {s} at 0x{x} to 0x{x}", .{ name, atom_ptr.value, atom_ptr.value + atom_ptr.size });
local_sym.value = atom_ptr.value;
local_esym.st_value = atom_ptr.value;
@@ -3740,14 +3792,6 @@ pub fn calcImageBase(self: Elf) u64 {
};
}
pub fn defaultEntryAddress(self: Elf) u64 {
if (self.entry_addr) |addr| return addr;
return switch (self.base.options.target.cpu.arch) {
.spu_2 => 0,
else => default_entry_addr,
};
}
pub fn isDynLib(self: Elf) bool {
return self.base.options.output_mode == .Lib and self.base.options.link_mode == .Dynamic;
}

53
src/link/Elf/Atom.zig
View File

@@ -25,11 +25,8 @@ relocs_section_index: Index = 0,
/// Index of this atom in the linker's atoms table.
atom_index: Index = 0,
/// Specifies whether this atom is alive or has been garbage collected.
alive: bool = false,
/// Specifies if the atom has been visited during garbage collection.
visited: bool = false,
/// Flags we use for state tracking.
flags: Flags = .{},
/// Start index of FDEs referencing this atom.
fde_start: u32 = 0,
@@ -48,8 +45,12 @@ pub fn name(self: Atom, elf_file: *Elf) []const u8 {
return elf_file.strtab.getAssumeExists(self.name_offset);
}
pub fn file(self: Atom, elf_file: *Elf) ?File {
return elf_file.file(self.file_index);
}
pub fn inputShdr(self: Atom, elf_file: *Elf) elf.Elf64_Shdr {
const object = elf_file.file(self.file_index).?.object;
const object = self.file(elf_file).?.object;
return object.shdrs.items[self.input_section_index];
}
@@ -59,7 +60,7 @@ pub fn outputShndx(self: Atom) ?u16 {
}
pub fn codeInObject(self: Atom, elf_file: *Elf) error{Overflow}![]const u8 {
const object = elf_file.file(self.file_index).?.object;
const object = self.file(elf_file).?.object;
return object.shdrContents(self.input_section_index);
}
@@ -91,7 +92,7 @@ pub fn codeInObjectUncompressAlloc(self: Atom, elf_file: *Elf) ![]u8 {
}
pub fn priority(self: Atom, elf_file: *Elf) u64 {
const index = elf_file.file(self.file_index).?.index();
const index = self.file(elf_file).?.index();
return (@as(u64, @intCast(index)) << 32) | @as(u64, @intCast(self.input_section_index));
}
@@ -178,6 +179,13 @@ pub fn allocate(self: *Atom, elf_file: *Elf) !void {
}
};
log.debug("allocated atom({d}) : '{s}' at 0x{x} to 0x{x}", .{
self.atom_index,
self.name(elf_file),
self.value,
self.value + self.size,
});
const expand_section = if (atom_placement) |placement_index|
elf_file.atom(placement_index).?.next_index == 0
else
@@ -222,6 +230,8 @@ pub fn allocate(self: *Atom, elf_file: *Elf) !void {
if (free_list_removal) |i| {
_ = free_list.swapRemove(i);
}
self.flags.allocated = true;
}
pub fn shrink(self: *Atom, elf_file: *Elf) void {
@@ -238,7 +248,7 @@ pub fn free(self: *Atom, elf_file: *Elf) void {
log.debug("freeAtom {d} ({s})", .{ self.atom_index, self.name(elf_file) });
const gpa = elf_file.base.allocator;
const zig_module = elf_file.file(self.file_index).?.zig_module;
const zig_module = self.file(elf_file).?.zig_module;
const shndx = self.outputShndx().?;
const meta = elf_file.last_atom_and_free_list_table.getPtr(shndx).?;
const free_list = &meta.free_list;
@@ -294,7 +304,7 @@ pub fn free(self: *Atom, elf_file: *Elf) void {
}
pub fn relocs(self: Atom, elf_file: *Elf) error{Overflow}![]align(1) const elf.Elf64_Rela {
return switch (elf_file.file(self.file_index).?) {
return switch (self.file(elf_file).?) {
.zig_module => |x| x.relocs.items[self.relocs_section_index].items,
.object => |x| x.getRelocs(self.relocs_section_index),
else => unreachable,
@@ -303,7 +313,7 @@ pub fn relocs(self: Atom, elf_file: *Elf) error{Overflow}![]align(1) const elf.E
pub fn addReloc(self: Atom, elf_file: *Elf, reloc: elf.Elf64_Rela) !void {
const gpa = elf_file.base.allocator;
const file_ptr = elf_file.file(self.file_index).?;
const file_ptr = self.file(elf_file).?;
assert(file_ptr == .zig_module);
const zig_module = file_ptr.zig_module;
const rels = &zig_module.relocs.items[self.relocs_section_index];
@@ -311,14 +321,14 @@ pub fn addReloc(self: Atom, elf_file: *Elf, reloc: elf.Elf64_Rela) !void {
}
pub fn freeRelocs(self: Atom, elf_file: *Elf) void {
const file_ptr = elf_file.file(self.file_index).?;
const file_ptr = self.file(elf_file).?;
assert(file_ptr == .zig_module);
const zig_module = file_ptr.zig_module;
zig_module.relocs.items[self.relocs_section_index].clearRetainingCapacity();
}
pub fn scanRelocs(self: Atom, elf_file: *Elf, undefs: anytype) !void {
const file_ptr = elf_file.file(self.file_index).?;
const file_ptr = self.file(elf_file).?;
const rels = try self.relocs(elf_file);
var i: usize = 0;
while (i < rels.len) : (i += 1) {
@@ -392,7 +402,7 @@ fn reportUndefined(
rel: elf.Elf64_Rela,
undefs: anytype,
) !void {
const rel_esym = switch (elf_file.file(self.file_index).?) {
const rel_esym = switch (self.file(elf_file).?) {
.zig_module => |x| x.elfSym(rel.r_sym()).*,
.object => |x| x.symtab[rel.r_sym()],
else => unreachable,
@@ -416,7 +426,7 @@ fn reportUndefined(
pub fn resolveRelocs(self: Atom, elf_file: *Elf, code: []u8) !void {
relocs_log.debug("0x{x}: {s}", .{ self.value, self.name(elf_file) });
const file_ptr = elf_file.file(self.file_index).?;
const file_ptr = self.file(elf_file).?;
var stream = std.io.fixedBufferStream(code);
const cwriter = stream.writer();
@@ -619,7 +629,7 @@ fn format2(
// try writer.writeAll(" }");
// }
const gc_sections = if (elf_file.base.options.gc_sections) |gc_sections| gc_sections else false;
if (gc_sections and !atom.alive) {
if (gc_sections and !atom.flags.alive) {
try writer.writeAll(" : [*]");
}
}
@@ -629,6 +639,17 @@ fn format2(
// future.
pub const Index = u16;
pub const Flags = packed struct {
/// Specifies whether this atom is alive or has been garbage collected.
alive: bool = false,
/// Specifies if the atom has been visited during garbage collection.
visited: bool = false,
/// Specifies whether this atom has been allocated in the output section.
allocated: bool = false,
};
const x86_64 = struct {
pub fn relaxGotpcrelx(code: []u8) !void {
const old_inst = disassemble(code) orelse return error.RelaxFail;

12
src/link/Elf/Object.zig
View File

@@ -180,7 +180,7 @@ fn addAtom(
atom.file_index = self.index;
atom.input_section_index = shndx;
atom.output_section_index = try self.getOutputSectionIndex(elf_file, shdr);
atom.alive = true;
atom.flags.alive = true;
self.atoms.items[shndx] = atom_index;
if (shdr.sh_flags & elf.SHF_COMPRESSED != 0) {
@@ -424,7 +424,7 @@ fn filterRelocs(
pub fn scanRelocs(self: *Object, elf_file: *Elf, undefs: anytype) !void {
for (self.atoms.items) |atom_index| {
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.alive) continue;
if (!atom.flags.alive) continue;
const shdr = atom.inputShdr(elf_file);
if (shdr.sh_flags & elf.SHF_ALLOC == 0) continue;
if (shdr.sh_type == elf.SHT_NOBITS) continue;
@@ -458,7 +458,7 @@ pub fn resolveSymbols(self: *Object, elf_file: *Elf) void {
if (esym.st_shndx != elf.SHN_ABS and esym.st_shndx != elf.SHN_COMMON) {
const atom_index = self.atoms.items[esym.st_shndx];
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.alive) continue;
if (!atom.flags.alive) continue;
}
const global = elf_file.symbol(index);
@@ -553,7 +553,7 @@ pub fn checkDuplicates(self: *Object, elf_file: *Elf) void {
if (this_sym.st_shndx != elf.SHN_ABS) {
const atom_index = self.atoms.items[this_sym.st_shndx];
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.alive) continue;
if (!atom.flags.alive) continue;
}
elf_file.base.fatal("multiple definition: {}: {}: {s}", .{
@@ -628,7 +628,7 @@ pub fn convertCommonSymbols(self: *Object, elf_file: *Elf) !void {
pub fn updateSymtabSize(self: *Object, elf_file: *Elf) void {
for (self.locals()) |local_index| {
const local = elf_file.symbol(local_index);
if (local.atom(elf_file)) |atom| if (!atom.alive) continue;
if (local.atom(elf_file)) |atom| if (!atom.flags.alive) continue;
const esym = local.elfSym(elf_file);
switch (esym.st_type()) {
elf.STT_SECTION, elf.STT_NOTYPE => continue,
@@ -641,7 +641,7 @@ pub fn updateSymtabSize(self: *Object, elf_file: *Elf) void {
for (self.globals()) |global_index| {
const global = elf_file.symbol(global_index);
if (global.file(elf_file)) |file| if (file.index() != self.index) continue;
if (global.atom(elf_file)) |atom| if (!atom.alive) continue;
if (global.atom(elf_file)) |atom| if (!atom.flags.alive) continue;
global.flags.output_symtab = true;
if (global.isLocal()) {
self.output_symtab_size.nlocals += 1;

12
src/link/Elf/ZigModule.zig
View File

@@ -53,17 +53,19 @@ pub fn addAtom(self: *ZigModule, elf_file: *Elf) !Symbol.Index {
const gpa = elf_file.base.allocator;
const atom_index = try elf_file.addAtom();
const symbol_index = try elf_file.addSymbol();
const esym_index = try self.addLocalEsym(gpa);
try self.atoms.putNoClobber(gpa, atom_index, {});
try self.local_symbols.append(gpa, symbol_index);
const atom_ptr = elf_file.atom(atom_index).?;
atom_ptr.file_index = self.index;
const symbol_index = try elf_file.addSymbol();
try self.local_symbols.append(gpa, symbol_index);
const symbol_ptr = elf_file.symbol(symbol_index);
symbol_ptr.file_index = self.index;
symbol_ptr.atom_index = atom_index;
const esym_index = try self.addLocalEsym(gpa);
const esym = &self.local_esyms.items[esym_index];
esym.st_shndx = atom_index;
symbol_ptr.esym_index = esym_index;
@@ -86,7 +88,7 @@ pub fn resolveSymbols(self: *ZigModule, elf_file: *Elf) void {
if (esym.st_shndx != elf.SHN_ABS and esym.st_shndx != elf.SHN_COMMON) {
const atom_index = esym.st_shndx;
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.alive) continue;
if (!atom.flags.alive) continue;
}
const global = elf_file.symbol(index);
@@ -141,7 +143,7 @@ pub fn claimUnresolved(self: *ZigModule, elf_file: *Elf) void {
pub fn scanRelocs(self: *ZigModule, elf_file: *Elf, undefs: anytype) !void {
for (self.atoms.keys()) |atom_index| {
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.alive) continue;
if (!atom.flags.alive) continue;
try atom.scanRelocs(elf_file, undefs);
}
}

16
src/link/Elf/file.zig
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@@ -89,6 +89,21 @@ pub const File = union(enum) {
}
}
pub fn atoms(file: File) []const Atom.Index {
return switch (file) {
.linker_defined => unreachable,
.zig_module => |x| x.atoms.keys(),
.object => |x| x.atoms.items,
};
}
pub fn locals(file: File) []const Symbol.Index {
return switch (file) {
.linker_defined => unreachable,
inline else => |x| x.locals(),
};
}
pub fn globals(file: File) []const Symbol.Index {
return switch (file) {
inline else => |x| x.globals(),
@@ -110,6 +125,7 @@ const std = @import("std");
const elf = std.elf;
const Allocator = std.mem.Allocator;
const Atom = @import("Atom.zig");
const Elf = @import("../Elf.zig");
const LinkerDefined = @import("LinkerDefined.zig");
const Object = @import("Object.zig");

15
src/link/Elf/synthetic_sections.zig
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@@ -169,6 +169,21 @@ pub const GotSection = struct {
}
}
pub fn writeAllEntries(got: GotSection, elf_file: *Elf, writer: anytype) !void {
assert(!got.dirty);
const entry_size: u16 = elf_file.archPtrWidthBytes();
const endian = elf_file.base.options.target.cpu.arch.endian();
for (got.entries.items) |entry| {
const value = elf_file.symbol(entry.symbol_index).value;
switch (entry_size) {
2 => try writer.writeInt(u16, @intCast(value), endian),
4 => try writer.writeInt(u32, @intCast(value), endian),
8 => try writer.writeInt(u64, @intCast(value), endian),
else => unreachable,
}
}
}
// pub fn write(got: GotSection, elf_file: *Elf, writer: anytype) !void {
// const is_shared = elf_file.options.output_mode == .lib;
// const apply_relocs = elf_file.options.apply_dynamic_relocs;