Commit a4feb97cdf
Changed files (3)
src
link
src/link/MachO/Object.zig
@@ -733,7 +733,7 @@ pub fn parseTextBlocks(self: *Object, macho_file: *MachO) !void {
try macho_file.locals.append(macho_file.base.allocator, .{
.n_strx = try macho_file.makeString(sym_name),
.n_type = macho.N_SECT,
- .n_sect = macho_file.sectionId(match),
+ .n_sect = macho_file.section_to_ordinal.get(match) orelse unreachable,
.n_desc = 0,
.n_value = sect.addr,
});
@@ -779,7 +779,7 @@ pub fn parseTextBlocks(self: *Object, macho_file: *MachO) !void {
const nlist = nlist_with_index.nlist;
const local_sym_index = self.symbol_mapping.get(nlist_with_index.index) orelse unreachable;
const local = &macho_file.locals.items[local_sym_index];
- local.n_sect = macho_file.sectionId(match);
+ local.n_sect = macho_file.section_to_ordinal.get(match) orelse unreachable;
const stab: ?TextBlock.Stab = if (self.debug_info) |di| blk: {
// TODO there has to be a better to handle this.
src/link/MachO/TextBlock.zig
@@ -620,7 +620,7 @@ fn initRelocFromObject(rel: macho.relocation_info, object: *Object, ctx: RelocCo
try ctx.macho_file.locals.append(ctx.macho_file.base.allocator, .{
.n_strx = try ctx.macho_file.makeString(sym_name),
.n_type = macho.N_SECT,
- .n_sect = ctx.macho_file.sectionId(match),
+ .n_sect = ctx.macho_file.section_to_ordinal.get(match) orelse unreachable,
.n_desc = 0,
.n_value = sect.addr,
});
@@ -832,7 +832,7 @@ pub fn parseRelocsFromObject(
},
.local => {
const source_sym = ctx.macho_file.locals.items[self.local_sym_index];
- const match = ctx.macho_file.unpackSectionId(source_sym.n_sect);
+ const match = ctx.macho_file.section_ordinals.items[source_sym.n_sect];
const seg = ctx.macho_file.load_commands.items[match.seg].Segment;
const sect = seg.sections.items[match.sect];
const sect_type = commands.sectionType(sect);
@@ -1096,7 +1096,7 @@ pub fn resolveRelocs(self: *TextBlock, macho_file: *MachO) !void {
const sym = macho_file.locals.items[rel.where_index];
const is_tlv = is_tlv: {
const source_sym = macho_file.locals.items[self.local_sym_index];
- const match = macho_file.unpackSectionId(source_sym.n_sect);
+ const match = macho_file.section_ordinals.items[source_sym.n_sect];
const seg = macho_file.load_commands.items[match.seg].Segment;
const sect = seg.sections.items[match.sect];
break :is_tlv commands.sectionType(sect) == macho.S_THREAD_LOCAL_VARIABLES;
src/link/MachO.zig
@@ -167,6 +167,9 @@ strtab_needs_relocation: bool = false,
has_dices: bool = false,
has_stabs: bool = false,
+section_ordinals: std.ArrayListUnmanaged(MatchingSection) = .{},
+section_to_ordinal: std.AutoHashMapUnmanaged(MatchingSection, u8) = .{},
+
pending_updates: std.ArrayListUnmanaged(struct {
kind: enum {
got,
@@ -925,6 +928,13 @@ fn linkWithZld(self: *MachO, comp: *Compilation) !void {
else => unreachable,
};
+ // Initialize section ordinals with null ordinal pointing at
+ // PAGEZERO segment.
+ try self.section_ordinals.append(self.base.allocator, .{
+ .seg = 0,
+ .sect = 0,
+ });
+
try self.populateMetadata();
try self.parseInputFiles(positionals.items, self.base.options.sysroot);
try self.parseLibs(libs.items, self.base.options.sysroot);
@@ -1482,6 +1492,10 @@ pub fn getMatchingSection(self: *MachO, sect: macho.section_64) !?MatchingSectio
}
};
+ if (res) |match| {
+ try self.createSectionOrdinal(match);
+ }
+
return res;
}
@@ -1606,6 +1620,38 @@ fn sortSections(self: *MachO) !void {
self.blocks.deinit(self.base.allocator);
self.blocks = transient;
}
+
+ {
+ // Create new section ordinals.
+ self.section_ordinals.clearRetainingCapacity();
+ self.section_to_ordinal.clearRetainingCapacity();
+ // First ordinal is always null
+ self.section_ordinals.appendAssumeCapacity(.{
+ .seg = 0,
+ .sect = 0,
+ });
+ const text_seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
+ for (text_seg.sections.items) |_, sect_id| {
+ try self.createSectionOrdinal(.{
+ .seg = self.text_segment_cmd_index.?,
+ .sect = @intCast(u16, sect_id),
+ });
+ }
+ const data_const_seg = self.load_commands.items[self.data_const_segment_cmd_index.?].Segment;
+ for (data_const_seg.sections.items) |_, sect_id| {
+ try self.createSectionOrdinal(.{
+ .seg = self.data_const_segment_cmd_index.?,
+ .sect = @intCast(u16, sect_id),
+ });
+ }
+ const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment;
+ for (data_seg.sections.items) |_, sect_id| {
+ try self.createSectionOrdinal(.{
+ .seg = self.data_segment_cmd_index.?,
+ .sect = @intCast(u16, sect_id),
+ });
+ }
+ }
}
fn allocateTextSegment(self: *MachO) !void {
@@ -1732,7 +1778,7 @@ fn allocateTextBlocks(self: *MachO) !void {
const sect = seg.sections.items[match.sect];
var base_addr: u64 = sect.addr;
- const n_sect = self.sectionId(match);
+ const n_sect = self.section_to_ordinal.get(match) orelse unreachable;
log.debug(" within section {s},{s}", .{ commands.segmentName(sect), commands.sectionName(sect) });
log.debug(" {}", .{sect});
@@ -2260,6 +2306,7 @@ fn resolveSymbols(self: *MachO) !void {
.sect = self.common_section_index.?,
};
};
+ try self.createSectionOrdinal(match);
const size = sym.n_value;
const code = try self.base.allocator.alloc(u8, size);
@@ -2272,7 +2319,7 @@ fn resolveSymbols(self: *MachO) !void {
var nlist = macho.nlist_64{
.n_strx = sym.n_strx,
.n_type = macho.N_SECT,
- .n_sect = self.sectionId(match),
+ .n_sect = self.section_to_ordinal.get(match) orelse unreachable,
.n_desc = 0,
.n_value = 0,
};
@@ -2402,7 +2449,7 @@ fn resolveSymbols(self: *MachO) !void {
var nlist = macho.nlist_64{
.n_strx = undef.n_strx,
.n_type = macho.N_SECT,
- .n_sect = self.sectionId(match),
+ .n_sect = self.section_to_ordinal.get(match) orelse unreachable,
.n_desc = 0,
.n_value = 0,
};
@@ -2498,6 +2545,10 @@ fn populateMetadata(self: *MachO) !void {
.@"align" = alignment,
.flags = macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS,
});
+ try self.createSectionOrdinal(.{
+ .seg = self.text_segment_cmd_index.?,
+ .sect = self.text_section_index.?,
+ });
}
if (self.stubs_section_index == null) {
@@ -2518,6 +2569,10 @@ fn populateMetadata(self: *MachO) !void {
.flags = macho.S_SYMBOL_STUBS | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS,
.reserved2 = stub_size,
});
+ try self.createSectionOrdinal(.{
+ .seg = self.text_segment_cmd_index.?,
+ .sect = self.stubs_section_index.?,
+ });
}
if (self.stub_helper_section_index == null) {
@@ -2538,6 +2593,10 @@ fn populateMetadata(self: *MachO) !void {
.@"align" = alignment,
.flags = macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS,
});
+ try self.createSectionOrdinal(.{
+ .seg = self.text_segment_cmd_index.?,
+ .sect = self.stub_helper_section_index.?,
+ });
}
if (self.data_const_segment_cmd_index == null) {
@@ -2557,6 +2616,10 @@ fn populateMetadata(self: *MachO) !void {
.@"align" = 3, // 2^3 = @sizeOf(u64)
.flags = macho.S_NON_LAZY_SYMBOL_POINTERS,
});
+ try self.createSectionOrdinal(.{
+ .seg = self.data_const_segment_cmd_index.?,
+ .sect = self.got_section_index.?,
+ });
}
if (self.data_segment_cmd_index == null) {
@@ -2576,6 +2639,10 @@ fn populateMetadata(self: *MachO) !void {
.@"align" = 3, // 2^3 = @sizeOf(u64)
.flags = macho.S_LAZY_SYMBOL_POINTERS,
});
+ try self.createSectionOrdinal(.{
+ .seg = self.data_segment_cmd_index.?,
+ .sect = self.la_symbol_ptr_section_index.?,
+ });
}
if (self.data_section_index == null) {
@@ -2584,6 +2651,10 @@ fn populateMetadata(self: *MachO) !void {
try data_seg.addSection(self.base.allocator, "__data", .{
.@"align" = 3, // 2^3 = @sizeOf(u64)
});
+ try self.createSectionOrdinal(.{
+ .seg = self.data_segment_cmd_index.?,
+ .sect = self.data_section_index.?,
+ });
}
if (self.linkedit_segment_cmd_index == null) {
@@ -3290,6 +3361,8 @@ pub fn deinit(self: *MachO) void {
ds.deinit(self.base.allocator);
}
+ self.section_ordinals.deinit(self.base.allocator);
+ self.section_to_ordinal.deinit(self.base.allocator);
self.pending_updates.deinit(self.base.allocator);
self.got_entries.deinit(self.base.allocator);
self.got_entries_map.deinit(self.base.allocator);
@@ -5816,37 +5889,6 @@ pub fn symbolIsTemp(sym: macho.nlist_64, sym_name: []const u8) bool {
return mem.startsWith(u8, sym_name, "l") or mem.startsWith(u8, sym_name, "L");
}
-pub fn sectionId(self: MachO, match: MatchingSection) u8 {
- // TODO there might be a more generic way of doing this.
- var section: u8 = 0;
- for (self.load_commands.items) |cmd, cmd_id| {
- if (cmd != .Segment) break;
- if (cmd_id == match.seg) {
- section += @intCast(u8, match.sect) + 1;
- break;
- }
- section += @intCast(u8, cmd.Segment.sections.items.len);
- }
- return section;
-}
-
-pub fn unpackSectionId(self: MachO, section_id: u8) MatchingSection {
- var match: MatchingSection = undefined;
- var section: u8 = 0;
- outer: for (self.load_commands.items) |cmd, cmd_id| {
- assert(cmd == .Segment);
- for (cmd.Segment.sections.items) |_, sect_id| {
- section += 1;
- if (section_id == section) {
- match.seg = @intCast(u16, cmd_id);
- match.sect = @intCast(u16, sect_id);
- break :outer;
- }
- }
- }
- return match;
-}
-
fn packDylibOrdinal(ordinal: u16) u16 {
return ordinal * macho.N_SYMBOL_RESOLVER;
}
@@ -5867,3 +5909,10 @@ pub fn findFirst(comptime T: type, haystack: []T, start: usize, predicate: anyty
}
return i;
}
+
+fn createSectionOrdinal(self: *MachO, match: MatchingSection) !void {
+ if (self.section_to_ordinal.contains(match)) return;
+ const ordinal = @intCast(u8, self.section_ordinals.items.len);
+ try self.section_ordinals.append(self.base.allocator, match);
+ try self.section_to_ordinal.putNoClobber(self.base.allocator, match, ordinal);
+}