mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-21 16:54:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

macho: set and reset file offset to zerofill sections in flush

Browse Source 
This way, there's no need to special the set/reset behaviour at
every stage of updating sections/atoms.
This commit is contained in:
Jakub Konka 2021-09-06 17:43:24 +02:00
parent 29d2e19c3e
commit 81e5320973
1 changed files with 49 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

106
src/link/MachO.zig
View File

@ -133,8 +133,8 @@ objc_selrefs_section_index: ?u16 = null,
objc_classrefs_section_index: ?u16 = null,
objc_data_section_index: ?u16 = null,
bss_file_offset: ?u32 = null,
tlv_bss_file_offset: ?u32 = null,
bss_file_offset: u32 = 0,
tlv_bss_file_offset: u32 = 0,
locals: std.ArrayListUnmanaged(macho.nlist_64) = .{},
globals: std.ArrayListUnmanaged(macho.nlist_64) = .{},
@ -749,6 +749,17 @@ pub fn flush(self: *MachO, comp: *Compilation) !void {
try self.parseInputFiles(positionals.items, self.base.options.sysroot);
try self.parseLibs(libs.items, self.base.options.sysroot);
if (self.bss_section_index) |idx| {
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = &seg.sections.items[idx];
sect.offset = self.bss_file_offset;
}
if (self.tlv_bss_section_index) |idx| {
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = &seg.sections.items[idx];
sect.offset = self.tlv_bss_file_offset;
}
try self.resolveSymbols();
try self.addRpathLCs(rpath_table.keys());
try self.addLoadDylibLCs();
@ -781,6 +792,20 @@ pub fn flush(self: *MachO, comp: *Compilation) !void {
}
}
try self.writeAtoms();
if (self.bss_section_index) |idx| {
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = &seg.sections.items[idx];
self.bss_file_offset = sect.offset;
sect.offset = 0;
}
if (self.tlv_bss_section_index) |idx| {
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = &seg.sections.items[idx];
self.tlv_bss_file_offset = sect.offset;
sect.offset = 0;
}
try self.flushModule(comp);
}
@ -1687,8 +1712,7 @@ pub fn writeAtom(self: *MachO, atom: *TextBlock, match: MatchingSection) !void {
const seg = self.load_commands.items[match.seg].Segment;
const sect = seg.sections.items[match.sect];
const sym = self.locals.items[atom.local_sym_index];
const sect_offset = self.getPtrToSectionOffset(match).*;
const file_offset = sect_offset + sym.n_value - sect.addr;
const file_offset = sect.offset + sym.n_value - sect.addr;
try atom.resolveRelocs(self);
log.debug("writing atom for symbol {s} at file offset 0x{x}", .{ self.getString(sym.n_strx), file_offset });
try self.base.file.?.pwriteAll(atom.code.items, file_offset);
@ -3469,13 +3493,9 @@ pub fn populateMissingMetadata(self: *MachO) !void {
.flags = macho.S_THREAD_LOCAL_ZEROFILL,
},
);
// We keep offset to the section in a separate variable as the actual section is usually pointing at the
// beginning of the file.
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const out_sect = &seg.sections.items[self.tlv_bss_section_index.?];
self.tlv_bss_file_offset = out_sect.offset;
out_sect.offset = 0;
const seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = seg.sections.items[self.tlv_bss_section_index.?];
self.tlv_bss_file_offset = sect.offset;
}
if (self.bss_section_index == null) {
@ -3490,13 +3510,9 @@ pub fn populateMissingMetadata(self: *MachO) !void {
.flags = macho.S_ZEROFILL,
},
);
// We keep offset to the section in a separate variable as the actual section is usually pointing at the
// beginning of the file.
const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const out_sect = &seg.sections.items[self.bss_section_index.?];
self.bss_file_offset = out_sect.offset;
out_sect.offset = 0;
const seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const sect = seg.sections.items[self.bss_section_index.?];
self.bss_file_offset = sect.offset;
}
if (self.linkedit_segment_cmd_index == null) {
@ -3767,8 +3783,7 @@ fn growSection(self: *MachO, match: MatchingSection, new_size: u32) !void {
const sect = &seg.sections.items[match.sect];
const alignment = try math.powi(u32, 2, sect.@"align");
const sect_offset = self.getPtrToSectionOffset(match);
const max_size = self.allocatedSize(match.seg, sect_offset.*);
const max_size = self.allocatedSize(match.seg, sect.offset);
const ideal_size = padToIdeal(new_size);
const needed_size = mem.alignForwardGeneric(u32, ideal_size, alignment);
@ -3830,24 +3845,22 @@ fn growSection(self: *MachO, match: MatchingSection, new_size: u32) !void {
});
for (next_seg.sections.items) |*moved_sect, moved_sect_id| {
const moved_match = MatchingSection{
.seg = @intCast(u16, next),
.sect = @intCast(u16, moved_sect_id),
};
const ptr_sect_offset = self.getPtrToSectionOffset(moved_match);
ptr_sect_offset.* += @intCast(u32, seg_offset_amt);
moved_sect.offset += @intCast(u32, seg_offset_amt);
moved_sect.addr += seg_offset_amt;
log.warn(" (new {s},{s} file offsets from 0x{x} to 0x{x} (in memory 0x{x} to 0x{x}))", .{
commands.segmentName(moved_sect.*),
commands.sectionName(moved_sect.*),
ptr_sect_offset.*,
ptr_sect_offset.* + moved_sect.size,
moved_sect.offset,
moved_sect.offset + moved_sect.size,
moved_sect.addr,
moved_sect.addr + moved_sect.size,
});
try self.allocateLocalSymbols(moved_match, @intCast(i64, seg_offset_amt));
try self.allocateLocalSymbols(.{
.seg = @intCast(u16, next),
.sect = @intCast(u16, moved_sect_id),
}, @intCast(i64, seg_offset_amt));
}
}
}
@ -3867,25 +3880,23 @@ fn growSection(self: *MachO, match: MatchingSection, new_size: u32) !void {
var next = match.sect + 1;
while (next < seg.sections.items.len) : (next += 1) {
const moved_match = MatchingSection{
.seg = match.seg,
.sect = next,
};
const moved_sect = &seg.sections.items[next];
const ptr_sect_offset = self.getPtrToSectionOffset(moved_match);
ptr_sect_offset.* += @intCast(u32, offset_amt);
moved_sect.offset += @intCast(u32, offset_amt);
moved_sect.addr += offset_amt;
log.warn(" (new {s},{s} file offsets from 0x{x} to 0x{x} (in memory 0x{x} to 0x{x}))", .{
commands.segmentName(moved_sect.*),
commands.sectionName(moved_sect.*),
ptr_sect_offset.*,
ptr_sect_offset.* + moved_sect.size,
moved_sect.offset,
moved_sect.offset + moved_sect.size,
moved_sect.addr,
moved_sect.addr + moved_sect.size,
});
try self.allocateLocalSymbols(moved_match, @intCast(i64, offset_amt));
try self.allocateLocalSymbols(.{
.seg = match.seg,
.sect = next,
}, @intCast(i64, offset_amt));
}
}
@ -3916,25 +3927,6 @@ fn getSectionMaxAlignment(self: *MachO, segment_id: u16, start_sect_id: u16) !u3
return max_alignment;
}
fn getPtrToSectionOffset(self: *MachO, match: MatchingSection) *u32 {
if (self.data_segment_cmd_index.? == match.seg) {
if (self.bss_section_index) |idx| {
if (idx == match.sect) {
return &self.bss_file_offset.?;
}
}
if (self.tlv_bss_section_index) |idx| {
if (idx == match.sect) {
return &self.tlv_bss_file_offset.?;
}
}
}
const seg = &self.load_commands.items[match.seg].Segment;
const sect = &seg.sections.items[match.sect];
return &sect.offset;
}
fn allocateTextBlock(self: *MachO, text_block: *TextBlock, new_block_size: u64, alignment: u64) !u64 {
const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment;
const text_section = &text_segment.sections.items[self.text_section_index.?];