authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2021-04-20 07:23:21+02:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2021-04-20 16:55:32+02:00
log7bc6554a58274730f762bffb1f031af8dcfdb1fb
treebb579da41605be61ed172c36d0882a8e175c2b6c
parente5b83056ae335b12caf5b8912ec40e9962ce27f7

zld: map __DATA,__common as __DATA_CONST,__common

1 files changed, 55 insertions(+), 16 deletions(-)

src/link/MachO/Zld.zig+55-16
...@@ -64,6 +64,7 @@ got_section_index: ?u16 = null,...@@ -64,6 +64,7 @@ got_section_index: ?u16 = null,
64mod_init_func_section_index: ?u16 = null,64mod_init_func_section_index: ?u16 = null,
65mod_term_func_section_index: ?u16 = null,65mod_term_func_section_index: ?u16 = null,
66data_const_section_index: ?u16 = null,66data_const_section_index: ?u16 = null,
67common_section_index: ?u16 = null,
6768
68// __DATA segment sections69// __DATA segment sections
69tlv_section_index: ?u16 = null,70tlv_section_index: ?u16 = null,
...@@ -483,23 +484,43 @@ fn updateMetadata(self: *Zld) !void {...@@ -483,23 +484,43 @@ fn updateMetadata(self: *Zld) !void {
483 },484 },
484 macho.S_ZEROFILL => {485 macho.S_ZEROFILL => {
485 if (!mem.eql(u8, segname, "__DATA")) continue;486 if (!mem.eql(u8, segname, "__DATA")) continue;
486 if (self.bss_section_index != null) continue;487 if (mem.eql(u8, sectname, "__common")) {
488 if (self.common_section_index != null) continue;
487489
488 self.bss_section_index = @intCast(u16, data_seg.sections.items.len);490 self.common_section_index = @intCast(u16, data_const_seg.sections.items.len);
489 try data_seg.addSection(self.allocator, .{491 try data_const_seg.addSection(self.allocator, .{
490 .sectname = makeStaticString("__bss"),492 .sectname = makeStaticString("__common"),
491 .segname = makeStaticString("__DATA"),493 .segname = makeStaticString("__DATA_CONST"),
492 .addr = 0,494 .addr = 0,
493 .size = 0,495 .size = 0,
494 .offset = 0,496 .offset = 0,
495 .@"align" = 0,497 .@"align" = 0,
496 .reloff = 0,498 .reloff = 0,
497 .nreloc = 0,499 .nreloc = 0,
498 .flags = macho.S_ZEROFILL,500 .flags = macho.S_ZEROFILL,
499 .reserved1 = 0,501 .reserved1 = 0,
500 .reserved2 = 0,502 .reserved2 = 0,
501 .reserved3 = 0,503 .reserved3 = 0,
502 });504 });
505 } else {
506 if (self.bss_section_index != null) continue;
507
508 self.bss_section_index = @intCast(u16, data_seg.sections.items.len);
509 try data_seg.addSection(self.allocator, .{
510 .sectname = makeStaticString("__bss"),
511 .segname = makeStaticString("__DATA"),
512 .addr = 0,
513 .size = 0,
514 .offset = 0,
515 .@"align" = 0,
516 .reloff = 0,
517 .nreloc = 0,
518 .flags = macho.S_ZEROFILL,
519 .reserved1 = 0,
520 .reserved2 = 0,
521 .reserved3 = 0,
522 });
523 }
503 },524 },
504 macho.S_THREAD_LOCAL_VARIABLES => {525 macho.S_THREAD_LOCAL_VARIABLES => {
505 if (!mem.eql(u8, segname, "__DATA")) continue;526 if (!mem.eql(u8, segname, "__DATA")) continue;
...@@ -586,7 +607,9 @@ fn updateMetadata(self: *Zld) !void {...@@ -586,7 +607,9 @@ fn updateMetadata(self: *Zld) !void {
586607
587 const segname = parseName(&source_sect.segname);608 const segname = parseName(&source_sect.segname);
588 const sectname = parseName(&source_sect.sectname);609 const sectname = parseName(&source_sect.sectname);
610
589 log.debug("section '{s}/{s}' will be unmapped", .{ segname, sectname });611 log.debug("section '{s}/{s}' will be unmapped", .{ segname, sectname });
612
590 try self.unhandled_sections.putNoClobber(self.allocator, .{613 try self.unhandled_sections.putNoClobber(self.allocator, .{
591 .object_id = object_id,614 .object_id = object_id,
592 .source_sect_id = source_sect_id,615 .source_sect_id = source_sect_id,
...@@ -603,6 +626,7 @@ const MatchingSection = struct {...@@ -603,6 +626,7 @@ const MatchingSection = struct {
603fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {626fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {
604 const segname = parseName(&section.segname);627 const segname = parseName(&section.segname);
605 const sectname = parseName(&section.sectname);628 const sectname = parseName(&section.sectname);
629
606 const res: ?MatchingSection = blk: {630 const res: ?MatchingSection = blk: {
607 switch (section.flags) {631 switch (section.flags) {
608 macho.S_4BYTE_LITERALS, macho.S_8BYTE_LITERALS, macho.S_16BYTE_LITERALS => {632 macho.S_4BYTE_LITERALS, macho.S_8BYTE_LITERALS, macho.S_16BYTE_LITERALS => {
...@@ -630,6 +654,12 @@ fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {...@@ -630,6 +654,12 @@ fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {
630 };654 };
631 },655 },
632 macho.S_ZEROFILL => {656 macho.S_ZEROFILL => {
657 if (mem.eql(u8, sectname, "__common")) {
658 break :blk .{
659 .seg = self.data_const_segment_cmd_index.?,
660 .sect = self.common_section_index.?,
661 };
662 }
633 break :blk .{663 break :blk .{
634 .seg = self.data_segment_cmd_index.?,664 .seg = self.data_segment_cmd_index.?,
635 .sect = self.bss_section_index.?,665 .sect = self.bss_section_index.?,
...@@ -685,6 +715,7 @@ fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {...@@ -685,6 +715,7 @@ fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {
685 },715 },
686 }716 }
687 };717 };
718
688 return res;719 return res;
689}720}
690721
...@@ -733,6 +764,7 @@ fn sortSections(self: *Zld) !void {...@@ -733,6 +764,7 @@ fn sortSections(self: *Zld) !void {
733 &self.mod_init_func_section_index,764 &self.mod_init_func_section_index,
734 &self.mod_term_func_section_index,765 &self.mod_term_func_section_index,
735 &self.data_const_section_index,766 &self.data_const_section_index,
767 &self.common_section_index,
736 };768 };
737 for (indices) |maybe_index| {769 for (indices) |maybe_index| {
738 const new_index: u16 = if (maybe_index.*) |index| blk: {770 const new_index: u16 = if (maybe_index.*) |index| blk: {
...@@ -1634,6 +1666,7 @@ fn resolveRelocsAndWriteSections(self: *Zld) !void {...@@ -1634,6 +1666,7 @@ fn resolveRelocsAndWriteSections(self: *Zld) !void {
1634 target_sect_off,1666 target_sect_off,
1635 target_sect_off + sect.code.len,1667 target_sect_off + sect.code.len,
1636 });1668 });
1669
1637 // Zero-out the space1670 // Zero-out the space
1638 var zeroes = try self.allocator.alloc(u8, sect.code.len);1671 var zeroes = try self.allocator.alloc(u8, sect.code.len);
1639 defer self.allocator.free(zeroes);1672 defer self.allocator.free(zeroes);
...@@ -2118,6 +2151,12 @@ fn populateMetadata(self: *Zld) !void {...@@ -2118,6 +2151,12 @@ fn populateMetadata(self: *Zld) !void {
2118}2151}
21192152
2120fn flush(self: *Zld) !void {2153fn flush(self: *Zld) !void {
2154 if (self.common_section_index) |index| {
2155 const seg = &self.load_commands.items[self.data_const_segment_cmd_index.?].Segment;
2156 const sect = &seg.sections.items[index];
2157 sect.offset = 0;
2158 }
2159
2121 if (self.bss_section_index) |index| {2160 if (self.bss_section_index) |index| {
2122 const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;2161 const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
2123 const sect = &seg.sections.items[index];2162 const sect = &seg.sections.items[index];