commit 9e051e365b689cb4e6ceae5910fb70fe6a7eb0f8 (tree)
parent 95aeb09b9b36874645eae648324e21cb2f89337a
Author: Jakub Konka <kubkon@jakubkonka.com>
Date: Sat, 10 Jul 2021 23:59:36 +0200
zld: correctly estimate TextBlock's alignment with
section's alignment serving as the maximum alignment that
can be seen in this particular section. However, TextBlocks are
still allowed to have at most that alignment.
Diffstat:
3 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/src/link/MachO/Object.zig b/src/link/MachO/Object.zig
@@ -413,6 +413,12 @@ const TextBlockParser = struct {
const code = self.code[start_addr..end_addr];
const size = code.len;
+ const max_align = self.section.@"align";
+ const actual_align = if (senior_nlist.nlist.n_value > 0)
+ math.min(@ctz(u64, senior_nlist.nlist.n_value), max_align)
+ else
+ max_align;
+
const alias_only_indices = if (aliases.items.len > 0) blk: {
var out = std.ArrayList(u32).init(self.allocator);
try out.ensureTotalCapacity(aliases.items.len);
@@ -435,7 +441,7 @@ const TextBlockParser = struct {
block.aliases = alias_only_indices;
block.code = try self.allocator.dupe(u8, code);
block.size = size;
- block.alignment = self.section.@"align";
+ block.alignment = actual_align;
const relocs = filterRelocs(self.relocs, start_addr, end_addr);
if (relocs.len > 0) {
@@ -524,7 +530,7 @@ pub fn parseTextBlocks(self: *Object, zld: *Zld) !void {
const reg = &sym.payload.regular;
if (reg.file) |file| {
if (file != self) {
- log.debug("deduping definition of {s} in {s}", .{ sym.name, self.name.? });
+ log.warn("deduping definition of {s} in {s}", .{ sym.name, self.name.? });
block.deinit();
self.allocator.destroy(block);
continue;
diff --git a/src/link/MachO/Zld.zig b/src/link/MachO/Zld.zig
@@ -320,15 +320,15 @@ pub fn link(self: *Zld, files: []const []const u8, output: Output, args: LinkArg
self.allocateLinkeditSegment();
try self.allocateTextBlocks();
- var it = self.blocks.iterator();
- while (it.next()) |entry| {
- const seg = self.load_commands.items[entry.key_ptr.seg].Segment;
- const sect = seg.sections.items[entry.key_ptr.sect];
+ // var it = self.blocks.iterator();
+ // while (it.next()) |entry| {
+ // const seg = self.load_commands.items[entry.key_ptr.seg].Segment;
+ // const sect = seg.sections.items[entry.key_ptr.sect];
- log.warn("\n\n{s},{s} contents:", .{ segmentName(sect), sectionName(sect) });
- log.warn(" {}", .{sect});
- entry.value_ptr.*.print(self);
- }
+ // log.warn("\n\n{s},{s} contents:", .{ segmentName(sect), sectionName(sect) });
+ // log.warn(" {}", .{sect});
+ // entry.value_ptr.*.print(self);
+ // }
try self.flush();
}
@@ -1056,8 +1056,8 @@ fn allocateTextBlocks(self: *Zld) !void {
var base_addr: u64 = sect.addr;
- log.warn(" within section {s},{s}", .{ segmentName(sect), sectionName(sect) });
- log.warn(" {}", .{sect});
+ log.debug(" within section {s},{s}", .{ segmentName(sect), sectionName(sect) });
+ log.debug(" {}", .{sect});
while (true) {
const block_alignment = try math.powi(u32, 2, block.alignment);
@@ -1067,7 +1067,7 @@ fn allocateTextBlocks(self: *Zld) !void {
assert(sym.payload == .regular);
sym.payload.regular.address = base_addr;
- log.warn(" {s}: start=0x{x}, end=0x{x}, size={}, align={}", .{
+ log.debug(" {s}: start=0x{x}, end=0x{x}, size={}, align={}", .{
sym.name,
base_addr,
base_addr + block.size,
@@ -1118,8 +1118,8 @@ fn writeTextBlocks(self: *Zld) !void {
const sect = seg.sections.items[match.sect];
const sect_type = sectionType(sect);
- log.warn(" for section {s},{s}", .{ segmentName(sect), sectionName(sect) });
- log.warn(" {}", .{sect});
+ log.debug(" for section {s},{s}", .{ segmentName(sect), sectionName(sect) });
+ log.debug(" {}", .{sect});
var code = try self.allocator.alloc(u8, sect.size);
defer self.allocator.free(code);
@@ -1134,7 +1134,7 @@ fn writeTextBlocks(self: *Zld) !void {
const aligned_base_off = mem.alignForwardGeneric(u64, base_off, block_alignment);
const sym = self.locals.items[block.local_sym_index];
- log.warn(" {s}: start=0x{x}, end=0x{x}, size={}, align={}", .{
+ log.debug(" {s}: start=0x{x}, end=0x{x}, size={}, align={}", .{
sym.name,
aligned_base_off,
aligned_base_off + block.size,
@@ -1433,7 +1433,7 @@ fn writeStubInStubHelper(self: *Zld, index: u32) !void {
fn resolveSymbolsInObject(self: *Zld, object: *Object) !void {
log.debug("resolving symbols in '{s}'", .{object.name});
- for (object.symtab.items) |sym, sym_id| {
+ for (object.symtab.items) |sym| {
const sym_name = object.getString(sym.n_strx);
if (Symbol.isStab(sym)) {
@@ -2152,7 +2152,6 @@ fn writeRebaseInfoTable(self: *Zld) !void {
if (match.seg == self.text_segment_cmd_index.?) continue; // __TEXT is non-writable
const seg = self.load_commands.items[match.seg].Segment;
- const sect = seg.sections.items[match.sect];
while (true) {
const sym = self.locals.items[block.local_sym_index];
diff --git a/src/link/MachO/reloc.zig b/src/link/MachO/reloc.zig
@@ -110,6 +110,7 @@ pub const Relocation = struct {
}
pub fn format(self: Branch, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
+ _ = self;
_ = fmt;
_ = options;
try std.fmt.format(writer, "Branch {{}}", .{});
@@ -179,7 +180,7 @@ pub const Relocation = struct {
load,
};
- pub fn resolve(self: PageOff, base: Relocation, source_addr: u64, target_addr: u64) !void {
+ pub fn resolve(self: PageOff, base: Relocation, _: u64, target_addr: u64) !void {
switch (self.kind) {
.page => {
const actual_target_addr = if (self.addend) |addend| target_addr + addend else target_addr;
@@ -325,12 +326,13 @@ pub const Relocation = struct {
};
pub const PointerToGot = struct {
- pub fn resolve(self: PointerToGot, base: Relocation, source_addr: u64, target_addr: u64) !void {
+ pub fn resolve(_: PointerToGot, base: Relocation, source_addr: u64, target_addr: u64) !void {
const result = try math.cast(i32, @intCast(i64, target_addr) - @intCast(i64, source_addr));
mem.writeIntLittle(u32, base.block.code[base.offset..][0..4], @bitCast(u32, result));
}
pub fn format(self: PointerToGot, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
+ _ = self;
_ = fmt;
_ = options;
try std.fmt.format(writer, "PointerToGot {{}}", .{});
@@ -342,6 +344,10 @@ pub const Relocation = struct {
correction: i4,
pub fn resolve(self: Signed, base: Relocation, source_addr: u64, target_addr: u64) !void {
+ _ = self;
+ _ = base;
+ _ = source_addr;
+ _ = target_addr;
// const target_addr = target_addr: {
// if (signed.base.target == .section) {
// const source_target = @intCast(i64, args.source_source_sect_addr.?) + @intCast(i64, signed.base.offset) + signed.addend + 4;
