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stage2 x86_64: try to fix RIP-relative offset to GOT for macho

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gracefu 2021-04-11 16:41:49 +08:00
parent 0409f9e024
commit b004c3da15
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1 changed files with 18 additions and 15 deletions
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src/codegen.zig
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@ -3860,24 +3860,14 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
.memory => |x| {
if (self.bin_file.options.pie) {
// RIP-relative displacement to the entry in the GOT table.
// TODO we should come up with our own, backend independent relocation types
// which each backend (Elf, MachO, etc.) would then translate into an actual
// fixup when linking.
if (self.bin_file.cast(link.File.MachO)) |macho_file| {
try macho_file.pie_fixups.append(self.bin_file.allocator, .{
.target_addr = x,
.offset = self.code.items.len + 3,
.size = 4,
});
} else {
return self.fail(src, "TODO implement genSetReg for PIE GOT indirection on this platform", .{});
}
const abi_size = ty.abiSize(self.target.*);
const encoder = try X8664Encoder.init(self.code, 7);
// LEA reg, [<offset>]
// TODO: Check if this breaks on macho if abi_size != 64 and reg is not extended
// this causes rex byte to be omitted, which might mean the offset (+3) above is wrong.
// We encode the instruction FIRST because prefixes may or may not appear.
// After we encode the instruction, we will know that the displacement bytes
// for [<offset>] will be at self.code.items.len - 4.
encoder.rex(.{
.w = abi_size == 64,
.r = reg.isExtended(),
@ -3886,6 +3876,19 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
encoder.modRm_RIPDisp32(reg.low_id());
encoder.disp32(0);
// TODO we should come up with our own, backend independent relocation types
// which each backend (Elf, MachO, etc.) would then translate into an actual
// fixup when linking.
if (self.bin_file.cast(link.File.MachO)) |macho_file| {
try macho_file.pie_fixups.append(self.bin_file.allocator, .{
.target_addr = x,
.offset = self.code.items.len - 4,
.size = 4,
});
} else {
return self.fail(src, "TODO implement genSetReg for PIE GOT indirection on this platform", .{});
}
// MOV reg, [reg]
encoder.rex(.{
.w = abi_size == 64,