zig/lib/std/start_windows_tls.zig
Andrew Kelley fff3c1fff4
un-special-case startup code in the std lib
Previously, the compiler had special logic to determine whether to
include the startup code, which was in `std/special/start.zig`. Now,
the file is moved to `std/start.zig`, and there is no special logic
in the compiler. Instead, the standard library unconditionally imports
the `start.zig` file, which then has a `comptime` block that does the
logic of determining what, if any, start symbols to export. Instead of
`start.zig` being in its own special package, it is just another normal
file that is part of the standard library.

`std.builtin.TestFn` is now part of the standard library rather than
specially generated by the compiler.
2019-12-12 18:33:44 -05:00

49 lines
1.8 KiB
Zig

const std = @import("std");
const builtin = std.builtin;
export var _tls_index: u32 = std.os.windows.TLS_OUT_OF_INDEXES;
export var _tls_start: u8 linksection(".tls") = 0;
export var _tls_end: u8 linksection(".tls$ZZZ") = 0;
export var __xl_a: std.os.windows.PIMAGE_TLS_CALLBACK linksection(".CRT$XLA") = null;
export var __xl_z: std.os.windows.PIMAGE_TLS_CALLBACK linksection(".CRT$XLZ") = null;
comptime {
if (builtin.arch == .i386) {
// The __tls_array is the offset of the ThreadLocalStoragePointer field
// in the TEB block whose base address held in the %fs segment.
asm (
\\ .global __tls_array
\\ __tls_array = 0x2C
);
}
}
// TODO this is how I would like it to be expressed
// TODO also note, ReactOS has a +1 on StartAddressOfRawData and AddressOfCallBacks. Investigate
// why they do that.
//export const _tls_used linksection(".rdata$T") = std.os.windows.IMAGE_TLS_DIRECTORY {
// .StartAddressOfRawData = @ptrToInt(&_tls_start),
// .EndAddressOfRawData = @ptrToInt(&_tls_end),
// .AddressOfIndex = @ptrToInt(&_tls_index),
// .AddressOfCallBacks = @ptrToInt(__xl_a),
// .SizeOfZeroFill = 0,
// .Characteristics = 0,
//};
// This is the workaround because we can't do @ptrToInt at comptime like that.
pub const IMAGE_TLS_DIRECTORY = extern struct {
StartAddressOfRawData: *c_void,
EndAddressOfRawData: *c_void,
AddressOfIndex: *c_void,
AddressOfCallBacks: *c_void,
SizeOfZeroFill: u32,
Characteristics: u32,
};
export const _tls_used linksection(".rdata$T") = IMAGE_TLS_DIRECTORY{
.StartAddressOfRawData = &_tls_start,
.EndAddressOfRawData = &_tls_end,
.AddressOfIndex = &_tls_index,
.AddressOfCallBacks = &__xl_a,
.SizeOfZeroFill = 0,
.Characteristics = 0,
};