Skip to content

Fix std.Io and std.heap.page_allocator on Wasm #25858

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
+18 −14
Open

Fix std.Io and std.heap.page_allocator on Wasm #25858

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
d05156e
Don't pull in a dependency on `pthread_kill` in single-threaded builds
castholm Nov 7, 2025
3f1e290
Use `mmap` `std.heap.page_allocator` impl when compiling for Wasm + libc
castholm Nov 7, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions lib/std/Io/Threaded.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -797,9 +797,10 @@ fn await(
result_alignment: std.mem.Alignment,
) void {
_ = result_alignment;
if (builtin.single_threaded) return;
const t: *Threaded = @ptrCast(@alignCast(userdata));
const closure: *AsyncClosure = @ptrCast(@alignCast(any_future));
closure.waitAndDeinit(t.allocator, result);
const ac: *AsyncClosure = @ptrCast(@alignCast(any_future));
ac.waitAndDeinit(t.allocator, result);
}

fn cancel(
Expand All @@ -809,6 +810,7 @@ fn cancel(
result_alignment: std.mem.Alignment,
) void {
_ = result_alignment;
if (builtin.single_threaded) return;
const t: *Threaded = @ptrCast(@alignCast(userdata));
const ac: *AsyncClosure = @ptrCast(@alignCast(any_future));
ac.closure.requestCancel();
Expand Down
15 changes: 13 additions & 2 deletions lib/std/c.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1830,7 +1830,16 @@ pub const POLL = switch (native_os) {
/// Basic memory protection flags
pub const PROT = switch (native_os) {
.linux => linux.PROT,
.emscripten => emscripten.PROT,
// https://github.com/emscripten-core/emscripten/blob/08e2de1031913e4ba7963b1c56f35f036a7d4d56/system/lib/libc/musl/include/sys/mman.h#L57-L62
// lib/libc/include/wasm-wasi-musl/sys/mman.h
.emscripten, .wasi => struct {
pub const NONE = 0;
pub const READ = 1;
pub const WRITE = 2;
pub const EXEC = 4;
pub const GROWSDOWN = 0x01000000;
pub const GROWSUP = 0x02000000;
},
// https://github.com/SerenityOS/serenity/blob/6d59d4d3d9e76e39112842ec487840828f1c9bfe/Kernel/API/POSIX/sys/mman.h#L28-L31
.openbsd, .haiku, .dragonfly, .netbsd, .illumos, .freebsd, .windows, .serenity => struct {
/// page can not be accessed
Expand Down Expand Up @@ -8692,7 +8701,9 @@ pub const O = switch (native_os) {

pub const MAP = switch (native_os) {
.linux => linux.MAP,
.emscripten => packed struct(u32) {
// https://github.com/emscripten-core/emscripten/blob/08e2de1031913e4ba7963b1c56f35f036a7d4d56/system/lib/libc/musl/include/sys/mman.h#L21-L39
// lib/libc/include/wasm-wasi-musl/sys/mman.h
.emscripten, .wasi => packed struct(u32) {
TYPE: enum(u4) {
SHARED = 0x01,
PRIVATE = 0x02,
Expand Down
2 changes: 1 addition & 1 deletion lib/std/heap.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -366,7 +366,7 @@ pub const page_allocator: Allocator = if (@hasDecl(root, "os") and
@hasDecl(root.os, "heap") and
@hasDecl(root.os.heap, "page_allocator"))
root.os.heap.page_allocator
else if (builtin.target.cpu.arch.isWasm()) .{
else if (builtin.target.cpu.arch.isWasm() and !builtin.link_libc) .{
.ptr = undefined,
.vtable = &WasmAllocator.vtable,
} else if (builtin.target.os.tag == .plan9) .{
Expand Down
9 changes: 0 additions & 9 deletions lib/std/os/emscripten.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -331,15 +331,6 @@ pub const POLL = struct {
pub const RDBAND = 0x080;
};

pub const PROT = struct {
pub const NONE = 0x0;
pub const READ = 0x1;
pub const WRITE = 0x2;
pub const EXEC = 0x4;
pub const GROWSDOWN = 0x01000000;
pub const GROWSUP = 0x02000000;
};

pub const rlim_t = u64;

pub const RLIM = struct {
Expand Down