linksection allowed on variables with comptime only types

[Hugne]

Zig Version

0.10.0-dev.1487+916a65cb7

Steps to Reproduce

main.zig

const s linksection(".bar")= @import("s.zig");
comptime {
    @export(entry, .{ .name = "foo", .linkage = .Strong, .section = ".bar"});
}

fn foo() callconv(.C) c_uint {
    return s.bork();
}

s.zig

pub fn bork()  u32  {
    var p:u32 = 94;
    return p;
}

zig.exe build-lib main.zig -target x86_64-windows -fno-stack-check -fPIC -fno-soname -fno-unwind-tables -dynamic -fsingle-threaded --entry foo

Expected Behavior

The s.zig import (code and data) should be placed in section .bar

Actual Behavior

Only the entrypoint 'foo' is placed in .bar. The linksection attribute is silently ignored for the @import statement

[Vexu]

@import returns a type, it makes no sense to give it a link section as it will never be emitted to binary. The bug here is stage1 not giving an error for this.

Related #11170

[Hugne]

I see. How can i control code placement for non-exported symbols then? (is it even possible?)

[Vexu]

If you want to set bork's linksection you need to add the linksection attribute directly to bork. That issue is related because it's another case of stage1 not handling global variables that well, not because you'd have to export symbols to control their placement.

// zig build-obj a.zig
fn bork() linksection(".foo") void {}
comptime { _ = bork(); }
// objdump a.o -t | grep bork
// 0000000000000000 l     F .foo   0000000000000006 bork

[Hugne]

Maybe it would be worth considering support for syntax like:

linksection(".foo") {
fn bork() void {}
...
}

Kind of like the msvc preprocessor

#pragma code_seg(push,1, ".foo")
void bork() {}
...
#pragma code_seg(pop)