Statics aligned to greater than a page cause linker error

[retep998]

On Windows link.exe requires that the alignment of any section is less than or equal to the /ALIGN value. Statics with an alignment of 8192 or greater cause the section to have an alignment of 8192 (but not greater, see #70022), but link.exe has a default /ALIGN of 4096 causing fatal error LNK1164: section 0x6 alignment (8192) greater than /ALIGN value. Specifying -Clink-arg="/ALIGN:8192" causes the error to go away.

Minimal example

#[repr(align(0x100000))]
struct Aligned(u8);

static X: Aligned = Aligned(0);

fn main() {
    println!("{:#x}", &X as *const _ as usize);
}

[ChrisDenton]

I no longer get a linker error. Instead rustc outright crashes with STATUS_ILLEGAL_INSTRUCTION. I don't think this is an improvement.

[retep998]

There is an issue here specific to Windows MSVC, that Rust is creating sections with a higher requirement, but not informing the linker of that via /ALIGN, thus resulting in a LNK1164 linker error.

It's just that now Rust no longer reaches that linker error due to another related bug, causing a crash in rustc itself...

[beetrees]

This error can still be reached by using an alignment of 8192:

#[repr(align(8192))]
struct Aligned(u8);

static X: Aligned = Aligned(0);

fn main() {
    println!("{:#x}", &X as *const _ as usize);
}

Note that MinGW and LLVM lld-link instead silently miscompile this example by completely ignoring the section alignment from the object file and use the value passed to /ALIGN (4096 by default) as the section alignment in the EXE/DLL. I've reported this to LLVM in llvm/llvm-project#137043.