Static rustc_lint::builtin::BAD_ASM_STYLE
source · pub static BAD_ASM_STYLE: &'static Lint
Expand description
The bad_asm_style
lint detects the use of the .intel_syntax
and
.att_syntax
directives.
Example
ⓘ
#[cfg(target_arch="x86_64")]
use std::arch::asm;
fn main() {
#[cfg(target_arch="x86_64")]
unsafe {
asm!(
".att_syntax",
"movq %{0}, %{0}", in(reg) 0usize
);
}
}
This will produce:
warning: avoid using `.att_syntax`, prefer using `options(att_syntax)` instead
--> src/main.rs:8:14
|
8 | ".att_syntax",
| ^^^^^^^^^^^
|
= note: `#[warn(bad_asm_style)]` on by default
Explanation
On x86, asm!
uses the intel assembly syntax by default. While this
can be switched using assembler directives like .att_syntax
, using the
att_syntax
option is recommended instead because it will also properly
prefix register placeholders with %
as required by AT&T syntax.