Fix wasm_import_module attribute cross-crate

This commit fixes an accidental regression from 144678 where wasm
targets would now accidentally use the wrong import module map for a
symbol causing a symbol to skip mangling. This can result in compilation
failures when symbols are used in cross-crate situations.

Closes 148347
This commit is contained in:
Alex Crichton 2025-11-01 02:39:55 -07:00 committed by Emily Albini
parent 1a7eff4024
commit 279ca7e533
3 changed files with 30 additions and 1 deletions

View file

@ -228,7 +228,7 @@ fn compute_symbol_name<'tcx>(
// However, we don't have the wasm import module map there yet.
tcx.is_foreign_item(def_id)
&& tcx.sess.target.is_like_wasm
&& tcx.wasm_import_module_map(LOCAL_CRATE).contains_key(&def_id.into())
&& tcx.wasm_import_module_map(def_id.krate).contains_key(&def_id.into())
};
if !wasm_import_module_exception_force_mangling {

View file

@ -0,0 +1,7 @@
#![no_std]
#[link(wasm_import_module = "test")]
unsafe extern "C" {
#[link_name = "close"]
pub fn close(x: u32) -> u32;
}

View file

@ -0,0 +1,22 @@
//@ only-wasm32
//@ aux-build:link-name-in-foreign-crate.rs
//@ compile-flags: --crate-type cdylib
//@ build-pass
//@ no-prefer-dynamic
extern crate link_name_in_foreign_crate;
// This test that the definition of a function named `close`, which collides
// with the `close` function in libc in theory, is handled correctly in
// cross-crate situations. The `link_name_in_foreign_crate` dependency declares
// `close` from a non-`env` wasm import module and then this crate attempts to
// use the symbol. This should properly ensure that the wasm module name is
// tagged as `test` and the `close` symbol, to LLD, is mangled, to avoid
// colliding with the `close` symbol in libc itself.
#[unsafe(no_mangle)]
pub extern "C" fn foo() {
unsafe {
link_name_in_foreign_crate::close(1);
}
}