From 2d9e61f0c7ae23f485a0dd55c73bcaf5302953dd Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 28 Sep 2022 14:40:53 -0700 Subject: [PATCH] Only export `__tls_*` on wasm32-unknown-unknown. From talking with @abrown, we aren't planning to have hosts call these `__tls_*` functions; instead, TLS initialization will be handled transparently within libc. Consequently, these functions don't need to be exported. Leave them exported on wasm32-unknown-unknown though, as wasm-bindgen does call them. --- compiler/rustc_codegen_ssa/src/back/linker.rs | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs index f59a753a5ceff..2cd746ccb6a6e 100644 --- a/compiler/rustc_codegen_ssa/src/back/linker.rs +++ b/compiler/rustc_codegen_ssa/src/back/linker.rs @@ -1180,16 +1180,19 @@ impl<'a> WasmLd<'a> { // sharing memory and instantiating the module multiple times. As a // result if it were exported then we'd just have no sharing. // - // * `--export=*tls*` - when `#[thread_local]` symbols are used these - // symbols are how the TLS segments are initialized and configured. + // On wasm32-unknown-unknown, we also export symbols for glue code to use: + // * `--export=*tls*` - when `#[thread_local]` symbols are used these + // symbols are how the TLS segments are initialized and configured. if sess.target_features.contains(&sym::atomics) { cmd.arg("--shared-memory"); cmd.arg("--max-memory=1073741824"); cmd.arg("--import-memory"); - cmd.arg("--export=__wasm_init_tls"); - cmd.arg("--export=__tls_size"); - cmd.arg("--export=__tls_align"); - cmd.arg("--export=__tls_base"); + if sess.target.os == "unknown" { + cmd.arg("--export=__wasm_init_tls"); + cmd.arg("--export=__tls_size"); + cmd.arg("--export=__tls_align"); + cmd.arg("--export=__tls_base"); + } } WasmLd { cmd, sess } }