diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs index 4c04fc60b9836..a1e322f4b3130 100644 --- a/compiler/rustc_codegen_ssa/src/back/linker.rs +++ b/compiler/rustc_codegen_ssa/src/back/linker.rs @@ -13,6 +13,7 @@ use std::{env, mem, str}; use rustc_hir::def_id::{CrateNum, LOCAL_CRATE}; use rustc_metadata::find_native_static_library; use rustc_middle::middle::dependency_format::Linkage; +use rustc_middle::middle::exported_symbols; use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo, SymbolExportKind}; use rustc_middle::ty::TyCtxt; use rustc_session::config::{self, CrateType, DebugInfo, LinkerPluginLto, Lto, OptLevel, Strip}; @@ -659,8 +660,6 @@ impl<'a> Linker for GccLinker<'a> { return; } - // FIXME(#99978) hide #[no_mangle] symbols for proc-macros - let is_windows = self.sess.target.is_like_windows; let path = tmpdir.join(if is_windows { "list.def" } else { "list" }); @@ -1679,8 +1678,15 @@ pub(crate) fn exported_symbols(tcx: TyCtxt<'_>, crate_type: CrateType) -> Vec, crate_type: CrateType) -> Vec { + let mut symbols = Vec::new(); let export_threshold = symbol_export::crates_export_threshold(&[crate_type]); for_each_exported_symbols_include_dep(tcx, crate_type, |symbol, info, cnum| { if info.level.is_below_threshold(export_threshold) { @@ -1691,6 +1697,19 @@ pub(crate) fn exported_symbols(tcx: TyCtxt<'_>, crate_type: CrateType) -> Vec) -> Vec { + // `exported_symbols` will be empty when !should_codegen. + if !tcx.sess.opts.output_types.should_codegen() { + return Vec::new(); + } + + let stable_crate_id = tcx.sess.local_stable_crate_id(); + let proc_macro_decls_name = tcx.sess.generate_proc_macro_decls_symbol(stable_crate_id); + let metadata_symbol_name = exported_symbols::metadata_symbol_name(tcx); + + vec![proc_macro_decls_name, metadata_symbol_name] +} + pub(crate) fn linked_symbols( tcx: TyCtxt<'_>, crate_type: CrateType, diff --git a/tests/ui/proc-macro/auxiliary/exports_no_mangle.rs b/tests/ui/proc-macro/auxiliary/exports_no_mangle.rs new file mode 100644 index 0000000000000..a8a478ffc74c4 --- /dev/null +++ b/tests/ui/proc-macro/auxiliary/exports_no_mangle.rs @@ -0,0 +1,11 @@ +// force-host +// no-prefer-dynamic +#![crate_type="lib"] + +// Issue 111888: this crate (1.) is imported by a proc-macro crate and (2.) +// exports a no_mangle function; that combination of acts was broken for some +// period of time. See further discussion in the test file that imports this +// crate. + +#[no_mangle] +pub fn some_no_mangle_function() { } diff --git a/tests/ui/proc-macro/no-mangle-in-proc-macro-issue-111888.rs b/tests/ui/proc-macro/no-mangle-in-proc-macro-issue-111888.rs new file mode 100644 index 0000000000000..4e5208e50580b --- /dev/null +++ b/tests/ui/proc-macro/no-mangle-in-proc-macro-issue-111888.rs @@ -0,0 +1,22 @@ +// build-pass +// force-host +// no-prefer-dynamic +// aux-build:exports_no_mangle.rs +#![crate_type = "proc-macro"] + +// Issue #111888: this proc-macro crate imports another crate that itself +// exports a no_mangle function. +// +// That combination was broken for a period of time, because: +// +// In PR #99944 we *stopped* exporting no_mangle symbols from +// proc-macro crates. The constructed linker version script still referred +// to them, but resolving that discrepancy was left as a FIXME in the code. +// +// In PR #108017 we started telling the linker to check (via the +// `--no-undefined-version` linker invocation flag) that every symbol referenced +// in the "linker version script" is actually present in the linker input. So +// the unresolved discrepancy from #99944 started surfacing as a compile-time +// error. + +extern crate exports_no_mangle;