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Export __rdl_* symbols to the allocator shim when doing LTO

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bjorn3
2025-08-28 13:01:40 +00:00
parent 033c0a4742
commit 7a01c7f676
1 changed files with 14 additions and 0 deletions
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14
compiler/rustc_codegen_ssa/src/back/lto.rs
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@@ -1,6 +1,7 @@
use std::ffi::CString;
use std::sync::Arc;
use rustc_ast::expand::allocator::AllocatorKind;
use rustc_data_structures::memmap::Mmap;
use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo, SymbolExportLevel};
@@ -95,6 +96,19 @@ pub(super) fn exported_symbols_for_lto(
.filter_map(|&(s, info): &(ExportedSymbol<'_>, SymbolExportInfo)| {
if info.level.is_below_threshold(export_threshold) || info.used {
Some(symbol_name_for_instance_in_crate(tcx, s, cnum))
} else if export_threshold == SymbolExportLevel::C
&& info.rustc_std_internal_symbol
&& let Some(AllocatorKind::Default) = allocator_kind_for_codegen(tcx)
{
// Export the __rdl_* exports for usage by the allocator shim when not using
// #[global_allocator]. Most of the conditions above are only used to avoid
// unnecessary expensive symbol_name_for_instance_in_crate calls.
let sym = symbol_name_for_instance_in_crate(tcx, s, cnum);
if sym.contains("__rdl_") || sym.contains("__rg_oom") {
Some(sym)
} else {
None
}
} else {
None
}