use rustc_codegen_ssa::traits::*;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LOCAL_CRATE};
use rustc_middle::bug;
use rustc_middle::mir::mono::{Linkage, Visibility};
use rustc_middle::ty::layout::{FnAbiOf, LayoutOf};
use rustc_middle::ty::{self, Instance, TypeVisitableExt};
use rustc_session::config::CrateType;
use rustc_target::spec::RelocModel;
use tracing::debug;
use crate::context::CodegenCx;
use crate::errors::SymbolAlreadyDefined;
use crate::type_of::LayoutLlvmExt;
use crate::{base, llvm};
impl<'tcx> PreDefineMethods<'tcx> for CodegenCx<'_, 'tcx> {
fn predefine_static(
&self,
def_id: DefId,
linkage: Linkage,
visibility: Visibility,
symbol_name: &str,
) {
let instance = Instance::mono(self.tcx, def_id);
let DefKind::Static { nested, .. } = self.tcx.def_kind(def_id) else { bug!() };
let ty = if nested {
self.tcx.types.unit
} else {
instance.ty(self.tcx, ty::ParamEnv::reveal_all())
};
let llty = self.layout_of(ty).llvm_type(self);
let g = self.define_global(symbol_name, llty).unwrap_or_else(|| {
self.sess()
.dcx()
.emit_fatal(SymbolAlreadyDefined { span: self.tcx.def_span(def_id), symbol_name })
});
unsafe {
llvm::LLVMRustSetLinkage(g, base::linkage_to_llvm(linkage));
llvm::LLVMRustSetVisibility(g, base::visibility_to_llvm(visibility));
if self.should_assume_dso_local(g, false) {
llvm::LLVMRustSetDSOLocal(g, true);
}
}
self.instances.borrow_mut().insert(instance, g);
}
fn predefine_fn(
&self,
instance: Instance<'tcx>,
linkage: Linkage,
visibility: Visibility,
symbol_name: &str,
) {
assert!(!instance.args.has_infer());
let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
let lldecl = self.declare_fn(symbol_name, fn_abi, Some(instance));
unsafe { llvm::LLVMRustSetLinkage(lldecl, base::linkage_to_llvm(linkage)) };
let attrs = self.tcx.codegen_fn_attrs(instance.def_id());
base::set_link_section(lldecl, attrs);
if linkage == Linkage::LinkOnceODR || linkage == Linkage::WeakODR {
llvm::SetUniqueComdat(self.llmod, lldecl);
}
if linkage != Linkage::Internal
&& linkage != Linkage::Private
&& self.tcx.is_compiler_builtins(LOCAL_CRATE)
{
unsafe {
llvm::LLVMRustSetVisibility(lldecl, llvm::Visibility::Hidden);
}
} else {
unsafe {
llvm::LLVMRustSetVisibility(lldecl, base::visibility_to_llvm(visibility));
}
}
debug!("predefine_fn: instance = {:?}", instance);
unsafe {
if self.should_assume_dso_local(lldecl, false) {
llvm::LLVMRustSetDSOLocal(lldecl, true);
}
}
self.instances.borrow_mut().insert(instance, lldecl);
}
}
impl CodegenCx<'_, '_> {
pub(crate) unsafe fn should_assume_dso_local(
&self,
llval: &llvm::Value,
is_declaration: bool,
) -> bool {
let linkage = unsafe { llvm::LLVMRustGetLinkage(llval) };
let visibility = unsafe { llvm::LLVMRustGetVisibility(llval) };
if matches!(linkage, llvm::Linkage::InternalLinkage | llvm::Linkage::PrivateLinkage) {
return true;
}
if visibility != llvm::Visibility::Default && linkage != llvm::Linkage::ExternalWeakLinkage
{
return true;
}
let all_exe = self.tcx.crate_types().iter().all(|ty| *ty == CrateType::Executable);
let is_declaration_for_linker =
is_declaration || linkage == llvm::Linkage::AvailableExternallyLinkage;
if all_exe && !is_declaration_for_linker {
return true;
}
if matches!(&*self.tcx.sess.target.arch, "powerpc64" | "powerpc64le") {
return false;
}
if self.tcx.sess.target.is_like_osx {
return false;
}
if self.tcx.sess.relocation_model() == RelocModel::Pie && !is_declaration {
return true;
}
let is_thread_local_var = unsafe { llvm::LLVMIsAGlobalVariable(llval) }
.is_some_and(|v| unsafe { llvm::LLVMIsThreadLocal(v) } == llvm::True);
if is_thread_local_var {
return false;
}
if let Some(direct) = self.tcx.sess.direct_access_external_data() {
return direct;
}
self.tcx.sess.relocation_model() == RelocModel::Static
}
}