rust/src/librustc_codegen_llvm/mono_item.rs
2019-06-02 22:32:42 -05:00

84 lines
3.1 KiB
Rust

use crate::attributes;
use crate::base;
use crate::context::CodegenCx;
use crate::llvm;
use crate::type_of::LayoutLlvmExt;
use rustc::hir::def_id::{DefId, LOCAL_CRATE};
use rustc::mir::mono::{Linkage, Visibility};
use rustc::ty::{TypeFoldable, Instance};
use rustc::ty::layout::{LayoutOf, HasTyCtxt};
use rustc_codegen_ssa::traits::*;
pub use rustc::mir::mono::MonoItem;
impl PreDefineMethods<'tcx> for CodegenCx<'ll, 'tcx> {
fn predefine_static(&self,
def_id: DefId,
linkage: Linkage,
visibility: Visibility,
symbol_name: &str) {
let instance = Instance::mono(self.tcx, def_id);
let ty = instance.ty(self.tcx);
let llty = self.layout_of(ty).llvm_type(self);
let g = self.define_global(symbol_name, llty).unwrap_or_else(|| {
self.sess().span_fatal(self.tcx.def_span(def_id),
&format!("symbol `{}` is already defined", symbol_name))
});
unsafe {
llvm::LLVMRustSetLinkage(g, base::linkage_to_llvm(linkage));
llvm::LLVMRustSetVisibility(g, base::visibility_to_llvm(visibility));
}
self.instances.borrow_mut().insert(instance, g);
}
fn predefine_fn(&self,
instance: Instance<'tcx>,
linkage: Linkage,
visibility: Visibility,
symbol_name: &str) {
assert!(!instance.substs.needs_infer() &&
!instance.substs.has_param_types());
let mono_sig = instance.fn_sig(self.tcx());
let attrs = self.tcx.codegen_fn_attrs(instance.def_id());
let lldecl = self.declare_fn(symbol_name, mono_sig);
unsafe { llvm::LLVMRustSetLinkage(lldecl, base::linkage_to_llvm(linkage)) };
base::set_link_section(lldecl, &attrs);
if linkage == Linkage::LinkOnceODR ||
linkage == Linkage::WeakODR {
llvm::SetUniqueComdat(self.llmod, lldecl);
}
// If we're compiling the compiler-builtins crate, e.g., the equivalent of
// compiler-rt, then we want to implicitly compile everything with hidden
// visibility as we're going to link this object all over the place but
// don't want the symbols to get exported.
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: mono_sig = {:?} instance = {:?}", mono_sig, instance);
if instance.def.is_inline(self.tcx) {
attributes::inline(self, lldecl, attributes::InlineAttr::Hint);
}
attributes::from_fn_attrs(
self,
lldecl,
Some(instance.def.def_id()),
mono_sig,
);
self.instances.borrow_mut().insert(instance, lldecl);
}
}