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Merge commit '08a6d6e16b' into sync-cg_gcc-2023-03-04

This commit is contained in:
Antoni Boucher 2023-03-05 12:03:19 -05:00
commit 6bb2af0e6d
61 changed files with 5730 additions and 1123 deletions

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@ -1,9 +1,10 @@
use gccjit::{FunctionType, RValue};
use rustc_codegen_ssa::traits::BaseTypeMethods;
#[cfg(feature="master")]
use gccjit::{FnAttribute, Visibility};
use gccjit::{FunctionType, Function};
use rustc_middle::ty::{self, Instance, TypeVisitableExt};
use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
use crate::abi::FnAbiGccExt;
use crate::attributes;
use crate::context::CodegenCx;
/// Codegens a reference to a fn/method item, monomorphizing and
@ -13,22 +14,26 @@ use crate::context::CodegenCx;
///
/// - `cx`: the crate context
/// - `instance`: the instance to be instantiated
pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>) -> RValue<'gcc> {
pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>) -> Function<'gcc> {
let tcx = cx.tcx();
assert!(!instance.substs.needs_infer());
assert!(!instance.substs.has_escaping_bound_vars());
let sym = tcx.symbol_name(instance).name;
if let Some(&func) = cx.function_instances.borrow().get(&instance) {
return func;
}
let sym = tcx.symbol_name(instance).name;
let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
let func =
if let Some(func) = cx.get_declared_value(&sym) {
if let Some(_func) = cx.get_declared_value(&sym) {
// FIXME(antoyo): we never reach this because get_declared_value only returns global variables
// and here we try to get a function.
unreachable!();
/*
// Create a fn pointer with the new signature.
let ptrty = fn_abi.ptr_to_gcc_type(cx);
@ -61,13 +66,105 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
}
else {
func
}
}*/
}
else {
cx.linkage.set(FunctionType::Extern);
let func = cx.declare_fn(&sym, &fn_abi);
attributes::from_fn_attrs(cx, func, instance);
let instance_def_id = instance.def_id();
// TODO(antoyo): set linkage and attributes.
// Apply an appropriate linkage/visibility value to our item that we
// just declared.
//
// This is sort of subtle. Inside our codegen unit we started off
// compilation by predefining all our own `MonoItem` instances. That
// is, everything we're codegenning ourselves is already defined. That
// means that anything we're actually codegenning in this codegen unit
// will have hit the above branch in `get_declared_value`. As a result,
// we're guaranteed here that we're declaring a symbol that won't get
// defined, or in other words we're referencing a value from another
// codegen unit or even another crate.
//
// So because this is a foreign value we blanket apply an external
// linkage directive because it's coming from a different object file.
// The visibility here is where it gets tricky. This symbol could be
// referencing some foreign crate or foreign library (an `extern`
// block) in which case we want to leave the default visibility. We may
// also, though, have multiple codegen units. It could be a
// monomorphization, in which case its expected visibility depends on
// whether we are sharing generics or not. The important thing here is
// that the visibility we apply to the declaration is the same one that
// has been applied to the definition (wherever that definition may be).
let is_generic = instance.substs.non_erasable_generics().next().is_some();
if is_generic {
// This is a monomorphization. Its expected visibility depends
// on whether we are in share-generics mode.
if cx.tcx.sess.opts.share_generics() {
// We are in share_generics mode.
if let Some(instance_def_id) = instance_def_id.as_local() {
// This is a definition from the current crate. If the
// definition is unreachable for downstream crates or
// the current crate does not re-export generics, the
// definition of the instance will have been declared
// as `hidden`.
if cx.tcx.is_unreachable_local_definition(instance_def_id)
|| !cx.tcx.local_crate_exports_generics()
{
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(Visibility::Hidden));
}
} else {
// This is a monomorphization of a generic function
// defined in an upstream crate.
if instance.upstream_monomorphization(tcx).is_some() {
// This is instantiated in another crate. It cannot
// be `hidden`.
} else {
// This is a local instantiation of an upstream definition.
// If the current crate does not re-export it
// (because it is a C library or an executable), it
// will have been declared `hidden`.
if !cx.tcx.local_crate_exports_generics() {
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(Visibility::Hidden));
}
}
}
} else {
// When not sharing generics, all instances are in the same
// crate and have hidden visibility
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(Visibility::Hidden));
}
} else {
// This is a non-generic function
if cx.tcx.is_codegened_item(instance_def_id) {
// This is a function that is instantiated in the local crate
if instance_def_id.is_local() {
// This is function that is defined in the local crate.
// If it is not reachable, it is hidden.
if !cx.tcx.is_reachable_non_generic(instance_def_id) {
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(Visibility::Hidden));
}
} else {
// This is a function from an upstream crate that has
// been instantiated here. These are always hidden.
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(Visibility::Hidden));
}
}
}
func
};