Skip to content

Commit

Permalink
Handle calls to upstream monomorphizations in compiler_builtins
Browse files Browse the repository at this point in the history
  • Loading branch information
saethlin committed Mar 16, 2024
1 parent 1ca424c commit 5f4f252
Show file tree
Hide file tree
Showing 12 changed files with 95 additions and 9 deletions.
1 change: 1 addition & 0 deletions Cargo.lock
Original file line number Diff line number Diff line change
Expand Up @@ -3673,6 +3673,7 @@ dependencies = [
"rustc_macros",
"rustc_metadata",
"rustc_middle",
"rustc_monomorphize",
"rustc_query_system",
"rustc_serialize",
"rustc_session",
Expand Down
14 changes: 14 additions & 0 deletions compiler/rustc_codegen_cranelift/src/abi/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,11 @@ use std::borrow::Cow;

use cranelift_codegen::ir::SigRef;
use cranelift_module::ModuleError;
use rustc_codegen_ssa::errors::CompilerBuiltinsCannotCall;
use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
use rustc_middle::ty::layout::FnAbiOf;
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_monomorphize::is_call_from_compiler_builtins_to_upstream_monomorphization;
use rustc_session::Session;
use rustc_span::source_map::Spanned;
use rustc_target::abi::call::{Conv, FnAbi};
Expand Down Expand Up @@ -372,6 +375,17 @@ pub(crate) fn codegen_terminator_call<'tcx>(
ty::Instance::expect_resolve(fx.tcx, ty::ParamEnv::reveal_all(), def_id, fn_args)
.polymorphize(fx.tcx);

if is_call_from_compiler_builtins_to_upstream_monomorphization(fx.tcx, instance) {
if target.is_some() {
let caller = with_no_trimmed_paths!(fx.tcx.def_path_str(fx.instance.def_id()));
let callee = with_no_trimmed_paths!(fx.tcx.def_path_str(def_id));
fx.tcx.dcx().emit_err(CompilerBuiltinsCannotCall { caller, callee });
} else {
fx.bcx.ins().trap(TrapCode::User(0));
return;
}
}

if fx.tcx.symbol_name(instance).name.starts_with("llvm.") {
crate::intrinsics::codegen_llvm_intrinsic_call(
fx,
Expand Down
7 changes: 7 additions & 0 deletions compiler/rustc_codegen_cranelift/src/base.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ use rustc_index::IndexVec;
use rustc_middle::ty::adjustment::PointerCoercion;
use rustc_middle::ty::layout::FnAbiOf;
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_monomorphize::is_call_from_compiler_builtins_to_upstream_monomorphization;

use crate::constant::ConstantCx;
use crate::debuginfo::FunctionDebugContext;
Expand Down Expand Up @@ -999,6 +1000,12 @@ fn codegen_panic_inner<'tcx>(
let def_id = fx.tcx.require_lang_item(lang_item, span);

let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);

if is_call_from_compiler_builtins_to_upstream_monomorphization(fx.tcx, instance) {
fx.bcx.ins().trap(TrapCode::User(0));
return;
}

let symbol_name = fx.tcx.symbol_name(instance).name;

fx.lib_call(
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_codegen_cranelift/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@ extern crate rustc_hir;
extern crate rustc_incremental;
extern crate rustc_index;
extern crate rustc_metadata;
extern crate rustc_monomorphize;
extern crate rustc_session;
extern crate rustc_span;
extern crate rustc_target;
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_codegen_ssa/Cargo.toml
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@ rustc_index = { path = "../rustc_index" }
rustc_macros = { path = "../rustc_macros" }
rustc_metadata = { path = "../rustc_metadata" }
rustc_middle = { path = "../rustc_middle" }
rustc_monomorphize = { path = "../rustc_monomorphize" }
rustc_query_system = { path = "../rustc_query_system" }
rustc_serialize = { path = "../rustc_serialize" }
rustc_session = { path = "../rustc_session" }
Expand Down
3 changes: 3 additions & 0 deletions compiler/rustc_codegen_ssa/messages.ftl
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,9 @@ codegen_ssa_cgu_not_recorded =
codegen_ssa_check_installed_visual_studio = please ensure that Visual Studio 2017 or later, or Build Tools for Visual Studio were installed with the Visual C++ option.
codegen_ssa_compiler_builtins_cannot_call =
`compiler_builtins` cannot call functions through upstream monomorphizations; encountered invalid call from `{$caller}` to `{$callee}`
codegen_ssa_copy_path = could not copy {$from} to {$to}: {$error}
codegen_ssa_copy_path_buf = unable to copy {$source_file} to {$output_path}: {$error}
Expand Down
5 changes: 3 additions & 2 deletions compiler/rustc_codegen_ssa/src/common.rs
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@

use rustc_hir::LangItem;
use rustc_middle::mir;
use rustc_middle::ty::Instance;
use rustc_middle::ty::{self, layout::TyAndLayout, Ty, TyCtxt};
use rustc_span::Span;

Expand Down Expand Up @@ -120,11 +121,11 @@ pub fn build_langcall<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &Bx,
span: Option<Span>,
li: LangItem,
) -> (Bx::FnAbiOfResult, Bx::Value) {
) -> (Bx::FnAbiOfResult, Bx::Value, Instance<'tcx>) {
let tcx = bx.tcx();
let def_id = tcx.require_lang_item(li, span);
let instance = ty::Instance::mono(tcx, def_id);
(bx.fn_abi_of_instance(instance, ty::List::empty()), bx.get_fn_addr(instance))
(bx.fn_abi_of_instance(instance, ty::List::empty()), bx.get_fn_addr(instance), instance)
}

// To avoid UB from LLVM, these two functions mask RHS with an
Expand Down
7 changes: 7 additions & 0 deletions compiler/rustc_codegen_ssa/src/errors.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1030,3 +1030,10 @@ pub struct FailedToGetLayout<'tcx> {
pub struct ErrorCreatingRemarkDir {
pub error: std::io::Error,
}

#[derive(Diagnostic)]
#[diag(codegen_ssa_compiler_builtins_cannot_call)]
pub struct CompilerBuiltinsCannotCall {
pub caller: String,
pub callee: String,
}
39 changes: 34 additions & 5 deletions compiler/rustc_codegen_ssa/src/mir/block.rs
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ use super::{CachedLlbb, FunctionCx, LocalRef};

use crate::base;
use crate::common::{self, IntPredicate};
use crate::errors::CompilerBuiltinsCannotCall;
use crate::meth;
use crate::traits::*;
use crate::MemFlags;
Expand All @@ -16,6 +17,7 @@ use rustc_middle::mir::{self, AssertKind, BasicBlock, SwitchTargets, UnwindTermi
use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement};
use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
use rustc_middle::ty::{self, Instance, Ty};
use rustc_monomorphize::is_call_from_compiler_builtins_to_upstream_monomorphization;
use rustc_session::config::OptLevel;
use rustc_span::{source_map::Spanned, sym, Span};
use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode, Reg};
Expand Down Expand Up @@ -157,8 +159,28 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>,
mut unwind: mir::UnwindAction,
copied_constant_arguments: &[PlaceRef<'tcx, <Bx as BackendTypes>::Value>],
instance: Option<Instance<'tcx>>,
mergeable_succ: bool,
) -> MergingSucc {
let tcx = bx.tcx();
if let Some(instance) = instance {
if is_call_from_compiler_builtins_to_upstream_monomorphization(tcx, instance) {
if destination.is_some() {
let caller = with_no_trimmed_paths!(tcx.def_path_str(fx.instance.def_id()));
let callee = with_no_trimmed_paths!(tcx.def_path_str(instance.def_id()));
tcx.dcx().emit_err(CompilerBuiltinsCannotCall { caller, callee });
} else {
info!(
"compiler_builtins call to diverging function {:?} replaced with abort",
instance.def_id()
);
bx.abort();
bx.unreachable();
return MergingSucc::False;
}
}
}

// If there is a cleanup block and the function we're calling can unwind, then
// do an invoke, otherwise do a call.
let fn_ty = bx.fn_decl_backend_type(fn_abi);
Expand Down Expand Up @@ -480,6 +502,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let ty = location.ty(self.mir, bx.tcx()).ty;
let ty = self.monomorphize(ty);
let drop_fn = Instance::resolve_drop_in_place(bx.tcx(), ty);
let instance = drop_fn.clone();

if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
// we don't actually need to drop anything.
Expand Down Expand Up @@ -582,6 +605,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
Some((ReturnDest::Nothing, target)),
unwind,
&[],
Some(instance),
mergeable_succ,
)
}
Expand Down Expand Up @@ -658,10 +682,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
}
};

let (fn_abi, llfn) = common::build_langcall(bx, Some(span), lang_item);
let (fn_abi, llfn, instance) = common::build_langcall(bx, Some(span), lang_item);

// Codegen the actual panic invoke/call.
let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &args, None, unwind, &[], false);
let merging_succ =
helper.do_call(self, bx, fn_abi, llfn, &args, None, unwind, &[], Some(instance), false);
assert_eq!(merging_succ, MergingSucc::False);
MergingSucc::False
}
Expand All @@ -677,7 +702,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
self.set_debug_loc(bx, terminator.source_info);

// Obtain the panic entry point.
let (fn_abi, llfn) = common::build_langcall(bx, Some(span), reason.lang_item());
let (fn_abi, llfn, instance) = common::build_langcall(bx, Some(span), reason.lang_item());

// Codegen the actual panic invoke/call.
let merging_succ = helper.do_call(
Expand All @@ -689,6 +714,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
None,
mir::UnwindAction::Unreachable,
&[],
Some(instance),
false,
);
assert_eq!(merging_succ, MergingSucc::False);
Expand Down Expand Up @@ -738,7 +764,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let msg = bx.const_str(&msg_str);

// Obtain the panic entry point.
let (fn_abi, llfn) =
let (fn_abi, llfn, instance) =
common::build_langcall(bx, Some(source_info.span), LangItem::PanicNounwind);

// Codegen the actual panic invoke/call.
Expand All @@ -751,6 +777,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)),
unwind,
&[],
Some(instance),
mergeable_succ,
)
} else {
Expand Down Expand Up @@ -798,6 +825,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
ty::FnPtr(_) => (None, Some(callee.immediate())),
_ => bug!("{} is not callable", callee.layout.ty),
};

let def = instance.map(|i| i.def);

if let Some(ty::InstanceDef::DropGlue(_, None)) = def {
Expand Down Expand Up @@ -1106,6 +1134,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
destination,
unwind,
&copied_constant_arguments,
instance,
mergeable_succ,
)
}
Expand Down Expand Up @@ -1664,7 +1693,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {

self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span));

let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, reason.lang_item());
let (fn_abi, fn_ptr, _instance) = common::build_langcall(&bx, None, reason.lang_item());
let fn_ty = bx.fn_decl_backend_type(fn_abi);

let llret = bx.call(fn_ty, None, Some(fn_abi), fn_ptr, &[], funclet.as_ref());
Expand Down
3 changes: 2 additions & 1 deletion compiler/rustc_codegen_ssa/src/size_of_val.rs
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,8 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
let msg = bx.const_str(&msg_str);

// Obtain the panic entry point.
let (fn_abi, llfn) = common::build_langcall(bx, None, LangItem::PanicNounwind);
let (fn_abi, llfn, _instance) =
common::build_langcall(bx, None, LangItem::PanicNounwind);

// Generate the call.
// Cannot use `do_call` since we don't have a MIR terminator so we can't create a `TerminationCodegenHelper`.
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_monomorphize/src/collector.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1020,7 +1020,7 @@ fn visit_instance_use<'tcx>(

/// Returns `true` if we should codegen an instance in the local crate, or returns `false` if we
/// can just link to the upstream crate and therefore don't need a mono item.
fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) -> bool {
pub(crate) fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) -> bool {
let Some(def_id) = instance.def.def_id_if_not_guaranteed_local_codegen() else {
return true;
};
Expand Down
21 changes: 21 additions & 0 deletions compiler/rustc_monomorphize/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,10 @@ use rustc_hir::lang_items::LangItem;
use rustc_middle::query::{Providers, TyCtxtAt};
use rustc_middle::traits;
use rustc_middle::ty::adjustment::CustomCoerceUnsized;
use rustc_middle::ty::Instance;
use rustc_middle::ty::TyCtxt;
use rustc_middle::ty::{self, Ty};
use rustc_span::def_id::LOCAL_CRATE;
use rustc_span::ErrorGuaranteed;

mod collector;
Expand All @@ -20,6 +23,8 @@ mod partitioning;
mod polymorphize;
mod util;

use collector::should_codegen_locally;

rustc_fluent_macro::fluent_messages! { "../messages.ftl" }

fn custom_coerce_unsize_info<'tcx>(
Expand All @@ -45,6 +50,22 @@ fn custom_coerce_unsize_info<'tcx>(
}
}

/// Returns whether a call from the current crate to the [`Instance`] would produce a call
/// from `compiler_builtins` to a symbol the linker must resolve.
///
/// Such calls from `compiler_bultins` are effectively impossible for the linker to handle. Some
/// linkers will optimize such that dead calls to unresolved symbols are not an error, but this is
/// not guaranteed. So we used this function in codegen backends to ensure we do not generate any
/// unlinkable calls.
pub fn is_call_from_compiler_builtins_to_upstream_monomorphization<'tcx>(
tcx: TyCtxt<'tcx>,
instance: Instance<'tcx>,
) -> bool {
!instance.def_id().is_local()
&& tcx.is_compiler_builtins(LOCAL_CRATE)
&& !should_codegen_locally(tcx, &instance)
}

pub fn provide(providers: &mut Providers) {
partitioning::provide(providers);
polymorphize::provide(providers);
Expand Down

0 comments on commit 5f4f252

Please sign in to comment.