Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Revert #113923 #119885

Merged
merged 2 commits into from
Jan 12, 2024
Merged

Revert #113923 #119885

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6d29eac
Revert "Auto merge of #118568 - DianQK:no-builtins-symbols, r=pnkfelix"
DianQK Jan 12, 2024
aa874c5
Revert "Auto merge of #113923 - DianQK:restore-no-builtins-lto, r=pnk…
DianQK Jan 12, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion compiler/rustc_codegen_llvm/src/back/lto.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,7 +60,7 @@ fn prepare_lto(
};

let symbol_filter = &|&(ref name, info): &(String, SymbolExportInfo)| {
if info.level.is_below_threshold(export_threshold) || info.used || info.used_compiler {
if info.level.is_below_threshold(export_threshold) || info.used {
Some(CString::new(name.as_str()).unwrap())
} else {
None
Expand Down
8 changes: 5 additions & 3 deletions compiler/rustc_codegen_llvm/src/back/write.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -569,6 +569,7 @@ pub(crate) unsafe fn llvm_optimize(
unroll_loops,
config.vectorize_slp,
config.vectorize_loop,
config.no_builtins,
config.emit_lifetime_markers,
sanitizer_options.as_ref(),
pgo_gen_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
Expand Down Expand Up @@ -677,14 +678,15 @@ pub(crate) unsafe fn codegen(
unsafe fn with_codegen<'ll, F, R>(
tm: &'ll llvm::TargetMachine,
llmod: &'ll llvm::Module,
no_builtins: bool,
f: F,
) -> R
where
F: FnOnce(&'ll mut PassManager<'ll>) -> R,
{
let cpm = llvm::LLVMCreatePassManager();
llvm::LLVMAddAnalysisPasses(tm, cpm);
llvm::LLVMRustAddLibraryInfo(cpm, llmod);
llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
f(cpm)
}

Expand Down Expand Up @@ -785,7 +787,7 @@ pub(crate) unsafe fn codegen(
} else {
llmod
};
with_codegen(tm, llmod, |cpm| {
with_codegen(tm, llmod, config.no_builtins, |cpm| {
write_output_file(
dcx,
tm,
Expand Down Expand Up @@ -820,7 +822,7 @@ pub(crate) unsafe fn codegen(
(_, SplitDwarfKind::Split) => Some(dwo_out.as_path()),
};

with_codegen(tm, llmod, |cpm| {
with_codegen(tm, llmod, config.no_builtins, |cpm| {
write_output_file(
dcx,
tm,
Expand Down
8 changes: 7 additions & 1 deletion compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2173,8 +2173,13 @@ extern "C" {
ArgsCstrBuff: *const c_char,
ArgsCstrBuffLen: usize,
) -> *mut TargetMachine;

pub fn LLVMRustDisposeTargetMachine(T: *mut TargetMachine);
pub fn LLVMRustAddLibraryInfo<'a>(PM: &PassManager<'a>, M: &'a Module);
pub fn LLVMRustAddLibraryInfo<'a>(
PM: &PassManager<'a>,
M: &'a Module,
DisableSimplifyLibCalls: bool,
);
pub fn LLVMRustWriteOutputFile<'a>(
T: &'a TargetMachine,
PM: &PassManager<'a>,
Expand All @@ -2196,6 +2201,7 @@ extern "C" {
UnrollLoops: bool,
SLPVectorize: bool,
LoopVectorize: bool,
DisableSimplifyLibCalls: bool,
EmitLifetimeMarkers: bool,
SanitizerOptions: Option<&SanitizerOptions>,
PGOGenPath: *const c_char,
Expand Down
46 changes: 34 additions & 12 deletions compiler/rustc_codegen_ssa/src/back/link.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -270,14 +270,8 @@ pub fn each_linked_rlib(

for &cnum in crates {
match fmts.get(cnum.as_usize() - 1) {
Some(&Linkage::NotLinked | &Linkage::Dynamic) => continue,
Some(&Linkage::IncludedFromDylib) => {
// We always link crate `compiler_builtins` statically. When enabling LTO, we include it as well.
if info.compiler_builtins != Some(cnum) {
continue;
}
}
Some(&Linkage::Static) => {}
Some(&Linkage::NotLinked | &Linkage::Dynamic | &Linkage::IncludedFromDylib) => continue,
Some(_) => {}
None => return Err(errors::LinkRlibError::MissingFormat),
}
let crate_name = info.crate_name[&cnum];
Expand Down Expand Up @@ -526,7 +520,8 @@ fn link_staticlib<'a>(
&codegen_results.crate_info,
Some(CrateType::Staticlib),
&mut |cnum, path| {
let lto = are_upstream_rust_objects_already_included(sess);
let lto = are_upstream_rust_objects_already_included(sess)
&& !ignored_for_lto(sess, &codegen_results.crate_info, cnum);

let native_libs = codegen_results.crate_info.native_libraries[&cnum].iter();
let relevant = native_libs.clone().filter(|lib| relevant_lib(sess, lib));
Expand Down Expand Up @@ -1277,6 +1272,24 @@ fn link_sanitizer_runtime(
}
}

/// Returns a boolean indicating whether the specified crate should be ignored
/// during LTO.
///
/// Crates ignored during LTO are not lumped together in the "massive object
/// file" that we create and are linked in their normal rlib states. See
/// comments below for what crates do not participate in LTO.
///
/// It's unusual for a crate to not participate in LTO. Typically only
/// compiler-specific and unstable crates have a reason to not participate in
/// LTO.
pub fn ignored_for_lto(sess: &Session, info: &CrateInfo, cnum: CrateNum) -> bool {
// If our target enables builtin function lowering in LLVM then the
// crates providing these functions don't participate in LTO (e.g.
// no_builtins or compiler builtins crates).
!sess.target.no_builtins
&& (info.compiler_builtins == Some(cnum) || info.is_no_builtins.contains(&cnum))
}

/// This functions tries to determine the appropriate linker (and corresponding LinkerFlavor) to use
pub fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) {
fn infer_from(
Expand Down Expand Up @@ -2742,6 +2755,10 @@ fn rehome_sysroot_lib_dir<'a>(sess: &'a Session, lib_dir: &Path) -> PathBuf {
// symbols). We must continue to include the rest of the rlib, however, as
// it may contain static native libraries which must be linked in.
//
// (*) Crates marked with `#![no_builtins]` don't participate in LTO and
// their bytecode wasn't included. The object files in those libraries must
// still be passed to the linker.
//
// Note, however, that if we're not doing LTO we can just pass the rlib
// blindly to the linker (fast) because it's fine if it's not actually
// included as we're at the end of the dependency chain.
Expand All @@ -2767,7 +2784,9 @@ fn add_static_crate<'a>(
cmd.link_rlib(&rlib_path);
};

if !are_upstream_rust_objects_already_included(sess) {
if !are_upstream_rust_objects_already_included(sess)
|| ignored_for_lto(sess, &codegen_results.crate_info, cnum)
{
link_upstream(cratepath);
return;
}
Expand All @@ -2781,6 +2800,8 @@ fn add_static_crate<'a>(
let canonical_name = name.replace('-', "_");
let upstream_rust_objects_already_included =
are_upstream_rust_objects_already_included(sess);
let is_builtins =
sess.target.no_builtins || !codegen_results.crate_info.is_no_builtins.contains(&cnum);

let mut archive = archive_builder_builder.new_archive_builder(sess);
if let Err(error) = archive.add_archive(
Expand All @@ -2797,8 +2818,9 @@ fn add_static_crate<'a>(

// If we're performing LTO and this is a rust-generated object
// file, then we don't need the object file as it's part of the
// LTO module.
if upstream_rust_objects_already_included && is_rust_object {
// LTO module. Note that `#![no_builtins]` is excluded from LTO,
// though, so we let that object file slide.
if upstream_rust_objects_already_included && is_rust_object && is_builtins {
return true;
}

Expand Down
22 changes: 3 additions & 19 deletions compiler/rustc_codegen_ssa/src/back/symbol_export.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -54,8 +54,8 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
// export level, however, as they're just implementation details.
// Down below we'll hardwire all of the symbols to the `Rust` export
// level instead.
let is_compiler_builtins = tcx.is_compiler_builtins(LOCAL_CRATE);
let special_runtime_crate = tcx.is_panic_runtime(LOCAL_CRATE) || is_compiler_builtins;
let special_runtime_crate =
tcx.is_panic_runtime(LOCAL_CRATE) || tcx.is_compiler_builtins(LOCAL_CRATE);

let mut reachable_non_generics: DefIdMap<_> = tcx
.reachable_set(())
Expand Down Expand Up @@ -105,21 +105,16 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
}
})
.map(|def_id| {
let codegen_attrs = tcx.codegen_fn_attrs(def_id.to_def_id());
// We won't link right if this symbol is stripped during LTO.
let name = tcx.symbol_name(Instance::mono(tcx, def_id.to_def_id())).name;
// We have to preserve the symbols of the built-in functions during LTO.
let is_builtin_fn = is_compiler_builtins
&& symbol_export_level(tcx, def_id.to_def_id())
.is_below_threshold(SymbolExportLevel::C)
&& codegen_attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE);
let used = name == "rust_eh_personality";

let export_level = if special_runtime_crate {
SymbolExportLevel::Rust
} else {
symbol_export_level(tcx, def_id.to_def_id())
};
let codegen_attrs = tcx.codegen_fn_attrs(def_id.to_def_id());
debug!(
"EXPORTED SYMBOL (local): {} ({:?})",
tcx.symbol_name(Instance::mono(tcx, def_id.to_def_id())),
Expand All @@ -139,7 +134,6 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
used: codegen_attrs.flags.contains(CodegenFnAttrFlags::USED)
|| codegen_attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)
|| used,
used_compiler: is_builtin_fn,
};
(def_id.to_def_id(), info)
})
Expand All @@ -152,7 +146,6 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
level: SymbolExportLevel::C,
kind: SymbolExportKind::Data,
used: false,
used_compiler: false,
},
);
}
Expand Down Expand Up @@ -201,7 +194,6 @@ fn exported_symbols_provider_local(
level: info.level,
kind: SymbolExportKind::Text,
used: info.used,
used_compiler: false,
},
)
})
Expand All @@ -218,7 +210,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::C,
kind: SymbolExportKind::Text,
used: false,
used_compiler: false,
},
));
}
Expand All @@ -238,7 +229,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::Rust,
kind: SymbolExportKind::Text,
used: false,
used_compiler: false,
},
));
}
Expand All @@ -251,7 +241,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::Rust,
kind: SymbolExportKind::Data,
used: false,
used_compiler: false,
},
))
}
Expand All @@ -271,7 +260,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::C,
kind: SymbolExportKind::Data,
used: false,
used_compiler: false,
},
)
}));
Expand All @@ -297,7 +285,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::C,
kind: SymbolExportKind::Data,
used: false,
used_compiler: false,
},
)
}));
Expand All @@ -315,7 +302,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::C,
kind: SymbolExportKind::Data,
used: true,
used_compiler: false,
},
));
}
Expand Down Expand Up @@ -356,7 +342,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::Rust,
kind: SymbolExportKind::Text,
used: false,
used_compiler: false,
},
));
}
Expand All @@ -373,7 +358,6 @@ fn exported_symbols_provider_local(
level: SymbolExportLevel::Rust,
kind: SymbolExportKind::Text,
used: false,
used_compiler: false,
},
));
}
Expand Down
16 changes: 15 additions & 1 deletion compiler/rustc_codegen_ssa/src/back/write.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -148,12 +148,23 @@ impl ModuleConfig {

let emit_obj = if !should_emit_obj {
EmitObj::None
} else if sess.target.obj_is_bitcode || sess.opts.cg.linker_plugin_lto.enabled() {
} else if sess.target.obj_is_bitcode
|| (sess.opts.cg.linker_plugin_lto.enabled() && !no_builtins)
{
// This case is selected if the target uses objects as bitcode, or
// if linker plugin LTO is enabled. In the linker plugin LTO case
// the assumption is that the final link-step will read the bitcode
// and convert it to object code. This may be done by either the
// native linker or rustc itself.
//
// Note, however, that the linker-plugin-lto requested here is
// explicitly ignored for `#![no_builtins]` crates. These crates are
// specifically ignored by rustc's LTO passes and wouldn't work if
// loaded into the linker. These crates define symbols that LLVM
// lowers intrinsics to, and these symbol dependencies aren't known
// until after codegen. As a result any crate marked
// `#![no_builtins]` is assumed to not participate in LTO and
// instead goes on to generate object code.
EmitObj::Bitcode
} else if need_bitcode_in_object(tcx) {
EmitObj::ObjectCode(BitcodeSection::Full)
Expand Down Expand Up @@ -1023,6 +1034,9 @@ fn start_executing_work<B: ExtraBackendMethods>(

let mut each_linked_rlib_for_lto = Vec::new();
drop(link::each_linked_rlib(crate_info, None, &mut |cnum, path| {
if link::ignored_for_lto(sess, crate_info, cnum) {
return;
}
each_linked_rlib_for_lto.push((cnum, path.to_path_buf()));
}));

Expand Down
8 changes: 7 additions & 1 deletion compiler/rustc_codegen_ssa/src/base.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -859,6 +859,7 @@ impl CrateInfo {
local_crate_name,
compiler_builtins,
profiler_runtime: None,
is_no_builtins: Default::default(),
native_libraries: Default::default(),
used_libraries: tcx.native_libraries(LOCAL_CRATE).iter().map(Into::into).collect(),
crate_name: Default::default(),
Expand All @@ -885,14 +886,19 @@ impl CrateInfo {
if tcx.is_profiler_runtime(cnum) {
info.profiler_runtime = Some(cnum);
}
if tcx.is_no_builtins(cnum) {
info.is_no_builtins.insert(cnum);
}
}

// Handle circular dependencies in the standard library.
// See comment before `add_linked_symbol_object` function for the details.
// If global LTO is enabled then almost everything (*) is glued into a single object file,
// so this logic is not necessary and can cause issues on some targets (due to weak lang
// item symbols being "privatized" to that object file), so we disable it.
// (*) Native libs are not glued, and we assume that they cannot define weak lang items.
// (*) Native libs, and `#[compiler_builtins]` and `#[no_builtins]` crates are not glued,
// and we assume that they cannot define weak lang items. This is not currently enforced
// by the compiler, but that's ok because all this stuff is unstable anyway.
let target = &tcx.sess.target;
if !are_upstream_rust_objects_already_included(tcx.sess) {
let missing_weak_lang_items: FxHashSet<Symbol> = info
Expand Down
3 changes: 2 additions & 1 deletion compiler/rustc_codegen_ssa/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ extern crate tracing;
extern crate rustc_middle;

use rustc_ast as ast;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::sync::Lrc;
use rustc_hir::def_id::CrateNum;
use rustc_middle::dep_graph::WorkProduct;
Expand Down Expand Up @@ -158,6 +158,7 @@ pub struct CrateInfo {
pub local_crate_name: Symbol,
pub compiler_builtins: Option<CrateNum>,
pub profiler_runtime: Option<CrateNum>,
pub is_no_builtins: FxHashSet<CrateNum>,
pub native_libraries: FxHashMap<CrateNum, Vec<NativeLib>>,
pub crate_name: FxHashMap<CrateNum, Symbol>,
pub used_libraries: Vec<NativeLib>,
Expand Down
Loading
Loading