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Merged
merged 8 commits into from
Mar 19, 2025
Merged

Various codegen_llvm cleanups #138674

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eef70a9
Create a safe wrapper around LLVMRustDIBuilderCreateTemplateTypeParam…
oli-obk Mar 17, 2025
b4acf7a
Immediately create an `Option` instead of reallocating for it later
oli-obk Mar 17, 2025
6adc2c1
Deduplicate template parameter creation
oli-obk Mar 17, 2025
e19e4e3
Create a safe wrapper around `LLVMRustDIBuilderCreateSubroutineType`
oli-obk Mar 17, 2025
cc41dd4
Create a safe wrapper function around `LLVMRustDIBuilderCreateFile`
oli-obk Mar 17, 2025
018032c
Create a safe wrapper around `LLVMRustDIBuilderCreateBasicType`
oli-obk Mar 17, 2025
1f34b19
Avoid splitting up a layout
oli-obk Mar 18, 2025
f4b0984
Create a safe wrapper around `LLVMRustDIBuilderCreateMemberType`
oli-obk Mar 17, 2025
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125 changes: 61 additions & 64 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ use std::borrow::Cow;
use std::fmt::{self, Write};
use std::hash::{Hash, Hasher};
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::{iter, ptr};

use libc::{c_char, c_longlong, c_uint};
Expand Down Expand Up @@ -38,8 +39,8 @@ use crate::debuginfo::metadata::type_map::build_type_with_children;
use crate::debuginfo::utils::{WidePtrKind, wide_pointer_kind};
use crate::llvm;
use crate::llvm::debuginfo::{
DIDescriptor, DIFile, DIFlags, DILexicalBlock, DIScope, DIType, DebugEmissionKind,
DebugNameTableKind,
DIBuilder, DICompositeType, DIDescriptor, DIFile, DIFlags, DILexicalBlock, DIScope, DIType,
DebugEmissionKind, DebugNameTableKind,
};
use crate::value::Value;

Expand Down Expand Up @@ -68,7 +69,8 @@ pub(super) const UNKNOWN_COLUMN_NUMBER: c_uint = 0;

const NO_SCOPE_METADATA: Option<&DIScope> = None;
/// A function that returns an empty list of generic parameter debuginfo nodes.
const NO_GENERICS: for<'ll> fn(&CodegenCx<'ll, '_>) -> SmallVec<&'ll DIType> = |_| SmallVec::new();
const NO_GENERICS: for<'ll> fn(&CodegenCx<'ll, '_>) -> SmallVec<Option<&'ll DIType>> =
|_| SmallVec::new();

// SmallVec is used quite a bit in this module, so create a shorthand.
// The actual number of elements is not so important.
Expand Down Expand Up @@ -311,12 +313,7 @@ fn build_subroutine_type_di_node<'ll, 'tcx>(

debug_context(cx).type_map.unique_id_to_di_node.borrow_mut().remove(&unique_type_id);

let fn_di_node = unsafe {
llvm::LLVMRustDIBuilderCreateSubroutineType(
DIB(cx),
create_DIArray(DIB(cx), &signature_di_nodes[..]),
)
};
let fn_di_node = create_subroutine_type(cx, create_DIArray(DIB(cx), &signature_di_nodes[..]));

// This is actually a function pointer, so wrap it in pointer DI.
let name = compute_debuginfo_type_name(cx.tcx, fn_ty, false);
Expand All @@ -340,6 +337,13 @@ fn build_subroutine_type_di_node<'ll, 'tcx>(
DINodeCreationResult::new(di_node, false)
}

pub(super) fn create_subroutine_type<'ll>(
cx: &CodegenCx<'ll, '_>,
signature: &'ll DICompositeType,
) -> &'ll DICompositeType {
unsafe { llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(cx), signature) }
}

/// Create debuginfo for `dyn SomeTrait` types. Currently these are empty structs
/// we with the correct type name (e.g. "dyn SomeTrait<Foo, Item=u32> + Sync").
fn build_dyn_type_di_node<'ll, 'tcx>(
Expand Down Expand Up @@ -620,42 +624,38 @@ pub(crate) fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFi
let source =
cx.sess().opts.unstable_opts.embed_source.then_some(()).and(source_file.src.as_ref());

unsafe {
llvm::LLVMRustDIBuilderCreateFile(
DIB(cx),
file_name.as_c_char_ptr(),
file_name.len(),
directory.as_c_char_ptr(),
directory.len(),
hash_kind,
hash_value.as_c_char_ptr(),
hash_value.len(),
source.map_or(ptr::null(), |x| x.as_c_char_ptr()),
source.map_or(0, |x| x.len()),
)
}
create_file(DIB(cx), &file_name, &directory, &hash_value, hash_kind, source)
}
}

fn unknown_file_metadata<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll DIFile {
debug_context(cx).created_files.borrow_mut().entry(None).or_insert_with(|| unsafe {
let file_name = "<unknown>";
let directory = "";
let hash_value = "";
debug_context(cx).created_files.borrow_mut().entry(None).or_insert_with(|| {
create_file(DIB(cx), "<unknown>", "", "", llvm::ChecksumKind::None, None)
})
}

fn create_file<'ll>(
builder: &DIBuilder<'ll>,
file_name: &str,
directory: &str,
hash_value: &str,
hash_kind: llvm::ChecksumKind,
source: Option<&Arc<String>>,
) -> &'ll DIFile {
unsafe {
llvm::LLVMRustDIBuilderCreateFile(
DIB(cx),
builder,
file_name.as_c_char_ptr(),
file_name.len(),
directory.as_c_char_ptr(),
directory.len(),
llvm::ChecksumKind::None,
hash_kind,
hash_value.as_c_char_ptr(),
hash_value.len(),
ptr::null(),
0,
source.map_or(ptr::null(), |x| x.as_c_char_ptr()),
source.map_or(0, |x| x.len()),
)
})
}
}

trait MsvcBasicName {
Expand Down Expand Up @@ -929,17 +929,13 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
};

unsafe {
let compile_unit_file = llvm::LLVMRustDIBuilderCreateFile(
let compile_unit_file = create_file(
debug_context.builder.as_ref(),
name_in_debuginfo.as_c_char_ptr(),
name_in_debuginfo.len(),
work_dir.as_c_char_ptr(),
work_dir.len(),
&name_in_debuginfo,
&work_dir,
"",
llvm::ChecksumKind::None,
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Maybe this. Empty string now, null pointer before

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But that wouldn't explain the query count changes

ptr::null(),
0,
ptr::null(),
0,
None,
);

let unit_metadata = llvm::LLVMRustDIBuilderCreateCompileUnit(
Expand Down Expand Up @@ -1287,32 +1283,33 @@ fn build_union_type_di_node<'ll, 'tcx>(
fn build_generic_type_param_di_nodes<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
ty: Ty<'tcx>,
) -> SmallVec<&'ll DIType> {
) -> SmallVec<Option<&'ll DIType>> {
if let ty::Adt(def, args) = *ty.kind() {
if args.types().next().is_some() {
let generics = cx.tcx.generics_of(def.did());
let names = get_parameter_names(cx, generics);
let template_params: SmallVec<_> = iter::zip(args, names)
.filter_map(|(kind, name)| {
kind.as_type().map(|ty| {
let actual_type = cx.tcx.normalize_erasing_regions(cx.typing_env(), ty);
let actual_type_di_node = type_di_node(cx, actual_type);
let name = name.as_str();
unsafe {
llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
DIB(cx),
None,
name.as_c_char_ptr(),
name.len(),
actual_type_di_node,
)
}
})
let generics = cx.tcx.generics_of(def.did());
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This generics_of is now called unconditionally and is likely the source of the perf regression

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Turns out that wasn't it

return get_template_parameters(cx, generics, args);
}

return smallvec![];
}

pub(super) fn get_template_parameters<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
generics: &ty::Generics,
args: ty::GenericArgsRef<'tcx>,
) -> SmallVec<Option<&'ll DIType>> {
if args.types().next().is_some() {
let names = get_parameter_names(cx, generics);
let template_params: SmallVec<_> = iter::zip(args, names)
.filter_map(|(kind, name)| {
kind.as_type().map(|ty| {
let actual_type = cx.tcx.normalize_erasing_regions(cx.typing_env(), ty);
let actual_type_di_node = type_di_node(cx, actual_type);
Some(cx.create_template_type_parameter(name.as_str(), actual_type_di_node))
})
.collect();
})
.collect();

return template_params;
}
return template_params;
}

return smallvec![];
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -363,6 +363,7 @@ fn build_coroutine_variant_struct_type_di_node<'ll, 'tcx>(

state_specific_fields.into_iter().chain(common_fields).collect()
},
// FIXME: this is a no-op. `build_generic_type_param_di_nodes` only works for Adts.
|cx| build_generic_type_param_di_nodes(cx, coroutine_type_and_layout.ty),
)
.di_node
Expand Down
5 changes: 2 additions & 3 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -257,16 +257,15 @@ pub(super) fn build_type_with_children<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
stub_info: StubInfo<'ll, 'tcx>,
members: impl FnOnce(&CodegenCx<'ll, 'tcx>, &'ll DIType) -> SmallVec<&'ll DIType>,
generics: impl FnOnce(&CodegenCx<'ll, 'tcx>) -> SmallVec<&'ll DIType>,
generics: impl FnOnce(&CodegenCx<'ll, 'tcx>) -> SmallVec<Option<&'ll DIType>>,
) -> DINodeCreationResult<'ll> {
assert_eq!(debug_context(cx).type_map.di_node_for_unique_id(stub_info.unique_type_id), None);

debug_context(cx).type_map.insert(stub_info.unique_type_id, stub_info.metadata);

let members: SmallVec<_> =
members(cx, stub_info.metadata).into_iter().map(|node| Some(node)).collect();
let generics: SmallVec<Option<&'ll DIType>> =
generics(cx).into_iter().map(|node| Some(node)).collect();
let generics = generics(cx);

if !(members.is_empty() && generics.is_empty()) {
unsafe {
Expand Down
69 changes: 24 additions & 45 deletions compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,10 +2,11 @@

use std::cell::{OnceCell, RefCell};
use std::ops::Range;
use std::ptr;
use std::sync::Arc;
use std::{iter, ptr};

use libc::c_uint;
use metadata::create_subroutine_type;
use rustc_abi::Size;
use rustc_codegen_ssa::debuginfo::type_names;
use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
Expand Down Expand Up @@ -34,8 +35,8 @@ use crate::builder::Builder;
use crate::common::{AsCCharPtr, CodegenCx};
use crate::llvm;
use crate::llvm::debuginfo::{
DIArray, DIBuilderBox, DIFile, DIFlags, DILexicalBlock, DILocation, DISPFlags, DIScope, DIType,
DIVariable,
DIArray, DIBuilderBox, DIFile, DIFlags, DILexicalBlock, DILocation, DISPFlags, DIScope,
DITemplateTypeParameter, DIType, DIVariable,
};
use crate::value::Value;

Expand Down Expand Up @@ -251,7 +252,7 @@ struct DebugLoc {
col: u32,
}

impl CodegenCx<'_, '_> {
impl<'ll> CodegenCx<'ll, '_> {
/// Looks up debug source information about a `BytePos`.
// FIXME(eddyb) rename this to better indicate it's a duplicate of
// `lookup_char_pos` rather than `dbg_loc`, perhaps by making
Expand Down Expand Up @@ -279,6 +280,22 @@ impl CodegenCx<'_, '_> {
DebugLoc { file, line, col }
}
}

fn create_template_type_parameter(
&self,
name: &str,
actual_type_metadata: &'ll DIType,
) -> &'ll DITemplateTypeParameter {
unsafe {
llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
DIB(self),
None,
name.as_c_char_ptr(),
name.len(),
actual_type_metadata,
)
}
}
}

impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
Expand Down Expand Up @@ -325,10 +342,8 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
let loc = self.lookup_debug_loc(span.lo());
let file_metadata = file_metadata(self, &loc.file);

let function_type_metadata = unsafe {
let fn_signature = get_function_signature(self, fn_abi);
llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(self), fn_signature)
};
let function_type_metadata =
create_subroutine_type(self, get_function_signature(self, fn_abi));

let mut name = String::with_capacity(64);
type_names::push_item_name(tcx, def_id, false, &mut name);
Expand Down Expand Up @@ -471,46 +486,10 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
generics: &ty::Generics,
args: GenericArgsRef<'tcx>,
) -> &'ll DIArray {
if args.types().next().is_none() {
return create_DIArray(DIB(cx), &[]);
}

// Again, only create type information if full debuginfo is enabled
let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
let names = get_parameter_names(cx, generics);
iter::zip(args, names)
.filter_map(|(kind, name)| {
kind.as_type().map(|ty| {
let actual_type = cx.tcx.normalize_erasing_regions(cx.typing_env(), ty);
let actual_type_metadata = type_di_node(cx, actual_type);
let name = name.as_str();
unsafe {
Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
DIB(cx),
None,
name.as_c_char_ptr(),
name.len(),
actual_type_metadata,
))
}
})
})
.collect()
} else {
vec![]
};

let template_params = metadata::get_template_parameters(cx, generics, args);
create_DIArray(DIB(cx), &template_params)
}

fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
let mut names = generics.parent.map_or_else(Vec::new, |def_id| {
get_parameter_names(cx, cx.tcx.generics_of(def_id))
});
names.extend(generics.own_params.iter().map(|param| param.name));
names
}

/// Returns a scope, plus `true` if that's a type scope for "class" methods,
/// otherwise `false` for plain namespace scopes.
fn get_containing_scope<'ll, 'tcx>(
Expand Down