Skip to content

Commit

Permalink
upstream fix for "Cannot represent a difference across sections"; rel 3
Browse files Browse the repository at this point in the history 
from: rust-lang/rust#111167
  • Loading branch information
@jpalus
jpalus committed May 26, 2023
1 parent ebe4488 commit 23c4a9f
Show file tree
Hide file tree
Showing 2 changed files with 251 additions and 1 deletion.
248 changes: 248 additions & 0 deletions 111167.patch
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,248 @@
From 10b69dde3fd15334ea2382d2dc9e9a261de1afaf Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Wed, 3 May 2023 15:52:31 -0700
Subject: [PATCH] debuginfo: split method declaration and definition

When we're adding a method to a type DIE, we only want a DW_AT_declaration
there, because LLVM LTO can't unify type definitions when a child DIE is a
full subprogram definition. Now the subprogram definition gets added at the
CU level with a specification link back to the abstract declaration.
---
.../rustc_codegen_llvm/src/debuginfo/mod.rs | 85 +++++++++++--------
compiler/rustc_codegen_llvm/src/llvm/ffi.rs | 15 ++++
.../rustc_llvm/llvm-wrapper/RustWrapper.cpp | 22 +++++
.../issue-109934-lto-debuginfo/Makefile | 12 +++
.../issue-109934-lto-debuginfo/lib.rs | 9 ++
5 files changed, 109 insertions(+), 34 deletions(-)
create mode 100644 tests/run-make/issue-109934-lto-debuginfo/Makefile
create mode 100644 tests/run-make/issue-109934-lto-debuginfo/lib.rs

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 2e9f89f419696..b138b0c0e70a1 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -322,7 +322,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
let tcx = self.tcx;

let def_id = instance.def_id();
- let containing_scope = get_containing_scope(self, instance);
+ let (containing_scope, is_method) = get_containing_scope(self, instance);
let span = tcx.def_span(def_id);
let loc = self.lookup_debug_loc(span.lo());
let file_metadata = file_metadata(self, &loc.file);
@@ -378,8 +378,29 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
}
}

- unsafe {
- return llvm::LLVMRustDIBuilderCreateFunction(
+ // When we're adding a method to a type DIE, we only want a DW_AT_declaration there, because
+ // LLVM LTO can't unify type definitions when a child DIE is a full subprogram definition.
+ // When we use this `decl` below, the subprogram definition gets created at the CU level
+ // with a DW_AT_specification pointing back to the type's declaration.
+ let decl = is_method.then(|| unsafe {
+ llvm::LLVMRustDIBuilderCreateMethod(
+ DIB(self),
+ containing_scope,
+ name.as_ptr().cast(),
+ name.len(),
+ linkage_name.as_ptr().cast(),
+ linkage_name.len(),
+ file_metadata,
+ loc.line,
+ function_type_metadata,
+ flags,
+ spflags & !DISPFlags::SPFlagDefinition,
+ template_parameters,
+ )
+ });
+
+ return unsafe {
+ llvm::LLVMRustDIBuilderCreateFunction(
DIB(self),
containing_scope,
name.as_ptr().cast(),
@@ -394,9 +415,9 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
spflags,
maybe_definition_llfn,
template_parameters,
- None,
- );
- }
+ decl,
+ )
+ };

fn get_function_signature<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
@@ -493,14 +514,16 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
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>(
cx: &CodegenCx<'ll, 'tcx>,
instance: Instance<'tcx>,
- ) -> &'ll DIScope {
+ ) -> (&'ll DIScope, bool) {
// First, let's see if this is a method within an inherent impl. Because
// if yes, we want to make the result subroutine DIE a child of the
// subroutine's self-type.
- let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
+ if let Some(impl_def_id) = cx.tcx.impl_of_method(instance.def_id()) {
// If the method does *not* belong to a trait, proceed
if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
@@ -511,39 +534,33 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {

// Only "class" methods are generally understood by LLVM,
// so avoid methods on other types (e.g., `<*mut T>::null`).
- match impl_self_ty.kind() {
- ty::Adt(def, ..) if !def.is_box() => {
- // Again, only create type information if full debuginfo is enabled
- if cx.sess().opts.debuginfo == DebugInfo::Full
- && !impl_self_ty.needs_subst()
- {
- Some(type_di_node(cx, impl_self_ty))
- } else {
- Some(namespace::item_namespace(cx, def.did()))
- }
+ if let ty::Adt(def, ..) = impl_self_ty.kind() && !def.is_box() {
+ // Again, only create type information if full debuginfo is enabled
+ if cx.sess().opts.debuginfo == DebugInfo::Full && !impl_self_ty.needs_subst()
+ {
+ return (type_di_node(cx, impl_self_ty), true);
+ } else {
+ return (namespace::item_namespace(cx, def.did()), false);
}
- _ => None,
}
} else {
// For trait method impls we still use the "parallel namespace"
// strategy
- None
}
- });
+ }

- self_type.unwrap_or_else(|| {
- namespace::item_namespace(
- cx,
- DefId {
- krate: instance.def_id().krate,
- index: cx
- .tcx
- .def_key(instance.def_id())
- .parent
- .expect("get_containing_scope: missing parent?"),
- },
- )
- })
+ let scope = namespace::item_namespace(
+ cx,
+ DefId {
+ krate: instance.def_id().krate,
+ index: cx
+ .tcx
+ .def_key(instance.def_id())
+ .parent
+ .expect("get_containing_scope: missing parent?"),
+ },
+ );
+ (scope, false)
}
}

diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index c95148013eb74..1f98d91c32054 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1987,6 +1987,21 @@ extern "C" {
Decl: Option<&'a DIDescriptor>,
) -> &'a DISubprogram;

+ pub fn LLVMRustDIBuilderCreateMethod<'a>(
+ Builder: &DIBuilder<'a>,
+ Scope: &'a DIDescriptor,
+ Name: *const c_char,
+ NameLen: size_t,
+ LinkageName: *const c_char,
+ LinkageNameLen: size_t,
+ File: &'a DIFile,
+ LineNo: c_uint,
+ Ty: &'a DIType,
+ Flags: DIFlags,
+ SPFlags: DISPFlags,
+ TParam: &'a DIArray,
+ ) -> &'a DISubprogram;
+
pub fn LLVMRustDIBuilderCreateBasicType<'a>(
Builder: &DIBuilder<'a>,
Name: *const c_char,
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index cadb6b1e23fe9..49acd71b3e106 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -831,6 +831,28 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateFunction(
return wrap(Sub);
}

+extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateMethod(
+ LLVMRustDIBuilderRef Builder, LLVMMetadataRef Scope,
+ const char *Name, size_t NameLen,
+ const char *LinkageName, size_t LinkageNameLen,
+ LLVMMetadataRef File, unsigned LineNo,
+ LLVMMetadataRef Ty, LLVMRustDIFlags Flags,
+ LLVMRustDISPFlags SPFlags, LLVMMetadataRef TParam) {
+ DITemplateParameterArray TParams =
+ DITemplateParameterArray(unwrap<MDTuple>(TParam));
+ DISubprogram::DISPFlags llvmSPFlags = fromRust(SPFlags);
+ DINode::DIFlags llvmFlags = fromRust(Flags);
+ DISubprogram *Sub = Builder->createMethod(
+ unwrapDI<DIScope>(Scope),
+ StringRef(Name, NameLen),
+ StringRef(LinkageName, LinkageNameLen),
+ unwrapDI<DIFile>(File), LineNo,
+ unwrapDI<DISubroutineType>(Ty),
+ 0, 0, nullptr, // VTable params aren't used
+ llvmFlags, llvmSPFlags, TParams);
+ return wrap(Sub);
+}
+
extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateBasicType(
LLVMRustDIBuilderRef Builder, const char *Name, size_t NameLen,
uint64_t SizeInBits, unsigned Encoding) {
diff --git a/tests/run-make/issue-109934-lto-debuginfo/Makefile b/tests/run-make/issue-109934-lto-debuginfo/Makefile
new file mode 100644
index 0000000000000..3b7a99d3dbc62
--- /dev/null
+++ b/tests/run-make/issue-109934-lto-debuginfo/Makefile
@@ -0,0 +1,12 @@
+# ignore-cross-compile
+include ../tools.mk
+
+# With the upgrade to LLVM 16, this was getting:
+#
+# error: Cannot represent a difference across sections
+#
+# The error stemmed from DI function definitions under type scopes, fixed by
+# only declaring in type scope and defining the subprogram elsewhere.
+
+all:
+ $(RUSTC) lib.rs --test -C lto=fat -C debuginfo=2 -C incremental=$(TMPDIR)/inc-fat
diff --git a/tests/run-make/issue-109934-lto-debuginfo/lib.rs b/tests/run-make/issue-109934-lto-debuginfo/lib.rs
new file mode 100644
index 0000000000000..c405928bd1824
--- /dev/null
+++ b/tests/run-make/issue-109934-lto-debuginfo/lib.rs
@@ -0,0 +1,9 @@
+extern crate alloc;
+
+#[cfg(test)]
+mod tests {
+ #[test]
+ fn something_alloc() {
+ assert_eq!(Vec::<u32>::new(), Vec::<u32>::new());
+ }
+}
4 changes: 3 additions & 1 deletion rust.spec
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@ Summary: The Rust Programming Language
Summary(pl.UTF-8): Język programowania Rust
Name: rust
Version: 1.69.0
Release: 2
Release: 3
# Licenses: (rust itself) and (bundled libraries)
License: (Apache v2.0 or MIT) and (BSD and ISC and MIT)
Group: Development/Languages
Expand All @@ -54,6 +54,7 @@ Source4: https://static.rust-lang.org/dist/%{bootstrap_date}/rust-%{bootstrap_ru
Source5: https://static.rust-lang.org/dist/%{bootstrap_date}/rust-%{bootstrap_rust}-armv7-unknown-linux-gnueabihf.tar.xz
# Source5-md5: 5691b194302d66b40c3e4eee0eeb1813
Patch0: llvm-tools-install.patch
Patch1: 111167.patch
URL: https://www.rust-lang.org/
# for src/compiler-rt
BuildRequires: cmake >= 3.4.3
Expand Down Expand Up @@ -333,6 +334,7 @@ Dopełnianie parametrów polecenia cargo w powłoce Zsh.
%prep
%setup -q -n %{rustc_package}
%patch0 -p1
%patch1 -p1

%if %{with bootstrap}
%ifarch %{x8664} x32
Expand Down

0 comments on commit 23c4a9f

Please sign in to comment.