rust/0001-debuginfo-split-method-declaration-and-definition.patch
Josh Stone d2ebf73bdc Update to 1.69.0.
Resolves: rhbz#2191741
2023-05-26 10:11:09 -07:00

255 lines
10 KiB
Diff

From 1476ebe761884e0cfc92f3f16809011663eb33f0 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.
(cherry picked from commit 10b69dde3fd15334ea2382d2dc9e9a261de1afaf)
---
.../rustc_codegen_llvm/src/debuginfo/mod.rs | 86 +++++++++++--------
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, 110 insertions(+), 34 deletions(-)
create mode 100644 tests/run-make-fulldeps/issue-109934-lto-debuginfo/Makefile
create mode 100644 tests/run-make-fulldeps/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 5392534cfcb7..11426b150b6c 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -322,7 +322,7 @@ fn dbg_scope_fn(
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 @@ fn dbg_scope_fn(
}
}
- 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 @@ fn dbg_scope_fn(
spflags,
maybe_definition_llfn,
template_parameters,
- None,
- );
- }
+ decl,
+ )
+ };
fn get_function_signature<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
@@ -495,14 +516,16 @@ fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<S
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(
@@ -513,39 +536,34 @@ fn get_containing_scope<'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 253c2ca7c768..9dd6db1929fc 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1968,6 +1968,21 @@ pub fn LLVMRustDIBuilderCreateFunction<'a>(
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 e3493caaaf74..c4a97af1f0f4 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -841,6 +841,28 @@ 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-fulldeps/issue-109934-lto-debuginfo/Makefile b/tests/run-make-fulldeps/issue-109934-lto-debuginfo/Makefile
new file mode 100644
index 000000000000..3b7a99d3dbc6
--- /dev/null
+++ b/tests/run-make-fulldeps/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-fulldeps/issue-109934-lto-debuginfo/lib.rs b/tests/run-make-fulldeps/issue-109934-lto-debuginfo/lib.rs
new file mode 100644
index 000000000000..c405928bd182
--- /dev/null
+++ b/tests/run-make-fulldeps/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());
+ }
+}
--
2.40.1