https://github.com/akash-manna-sky created
https://github.com/llvm/llvm-project/pull/216348
Fixes #196982
When filling in source locations for a dependent `address_space` type, we only
looked at the declarator chunk we happened to be visiting. But an attribute
written after the declarator-id appertains to the declared entity, so it never
lands on a chunk — it gets applied to the outermost type instead. The search
came up empty and we hit an `llvm_unreachable`. Nothing to do with the
malformed code in the bug report, by the way: plain `template <int AS> void f()
{ void *p [[clang::address_space(AS)]]; }` crashes too.
So we now check the declarator's own attributes as well, and if there's still
no match, fall back to the location stored on the type rather than asserting. I
kept the attribute search first because the type is uniqued without its
location in the profile, so two declarators with the same operand share a node
and the type would give us the wrong one. Leading-position attributes aren't
searched — `address_space` always slides to the decl-spec, so they can't
produce this type. Tests in
`clang/test/SemaTemplate/address_space-dependent.cpp`.
>From 38a456e345f0015e6ab8e07e34b586037c0e526f Mon Sep 17 00:00:00 2001
From: Akash Manna <[email protected]>
Date: Fri, 14 Aug 2026 21:44:45 +0530
Subject: [PATCH] [clang][Sema] Fix crash on address_space attribute written
after the declarator-id
---
clang/docs/ReleaseNotes.md | 4 ++++
clang/lib/Sema/SemaType.cpp | 24 ++++++++++++-------
.../SemaTemplate/address_space-dependent.cpp | 14 +++++++++++
3 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md
index d9b9c92950c98..e08a059be1a47 100644
--- a/clang/docs/ReleaseNotes.md
+++ b/clang/docs/ReleaseNotes.md
@@ -410,6 +410,10 @@ features cannot lower the translation-unit ABI level;
`sized_by_or_null` describe the size in bytes rather than a count of
elements,
they are now correctly accepted on such pointers.
+- Fixed a crash when an `address_space` attribute with a dependent argument was
+ written after the declarator-id, where it appertains to the declared entity
+ rather than to a declarator chunk. (#GH196982)
+
#### Bug Fixes to C++ Support
- Fixed an issue where `__typeof__` incorrectly rejected cv-qualified function
types.
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index c19022ac1aee8..e9286aaa9de79 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -6344,11 +6344,20 @@ namespace {
};
} // end anonymous namespace
-static void
-fillDependentAddressSpaceTypeLoc(DependentAddressSpaceTypeLoc DASTL,
- const ParsedAttributesView &Attrs) {
- for (const ParsedAttr &AL : Attrs) {
- if (AL.getKind() == ParsedAttr::AT_AddressSpace) {
+static void fillDependentAddressSpaceTypeLoc(ASTContext &Context,
+ DependentAddressSpaceTypeLoc
DASTL,
+ const Declarator &D,
+ const DeclaratorChunk &Chunk) {
+ // An attribute written after the declarator-id appertains to the declared
+ // entity, so it is applied to the outermost type instead of to the chunk
+ // that is being visited.
+ const ParsedAttributesView *AttrLists[] = {&Chunk.getAttrs(),
+ &D.getAttributes()};
+ for (const ParsedAttributesView *Attrs : AttrLists) {
+ for (const ParsedAttr &AL : *Attrs) {
+ if (AL.getKind() != ParsedAttr::AT_AddressSpace || AL.getNumArgs() != 1
||
+ !AL.isArgExpr(0))
+ continue;
DASTL.setAttrNameLoc(AL.getLoc());
DASTL.setAttrExprOperand(AL.getArgAsExpr(0));
DASTL.setAttrOperandParensRange(SourceRange());
@@ -6356,8 +6365,7 @@
fillDependentAddressSpaceTypeLoc(DependentAddressSpaceTypeLoc DASTL,
}
}
- llvm_unreachable(
- "no address_space attribute found at the expected location!");
+ DASTL.initializeLocal(Context, DASTL.getTypePtr()->getAttributeLoc());
}
/// Create and instantiate a TypeSourceInfo with type source information.
@@ -6423,7 +6431,7 @@ GetTypeSourceInfoForDeclarator(TypeProcessingState &State,
case TypeLoc::DependentAddressSpace: {
auto TL = CurrTL.castAs<DependentAddressSpaceTypeLoc>();
- fillDependentAddressSpaceTypeLoc(TL, D.getTypeObject(i).getAttrs());
+ fillDependentAddressSpaceTypeLoc(S.Context, TL, D, D.getTypeObject(i));
CurrTL = TL.getPointeeTypeLoc().getUnqualifiedLoc();
break;
}
diff --git a/clang/test/SemaTemplate/address_space-dependent.cpp
b/clang/test/SemaTemplate/address_space-dependent.cpp
index d6f25923b69b5..9c90c9831b7e3 100644
--- a/clang/test/SemaTemplate/address_space-dependent.cpp
+++ b/clang/test/SemaTemplate/address_space-dependent.cpp
@@ -130,3 +130,17 @@ struct EntryTy {
ASPtrTy<1> x;
EntryTy<2> y;
}
+
+namespace gh196982 {
+template <int AS>
+void trailing() {
+ void *p [[clang::address_space(AS)]]; // expected-warning {{applying
attribute 'clang::address_space' to a declaration is deprecated; apply it to
the type instead}}
+ void *q __attribute__((address_space(AS)));
+ int r[2] __attribute__((address_space(AS)));
+}
+
+void invalidOperand() {
+ void *p [[clang::address_space(undeclared())]]; // expected-error {{use of
undeclared identifier 'undeclared'}} \
+ // expected-warning
{{applying attribute 'clang::address_space' to a declaration is deprecated;
apply it to the type instead}}
+}
+}
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