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https://llvm.org/pr58819 - clang is giving an externally visible lambda in a
static data member internal linkage and the wrong linkage name.
Looks like we should be classifying this case the same as a non-static data
member, so far as I can tell from the ABI docs and template examples (seems
like the non-template inline-defined case should be the same).
This is a change in ABI, but not sure it qualifies as an ABI break as far as
Apple and Sony are concerned - do you folks want this change? (it should fix
the example in the bug where a static member in such a lambda ends up
bifurcated, and I don't /think/ it'll break existing code since the symbol was
previously internal anyway)
Looks like GCC has got this mangling slightly wrong (so we'd still end up with
GCC+Clang bifurcation of the local static in the lambda, function address
inequality, etc) in that they miss the variable name in the mangling in the
non-template case. GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107741
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D138247
Files:
clang/lib/Sema/SemaLambda.cpp
clang/test/CodeGenCXX/mangle-lambdas.cpp
Index: clang/test/CodeGenCXX/mangle-lambdas.cpp
===================================================================
--- clang/test/CodeGenCXX/mangle-lambdas.cpp
+++ clang/test/CodeGenCXX/mangle-lambdas.cpp
@@ -290,6 +290,17 @@
// CHECK-LABEL: define linkonce_odr noundef i32
@_ZZZ3ft4IiEvvEN2lc2mfEiEd_NKUlvE_clEv
+extern int ExternalVariable;
+struct StaticInlineMember {
+ static constexpr auto x = [] { return ExternalVariable; };
+};
+
+// CHECK-LABEL: define void @_Z23test_StaticInlineMemberv
+// CHECK: call {{.*}} @_ZNK18StaticInlineMember1xMUlvE_clEv
+void test_StaticInlineMember() {
+ StaticInlineMember::x();
+}
+
// Check linkage of the various lambdas.
// CHECK-LABEL: define linkonce_odr noundef i32 @_ZZ11inline_funciENKUlvE_clEv
// CHECK: ret i32 1
Index: clang/lib/Sema/SemaLambda.cpp
===================================================================
--- clang/lib/Sema/SemaLambda.cpp
+++ clang/lib/Sema/SemaLambda.cpp
@@ -296,10 +296,10 @@
if (LexicalDC->isRecord())
Kind = DefaultArgument;
} else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
- if (Var->getDeclContext()->isRecord())
- Kind = StaticDataMember;
- else if (Var->getMostRecentDecl()->isInline())
+ if (Var->getMostRecentDecl()->isInline())
Kind = InlineVariable;
+ else if (Var->getDeclContext()->isRecord())
+ Kind = StaticDataMember;
else if (Var->getDescribedVarTemplate())
Kind = VariableTemplate;
else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
Index: clang/test/CodeGenCXX/mangle-lambdas.cpp
===================================================================
--- clang/test/CodeGenCXX/mangle-lambdas.cpp
+++ clang/test/CodeGenCXX/mangle-lambdas.cpp
@@ -290,6 +290,17 @@
// CHECK-LABEL: define linkonce_odr noundef i32 @_ZZZ3ft4IiEvvEN2lc2mfEiEd_NKUlvE_clEv
+extern int ExternalVariable;
+struct StaticInlineMember {
+ static constexpr auto x = [] { return ExternalVariable; };
+};
+
+// CHECK-LABEL: define void @_Z23test_StaticInlineMemberv
+// CHECK: call {{.*}} @_ZNK18StaticInlineMember1xMUlvE_clEv
+void test_StaticInlineMember() {
+ StaticInlineMember::x();
+}
+
// Check linkage of the various lambdas.
// CHECK-LABEL: define linkonce_odr noundef i32 @_ZZ11inline_funciENKUlvE_clEv
// CHECK: ret i32 1
Index: clang/lib/Sema/SemaLambda.cpp
===================================================================
--- clang/lib/Sema/SemaLambda.cpp
+++ clang/lib/Sema/SemaLambda.cpp
@@ -296,10 +296,10 @@
if (LexicalDC->isRecord())
Kind = DefaultArgument;
} else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
- if (Var->getDeclContext()->isRecord())
- Kind = StaticDataMember;
- else if (Var->getMostRecentDecl()->isInline())
+ if (Var->getMostRecentDecl()->isInline())
Kind = InlineVariable;
+ else if (Var->getDeclContext()->isRecord())
+ Kind = StaticDataMember;
else if (Var->getDescribedVarTemplate())
Kind = VariableTemplate;
else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
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