https://github.com/erichkeane created
https://github.com/llvm/llvm-project/pull/238509
This ends up being a horrifically trivial implementation: it just changes the
name of the static local to use the 'mangled name' (which
pays attention to the attribute) rather than just the static decl
name. This patch implements that and adds some trivial tests to show the
behavior.
>From dd85a652f7c57b96e75eb77944313fece6b63e31 Mon Sep 17 00:00:00 2001
From: erichkeane <[email protected]>
Date: Tue, 3 Nov 2026 11:44:10 -0800
Subject: [PATCH] [CIR] Implement 'asm label' lowering.
This ends up being a horrifically trivial implementation: it just
changes the name of the static local to use the 'mangled name' (which
pays attention to the attribute) rather than just the static decl
name. This patch implements that and adds some trivial tests to show
the behavior.
---
clang/lib/CIR/CodeGen/CIRGenDecl.cpp | 7 ++--
clang/test/CIR/CodeGen/static-local.cpp | 50 +++++++++++++++++++++++++
2 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
index f74d7b643debb7..b9acdf95287f15 100644
--- a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
@@ -627,10 +627,11 @@ CIRGenModule::getOrCreateStaticVarDecl(const VarDecl &d,
assert(ty->isConstantSizeType() && "VLAs can't be static");
// Use the label if the variable is renamed with the asm-label extension.
+ std::string name;
if (d.hasAttr<AsmLabelAttr>())
- errorNYI(d.getSourceRange(), "getOrCreateStaticVarDecl: asm label");
-
- std::string name = getStaticDeclName(*this, d);
+ name = std::string(getMangledName(&d));
+ else
+ name = getStaticDeclName(*this, d);
mlir::Type lty = getTypes().convertTypeForMem(ty);
diff --git a/clang/test/CIR/CodeGen/static-local.cpp
b/clang/test/CIR/CodeGen/static-local.cpp
index c2e4fc00544907..69390fb82701f6 100644
--- a/clang/test/CIR/CodeGen/static-local.cpp
+++ b/clang/test/CIR/CodeGen/static-local.cpp
@@ -33,6 +33,14 @@
// CIR-DAG: cir.global "private" internal dso_local
@_ZGVZ23array_static_local_dtorvE2sm = #cir.int<0> : !s64i
// LLVM-DAG: @_ZGVZ23array_static_local_dtorvE2sm = internal global i64 0
+// Static locals with an asm label are named by the label:
+// CIR-BOTH-DAG: cir.global "private" internal dso_local @foo = #cir.int<1> :
!s32i
+// LLVM-DAG: @foo = internal global i32 1, align 4
+// CIR-BOTH-DAG: cir.global "private" internal dso_local @bar = #cir.int<0> :
!s32i
+// LLVM-DAG: @bar = internal global i32 0, align 4
+// CIR-BOTH-DAG: cir.global linkonce_odr comdat @baz = #cir.int<3> : !s32i
+// LLVM-DAG: @baz = linkonce_odr global i32 3, comdat, align 4
+
// CIR-BOTH-DAG: cir.global linkonce_odr comdat
dynamic_init_guard<"_ZGVZ10getInlineAvE1a"> @_ZZ10getInlineAvE1a = #cir.zero :
!rec_A
// LLVM-DAG: @_ZZ10getInlineAvE1a = linkonce_odr global %class.A
zeroinitializer, comdat
// CIR-BOTH-DAG: cir.global "private" internal dso_local
@_ZZ23referenced_inside_constvE12static_local = #cir.int<42> : !s32i
@@ -833,3 +841,45 @@ void array_static_local_dtor() {
// CIR: }
// CIR-BOTH: cir.return
}
+
+// A static local with an asm label is named by the label, rather than by its
+// usual function-scoped static name.
+int asm_label_initialized() {
+ static int x __asm__("foo") = 1;
+ return x++;
+// CIR-BOTH-LABEL: cir.func {{.*}}@_Z21asm_label_initializedv()
+// CIR-BOTH: %[[FOO:.*]] = cir.get_global @foo : !cir.ptr<!s32i>
+// CIR-BOTH: cir.load {{.*}}%[[FOO]]
+
+// LLVM-LABEL: define dso_local noundef i32 @_Z21asm_label_initializedv()
+// LLVM: load i32, ptr @foo
+// LLVM: store i32 %{{.*}}, ptr @foo
+}
+
+int asm_label_zero_initialized() {
+ static int y __asm__("bar");
+ return y++;
+// CIR-BOTH-LABEL: cir.func {{.*}}@_Z26asm_label_zero_initializedv()
+// CIR-BOTH: %[[BAR:.*]] = cir.get_global @bar : !cir.ptr<!s32i>
+// CIR-BOTH: cir.load {{.*}}%[[BAR]]
+
+// LLVM-LABEL: define dso_local noundef i32 @_Z26asm_label_zero_initializedv()
+// LLVM: load i32, ptr @bar
+// LLVM: store i32 %{{.*}}, ptr @bar
+}
+
+// The label is used as-is, even for a variable with linkonce_odr linkage.
+inline int asm_label_inline() {
+ static int z __asm__("baz") = 3;
+ return z;
+}
+
+int use_asm_label_inline() { return asm_label_inline(); }
+
+// The inline function is emitted after its user.
+// CIR-BOTH-LABEL: cir.func {{.*}}@_Z16asm_label_inlinev()
+// CIR-BOTH: %[[BAZ:.*]] = cir.get_global @baz : !cir.ptr<!s32i>
+// CIR-BOTH: cir.load {{.*}}%[[BAZ]]
+
+// LLVM-LABEL: define linkonce_odr noundef i32 @_Z16asm_label_inlinev()
+// LLVM: load i32, ptr @baz
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