[clang] [CIR] Implement lowering for member-expr of function decl type (PR #190655)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clangir

@llvm/pr-subscribers-clang

Author: Erich Keane (erichkeane)

<details>
<summary>Changes</summary>

This patch ends up being pretty trivial to reproduce, and the implementation is just to call an already implemented function, however this shows up a few times in various test suites.  So I've implemented it.

---
Full diff: https://github.com/llvm/llvm-project/pull/190655.diff


2 Files Affected:

- (modified) clang/lib/CIR/CodeGen/CIRGenExpr.cpp (+2-4) 
- (added) clang/test/CIR/CodeGen/mem-expr-fn.cpp (+26) 


``````````diff
diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
index 91de4581cc8a8..81737aeb4c847 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -1654,10 +1654,8 @@ LValue CIRGenFunction::emitMemberExpr(const MemberExpr *e) {
     return lv;
   }
 
-  if (isa<FunctionDecl>(nd)) {
-    cgm.errorNYI(e->getSourceRange(), "emitMemberExpr: FunctionDecl");
-    return LValue();
-  }
+  if (const auto *fd = dyn_cast<FunctionDecl>(nd))
+    return emitFunctionDeclLValue(*this, e, fd);
 
   llvm_unreachable("Unhandled member declaration!");
 }
diff --git a/clang/test/CIR/CodeGen/mem-expr-fn.cpp b/clang/test/CIR/CodeGen/mem-expr-fn.cpp
new file mode 100644
index 0000000000000..c63fbd848236b
--- /dev/null
+++ b/clang/test/CIR/CodeGen/mem-expr-fn.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=LLVM
+
+struct WithStaticMem {
+  static void StaticMem();
+};
+
+extern "C" void use(WithStaticMem m) {
+  // CIR-LABEL: use(
+   auto x = m.StaticMem;
+  // CIR: %[[ARG_ALLOCA:.*]] = cir.alloca !rec_WithStaticMem, !cir.ptr<!rec_WithStaticMem>, ["m", init]
+  // CIR: %[[X_ALLOCA:.*]] = cir.alloca !cir.ptr<!cir.func<()>>, !cir.ptr<!cir.ptr<!cir.func<()>>>, ["x", init]
+  // CIR: cir.store %{{.*}}, %[[ARG_ALLOCA]] : !rec_WithStaticMem, !cir.ptr<!rec_WithStaticMem>
+  // CIR: %[[GET_STATIC_FUNC:.*]] = cir.get_global @_ZN13WithStaticMem9StaticMemEv : !cir.ptr<!cir.func<()>> 
+  // CIR: cir.store {{.*}}%[[GET_STATIC_FUNC]], %[[X_ALLOCA]] : !cir.ptr<!cir.func<()>>, !cir.ptr<!cir.ptr<!cir.func<()>>>
+
+   // LLVM-LABEL: use(
+   // LLVM: %[[ARG_ALLOCA:.*]] = alloca %struct.WithStaticMem
+   // LLVM: %[[X_ALLOCA:.*]] = alloca ptr
+   // LLVM: store ptr @_ZN13WithStaticMem9StaticMemEv, ptr %[[X_ALLOCA]]
+}
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/190655