[llvm-branch-commits] [llvm] [SystemZ] Emit external aliases for indirect function descriptors in the ADA section (PR #183443)

[Amy Kwan via llvm-branch-commits]

https://github.com/amy-kwan updated https://github.com/llvm/llvm-project/pull/183443

>From d2154271ce73d0c3345f798cc0741fe05a777814 Mon Sep 17 00:00:00 2001
From: Amy Kwan <amy.kwan1 at ibm.com>
Date: Wed, 25 Feb 2026 23:21:18 -0500
Subject: [PATCH] [SystemZ] Emit external aliases for indirect function
 descriptors in the ADA section

This is the last of the three patches aimed to support indirect symbol handling for
the SystemZ backend.

An external alias is emitted for indirect function descriptors within the ADA
section, rather than a temporary alias, while also setting all of the appropriate
symbol attributes that are needed for the HLASM streamer to emit the correct XATTR
and ALIAS instructions for the indirect symbols.

Moreover, this patch updates the `CodeGen/SystemZ/zos-ada-relocations.ll` test
as the ADA section is currently the only user of indirect symbols on z/OS.
---
 llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp    | 11 +++++++----
 llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll |  6 +++++-
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
index 58c8b30f96b4c..cb451a1ca4f55 100644
--- a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
@@ -1275,12 +1275,15 @@ void SystemZAsmPrinter::emitADASection() {
       EmittedBytes += PointerSize;
       break;
     case SystemZII::MO_ADA_INDIRECT_FUNC_DESC: {
-      MCSymbol *Alias = OutContext.createTempSymbol(
+      MCSymbol *Alias = OutContext.getOrCreateSymbol(
           Twine(Sym->getName()).concat("@indirect"));
-      OutStreamer->emitAssignment(Alias,
-                                  MCSymbolRefExpr::create(Sym, OutContext));
       OutStreamer->emitSymbolAttribute(Alias, MCSA_IndirectSymbol);
-
+      OutStreamer->emitSymbolAttribute(Alias, MCSA_ELF_TypeFunction);
+      OutStreamer->emitSymbolAttribute(Alias, MCSA_Global);
+      OutStreamer->emitSymbolAttribute(Alias, MCSA_Extern);
+      MCSymbolGOFF *GOFFSym =
+          static_cast<llvm::MCSymbolGOFF *>(const_cast<llvm::MCSymbol *>(Sym));
+      getTargetStreamer()->emitExternalName(Alias, GOFFSym->getExternalName());
       EMIT_COMMENT("pointer to function descriptor");
       OutStreamer->emitValue(
           MCSpecifierExpr::create(MCSymbolRefExpr::create(Alias, OutContext),
diff --git a/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll b/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
index f3bdf64683bb6..dd12226049ed9 100644
--- a/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
+++ b/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
@@ -60,7 +60,7 @@ declare signext i32 @callout(i32 signext)
 ; CHECK:                in#S)
 ; CHECK: stdin#S XATTR LINKAGE(XPLINK),REFERENCE(DATA),SCOPE(SECTION)
 ; CHECK: * Offset 0 pointer to function descriptor DoFunc
-; CHECK:  DC VD(L#DoFunc at indirect0)
+; CHECK:  DC VD(DoFunc at indirect)
 ; CHECK: * Offset 8 function descriptor of Caller
 ; CHECK:  DC RD(Caller)
 ; CHECK:  DC VD(Caller)
@@ -71,3 +71,7 @@ declare signext i32 @callout(i32 signext)
 ; CHECK: * Offset 40 function descriptor of callout
 ; CHECK:  DC RD(callout)
 ; CHECK:  DC VD(callout)
+; CHECK: EXTRN DoFunc at indirect
+; CHECK: DoFunc at indirect XATTR LINKAGE(XPLINK),REFERENCE(CODE,INDIRECT),SCOPE(EX
+; CHECK:                PORT)
+; CHECK: DoFunc at indirect ALIAS "DoFunc"