From 1ea1e053f6a10955a5aa8f5a8007544a846766e5 Mon Sep 17 00:00:00 2001
From: David Tenty <daltenty@ibm.com>
Date: Thu, 5 Dec 2019 15:21:53 -0500
Subject: [PATCH] [AIX] Make sure to use QualNames for external global objects

Summary: Previously we only handled the case where the csect hadn't been set up yet, so we'd hit an assert later on.

Reviewers: jasonliu, DiggerLin, stevewan

Reviewed By: jasonliu

Subscribers: hubert.reinterpretcast, wuzish, nemanjai, hiraditya, kbarton, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71032
---
 llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp  | 26 ++++++++++++++------------
 llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll | 24 ++++++++++++++++--------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 9b8fb4d..db2352b 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1883,18 +1883,20 @@ PPCAIXAsmPrinter::getMCSymbolForTOCPseudoMO(const MachineOperand &MO) {
   // declaration of a function, then XSym is an external referenced symbol.
   // Hence we may need to explictly create a MCSectionXCOFF for it so that we
   // can return its symbol later.
-  if (GO->isDeclaration() && !XSym->hasContainingCsect()) {
-    // Make sure the storage class is set.
-    const XCOFF::StorageClass SC =
-        TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO);
-    XSym->setStorageClass(SC);
-
-    MCSectionXCOFF *Csect = OutStreamer->getContext().getXCOFFSection(
-        XSym->getName(), isa<Function>(GO) ? XCOFF::XMC_DS : XCOFF::XMC_UA,
-        XCOFF::XTY_ER, SC, SectionKind::getMetadata());
-    XSym->setContainingCsect(Csect);
-
-    return Csect->getQualNameSymbol();
+  if (GO->isDeclaration()) {
+    if (!XSym->hasContainingCsect()) {
+      // Make sure the storage class is set.
+      const XCOFF::StorageClass SC =
+          TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO);
+      XSym->setStorageClass(SC);
+
+      MCSectionXCOFF *Csect = OutStreamer->getContext().getXCOFFSection(
+          XSym->getName(), isa<Function>(GO) ? XCOFF::XMC_DS : XCOFF::XMC_UA,
+          XCOFF::XTY_ER, SC, SectionKind::getMetadata());
+      XSym->setContainingCsect(Csect);
+    }
+
+    return XSym->getContainingCsect()->getQualNameSymbol();
   }
 
   // Handle initialized global variables.
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
index 57f9706..8949883 100644
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
@@ -28,6 +28,14 @@ define void @bar() {
   ret void
 }
 
+; We initialize a csect when we first reference an external global, so make sure we don't run into problems when we see it again.
+define void @bar2() {
+  store i32 0, i32* @a, align 4
+  store i64 0, i64* @b, align 8
+  store i16 0, i16* @c, align 2
+  ret void
+}
+
 ; CHECK-NOT: .comm a
 ; CHECK-NOT: .lcomm a
 ; CHECK-NOT: .comm b
@@ -55,7 +63,7 @@ define void @bar() {
 
 ; SYM:       File: {{.*}}aix-xcoff-toc.ll.tmp.o
 ; SYM:       Symbol {{[{][[:space:]] *}}Index: [[#INDX:]]{{[[:space:]] *}}Name: TOC
-; SYM-NEXT:    Value (RelocatableAddress): 0x54
+; SYM-NEXT:    Value (RelocatableAddress): 0x8C
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -75,7 +83,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+2]]
 ; SYM-NEXT:    Name: a
-; SYM-NEXT:    Value (RelocatableAddress): 0x54
+; SYM-NEXT:    Value (RelocatableAddress): 0x8C
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -95,7 +103,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+4]]
 ; SYM-NEXT:    Name: b
-; SYM-NEXT:    Value (RelocatableAddress): 0x58
+; SYM-NEXT:    Value (RelocatableAddress): 0x90
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -115,7 +123,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+6]]
 ; SYM-NEXT:    Name: c
-; SYM-NEXT:    Value (RelocatableAddress): 0x5C
+; SYM-NEXT:    Value (RelocatableAddress): 0x94
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -135,7 +143,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+8]]
 ; SYM-NEXT:    Name: globa
-; SYM-NEXT:    Value (RelocatableAddress): 0x60
+; SYM-NEXT:    Value (RelocatableAddress): 0x98
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -155,7 +163,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+10]]
 ; SYM-NEXT:    Name: ptr
-; SYM-NEXT:    Value (RelocatableAddress): 0x64
+; SYM-NEXT:    Value (RelocatableAddress): 0x9C
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -175,7 +183,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+12]]
 ; SYM-NEXT:    Name: bar
-; SYM-NEXT:    Value (RelocatableAddress): 0x68
+; SYM-NEXT:    Value (RelocatableAddress): 0xA0
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
@@ -195,7 +203,7 @@ define void @bar() {
 ; SYM-NEXT:  Symbol {
 ; SYM-NEXT:    Index: [[#INDX+14]]
 ; SYM-NEXT:    Name: foo
-; SYM-NEXT:    Value (RelocatableAddress): 0x6C
+; SYM-NEXT:    Value (RelocatableAddress): 0xA4
 ; SYM-NEXT:    Section: .data
 ; SYM-NEXT:    Type: 0x0
 ; SYM-NEXT:    StorageClass: C_HIDEXT (0x6B)
-- 
2.7.4