From 0cea6e682190f502c5daa10d0cf3d27eb3a2d6b2 Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dimitry@andric.com>
Date: Thu, 24 Oct 2024 17:42:28 +0200
Subject: [PATCH] Ensure !NDEBUG with LLVM_ENABLE_ABI_BREAKING_CHECKS does not
 segfault

In SelectionDAG, `TargetTransformInfo::hasBranchDivergence()` can be
called when both `NDEBUG` and `LLVM_ENABLE_ABI_BREAKING_CHECKS` are
enabled. In that case, the class member `TTI` is still initialized to
`nullptr`, causing a segfault.

Fix this by ensuring that all the calls to `hasBranchDivergence` and
`VerifyDAGDivergence` only occur when `NDEBUG` is disabled, and
`LLVM_ENABLE_ABI_BREAKING_CHECKS` is enabled.
---
 llvm/include/llvm/CodeGen/SelectionDAG.h       |  2 +-
 llvm/include/llvm/CodeGen/SelectionDAGISel.h   |  2 +-
 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp |  2 +-
 .../CodeGen/SelectionDAG/SelectionDAGISel.cpp  | 18 +++++++++---------
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index 12ff36c89e33e..e82bdb6906163 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -584,7 +584,7 @@ class SelectionDAG {
     return Root;
   }
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   void VerifyDAGDivergence();
 #endif
 
diff --git a/llvm/include/llvm/CodeGen/SelectionDAGISel.h b/llvm/include/llvm/CodeGen/SelectionDAGISel.h
index f6191c6fdb7fe..32b2ea48179f4 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAGISel.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAGISel.h
@@ -56,7 +56,7 @@ class SelectionDAGISel {
   AssumptionCache *AC = nullptr;
   GCFunctionInfo *GFI = nullptr;
   SSPLayoutInfo *SP = nullptr;
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   TargetTransformInfo *TTI = nullptr;
 #endif
   CodeGenOptLevel OptLevel;
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 55cebc28e4927..0770355ec18c0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -11744,7 +11744,7 @@ void SelectionDAG::CreateTopologicalOrder(std::vector<SDNode *> &Order) {
   }
 }
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
 void SelectionDAG::VerifyDAGDivergence() {
   std::vector<SDNode *> TopoOrder;
   CreateTopologicalOrder(TopoOrder);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 9bd894dd952bd..981ab18b59c1c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -940,7 +940,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                    << "'\n";
             CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   if (TTI->hasBranchDivergence())
     CurDAG->VerifyDAGDivergence();
 #endif
@@ -960,7 +960,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                    << "'\n";
             CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   if (TTI->hasBranchDivergence())
     CurDAG->VerifyDAGDivergence();
 #endif
@@ -982,7 +982,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                    << "'\n";
             CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   if (TTI->hasBranchDivergence())
     CurDAG->VerifyDAGDivergence();
 #endif
@@ -1006,7 +1006,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                      << "'\n";
               CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
     if (TTI->hasBranchDivergence())
       CurDAG->VerifyDAGDivergence();
 #endif
@@ -1024,7 +1024,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                      << "'\n";
               CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
     if (TTI->hasBranchDivergence())
       CurDAG->VerifyDAGDivergence();
 #endif
@@ -1040,7 +1040,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                      << "'\n";
               CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
     if (TTI->hasBranchDivergence())
       CurDAG->VerifyDAGDivergence();
 #endif
@@ -1060,7 +1060,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                      << "'\n";
               CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
     if (TTI->hasBranchDivergence())
       CurDAG->VerifyDAGDivergence();
 #endif
@@ -1080,7 +1080,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                    << "'\n";
             CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   if (TTI->hasBranchDivergence())
     CurDAG->VerifyDAGDivergence();
 #endif
@@ -1100,7 +1100,7 @@ void SelectionDAGISel::CodeGenAndEmitDAG() {
                    << "'\n";
             CurDAG->dump());
 
-#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+#if !defined(NDEBUG) && LLVM_ENABLE_ABI_BREAKING_CHECKS
   if (TTI->hasBranchDivergence())
     CurDAG->VerifyDAGDivergence();
 #endif