[llvm] [LLVM][DWARF] Fix uniquness of AccelTable Values (PR #74391)

[Alexander Yermolovich via llvm-commits]

https://github.com/ayermolo created https://github.com/llvm/llvm-project/pull/74391

The finalize function sorts by order, which is DieOffset. It then uses erase in
combination of std::unique to remove duplicates, but it doesn't specify
comparison function. So pointer addresses are used. Presumably it should also use
order() for compare?


>From 209f01bbbe8d726d59c5687a48f921932148ed68 Mon Sep 17 00:00:00 2001
From: Alexander Yermolovich <ayermolo at meta.com>
Date: Mon, 4 Dec 2023 15:53:53 -0800
Subject: [PATCH] [LLVM][DWARF] Fix uniquness of AccelTable Values

The finalize function sorts by order, which is DieOffset. It then uses erase in
combination of std::unique to remove duplicates, but it doesn't specify
comparison function. Presumably it should also use order() for compare?
---
 llvm/include/llvm/CodeGen/AccelTable.h     | 4 ++++
 llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/CodeGen/AccelTable.h b/llvm/include/llvm/CodeGen/AccelTable.h
index 0f35fd3514fae..404d6f0baf8d3 100644
--- a/llvm/include/llvm/CodeGen/AccelTable.h
+++ b/llvm/include/llvm/CodeGen/AccelTable.h
@@ -120,6 +120,10 @@ class AccelTableData {
     return order() < Other.order();
   }
 
+  bool operator==(const AccelTableData &Other) const {
+    return order() == Other.order();
+  }
+
     // Subclasses should implement:
     // static uint32_t hash(StringRef Name);
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
index d6f487c18b030..801fa558dac8e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -59,7 +59,10 @@ void AccelTableBase::finalize(AsmPrinter *Asm, StringRef Prefix) {
                         return *A < *B;
                       });
     E.second.Values.erase(
-        std::unique(E.second.Values.begin(), E.second.Values.end()),
+        std::unique(E.second.Values.begin(), E.second.Values.end(),
+                    [](const AccelTableData *A, const AccelTableData *B) {
+                      return *A == *B;
+                    }),
         E.second.Values.end());
   }