[PATCH] D95329: [llvm-link] Fix crash when materializing appending global

[Sergey Dmitriev via Phabricator via llvm-commits]

sdmitriev updated this revision to Diff 319173.
sdmitriev added a comment.

Addressed review comments.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95329/new/

https://reviews.llvm.org/D95329

Files:
  llvm/lib/Transforms/Utils/ValueMapper.cpp
  llvm/test/Linker/appending-global-crash.ll


Index: llvm/test/Linker/appending-global-crash.ll
===================================================================
--- /dev/null
+++ llvm/test/Linker/appending-global-crash.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-link %s -S -o - | FileCheck %s
+
+; Check that llvm-link does not crash when materializing appending global with
+; initializer depending on another appending global.
+
+; CHECK-DAG: @use = appending global [1 x i8*] [i8* bitcast ([1 x i8*]* @var to i8*)]
+; CHECK-DAG: @var = appending global [1 x i8*] undef
+
+ at use = appending global [1 x i8*] [i8* bitcast ([1 x i8*]* @var to i8*)]
+ at var = appending global [1 x i8*] undef
Index: llvm/lib/Transforms/Utils/ValueMapper.cpp
===================================================================
--- llvm/lib/Transforms/Utils/ValueMapper.cpp
+++ llvm/lib/Transforms/Utils/ValueMapper.cpp
@@ -819,11 +819,15 @@
       break;
     case WorklistEntry::MapAppendingVar: {
       unsigned PrefixSize = AppendingInits.size() - E.AppendingGVNumNewMembers;
+      // mapAppendingVariable call can change AppendingInits if initalizer for
+      // the variable depends on another appending global, because of that inits
+      // need to be extracted and updated before the call.
+      SmallVector<Constant *, 8> NewInits(
+          drop_begin(AppendingInits, PrefixSize));
+      AppendingInits.resize(PrefixSize);
       mapAppendingVariable(*E.Data.AppendingGV.GV,
                            E.Data.AppendingGV.InitPrefix,
-                           E.AppendingGVIsOldCtorDtor,
-                           makeArrayRef(AppendingInits).slice(PrefixSize));
-      AppendingInits.resize(PrefixSize);
+                           E.AppendingGVIsOldCtorDtor, makeArrayRef(NewInits));
       break;
     }
     case WorklistEntry::MapGlobalIndirectSymbol:


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