[PATCH] D138986: [BigArchive] Treat the archive is empty if the first child member offset is zero

[Kai Luo via Phabricator via llvm-commits]

lkail created this revision.
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If the archive contains free list and contains no member file, the buffer length doesn't equal to length of the header.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D138986

Files:
  llvm/include/llvm/Object/Archive.h
  llvm/test/Object/archive-big-read-empty-with-freelist.test


Index: llvm/test/Object/archive-big-read-empty-with-freelist.test
===================================================================
--- llvm/test/Object/archive-big-read-empty-with-freelist.test
+++ llvm/test/Object/archive-big-read-empty-with-freelist.test
@@ -1,3 +1,3 @@
 # Test reading an empty archive with free list in it.
-# RUN: env TZ=GMT not llvm-ar tv %p/Inputs/aix-empty-big-archive-with-freelist.a 2>&1 \
-# RUN:   | grep 'truncated or malformed archive'
+# RUN: env TZ=GMT llvm-ar tv %p/Inputs/aix-empty-big-archive-with-freelist.a 2>&1 \
+# RUN:   | not grep 'truncated or malformed archive'
Index: llvm/include/llvm/Object/Archive.h
===================================================================
--- llvm/include/llvm/Object/Archive.h
+++ llvm/include/llvm/Object/Archive.h
@@ -414,7 +414,8 @@
   uint64_t getFirstChildOffset() const override { return FirstChildOffset; }
   uint64_t getLastChildOffset() const { return LastChildOffset; }
   bool isEmpty() const override {
-    return Data.getBufferSize() == sizeof(FixLenHdr);
+    return Data.getBufferSize() == sizeof(FixLenHdr) ||
+           getFirstChildOffset() == 0;
   };
 };
 


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