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author | Chris Lattner <sabre@nondot.org> | 2011-08-12 04:31:38 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2011-08-12 04:31:38 +0000 |
commit | 823eb1ca11d684530048f1fe85a727aa1ef622d1 (patch) | |
tree | 398a5ff71bd0f1d14900b08fc23e3eaf4fcb2389 /include/llvm/ADT/PointerUnion.h | |
parent | 79d7de7650f20bb95aa5a4799e89e06fde57f005 (diff) | |
download | llvm-823eb1ca11d684530048f1fe85a727aa1ef622d1.tar.gz llvm-823eb1ca11d684530048f1fe85a727aa1ef622d1.tar.bz2 llvm-823eb1ca11d684530048f1fe85a727aa1ef622d1.tar.xz |
Fix an obscure bug in PointerUnion that would bite PointerUnion3/4. Basically,
when checking isNull(), we'd pick off the sentinel bit for the outer
PointerUnion, but would not recursively convert the inner pointerunion to bool,
so if *its* sentinel bit is set, isNull() would incorrectly return false.
No testcase, because someone hit this when they were trying to refactor code
to use PointerUnion3, but they since found a better solution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137428 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/ADT/PointerUnion.h')
-rw-r--r-- | include/llvm/ADT/PointerUnion.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/llvm/ADT/PointerUnion.h b/include/llvm/ADT/PointerUnion.h index 13b98cef07..487096a171 100644 --- a/include/llvm/ADT/PointerUnion.h +++ b/include/llvm/ADT/PointerUnion.h @@ -108,7 +108,11 @@ namespace llvm { /// isNull - Return true if the pointer held in the union is null, /// regardless of which type it is. - bool isNull() const { return Val.getPointer() == 0; } + bool isNull() const { + // Convert from the void* to one of the pointer types, to make sure that + // we recursively strip off low bits if we have a nested PointerUnion. + return !PointerLikeTypeTraits<PT1>::getFromVoidPointer(Val.getPointer()); + } operator bool() const { return !isNull(); } /// is<T>() return true if the Union currently holds the type matching T. |