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author | Adrian Prantl <aprantl@apple.com> | 2014-04-01 21:04:24 +0000 |
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committer | Adrian Prantl <aprantl@apple.com> | 2014-04-01 21:04:24 +0000 |
commit | 2f1e34736e4f14c57d1c1fdcfc8b9e133c4885d9 (patch) | |
tree | e36cb8aaa21d50ace0c4239832009cb8dcde6dce | |
parent | ccd539282b4433bf4d3fca0e23b33799966cdbc0 (diff) | |
download | llvm-2f1e34736e4f14c57d1c1fdcfc8b9e133c4885d9.tar.gz llvm-2f1e34736e4f14c57d1c1fdcfc8b9e133c4885d9.tar.bz2 llvm-2f1e34736e4f14c57d1c1fdcfc8b9e133c4885d9.tar.xz |
Add a comment about the DIDescriptor class hierarchy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205358 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | include/llvm/IR/DebugInfo.h | 7 | ||||
-rw-r--r-- | lib/IR/DebugInfo.cpp | 6 |
2 files changed, 11 insertions, 2 deletions
diff --git a/include/llvm/IR/DebugInfo.h b/include/llvm/IR/DebugInfo.h index 69beaada9c..bf3ae98381 100644 --- a/include/llvm/IR/DebugInfo.h +++ b/include/llvm/IR/DebugInfo.h @@ -197,6 +197,13 @@ typedef DIRef<DIScope> DIScopeRef; typedef DIRef<DIType> DITypeRef; /// DIScope - A base class for various scopes. +/// +/// Although, implementation-wise, DIScope is the parent class of most +/// other DIxxx classes, including DIType and its descendants, most of +/// DIScope’s descendants are not a substitutable subtype of +/// DIScope. The DIDescriptor::isScope() method only is true for +/// DIScopes that are scopes in the strict lexical scope sense +/// (DICompileUnit, DISubprogram, etc.), but not for, e.g., a DIType. class DIScope : public DIDescriptor { protected: friend class DIDescriptor; diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp index f9bc63b389..c9d68afa44 100644 --- a/lib/IR/DebugInfo.cpp +++ b/lib/IR/DebugInfo.cpp @@ -429,8 +429,10 @@ static bool fieldIsTypeRef(const MDNode *DbgNode, unsigned Elt) { /// Check if a value can be a ScopeRef. static bool isScopeRef(const Value *Val) { return !Val || - (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) || - isa<MDNode>(Val); + (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) || + // Not checking for Val->isScope() here, because it would work + // only for lexical scopes and not all subclasses of DIScope. + isa<MDNode>(Val); } /// Check if a field at position Elt of a MDNode can be a ScopeRef. |