-/// \brief Including \p Parent adds the context of Parent to \p Hash.
-static void addParentContextToHash(MD5 &Hash, DIE *Parent) {
-
- DEBUG(dbgs() << "Adding parent context to hash...\n");
-
- // [7.27.2] For each surrounding type or namespace beginning with the
- // outermost such construct...
- SmallVector<DIE *, 1> Parents;
- while (Parent->getTag() != dwarf::DW_TAG_compile_unit) {
- Parents.push_back(Parent);
- Parent = Parent->getParent();
- }
-
- // Reverse iterate over our list to go from the outermost construct to the
- // innermost.
- for (SmallVectorImpl<DIE *>::reverse_iterator I = Parents.rbegin(),
- E = Parents.rend();
- I != E; ++I) {
- DIE *Die = *I;
-
- // ... Append the letter "C" to the sequence...
- addULEB128ToHash(Hash, 'C');
-
- // ... Followed by the DWARF tag of the construct...
- addULEB128ToHash(Hash, Die->getTag());
-
- // ... Then the name, taken from the DW_AT_name attribute.
- StringRef Name = getDIEStringAttr(Die, dwarf::DW_AT_name);
- DEBUG(dbgs() << "... adding context: " << Name << "\n");
- if (!Name.empty())
- addStringToHash(Hash, Name);
- }
-}
-
-/// This is based on the type signature computation given in section 7.27 of the
-/// DWARF4 standard. It is the md5 hash of a flattened description of the DIE with
-/// the exception that we are hashing only the context and the name of the type.
-static void addDIEODRSignature(MD5 &Hash, CompileUnit *CU, DIE *Die) {
-
- // Add the contexts to the hash. We won't be computing the ODR hash for
- // function local types so it's safe to use the generic context hashing
- // algorithm here.
- // FIXME: If we figure out how to account for linkage in some way we could
- // actually do this with a slight modification to the parent hash algorithm.
- DIE *Parent = Die->getParent();
- if (Parent)
- addParentContextToHash(Hash, Parent);
-
- // Add the current DIE information.
-
- // Add the DWARF tag of the DIE.
- addULEB128ToHash(Hash, Die->getTag());
-
- // Add the name of the type to the hash.
- addStringToHash(Hash, getDIEStringAttr(Die, dwarf::DW_AT_name));
-
- // Now get the result.
- MD5::MD5Result Result;
- Hash.final(Result);
-
- // ... take the least significant 8 bytes and store those as the attribute.
- // Our MD5 implementation always returns its results in little endian, swap
- // bytes appropriately.
- uint64_t Signature = *reinterpret_cast<support::ulittle64_t *>(Result + 8);
-
- // FIXME: This should be added onto the type unit, not the type, but this
- // works as an intermediate stage.
- CU->addUInt(Die, dwarf::DW_AT_GNU_odr_signature, dwarf::DW_FORM_data8,
- Signature);
-}
-
-/// Return true if the current DIE is contained within an anonymous namespace.
-static bool isContainedInAnonNamespace(DIE *Die) {
- DIE *Parent = Die->getParent();
-
- while (Parent) {
- if (Parent->getTag() == dwarf::DW_TAG_namespace &&
- getDIEStringAttr(Parent, dwarf::DW_AT_name) == "")
- return true;
- Parent = Parent->getParent();
- }
-
- return false;
-}
-
-/// Test if the current CU language is C++ and that we have
-/// a named type that is not contained in an anonymous namespace.
-static bool shouldAddODRHash(CompileUnit *CU, DIE *Die) {
- return CU->getLanguage() == dwarf::DW_LANG_C_plus_plus &&
- getDIEStringAttr(Die, dwarf::DW_AT_name) != "" &&
- !isContainedInAnonNamespace(Die);
- }
-