Move hash computation code into a separate class and file.
No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188028 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 7bd2bb2..4a10a0e 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -14,6 +14,7 @@
#define DEBUG_TYPE "dwarfdebug"
#include "DwarfDebug.h"
#include "DIE.h"
+#include "DIEHash.h"
#include "DwarfAccelTable.h"
#include "DwarfCompileUnit.h"
#include "llvm/ADT/STLExtras.h"
@@ -962,8 +963,7 @@
DeleteContainerSeconds(DeadFnScopeMap);
}
-// Type Signature [7.27] computation code.
-typedef ArrayRef<uint8_t> HashValue;
+// Type Signature [7.27] and ODR Hash code.
/// \brief Grabs the string in whichever attribute is passed in and returns
/// a reference to it. Returns "" if the attribute doesn't exist.
@@ -976,100 +976,6 @@
return StringRef("");
}
-/// \brief Adds the string in \p Str to the hash in \p Hash. This also hashes
-/// a trailing NULL with the string.
-static void addStringToHash(MD5 &Hash, StringRef Str) {
- DEBUG(dbgs() << "Adding string " << Str << " to hash.\n");
- Hash.update(Str);
- Hash.update(makeArrayRef((uint8_t)'\0'));
-}
-
-// FIXME: These are copied and only slightly modified out of LEB128.h.
-
-/// \brief Adds the unsigned in \p N to the hash in \p Hash. This also encodes
-/// the unsigned as a ULEB128.
-static void addULEB128ToHash(MD5 &Hash, uint64_t Value) {
- DEBUG(dbgs() << "Adding ULEB128 " << Value << " to hash.\n");
- do {
- uint8_t Byte = Value & 0x7f;
- Value >>= 7;
- if (Value != 0)
- Byte |= 0x80; // Mark this byte to show that more bytes will follow.
- Hash.update(Byte);
- } while (Value != 0);
-}
-
-/// \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();
@@ -1090,7 +996,7 @@
return CU->getLanguage() == dwarf::DW_LANG_C_plus_plus &&
getDIEStringAttr(Die, dwarf::DW_AT_name) != "" &&
!isContainedInAnonNamespace(Die);
- }
+}
void DwarfDebug::finalizeModuleInfo() {
// Collect info for variables that were optimized out.
@@ -1111,12 +1017,16 @@
// out type.
// FIXME: Do type splitting.
for (unsigned i = 0, e = TypeUnits.size(); i != e; ++i) {
- MD5 Hash;
DIE *Die = TypeUnits[i];
+ DIEHash Hash;
// If we've requested ODR hashes and it's applicable for an ODR hash then
// add the ODR signature now.
+ // FIXME: This should be added onto the type unit, not the type, but this
+ // works as an intermediate stage.
if (GenerateODRHash && shouldAddODRHash(CUMap.begin()->second, Die))
- addDIEODRSignature(Hash, CUMap.begin()->second, Die);
+ CUMap.begin()->second->addUInt(Die, dwarf::DW_AT_GNU_odr_signature,
+ dwarf::DW_FORM_data8,
+ Hash.computeDIEODRSignature(Die));
}
// Compute DIE offsets and sizes.