Revert r70075 and r70078, which reorganized the PCH on-disk hash table

for identifiers to separate "interesting" from "uninteresting"
identifiers. However, to cope with compiler invocations where the
predefines buffers mismatch, we need to be able to search the complete
identifier table. Cocoa.h.pch is now about 500k larger that it used to
be :(

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70320 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index df9f301f7916edc0981b2c03b065ec46c4aae716..f1d7e7a5586ce4b50a6f8fc2b36e9d973e2e196e 100644 (file)
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -1943,47 +1943,14 @@ IdentifierInfo *PCHReader::DecodeIdentifierInfo(unsigned ID) {
     uint32_t Offset = IdentifierOffsets[ID - 1];
     const char *Str = IdentifierTableData + Offset;
 
-    // If there is an identifier lookup table, but the offset of this
-    // string is after the identifier table itself, then we know that
-    // this string is not in the on-disk hash table. Therefore,
-    // disable lookup into the hash table when looking for this
-    // identifier.
-    PCHIdentifierLookupTable *IdTable 
-      = (PCHIdentifierLookupTable *)IdentifierLookupTable;
-    if (!IdTable ||
-        Offset >= uint32_t(IdTable->getBuckets() - IdTable->getBase())) {
-      // Turn off lookup into the on-disk hash table. We know that
-      // this identifier is not there.
-      if (IdTable)
-        PP.getIdentifierTable().setExternalIdentifierLookup(0);
-
-      // All of the strings in the PCH file are preceded by a 16-bit
-      // length. Extract that 16-bit length to avoid having to execute
-      // strlen().
-      const char *StrLenPtr = Str - 2;
-      unsigned StrLen = (((unsigned) StrLenPtr[0])
-                         | (((unsigned) StrLenPtr[1]) << 8)) - 1;
-      IdentifiersLoaded[ID - 1]=&PP.getIdentifierTable().get(Str, Str + StrLen);
-
-      // Turn on lookup into the on-disk hash table, if we have an
-      // on-disk hash table.
-      if (IdTable)
-        PP.getIdentifierTable().setExternalIdentifierLookup(this);
-    } else {
-      // The identifier is a key in our on-disk hash table. Since we
-      // know where the hash table entry starts, just read in this
-      // (key, value) pair.
-      PCHIdentifierLookupTrait Trait(const_cast<PCHReader &>(*this));
-      const unsigned char *Pos = (const unsigned char *)Str - 4;
-      std::pair<unsigned, unsigned> KeyDataLengths
-        = Trait.ReadKeyDataLength(Pos);
-
-      PCHIdentifierLookupTrait::internal_key_type InternalKey
-        = Trait.ReadKey(Pos, KeyDataLengths.first);
-      Pos = (const unsigned char *)Str + KeyDataLengths.first;
-      IdentifiersLoaded[ID - 1] = Trait.ReadData(InternalKey, Pos,
-                                                 KeyDataLengths.second);
-    }
+    // All of the strings in the PCH file are preceded by a 16-bit
+    // length. Extract that 16-bit length to avoid having to execute
+    // strlen().
+    const char *StrLenPtr = Str - 2;
+    unsigned StrLen = (((unsigned) StrLenPtr[0])
+                       | (((unsigned) StrLenPtr[1]) << 8)) - 1;
+    IdentifiersLoaded[ID - 1] 
+      = &PP.getIdentifierTable().get(Str, Str + StrLen);
   }
   
   return IdentifiersLoaded[ID - 1];

diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index cd2021479ff53d1c00c985bc68bee0b5605a2a00..e61cca554bc0bd8b003cdfc61319e6ea07422f98 100644 (file)
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1318,12 +1318,10 @@ public:
                                    DEnd = IdentifierResolver::end();
          D != DEnd; ++D)
       DataLen += sizeof(pch::DeclID);
-    // We emit the key length after the data length so that the
-    // "uninteresting" identifiers following the identifier hash table
-    // structure will have the same (key length, key characters)
-    // layout as the keys in the hash table. This also matches the
-    // format for identifiers in pretokenized headers.
     clang::io::Emit16(Out, DataLen);
+    // We emit the key length after the data length so that every
+    // string is preceded by a 16-bit length. This matches the PTH
+    // format for storing identifiers.
     clang::io::Emit16(Out, KeyLen);
     return std::make_pair(KeyLen, DataLen);
   }
@@ -1384,33 +1382,12 @@ void PCHWriter::WriteIdentifierTable(Preprocessor &PP) {
   {
     OnDiskChainedHashTableGenerator<PCHIdentifierTableTrait> Generator;
     
-    llvm::SmallVector<const IdentifierInfo *, 32> UninterestingIdentifiers;
-
     // Create the on-disk hash table representation.
     for (llvm::DenseMap<const IdentifierInfo *, pch::IdentID>::iterator
            ID = IdentifierIDs.begin(), IDEnd = IdentifierIDs.end();
          ID != IDEnd; ++ID) {
       assert(ID->first && "NULL identifier in identifier table");
-
-      // Classify each identifier as either "interesting" or "not
-      // interesting". Interesting identifiers are those that have
-      // additional information that needs to be read from the PCH
-      // file, e.g., a built-in ID, declaration chain, or macro
-      // definition. These identifiers are placed into the hash table
-      // so that they can be found when looked up in the user program.
-      // All other identifiers are "uninteresting", which means that
-      // the IdentifierInfo built by default has all of the
-      // information we care about. Such identifiers are placed after
-      // the hash table.
-      const IdentifierInfo *II = ID->first;
-      if (II->isPoisoned() ||
-          II->isExtensionToken() ||
-          II->hasMacroDefinition() ||
-          II->getObjCOrBuiltinID() ||
-          II->getFETokenInfo<void>())
-        Generator.insert(ID->first, ID->second);
-      else
-        UninterestingIdentifiers.push_back(II);
+      Generator.insert(ID->first, ID->second);
     }
 
     // Create the on-disk hash table in a buffer.
@@ -1422,14 +1399,6 @@ void PCHWriter::WriteIdentifierTable(Preprocessor &PP) {
       // Make sure that no bucket is at offset 0
       clang::io::Emit32(Out, 0);
       BucketOffset = Generator.Emit(Out, Trait);
-      
-      for (unsigned I = 0, N = UninterestingIdentifiers.size(); I != N; ++I) {
-        const IdentifierInfo *II = UninterestingIdentifiers[I];
-        unsigned N = II->getLength() + 1;
-        clang::io::Emit16(Out, N);
-        SetIdentifierOffset(II, Out.tell());
-        Out.write(II->getName(), N);
-      }
     }
 
     // Create a blob abbreviation