Restore "[ThinLTO] Use MD5 hash in function index." with fix

This restores commit r260408, along with a fix for a bot failure.

The bot failure was caused by dereferencing a unique_ptr in the same
call instruction parameter list where it was passed via std::move.
Apparently due to luck this was not exposed when I built the compiler
with clang, only with gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260442 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/LLVMBitCodes.h

@@ -105,6 +105,9 @@ enum { BITCODE_CURRENT_EPOCH = 0 };
 
     // METADATA_VALUES: [numvals]
     MODULE_CODE_METADATA_VALUES = 15,
+
+    // SOURCE_FILENAME: [namechar x N]
+    MODULE_CODE_SOURCE_FILENAME = 16,
   };
 
   /// PARAMATTR blocks have code for defining a parameter attribute set.
@@ -172,7 +175,7 @@ enum { BITCODE_CURRENT_EPOCH = 0 };
     VST_CODE_ENTRY   = 1,   // VST_ENTRY: [valueid, namechar x N]
     VST_CODE_BBENTRY = 2,   // VST_BBENTRY: [bbid, namechar x N]
     VST_CODE_FNENTRY = 3,   // VST_FNENTRY: [valueid, offset, namechar x N]
-    // VST_COMBINED_FNENTRY: [offset, namechar x N]
+    // VST_COMBINED_FNENTRY: [funcsumoffset, funcguid]
     VST_CODE_COMBINED_FNENTRY = 4
   };
 

include/llvm/IR/Function.h

@@ -27,6 +27,7 @@
 #include "llvm/IR/GlobalObject.h"
 #include "llvm/IR/OperandTraits.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/MD5.h"
 
 namespace llvm {
 
@@ -650,6 +651,12 @@ class Function : public GlobalObject, public ilist_node<Function> {
                                          GlobalValue::LinkageTypes Linkage,
                                          StringRef FileName);
 
+  /// Return a 64-bit global unique ID constructed from global function name
+  /// (i.e. returned by getGlobalIdentifier).
+  static uint64_t getGUID(StringRef GlobalFuncName) {
+    return MD5Hash(GlobalFuncName);
+  }
+
 private:
   void allocHungoffUselist();
   template<int Idx> void setHungoffOperand(Constant *C);

include/llvm/IR/FunctionInfo.h

@@ -18,6 +18,7 @@
 
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/IR/Function.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
@@ -146,8 +147,12 @@ class FunctionInfo {
 /// COMDAT functions of the same name.
 typedef std::vector<std::unique_ptr<FunctionInfo>> FunctionInfoList;
 
-/// Map from function name to corresponding function info structures.
-typedef StringMap<FunctionInfoList> FunctionInfoMapTy;
+/// Map from function GUID to corresponding function info structures.
+/// Use a std::map rather than a DenseMap since it will likely incur
+/// less overhead, as the value type is not very small and the size
+/// of the map is unknown, resulting in inefficiencies due to repeated
+/// insertions and resizing.
+typedef std::map<uint64_t, FunctionInfoList> FunctionInfoMapTy;
 
 /// Type used for iterating through the function info map.
 typedef FunctionInfoMapTy::const_iterator const_funcinfo_iterator;
@@ -184,17 +189,21 @@ class FunctionInfoIndex {
 
   /// Get the list of function info objects for a given function.
   const FunctionInfoList &getFunctionInfoList(StringRef FuncName) {
-    return FunctionMap[FuncName];
+    return FunctionMap[Function::getGUID(FuncName)];
   }
 
   /// Get the list of function info objects for a given function.
   const const_funcinfo_iterator findFunctionInfoList(StringRef FuncName) const {
-    return FunctionMap.find(FuncName);
+    return FunctionMap.find(Function::getGUID(FuncName));
   }
 
   /// Add a function info for a function of the given name.
   void addFunctionInfo(StringRef FuncName, std::unique_ptr<FunctionInfo> Info) {
-    FunctionMap[FuncName].push_back(std::move(Info));
+    FunctionMap[Function::getGUID(FuncName)].push_back(std::move(Info));
+  }
+
+  void addFunctionInfo(uint64_t FuncGUID, std::unique_ptr<FunctionInfo> Info) {
+    FunctionMap[FuncGUID].push_back(std::move(Info));
   }
 
   /// Iterator to allow writer to walk through table during emission.

include/llvm/IR/Module.h

@@ -170,6 +170,8 @@ class Module {
   std::unique_ptr<GVMaterializer>
   Materializer;                   ///< Used to materialize GlobalValues
   std::string ModuleID;           ///< Human readable identifier for the module
+  std::string SourceFileName;     ///< Original source file name for module,
+                                  ///< recorded in bitcode.
   std::string TargetTriple;       ///< Platform target triple Module compiled on
                                   ///< Format: (arch)(sub)-(vendor)-(sys0-(abi)
   void *NamedMDSymTab;            ///< NamedMDNode names.
@@ -195,6 +197,12 @@ class Module {
   /// @returns the module identifier as a string
   const std::string &getModuleIdentifier() const { return ModuleID; }
 
+  /// Get the module's original source file name. When compiling from
+  /// bitcode, this is taken from a bitcode record where it was recorded.
+  /// For other compiles it is the same as the ModuleID, which would
+  /// contain the source file name.
+  const std::string &getSourceFileName() const { return SourceFileName; }
+
   /// \brief Get a short "name" for the module.
   ///
   /// This is useful for debugging or logging. It is essentially a convenience
@@ -240,6 +248,9 @@ class Module {
   /// Set the module identifier.
   void setModuleIdentifier(StringRef ID) { ModuleID = ID; }
 
+  /// Set the module's original source file name.
+  void setSourceFileName(StringRef Name) { SourceFileName = Name; }
+
   /// Set the data layout
   void setDataLayout(StringRef Desc);
   void setDataLayout(const DataLayout &Other);

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -458,6 +458,9 @@ class FunctionIndexBitcodeReader {
   /// summary records.
   DenseMap<uint64_t, StringRef> ModuleIdMap;
 
+  /// Original source file name recorded in a bitcode record.
+  std::string SourceFileName;
+
 public:
   std::error_code error(BitcodeError E, const Twine &Message);
   std::error_code error(BitcodeError E);
@@ -3697,6 +3700,13 @@ std::error_code BitcodeReader::parseModule(uint64_t ResumeBit,
       assert(MetadataList.size() == 0);
       MetadataList.resize(NumModuleMDs);
       break;
+    /// MODULE_CODE_SOURCE_FILENAME: [namechar x N]
+    case bitc::MODULE_CODE_SOURCE_FILENAME:
+      SmallString<128> ValueName;
+      if (convertToString(Record, 0, ValueName))
+        return error("Invalid record");
+      TheModule->setSourceFileName(ValueName);
+      break;
     }
     Record.clear();
   }
@@ -5454,24 +5464,30 @@ std::error_code FunctionIndexBitcodeReader::parseValueSymbolTable() {
         return error("Invalid record");
       unsigned ValueID = Record[0];
       uint64_t FuncOffset = Record[1];
-      std::unique_ptr<FunctionInfo> FuncInfo =
-          llvm::make_unique<FunctionInfo>(FuncOffset);
-      if (foundFuncSummary() && !IsLazy) {
+      assert(!IsLazy && "Lazy summary read only supported for combined index");
+      // Gracefully handle bitcode without a function summary section,
+      // which will simply not populate the index.
+      if (foundFuncSummary()) {
         DenseMap<uint64_t, std::unique_ptr<FunctionSummary>>::iterator SMI =
             SummaryMap.find(ValueID);
         assert(SMI != SummaryMap.end() && "Summary info not found");
+        std::unique_ptr<FunctionInfo> FuncInfo =
+            llvm::make_unique<FunctionInfo>(FuncOffset);
         FuncInfo->setFunctionSummary(std::move(SMI->second));
+        assert(!SourceFileName.empty());
+        std::string FunctionGlobalId = Function::getGlobalIdentifier(
+            ValueName, FuncInfo->functionSummary()->getFunctionLinkage(),
+            SourceFileName);
+        TheIndex->addFunctionInfo(FunctionGlobalId, std::move(FuncInfo));
       }
-      TheIndex->addFunctionInfo(ValueName, std::move(FuncInfo));
 
       ValueName.clear();
       break;
     }
     case bitc::VST_CODE_COMBINED_FNENTRY: {
-      // VST_CODE_FNENTRY: [offset, namechar x N]
-      if (convertToString(Record, 1, ValueName))
-        return error("Invalid record");
+      // VST_CODE_COMBINED_FNENTRY: [offset, funcguid]
       uint64_t FuncSummaryOffset = Record[0];
+      uint64_t FuncGUID = Record[1];
       std::unique_ptr<FunctionInfo> FuncInfo =
           llvm::make_unique<FunctionInfo>(FuncSummaryOffset);
       if (foundFuncSummary() && !IsLazy) {
@@ -5480,7 +5496,7 @@ std::error_code FunctionIndexBitcodeReader::parseValueSymbolTable() {
         assert(SMI != SummaryMap.end() && "Summary info not found");
         FuncInfo->setFunctionSummary(std::move(SMI->second));
       }
-      TheIndex->addFunctionInfo(ValueName, std::move(FuncInfo));
+      TheIndex->addFunctionInfo(FuncGUID, std::move(FuncInfo));
 
       ValueName.clear();
       break;
@@ -5499,6 +5515,8 @@ std::error_code FunctionIndexBitcodeReader::parseModule() {
   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
     return error("Invalid record");
 
+  SmallVector<uint64_t, 64> Record;
+
   // Read the function index for this module.
   while (1) {
     BitstreamEntry Entry = Stream.advance();
@@ -5551,7 +5569,24 @@ std::error_code FunctionIndexBitcodeReader::parseModule() {
       continue;
 
     case BitstreamEntry::Record:
-      Stream.skipRecord(Entry.ID);
+      // Once we find the single record of interest, skip the rest.
+      if (!SourceFileName.empty())
+        Stream.skipRecord(Entry.ID);
+      else {
+        Record.clear();
+        auto BitCode = Stream.readRecord(Entry.ID, Record);
+        switch (BitCode) {
+        default:
+          break; // Default behavior, ignore unknown content.
+        /// MODULE_CODE_SOURCE_FILENAME: [namechar x N]
+        case bitc::MODULE_CODE_SOURCE_FILENAME:
+          SmallString<128> ValueName;
+          if (convertToString(Record, 0, ValueName))
+            return error("Invalid record");
+          SourceFileName = ValueName.c_str();
+          break;
+        }
+      }
       continue;
     }
   }

lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -618,6 +618,24 @@ static uint64_t WriteValueSymbolTableForwardDecl(const ValueSymbolTable &VST,
   return Stream.GetCurrentBitNo() - 32;
 }
 
+enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
+
+/// Determine the encoding to use for the given string name and length.
+static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
+  bool isChar6 = true;
+  for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
+    if (isChar6)
+      isChar6 = BitCodeAbbrevOp::isChar6(*C);
+    if ((unsigned char)*C & 128)
+      // don't bother scanning the rest.
+      return SE_Fixed8;
+  }
+  if (isChar6)
+    return SE_Char6;
+  else
+    return SE_Fixed7;
+}
+
 /// Emit top-level description of module, including target triple, inline asm,
 /// descriptors for global variables, and function prototype info.
 /// Returns the bit offset to backpatch with the location of the real VST.
@@ -791,13 +809,40 @@ static uint64_t WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   // function importing where we lazy load the metadata as a postpass,
   // we want to avoid parsing the module-level metadata before parsing
   // the imported functions.
-  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_METADATA_VALUES));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
-  unsigned MDValsAbbrev = Stream.EmitAbbrev(Abbv);
-  Vals.push_back(VE.numMDs());
-  Stream.EmitRecord(bitc::MODULE_CODE_METADATA_VALUES, Vals, MDValsAbbrev);
-  Vals.clear();
+  {
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_METADATA_VALUES));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
+    unsigned MDValsAbbrev = Stream.EmitAbbrev(Abbv);
+    Vals.push_back(VE.numMDs());
+    Stream.EmitRecord(bitc::MODULE_CODE_METADATA_VALUES, Vals, MDValsAbbrev);
+    Vals.clear();
+  }
+
+  // Emit the module's source file name.
+  {
+    StringEncoding Bits =
+        getStringEncoding(M->getName().data(), M->getName().size());
+    BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
+    if (Bits == SE_Char6)
+      AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
+    else if (Bits == SE_Fixed7)
+      AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
+
+    // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(AbbrevOpToUse);
+    unsigned FilenameAbbrev = Stream.EmitAbbrev(Abbv);
+
+    for (const auto P : M->getSourceFileName())
+      Vals.push_back((unsigned char)P);
+
+    // Emit the finished record.
+    Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
+    Vals.clear();
+  }
 
   uint64_t VSTOffsetPlaceholder =
       WriteValueSymbolTableForwardDecl(M->getValueSymbolTable(), Stream);
@@ -2195,24 +2240,6 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
   Vals.clear();
 }
 
-enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
-
-/// Determine the encoding to use for the given string name and length.
-static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
-  bool isChar6 = true;
-  for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
-    if (isChar6)
-      isChar6 = BitCodeAbbrevOp::isChar6(*C);
-    if ((unsigned char)*C & 128)
-      // don't bother scanning the rest.
-      return SE_Fixed8;
-  }
-  if (isChar6)
-    return SE_Char6;
-  else
-    return SE_Fixed7;
-}
-
 /// Emit names for globals/functions etc. The VSTOffsetPlaceholder,
 /// BitcodeStartBit and FunctionIndex are only passed for the module-level
 /// VST, where we are including a function bitcode index and need to
@@ -2352,51 +2379,24 @@ static void WriteCombinedValueSymbolTable(const FunctionInfoIndex &Index,
                                           BitstreamWriter &Stream) {
   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 
-  // 8-bit fixed-width VST_CODE_COMBINED_FNENTRY function strings.
   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
-  unsigned FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcsumoffset
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcguid
+  unsigned FnEntryAbbrev = Stream.EmitAbbrev(Abbv);
 
-  // 7-bit fixed width VST_CODE_COMBINED_FNENTRY function strings.
-  Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
-  unsigned FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
-
-  // 6-bit char6 VST_CODE_COMBINED_FNENTRY function strings.
-  Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
-  unsigned FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
-
-  // FIXME: We know if the type names can use 7-bit ascii.
-  SmallVector<unsigned, 64> NameVals;
+  SmallVector<uint64_t, 64> NameVals;
 
   for (const auto &FII : Index) {
-    for (const auto &FI : FII.getValue()) {
+    for (const auto &FI : FII.second) {
       NameVals.push_back(FI->bitcodeIndex());
 
-      StringRef FuncName = FII.first();
-
-      // Figure out the encoding to use for the name.
-      StringEncoding Bits = getStringEncoding(FuncName.data(), FuncName.size());
+      uint64_t FuncGUID = FII.first;
 
-      // VST_CODE_COMBINED_FNENTRY: [funcsumoffset, namechar x N]
-      unsigned AbbrevToUse = FnEntry8BitAbbrev;
-      if (Bits == SE_Char6)
-        AbbrevToUse = FnEntry6BitAbbrev;
-      else if (Bits == SE_Fixed7)
-        AbbrevToUse = FnEntry7BitAbbrev;
+      // VST_CODE_COMBINED_FNENTRY: [funcsumoffset, funcguid]
+      unsigned AbbrevToUse = FnEntryAbbrev;
 
-      for (const auto P : FuncName)
-        NameVals.push_back((unsigned char)P);
+      NameVals.push_back(FuncGUID);
 
       // Emit the finished record.
       Stream.EmitRecord(bitc::VST_CODE_COMBINED_FNENTRY, NameVals, AbbrevToUse);
@@ -2855,7 +2855,7 @@ static void WriteCombinedFunctionSummary(const FunctionInfoIndex &I,
 
   SmallVector<unsigned, 64> NameVals;
   for (const auto &FII : I) {
-    for (auto &FI : FII.getValue()) {
+    for (auto &FI : FII.second) {
       FunctionSummary *FS = FI->functionSummary();
       assert(FS);