Revert r196358: "llvm-cov: Added support for function checksums."

This currently breaks clang/test/CodeGen/code-coverage.c. The root cause
is that the newly introduced access to Funcs[j] is out of bounds.

llvm-svn: 196365

llvm/include/llvm/Support/GCOV.h

@@ -250,7 +250,6 @@ public:
 private:
   GCOVFile &Parent;
   uint32_t Ident;
-  uint32_t Checksum;
   uint32_t LineNumber;
   StringRef Name;
   StringRef Filename;

llvm/lib/IR/GCOV.cpp

@@ -125,7 +125,7 @@ bool GCOVFunction::readGCNO(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
   uint32_t Dummy;
   if (!Buff.readInt(Dummy)) return false; // Function header length
   if (!Buff.readInt(Ident)) return false;
-  if (!Buff.readInt(Checksum)) return false;
+  if (!Buff.readInt(Dummy)) return false; // Checksum #1
   if (Version != GCOV::V402) {
     uint32_t CfgChecksum;
     if (!Buff.readInt(CfgChecksum)) return false;
@@ -212,7 +212,6 @@ bool GCOVFunction::readGCNO(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
 bool GCOVFunction::readGCDA(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
   uint32_t Dummy;
   if (!Buff.readInt(Dummy)) return false; // Function header length
-
   uint32_t GCDAIdent;
   if (!Buff.readInt(GCDAIdent)) return false;
   if (Ident != GCDAIdent) {
@@ -221,13 +220,8 @@ bool GCOVFunction::readGCDA(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
     return false;
   }
 
-  uint32_t GCDAChecksum;
-  if (!Buff.readInt(GCDAChecksum)) return false;
-  if (Checksum != GCDAChecksum) {
-    errs() << "Function checksums do not match: " << Checksum << " != "
-           << GCDAChecksum << " (in " << Name << ").\n";
-    return false;
-  }
+  if (!Buff.readInt(Dummy)) return false; // Checksum #1
+
 
   uint32_t CfgChecksum;
   if (Version != GCOV::V402) {

llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp

@@ -314,18 +314,12 @@ namespace {
       this->os = os;
 
       Function *F = SP.getFunction();
-      DEBUG(dbgs() << "Function: " << getFunctionName(SP) << "\n");
+      DEBUG(dbgs() << "Function: " << F->getName() << "\n");
       uint32_t i = 0;
       for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
         Blocks[BB] = new GCOVBlock(i++, os);
       }
       ReturnBlock = new GCOVBlock(i++, os);
-
-      std::string FunctionNameAndLine;
-      raw_string_ostream FNLOS(FunctionNameAndLine);
-      FNLOS << getFunctionName(SP) << SP.getLineNumber();
-      FNLOS.flush();
-      FuncChecksum = hash_value(FunctionNameAndLine);
     }
 
     ~GCOVFunction() {
@@ -353,10 +347,6 @@ namespace {
       return EdgeDestinations;
     }
 
-    uint32_t getFuncChecksum() {
-      return FuncChecksum;
-    }
-
     void setCfgChecksum(uint32_t Checksum) {
       CfgChecksum = Checksum;
     }
@@ -369,7 +359,7 @@ namespace {
         ++BlockLen;
       write(BlockLen);
       write(Ident);
-      write(FuncChecksum);
+      write(0);  // lineno checksum
       if (UseCfgChecksum)
         write(CfgChecksum);
       writeGCOVString(getFunctionName(SP));
@@ -411,7 +401,6 @@ namespace {
    private:
     DISubprogram SP;
     uint32_t Ident;
-    uint32_t FuncChecksum;
     bool UseCfgChecksum;
     uint32_t CfgChecksum;
     DenseMap<BasicBlock *, GCOVBlock *> Blocks;
@@ -742,7 +731,6 @@ Constant *GCOVProfiler::getEmitFunctionFunc() {
   Type *Args[] = {
     Type::getInt32Ty(*Ctx),    // uint32_t ident
     Type::getInt8PtrTy(*Ctx),  // const char *function_name
-    Type::getInt32Ty(*Ctx),    // uint32_t func_checksum
     Type::getInt8Ty(*Ctx),     // uint8_t use_extra_checksum
     Type::getInt32Ty(*Ctx),    // uint32_t cfg_checksum
   };
@@ -825,12 +813,11 @@ Function *GCOVProfiler::insertCounterWriteout(
                           Builder.getInt32(CfgChecksum));
       for (unsigned j = 0, e = CountersBySP.size(); j != e; ++j) {
         DISubprogram SP(CountersBySP[j].second);
-        Builder.CreateCall5(
+        Builder.CreateCall4(
             EmitFunction, Builder.getInt32(j),
             Options.FunctionNamesInData ?
               Builder.CreateGlobalStringPtr(getFunctionName(SP)) :
               Constant::getNullValue(Builder.getInt8PtrTy()),
-            Builder.getInt32(Funcs[j]->getFuncChecksum()),
             Builder.getInt8(Options.UseCfgChecksum),
             Builder.getInt32(CfgChecksum));
 

llvm/test/tools/llvm-cov/llvm-cov.test

@@ -11,8 +11,6 @@ RUN: rm test.cpp.llcov
 
 RUN: not llvm-cov -gcno=test_read_fail.gcno -gcda=test.gcda
 
-RUN: not llvm-cov -gcno=test.gcno -gcda=test_file_checksum_fail.gcda
-
-RUN: not llvm-cov -gcno=test.gcno -gcda=test_func_checksum_fail.gcda
+RUN: not llvm-cov -gcno=test.gcno -gcda=test_checksum_mismatch.gcda
 
 XFAIL: powerpc64, s390x, mips