[llvm] [llvm-profgen] Loading binary functions from .symtab when DWARF info is incomplete (PR #163654)

[via llvm-commits]

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@@ -449,29 +449,62 @@ bool ProfileGeneratorBase::collectFunctionsFromRawProfile(
   // Go through all the stacks, ranges and branches in sample counters, use
   // the start of the range to look up the function it belongs and record the
   // function.
+  uint64_t ErrStkAddr = 0, ErrFuncRange = 0, ErrSrc = 0, ErrTgt = 0;
+  uint64_t TotalStkAddr = 0, TotalFuncRange = 0, TotalSrc = 0, TotalTgt = 0;
   for (const auto &CI : *SampleCounters) {
     if (const auto *CtxKey = dyn_cast<AddrBasedCtxKey>(CI.first.getPtr())) {
       for (auto StackAddr : CtxKey->Context) {
+        uint64_t Inc = Binary->addressIsCode(StackAddr) ? 1 : 0;
+        TotalStkAddr += Inc;
         if (FuncRange *FRange = Binary->findFuncRange(StackAddr))
           ProfiledFunctions.insert(FRange->Func);
+        else
+          ErrStkAddr += Inc;
       }
     }
 
     for (auto Item : CI.second.RangeCounter) {
       uint64_t StartAddress = Item.first.first;
+      uint64_t Inc = Binary->addressIsCode(StartAddress) ? Item.second : 0;
+      TotalFuncRange += Inc;
       if (FuncRange *FRange = Binary->findFuncRange(StartAddress))
         ProfiledFunctions.insert(FRange->Func);
+      else
+        ErrFuncRange += Inc;
     }
 
     for (auto Item : CI.second.BranchCounter) {
       uint64_t SourceAddress = Item.first.first;
       uint64_t TargetAddress = Item.first.second;
+      uint64_t SrcInc = Binary->addressIsCode(SourceAddress) ? Item.second : 0;
+      uint64_t TgtInc = Binary->addressIsCode(TargetAddress) ? Item.second : 0;
+      TotalSrc += SrcInc;
       if (FuncRange *FRange = Binary->findFuncRange(SourceAddress))
         ProfiledFunctions.insert(FRange->Func);
+      else
+        ErrSrc += SrcInc;
+      TotalTgt += TgtInc;
       if (FuncRange *FRange = Binary->findFuncRange(TargetAddress))
         ProfiledFunctions.insert(FRange->Func);
+      else
+        ErrTgt += TgtInc;
     }
   }
+
+  if (ErrStkAddr)
+    emitWarningSummary(
+        ErrStkAddr, TotalStkAddr,
+        "of stack address samples do not belong to any function");
+  if (ErrFuncRange)
+    emitWarningSummary(
+        ErrFuncRange, TotalFuncRange,
+        "of function range samples do not belong to any function");
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WenleiHe wrote:

ideally, we'd like to how the count that 1) does not belong to any function in Dwarf, and 2) the count that does not belong to any function in Dwarf and symbol table. 

This tells us how much loading symbol table is helping, and how much dwarf is screwed (due to relo overflow).

https://github.com/llvm/llvm-project/pull/163654