[compiler-rt] Changing function prototype returning unused value

[etienneb]

Summary

The return value of maybeInsertAsanInitAtFunctionEntry is ignored.

[rnk]

lib/Transforms/Instrumentation/AddressSanitizer.cpp

1891

I think the correct fix is to OR this into a bool like res below and return that instead of false.

[etienneb]

fix runFunction semantic (rnk comment)

lib/Transforms/Instrumentation/AddressSanitizer.cpp

1891

ok. I moved to your semantic.
I wasn't aware that runFunction should return true when modified.

[rnk]

looks good with right naming convention

lib/Transforms/Instrumentation/AddressSanitizer.cpp

1888

We're back in LLVM, we should follow LLVM conventiosn, not Google style. =P

[etienneb]

fix naming

lib/Transforms/Instrumentation/AddressSanitizer.cpp

1888

I'm having too many personalities now!

lib/Transforms/Instrumentation/AddressSanitizer.cpp

 }
 
 bool AddressSanitizer::runOnFunction(Function &F) {
   if (&F == AsanCtorFunction) return false;
   if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
   if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
   if (F.getName().find("__asan_") != std::string::npos) return false;
 
+  bool FunctionModified = false;
+
   // If needed, insert __asan_init before checking for SanitizeAddress attr.
   // This function needs to be called even if the function body is not
   // instrumented.  
-  maybeInsertAsanInitAtFunctionEntry(F);
+  if (maybeInsertAsanInitAtFunctionEntry(F))
+    FunctionModified = true;
   
   // Leave if the function doesn't need instrumentation.
-  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return false;
+  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
 
   DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
 
   initializeCallbacks(*F.getParent());
   DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
 
   FunctionStateRAII CleanupObj(this);
 
for (auto CI : NoReturnCalls) {
     IRB.CreateCall(AsanHandleNoReturnFunc, {});
   }
 
   for (auto Inst : PointerComparisonsOrSubtracts) {
     instrumentPointerComparisonOrSubtraction(Inst);
     NumInstrumented++;
   }
 
-  bool res = NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
+  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
+    FunctionModified = true;
 
-  DEBUG(dbgs() << "ASAN done instrumenting: " << res << " " << F << "\n");
+  DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
+               << F << "\n");
 
-  return res;
+  return FunctionModified;
 }
 
 // Workaround for bug 11395: we don't want to instrument stack in functions
 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
 // FIXME: remove once the bug 11395 is fixed.
 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
   if (LongSize != 32) return false;
   CallInst *CI = dyn_cast<CallInst>(I);