[clang][bytecode][NFC] Only collect non-null args if we have to

Only do this if the function really has a NonNullArg.

Author: tbaederr

clang/lib/AST/ByteCode/Compiler.cpp

@@ -2038,7 +2038,12 @@ bool Compiler<Emitter>::visitCallArgs(ArrayRef<const Expr *> Args,
                                       const FunctionDecl *FuncDecl,
                                       bool Activate) {
   assert(VarScope->getKind() == ScopeKind::Call);
-  llvm::BitVector NonNullArgs = collectNonNullArgs(FuncDecl, Args);
+  bool HasNonNullAttr = false;
+  llvm::BitVector NonNullArgs;
+  if (FuncDecl && FuncDecl->hasAttr<NonNullAttr>()) {
+    HasNonNullAttr = true;
+    NonNullArgs = collectNonNullArgs(FuncDecl, Args);
+  }
 
   unsigned ArgIndex = 0;
   for (const Expr *Arg : Args) {
@@ -2064,7 +2069,7 @@ bool Compiler<Emitter>::visitCallArgs(ArrayRef<const Expr *> Args,
         return false;
     }
 
-    if (FuncDecl && NonNullArgs[ArgIndex]) {
+    if (FuncDecl && HasNonNullAttr && NonNullArgs[ArgIndex]) {
       PrimType ArgT = classify(Arg).value_or(PT_Ptr);
       if (ArgT == PT_Ptr) {
         if (!this->emitCheckNonNullArg(ArgT, Arg))

clang/lib/AST/ByteCode/InterpShared.cpp

@@ -16,23 +16,23 @@ namespace interp {
 llvm::BitVector collectNonNullArgs(const FunctionDecl *F,
                                    ArrayRef<const Expr *> Args) {
   llvm::BitVector NonNullArgs;
-  if (!F)
-    return NonNullArgs;
 
   assert(F);
+  assert(F->hasAttr<NonNullAttr>());
   NonNullArgs.resize(Args.size());
 
   for (const auto *Attr : F->specific_attrs<NonNullAttr>()) {
     if (!Attr->args_size()) {
       NonNullArgs.set();
       break;
-    } else
-      for (auto Idx : Attr->args()) {
-        unsigned ASTIdx = Idx.getASTIndex();
-        if (ASTIdx >= Args.size())
-          continue;
-        NonNullArgs[ASTIdx] = true;
-      }
+    }
+
+    for (auto Idx : Attr->args()) {
+      unsigned ASTIdx = Idx.getASTIndex();
+      if (ASTIdx >= Args.size())
+        continue;
+      NonNullArgs[ASTIdx] = true;
+    }
   }
 
   return NonNullArgs;