Add a clang-tidy configuration file

Also add some annotations to remove some false positives.

There remain some boost-related false positives, it’s unclear how to suppress
them.

.clang-tidy

@@ -0,0 +1,9 @@
+# TODO: add the following check families:
+# - performance-*
+# - bugprone-*
+# - cppcoreguidelines-
+
+# NB: as of clang-tidy 16, we get several false positives inside boost, notably this one:
+#  https://github.com/llvm/llvm-project/issues/40486
+
+Checks: 'modernize-*,-modernize-use-trailing-return-type,-clang-diagnostic-unqualified-std-cast-call'

src/DataTree.cc

@@ -205,7 +205,7 @@ DataTree::AddPlus(expr_t iArg1, expr_t iArg2)
 
   // To treat commutativity of "+"
   // Nodes iArg1 and iArg2 are sorted by index
-  if (iArg1->idx > iArg2->idx && !no_commutativity)
+  if (iArg1->idx > iArg2->idx && !no_commutativity) // NOLINT(clang-analyzer-core.NullDereference)
     swap(iArg1, iArg2);
   return AddBinaryOp(iArg1, BinaryOpcode::plus, iArg2);
 }
@@ -283,7 +283,7 @@ DataTree::AddTimes(expr_t iArg1, expr_t iArg2)
 
   // To treat commutativity of "*"
   // Nodes iArg1 and iArg2 are sorted by index
-  if (iArg1->idx > iArg2->idx && !no_commutativity)
+  if (iArg1->idx > iArg2->idx && !no_commutativity) // NOLINT(clang-analyzer-core.NullDereference)
     swap(iArg1, iArg2);
   return AddBinaryOp(iArg1, BinaryOpcode::times, iArg2);
 }

src/DataTree.hh

@@ -431,7 +431,7 @@ DataTree::AddUnaryOp(UnaryOpcode op_code, expr_t arg, int arg_exp_info_set, int
     {
       try
         {
-          double argval = arg->eval({});
+          double argval = arg->eval({}); // NOLINT(clang-analyzer-core.CallAndMessage)
           double val = UnaryOpNode::eval_opcode(op_code, argval);
           return AddPossiblyNegativeConstant(val);
         }
@@ -460,8 +460,8 @@ DataTree::AddBinaryOp(expr_t arg1, BinaryOpcode op_code, expr_t arg2, int powerD
   // Try to reduce to a constant
   try
     {
-      double argval1 = arg1->eval({});
+      double argval1 = arg1->eval({}); // NOLINT(clang-analyzer-core.CallAndMessage)
-      double argval2 = arg2->eval({});
+      double argval2 = arg2->eval({}); // NOLINT(clang-analyzer-core.CallAndMessage)
       double val = BinaryOpNode::eval_opcode(argval1, op_code, argval2, powerDerivOrder);
       return AddPossiblyNegativeConstant(val);
     }

src/ExprNode.cc

@@ -3727,7 +3727,7 @@ UnaryOpNode::substituteDiff(const lag_equivalence_table_t& nodes, subst_table_t&
           if (vn)
             symb_id = datatree.symbol_table.addDiffAuxiliaryVar(argsubst->idx, rit->second,
                                                                 vn->symb_id, vn->lag);
-          else
+          else // NOLINTNEXTLINE(clang-analyzer-core.NullDereference)
             symb_id = datatree.symbol_table.addDiffAuxiliaryVar(argsubst->idx, rit->second);
 
           // make originating aux var & equation
@@ -3745,8 +3745,10 @@ UnaryOpNode::substituteDiff(const lag_equivalence_table_t& nodes, subst_table_t&
           for (int i = last_index; i > rit->first; i--)
             {
               if (i == last_index)
+                // NOLINTBEGIN(clang-analyzer-core.NullDereference)
                 symb_id = datatree.symbol_table.addDiffLagAuxiliaryVar(argsubst->idx, rit->second,
                                                                        last_aux_var->symb_id, -1);
+              // NOLINTEND(clang-analyzer-core.NullDereference)
               else
                 symb_id = datatree.symbol_table.addDiffLagAuxiliaryVar(
                     new_aux_var->idx, rit->second, last_aux_var->symb_id, -1);
@@ -3884,6 +3886,7 @@ UnaryOpNode::substituteUnaryOpNodes(const lag_equivalence_table_t& nodes,
       }
     else
       subst_table[rit->second]
+          // NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage)
           = dynamic_cast<VariableNode*>(aux_var->decreaseLeadsLags(base_index - rit->first));
 
   assert(subst_table.contains(this));
@@ -5692,6 +5695,7 @@ BinaryOpNode::getPacAREC(
       vector<tuple<int, int, optional<int>, double>> linear_combination;
       try
         {
+          // NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage)
           auto [vid, lag, pid, constant] = term->matchVariableTimesConstantTimesParam(true);
           linear_combination.emplace_back(vid.value(), lag, move(pid), constant);
         }
@@ -5773,6 +5777,7 @@ BinaryOpNode::isParamTimesEndogExpr() const
         }
       else
         {
+          // NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage)
           arg1->collectDynamicVariables(SymbolType::endogenous, endogs);
           arg1->collectDynamicVariables(SymbolType::exogenous, exogs);
           arg1->collectVariables(SymbolType::parameter, params);
@@ -9311,6 +9316,7 @@ BinaryOpNode::matchEndogenousTimesConstant() const
           varg1 && varg1->get_type() == SymbolType::endogenous && arg2->isConstant())
         return {varg1->symb_id, arg2};
       if (auto varg2 = dynamic_cast<VariableNode*>(arg2);
+          // NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage)
           varg2 && varg2->get_type() == SymbolType::endogenous && arg1->isConstant())
         return {varg2->symb_id, arg1};
     }

src/ModelTree.cc

@@ -393,7 +393,7 @@ ModelTree::evaluateAndReduceJacobian(const eval_context_t& eval_context) const
           double val {[&] {
             try
               {
-                return d1->eval(eval_context);
+                return d1->eval(eval_context); // NOLINT(clang-analyzer-core.NullDereference)
               }
             catch (ExprNode::EvalExternalFunctionException& e)
               {

src/ModelTree.hh

@@ -751,6 +751,7 @@ ModelTree::writeTemporaryTerms(const temporary_terms_t& tt, temporary_terms_t& t
       if (dynamic_cast<AbstractExternalFunctionNode*>(it))
         it->writeExternalFunctionOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);
 
+      // NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage)
       it->writeOutput(output, output_type, tt, tt_idxs, tef_terms);
       output << " = ";
       it->writeOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);

src/Statement.cc

@@ -184,6 +184,7 @@ OptionsList::writeOutput(ostream& output, const string& option_group) const
 void
 OptionsList::writeOutputCommon(ostream& output, const string& option_group) const
 {
+  // NOLINTBEGIN(clang-analyzer-core.CallAndMessage)
   for (const auto& [name, val] : options)
     std::visit(
         [&]<class T>(const T& v) {
@@ -261,6 +262,7 @@ OptionsList::writeOutputCommon(ostream& output, const string& option_group) cons
             }
         },
         val);
+  // NOLINTEND(clang-analyzer-core.CallAndMessage)
 }
 
 void

src/macro/Expressions.cc

@@ -623,12 +623,15 @@ Range::eval(Environment& env) const
                      "the arguments must evaluate to reals");
 
   vector<ExpressionPtr> arr;
+  // We do want a float counter, because that’s the macro-language semantics
+  // NOLINTBEGIN(clang-analyzer-security.FloatLoopCounter)
   if (*incdbl > 0 && *startdbl <= *enddbl)
     for (double i = *startdbl; i <= *enddbl; i += *incdbl)
       arr.emplace_back(make_shared<Real>(i));
   else if (*startdbl >= *enddbl && *incdbl < 0)
     for (double i = *startdbl; i >= *enddbl; i += *incdbl)
       arr.emplace_back(make_shared<Real>(i));
+  // NOLINTEND(clang-analyzer-security.FloatLoopCounter)
 
   return make_shared<Array>(arr, location);
 }