[clang] [RFC] Initial implementation of P2719 (PR #113510)

[Oliver Hunt via cfe-commits]

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@@ -9753,27 +9753,46 @@ def err_operator_new_delete_invalid_result_type : Error<
 def err_operator_new_delete_dependent_result_type : Error<
   "%0 cannot have a dependent return type; use %1 instead">;
 def err_operator_new_delete_too_few_parameters : Error<
-  "%0 must have at least one parameter">;
+  "%select{|type aware }0%select{|destroying }1%2 must have at least %select{|one|two|three|four|five}3 parameter%s3">;
 def err_operator_new_delete_template_too_few_parameters : Error<
   "%0 template must have at least two parameters">;
 def warn_operator_new_returns_null : Warning<
   "%0 should not return a null pointer unless it is declared 'throw()'"
   "%select{| or 'noexcept'}1">, InGroup<OperatorNewReturnsNull>;
 
 def err_operator_new_dependent_param_type : Error<
-  "%0 cannot take a dependent type as first parameter; "
-  "use size_t (%1) instead">;
+  "%select{|type aware }0%select{|destroying }1%2 cannot take a dependent type as its %select{first|second|third|fourth|fifth}3 parameter; "
+  "use %5 (%4) instead">;
 def err_operator_new_param_type : Error<
-  "%0 takes type size_t (%1) as first parameter">;
+  "%select{|type aware }0%select{|destroying }1%2 takes type %5 (%4) as %select{first|second|third|fourth|fifth}3 parameter">;
 def err_operator_new_default_arg: Error<
   "parameter of %0 cannot have a default argument">;
 def err_operator_delete_dependent_param_type : Error<
-  "%0 cannot take a dependent type as first parameter; use %1 instead">;
+  "%select{|type aware }0%select{|destroying }1%2 cannot take a dependent type as its %select{first|second|third|fourth|fifth}3 parameter; "
+  "use %4 instead">;
 def err_operator_delete_param_type : Error<
-  "first parameter of %0 must have type %1">;
+  "%select{first|second|third|fourth|fifth}3 parameter of%select{| type aware}0%select{| destroying}1 %2 must have type %4">;
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ojhunt wrote:

@AaronBallman so I think we need to"parameter X must be Y" for the error message to be meaningful, as otherwise the error message is just "this parameter must be of type Y", and you can only see which parameter is involved if you can see the pointer.

I will switch to %ordinal, but there are numerous cases of first|second|third etc in the diagnostics which should be switched over, but that also takes us to %ordinal using 1st, 2nd, 3rd, etc instead of first, second, third, which was why I did not use ordinal in the first place.

https://github.com/llvm/llvm-project/pull/113510