[LLVMbugs] [Bug 10326] New: Unfortunate error message for incorrect operator precedence between 'new' and '->'

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=10326

           Summary: Unfortunate error message for incorrect operator
                    precedence between 'new' and '->'
           Product: clang
           Version: unspecified
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Frontend
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: chandlerc at gmail.com
                CC: llvmbugs at cs.uiuc.edu


The following program is clearly invalid, but I think we could do better
diagnosing it:

% cat x.cc
struct S {
  S* foo(int) { return this; }
};

S* test() {
  return new S()->foo(42);
}

% ./bin/clang -fsyntax-only x.cc
x.cc:6:17: error: expected ';' after return statement
  return new S()->foo(42);
                ^
                ;
1 error generated.

It seems like it would be better to say in the error that the new operator has
lower precedence than '->', and thus the new expression must be explicitly
grouped. Then we could recover and continue parsing the rest of the expression
as if that grouping had been performed. This seems reasonable to do for most of
the postfix expressions which form a suffix but could not reasonable be part of
a new-type-id: '->', '--', '++', and even '(...)' when the parentheses are not
parsed as part of the new-initializer.

-- 
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.