[cfe-dev] How to get more info from macro expansion

[Abramo Bagnara]

Given a macro expansion I'd need to have the source range for each
expansion arguments and the range of expanded tokens.

This info can be used to check that the source range of each macro
arguments match with an expression source range and the same is true for
expanded tokens range.

This would permit to diagnose the following two kinds of macro misuse.

#define ADD(a, b) a + b
#define MUL(a, b) (a * b)

void f() {
  int x, y;
  x * ADD(x, y);
  MUL(x, x + y);
}