Simplify instrumentation?

[thetheodor]

DCEMarkers

to avoid inserting curly braces everywhere, I could instrument like so:

if (C)
  STMT;

if (C && (Marker1(), 1)  || (Marker2(), 0) )
   STMT();

or

if ( C ? (Marker1(), 1) :  (Marker2(), 0))
   STMT();

loops can be handled similarly, except for range-based for loops and do while loops which must be instrumented via their bodies. It also doesn't work for if statement with a complex initializer (if (auto* X = expr())), for simple cases it would work: if (auto* X = ptr ? (Marker1(), ptr): (Marker2(), ptr)
.

The downside is that Marker() must be an expression, but I could implement is an always_inline function:

__attribute__((always_inline))
void Marker(){
 //...
}

VRMarkers

VRMarkers can be baked into expressions, e.g.:

T V = expr(x);

T V = (marker(x), expr(x));