Re: Compiler analysis fault?

[Dennis via Digitalmars-d-learn]

On Wednesday, 20 December 2023 at 11:33:22 UTC, DLearner wrote:

The code below fails to compile with
 Error: function `test1.foo` no `return exp;` or `assert(0);` 
at end of function

unless the commented-out assert(0) is included.


The compiler basically gives up control flow analysis when 
encountering a goto statement or labeled break/continue.

```D
bool foo()
{
   while(true)
   {
L2:
goto L2;
   }
//   assert(0);
}
```

Compiler analysis fault?

[DLearner via Digitalmars-d-learn]

The code below fails to compile with
 Error: function `test1.foo` no `return exp;` or `assert(0);` at 
end of function

unless the commented-out assert(0) is included.

Please, what rule of D is being broken?
foo does not unconditionally loop, and the only places where foo 
returns, it returns with a bool.


```
bool foo() {
   import std.stdio;
   int I1;
   int nogoagain;

   while(true) {

  I1 = 2;
  while( I1 <= 10) {

 if (I1 != 5) {
 } else {
 goto L2;
 }
 I1 = I1 + 1;
  }
  return true;


  L2:;
  readf(" %s", nogoagain);
  if (nogoagain == 5) {
 return false;
  } else {
  }
   }
//   assert(0);
}


void main() {

   import std.stdio;

   writeln("A");

   writeln(foo());
}

```