[flang][test] Make tests warning-correct for integer division-by-zero

[ekieri]

Summary

Add WARNING-directives for integer division-by-zero in semantics tests.
Note that the warning is triggered by all subexpressions, i.e.,

1 + 1 / 0

triggers it twice.

This is a preparation for D125804, which makes test_errors.py test
warnings the same way it already tests errors, i.e., assert that the
emitted and expected diagnostics are identical.

[ekieri]

I post these in a separate patch for the extra visibility, as I would like some input. What do you make of this? resolve37.f90, with the four consecutive WARNING-directives, looks a bit silly, and the repetition is not particularly helpful. But the logic behind each of them is clear (the subexpression in question is marked for each warning). I expect that limiting to one warning per expression would complicate the logic. Would that be worth it, or even desired? Note that integer division-by-zero in a constant expression also triggers an error.

[ekieri]

ping.

[ekieri]

ping

[jeanPerier]

Sorry for the late feedback.

But the logic behind each of them is clear (the subexpression in question is marked for each warning). I expect that limiting to one warning per expression would complicate the logic. Would that be worth it, or even desired?

As far as I am concerned, I think the warning duplication is noise, and I think it would be worth trying to limit them.

[ekieri]

In D127337#3815169, @jeanPerier wrote:

Sorry for the late feedback.

But the logic behind each of them is clear (the subexpression in question is marked for each warning). I expect that limiting to one warning per expression would complicate the logic. Would that be worth it, or even desired?

As far as I am concerned, I think the warning duplication is noise, and I think it would be worth trying to limit them.

Thanks for your input, I'll make an attempt!

[ekieri]

Fixed in D136479.

flang/test/Semantics/resolve108.f90

real(kind=k) function foo(n)
     foo = n
   end function
 end module
 
 subroutine s2
   use :: m2, only: foo
   !If we got the type of foo right, this declaration will fail
   !due to an attempted division by zero.
+  !WARNING: INTEGER(4) division by zero
   !ERROR: Must be a constant value
   integer, parameter :: test = 1 / (kind(foo(1)) - kind(1.d0))
 end subroutine
 
 module m3
   real(kind=kind(1.0e0)) :: x
  contains
   real(kind=kind(x)) function foo(x)
     real(kind=kind(1.0d0)) x
+    !WARNING: INTEGER(4) division by zero
     !ERROR: Must be a constant value
     integer, parameter :: test = 1 / (kind(foo) - kind(1.d0))
     foo = n
   end function
 end module
 
 module m4
  contains
   real(n) function foo(x)
     !ERROR: 'foo' is not an object that can appear in an expression
     integer, parameter :: n = kind(foo)
     real(n), intent(in) :: x
     !ERROR: 'x' is not an object that can appear in an expression
     foo = x
   end function
 end module

flang/test/Semantics/resolve37.f90

 !ERROR: Must have INTEGER type, but is LOGICAL(4)
   .true.)) :: w
 !ERROR: Must have INTEGER type, but is REAL(4)
 real :: u(l*2)
 !ERROR: Must have INTEGER type, but is REAL(4)
 character(len=l) :: v
 !ERROR: Value of named constant 'o' (o) cannot be computed as a constant value
 real, parameter ::  o = o
+!WARNING: INTEGER(4) division by zero
 !ERROR: Must be a constant value
 integer, parameter ::  p = 0/0
+!WARNING: INTEGER(4) division by zero
+!WARNING: INTEGER(4) division by zero
+!WARNING: INTEGER(4) division by zero
+!WARNING: INTEGER(4) division by zero
 !ERROR: Must be a constant value
 integer, parameter ::  q = 1+2*(1/0)
 integer not_constant
 !ERROR: Must be a constant value
 integer, parameter :: s1 = not_constant/2
 !ERROR: Must be a constant value
 integer, parameter :: s2 = 3/not_constant
+!WARNING: INTEGER(4) division by zero
 !ERROR: Must be a constant value
 integer(kind=2/0) r
 integer, parameter :: sok(*)=[1,2]/[1,2]
+!WARNING: INTEGER(4) division by zero
 !ERROR: Must be a constant value
 integer, parameter :: snok(*)=[1,2]/[1,0]
 end

flang/test/Semantics/resolve60.f90

enum, bind(C)
     enumerator :: pear
     !ERROR: 'peach' is already declared in this scoping unit
     enumerator :: peach
     !ERROR: 'red' is already declared in this scoping unit
     enumerator :: red
   end enum
 
   enum, bind(C)
+    !WARNING: INTEGER(4) division by zero
     !ERROR: Enumerator value could not be computed from the given expression
     !ERROR: Must be a constant value
     enumerator :: wrong = 0/0
   end enum
 
 end