opcLdDeref (eg via addr) gives wrong results in inside static block

[timotheecour]

opcLdDeref gives wrong results in VM inside static block

Example 1

when true: # D20200405T172240
  # proc fun() = # would work
  template fun() = # fails
    var s = @[10,11,12]
    let z = s[0].addr
    doAssert z[] == 10
    z[] = 100
    doAssert z[] == 100
    doAssert s[0] == 100 # fails here
  static: fun() # fails
  fun() # would work

Current Output

doAssert s[0] == 100 fails

Expected Output

works

Example 2

shows that pointer is conflated for value:

  template fun() =
    var s = @[10,11,12]
    echo cast[int](s[0].addr) # 4323682360
    let z = s[0].addr 
    echo cast[int](z) # 10 => BUG
  static: fun() # fails

Example 3

when true: # D20200405T172849:here
  template fun() =
  # proc fun() = # would work
    var s = @[10.1,11.2,12.3]
    echo cast[int](s[0].addr)
    let z = s[0].addr
    echo cast[int](z)
  static: fun() # fails

Error: unhandled exception: 'intVal' is not accessible using discriminant 'kind' of type 'TNode' [FieldError]

Possible Solution

• a fix similar to fix SIGSEGV in VM in opcLdDeref #13865 could help
• maybe it's time to introduce nkPtrLit (right now it's an alias of nkIntLit) unless we can fix this cleanly with nfIsPtr+ tyPtr checks
• EDIT: as many other issues, this would be fixed by transform static: stmt and const foo = expr into immediately invoked lambas => fixes many bugs RFCs#276

Additional Information

• devel f1fd3ef
• never worked

[recloser]

No need to get fancy with seqs, even the simplest code fails:

static:
  var x = 5
  var y = addr(x)
  y[] += 10
  doAssert x == y[]

[timotheecour]

as many other issues, this would be fixed by nim-lang/RFCs#276