misc nimvm

[timotheecour]

• Clarify JS cstring len nim-lang/Nim#14184 (comment)
  this issue is nasty

when not defined(nimscript): reduces to when true because nimscript always runs in nimvm

Yes but it semantic checks the else branch. We dealt with this already. If you change this to when true you get undeclared identifier nimCmpMem

D20200524T194136

  when notJSnotNims:
    const nimCmpMem = 1
  proc cmp(x, y: string): int =
    when nimvm:
      discard
    else:
      when not defined(nimscript):
        discard nimCmpMem

wondering whether nim-lang#13038 would help...

links

[Meta] Generics/Static early symbol resolution · Issue #8677 · nim-lang/Nim

example where my previous proposed if nimct: doens't work:

nim-lang#13038 (comment)

whereas this works:

when defined case2:
  proc c_printf(frmt: cstring): cint {.importc: "printf", header: "<stdio.h>", varargs, discardable.}
  proc main() =
    when nimvm: echo "in nimvm"
    else:
      echo "notin nimvm"
      c_printf("hello\n")
  static: main()
  main()

[timotheecour]

see whether we can overload by nimvm vs rt:

proc fn(): int {.nimvm.} = 1
proc fn(): int {.nimvm:off.} = 2
proc main=
	doAssert fn() == 2
	static: doAssert fn() == 1

links

• tfTriggersCompileTime

  # constant folding that is necessary for correctness of semantic pass:
  if callee.magic != mNone and callee.magic in ctfeWhitelist and n.typ != nil: