`push warning[Deprecated]: off` doesn't work with templates

[timotheecour]

2 bugs:

• push warning[Deprecated]: off doesn't work with templates;
• the warnings get duplicated at each template call stack and need to be suppressed an equivalent number of times

Example

# lib.nim:
  proc foo2*() {.deprecated: "use foo2 instead".} = echo "ok1"

# main.nim:
  import ./lib
  template myfun*() =
    {.push warning[Deprecated]: off.}
    foo2()
    {.pop.}
  myfun()

Current Output

Warning: use foo2 instead; foo2 is deprecated [Deprecated]

Expected Output

no warning

Furthermore, if you remove the push/pop, you'll get 2 warnings instead of 1.

with double push it finally suppresses the warning:

  import ./lib
  {.push warning[Deprecated]: off.}
  template myfun*() =
    {.push warning[Deprecated]: off.}
    foo2()
    {.pop.}
  {.pop.}
  myfun()

but this isn't practical in more complex settings

Additional Information

• Your Nim version (output of nim -v).
  latest devel f50e450
• in my use case, I needed to suppress callsite deprecation warnings; callsite was needed for my use case (args: varargs[untyped] doesn't contain enough information)

[alaviss]

• in my use case, I needed to suppress callsite deprecation warnings; callsite was needed for my use case (args: varargs[untyped] doesn't contain enough information)

I don't think that's a good idea as callsite might be removed in the future. You should open an issue for why you'd want to use callsite instead and ask for it to not be deprecated.

Also, from what I can see it currently works like this:

template myfun*() =
    {.push warning[Deprecated]: off.}
    foo2()
    {.pop.}

• The compiler turns the template into AST.
• The compiler bounds symbols in the AST tree, triggering a deprecation warning because {.push.} is not consumed.
• When the template is invoked, the compiler pastes the AST to the target area and evaluate it, this is where {.push.} is actually consumed.

This explains why you currently need two layers: One for the template itself, and one for the AST it constructed.