Too many warnings for when defined

[PavelVozenilek]

Current 0.10 compiler issues a warning for every location where when defined is not found true.

Example:

proc foo =
  echo "foo"
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"

foo()

Compiler output:

C:\Nimrod\bin>nim c a.nim
c:\nimrod\config\nim.cfg(42, 2) Hint: added path: 'C:\Users\U┼żivatel\.babel\pkgs\babel-0.4.0' [Path]
c:\nimrod\config\nim.cfg(42, 2) Hint: added path: 'C:\Users\U┼żivatel\.babel\pkgs\' [Path]
c:\nimrod\config\nim.cfg(43, 2) Hint: added path: 'C:\Users\U┼żivatel\.nimble\pkgs\' [Path]
Hint: used config file 'C:\Nimrod\config\nim.cfg' [Conf]
Hint: system [Processing]
Hint: a [Processing]
a.nim(3, 15) Warning: undeclared conditional symbol; use --symbol to declare it: x [User]
a.nim(4, 15) Warning: undeclared conditional symbol; use --symbol to declare it: x [User]
a.nim(5, 15) Warning: undeclared conditional symbol; use --symbol to declare it: x [User]
a.nim(6, 15) Warning: undeclared conditional symbol; use --symbol to declare it: x [User]
a.nim(7, 15) Warning: undeclared conditional symbol; use --symbol to declare it: x [User]
gcc.exe -c  -w  -IC:\Nimrod\lib -o c:\nimrod\bin\nimcache\a.o c:\nimrod\bin\nimcache\a.c
gcc.exe   -o c:\nimrod\bin\a.exe  c:\nimrod\bin\nimcache\stdlib_system.o c:\nimrod\bin\nimcache\a.o
Hint: operation successful (8869 lines compiled; 0.472 sec total; 15.153MB) [SuccessX]

C:\Nimrod\bin>

All five instances of when defined produce their own warning. What is --symbol doing here is not clear to me. The documentation gives no hint why this cmdline option even exists, what is wrong with --define.

Perhaps only the first generated warning should be shown.

A pragma/cmdline option to get rid of individual warnings would be also useful.

[jovial]

you can do:

proc foo =
  echo "foo"
  {.push warning[user]: off}
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"
  when defined (x): echo "x"
  {.pop.}

foo()

maybe worth putting in a template if you use it often.

[PavelVozenilek]

This works for my code.

The docs could an example.

I am closing the issue.

[superfunc]

Why not make a PR to the docs then?