pragmas don't always affect immediately subsequent code

[tersec]

Pragmas affect unintuitive parts of code.

Example

Example #1

proc foo() =
  {.checks: off.}
  var s2 = newSeq[int](0)
  s2[0] = 0

foo()

Example #2

proc foo() =
  {.checks: off.}
  # Does trigger IndexDefect
  var s2 = newSeq[int](0)
  s2[0] = 0

foo()
# Doesn't trigger IndexDefect
var s = newSeq[int](0)
s[0] = 0

Example #3

{.checks: off.}
var s2 = newSeq[int](0)
s2[0] = 0

Example #4

template foo() =
  {.checks: off.}
  var s2 = newSeq[int](0)
  s2[0] = 0

foo()

Current Output

Example #1: Error: unhandled exception: index out of bounds, the container is empty [IndexDefect]
Example #2: IndexDefect, but not in foo(), but rather in the global/module scope array indexing
Example #3: no IndexDefect, i.e. the pragma appears to function as intended
Example #4: no IndexDefect, so unlike with the proc() (example #1), a template indeed behaves more like example #3

Tested with

Nim Compiler Version 1.2.16 [Linux: amd64]
Compiled at 2022-03-07
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: c6a9f27b3e36bae9aacec1bd6c37893fb98fd33f
active boot switches: -d:release

(s/Defect/Error/, but otherwise the same)

Nim Compiler Version 1.6.4 [Linux: amd64]
Compiled at 2022-02-10
Copyright (c) 2006-2021 by Andreas Rumpf

Nim Compiler Version 1.7.1 [Linux: amd64]
Compiled at 2022-03-14
Copyright (c) 2006-2022 by Andreas Rumpf

git hash: 4c76f9f1523a72f560138709642c2d51ea365b85
active boot switches: -d:release

Expected Output

Not this.

Possible Solution

Avoid pragmas?

Additional Information

I came across these when attempting to selectively enable and disable pragmas to potentially isolate sections of code which

These are related to #19603 but whereas that issue points to a case where pragmas have too much effect, this points to them having too little effect. Reasonably likely a shared set of root causes though.

[tersec]

Maybe fixed by 51df9ff the same as #19603 -- I tested it with the same set of pragmas, and likewise it depends on non-module-scope.

[ringabout]

Maybe fixed by 51df9ff the same as #19603 -- I tested it with the same set of pragmas, and likewise it depends on non-module-scope.

Indeed.