fix #12640 (#15829)

compiler/ccgstmts.nim

@@ -382,7 +382,13 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
 
 proc genSingleVar(p: BProc, a: PNode) =
   let v = a[0].sym
-  if sfCompileTime in v.flags: return
+  if sfCompileTime in v.flags:
+    # fix issue #12640
+    # {.global, compileTime.} pragma in proc
+    if sfGlobal in v.flags and p.prc != nil and p.prc.kind == skProc:
+      discard
+    else:
+      return
   genSingleVar(p, v, a[0], a[2])
 
 proc genClosureVar(p: BProc, a: PNode) =

tests/pragmas/t12640.nim

@@ -0,0 +1,25 @@
+discard """
+  nimout: '''1
+2
+3
+[1, 2, 3]'''
+
+  output: '''1
+2
+3
+[1, 2, 3]'''
+"""
+
+
+proc doIt(a: openArray[int]) =
+  echo a
+
+proc foo() = 
+  var bug {.global, compiletime.}: seq[int]
+  bug = @[1, 2 ,3]
+  for i in 0 .. high(bug): echo bug[i]
+  doIt(bug)
+
+static:
+  foo()
+foo()