fixes #24940; fixes #17552; lifts {.global.} in injectDestructorCalls (#24962)

fixes #24940
fixes #17552

Collects `{.global.}` (i.e. if it was changed into a hook call: `=copy`,
`=sink`) in `injectDestructorCalls` and generates it in the init
sections in cgen

(cherry picked from commit 3c0446b082)

compiler/cgen.nim

@@ -2183,6 +2183,9 @@ proc genTopLevelStmt*(m: BModule; n: PNode) =
   else:
     genProcBody(m.initProc, transformedN)
 
+  for g in m.g.graph.procGlobals:
+    genStmts(m.preInitProc, g)
+
 proc shouldRecompile(m: BModule; code: Rope, cfile: Cfile): bool =
   if optForceFullMake notin m.config.globalOptions:
     if not moduleHasChanged(m.g.graph, m.module):

compiler/injectdestructors.nim

@@ -936,6 +936,9 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
     of nkVarSection, nkLetSection:
       # transform; var x = y to  var x; x op y  where op is a move or copy
       result = newNodeI(nkStmtList, n.info)
+
+      let isInProc = c.owner.kind in {skProc, skFunc, skMethod, skIterator, skConverter}
+
       for it in n:
         var ri = it[^1]
         if it.kind == nkVarTuple and hasDestructor(c, ri.typ):
@@ -951,7 +954,15 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
               s.locals.add v.sym
               pVarTopLevel(v, c, s, result)
             if ri.kind != nkEmpty:
-              result.add moveOrCopy(v, ri, c, s, if v.kind == nkSym: {IsDecl} else: {})
+              let isGlobalPragma = v.kind == nkSym and 
+                      {sfPure, sfGlobal} <= v.sym.flags and
+                      isInProc
+
+              let value = moveOrCopy(v, ri, c, s, if v.kind == nkSym: {IsDecl} else: {})
+              if isGlobalPragma:
+                c.graph.procGlobals.add value
+              else:
+                result.add value
             elif ri.kind == nkEmpty and c.inLoop > 0:
               let skipInit = v.kind == nkDotExpr and # Closure var
                              sfNoInit in v[1].sym.flags

compiler/modulegraphs.nim

@@ -136,6 +136,8 @@ type
 
     cachedFiles*: StringTableRef
 
+    procGlobals*: seq[PNode]
+
   TPassContext* = object of RootObj # the pass's context
     idgen*: IdGenerator
   PPassContext* = ref TPassContext

tests/global/tglobal3.nim

@@ -0,0 +1,30 @@
+discard """
+  matrix: "--mm:refc; --mm:orc"
+  targets: "c cpp"
+"""
+
+block: # bug #17552
+  proc main: string = 
+    var tc {.global.} = "hi"
+    tc &= "hi"
+    result = tc
+
+  doAssert main() == "hihi"
+  doAssert main() == "hihihi"
+  doAssert main() == "hihihihi"
+
+# bug #24940
+var v: int
+
+proc ccc(): ref int =
+  let tmp = new int
+  v += 1
+  tmp[] = v
+  tmp
+
+proc f(v: static string): int =
+  let xxx {.global.} = ccc()
+  xxx[]
+
+doAssert f("1") == 1
+doAssert f("1") == 1