From faa4042e26619043b63a25f2b8c4b1ccb70ab0f8 Mon Sep 17 00:00:00 2001
From: narimiran <narimiran@disroot.org>
Date: Tue, 18 Mar 2025 08:49:45 +0100
Subject: [PATCH] Revert "implements internal sink copy (#24747)"

This reverts commit 6651c40ba022f84bdc77f5997a9d9a30ba4f9414.
---
 compiler/ccgcalls.nim          | 29 +++++++++++++++
 compiler/ccgutils.nim          |  3 ++
 compiler/injectdestructors.nim | 64 ++--------------------------------
 compiler/trees.nim             | 29 ---------------
 4 files changed, 35 insertions(+), 90 deletions(-)

diff --git a/compiler/ccgcalls.nim b/compiler/ccgcalls.nim
index e022c64986..0bf16ba9f8 100644
--- a/compiler/ccgcalls.nim
+++ b/compiler/ccgcalls.nim
@@ -387,6 +387,35 @@ proc skipTrivialIndirections(n: PNode): PNode =
       result = result[1]
     else: break
 
+proc getPotentialWrites(n: PNode; mutate: bool; result: var seq[PNode]) =
+  case n.kind:
+  of nkLiterals, nkIdent, nkFormalParams: discard
+  of nkSym:
+    if mutate: result.add n
+  of nkAsgn, nkFastAsgn, nkSinkAsgn:
+    getPotentialWrites(n[0], true, result)
+    getPotentialWrites(n[1], mutate, result)
+  of nkAddr, nkHiddenAddr:
+    getPotentialWrites(n[0], true, result)
+  of nkBracketExpr, nkDotExpr, nkCheckedFieldExpr:
+    getPotentialWrites(n[0], mutate, result)
+  of nkCallKinds:
+    case n.getMagic:
+    of mIncl, mExcl, mInc, mDec, mAppendStrCh, mAppendStrStr, mAppendSeqElem,
+        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy:
+      getPotentialWrites(n[1], true, result)
+      for i in 2..<n.len:
+        getPotentialWrites(n[i], mutate, result)
+    of mSwap:
+      for i in 1..<n.len:
+        getPotentialWrites(n[i], true, result)
+    else:
+      for i in 1..<n.len:
+        getPotentialWrites(n[i], mutate, result)
+  else:
+    for s in n:
+      getPotentialWrites(s, mutate, result)
+
 proc getPotentialReads(n: PNode; result: var seq[PNode]) =
   case n.kind:
   of nkLiterals, nkIdent, nkFormalParams: discard
diff --git a/compiler/ccgutils.nim b/compiler/ccgutils.nim
index 2811aa7a35..d0efc20bd2 100644
--- a/compiler/ccgutils.nim
+++ b/compiler/ccgutils.nim
@@ -90,6 +90,9 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
     if s.typ.sym != nil and sfForward in s.typ.sym.flags:
       # forwarded objects are *always* passed by pointers for consistency!
       result = true
+    elif s.typ.kind == tySink and conf.selectedGC notin {gcArc, gcAtomicArc, gcOrc, gcHooks}:
+      # bug #23354:
+      result = false
     elif (optByRef in s.options) or (getSize(conf, pt) > conf.target.floatSize * 3):
       result = true           # requested anyway
     elif (tfFinal in pt.flags) and (pt[0] == nil):
diff --git a/compiler/injectdestructors.nim b/compiler/injectdestructors.nim
index 90c83124b1..57949dbc4f 100644
--- a/compiler/injectdestructors.nim
+++ b/compiler/injectdestructors.nim
@@ -17,7 +17,7 @@ import
   ast, astalgo, msgs, renderer, magicsys, types, idents,
   options, lowerings, modulegraphs,
   lineinfos, parampatterns, sighashes, liftdestructors, optimizer,
-  varpartitions, aliasanalysis, dfa, wordrecg, trees
+  varpartitions, aliasanalysis, dfa, wordrecg
 
 import std/[strtabs, tables, strutils, intsets]
 
@@ -1244,55 +1244,6 @@ when false:
       for i in 0..<n.safeLen:
         injectDefaultCalls(n[i], c)
 
-proc replaceSinkParam(n: PNode, mapping: Table[int, PSym]): PNode =
-  case n.kind
-  of nkSym:
-    if n.sym.id in mapping:
-      result = newSymNode(mapping[n.sym.id])
-    else:
-      result = n
-  of nkVarSection, nkLetSection:
-    result = copyNode(n)
-    newSons(result, n.len)
-    for i in 0..<n.len:
-      result[i] = copyNode(n[i])
-      for j in 0..<n[i].len-1:
-        result[i].add n[i][j]
-      result[i].add replaceSinkParam(n[i][^1], mapping)
-  of {nkNone..nkNilLit}-{nkSym}, nkTypeSection, nkProcDef, nkConverterDef,
-      nkMethodDef, nkIteratorDef, nkMacroDef, nkTemplateDef, nkLambda, nkDo,
-      nkFuncDef, nkConstSection, nkConstDef, nkIncludeStmt, nkImportStmt,
-      nkExportStmt, nkPragma, nkCommentStmt, nkBreakState,
-      nkTypeOfExpr, nkMixinStmt, nkBindStmt:
-    result = n
-  else:
-    result = copyNode(n)
-    for i in 0..<n.len:
-      result.add replaceSinkParam(n[i], mapping)
-
-proc addSinkCopy(c: var Con; s: var Scope; sinkParams: seq[PSym]; n: PNode): PNode =
-  result = newNodeI(nkStmtList, n.info)
-  var mapping = initTable[int, PSym]()
-
-  var mutated = newSeq[PNode]()
-  getPotentialWrites(n, false, mutated)
-  var mutatedSet = initIntSet()
-  for m in mutated:
-    mutatedSet.incl m.sym.id
-  for param in sinkParams:
-    if param.id in mutatedSet:
-      let newSym = newSym(skTemp, getIdent(c.graph.cache, "sinkCopy"), c.idgen, param.owner, n.info)
-      newSym.flags.incl sfFromGeneric
-      newSym.typ = param.typ.elementType
-      mapping[param.id] = newSym
-      let v = newNodeI(nkVarSection, n.info)
-      v.addVar(newSymNode(newSym), newSymNode(param))
-      result.add v
-  if mapping.len > 0:
-    result.add replaceSinkParam(n, mapping)
-  else:
-    result = n
-
 proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n: PNode): PNode =
   when toDebug.len > 0:
     shouldDebug = toDebug == owner.name.s or toDebug == "always"
@@ -1306,24 +1257,15 @@ proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n:
   var scope = Scope(body: n)
   let body = p(n, c, scope, normal)
 
-  var sinkParams = newSeq[PSym]()
-
   if owner.kind in {skProc, skFunc, skMethod, skIterator, skConverter}:
     let params = owner.typ.n
     for i in 1..<params.len:
       let t = params[i].sym.typ
-      if isSinkTypeForParam(t):
-        let baseType = t.skipTypes({tySink})
-        if baseType.kind in {tyString, tySequence, tyArray, tyTuple, tyObject}:
-          sinkParams.add params[i].sym
-        if hasDestructor(c, baseType):
-          scope.final.add c.genDestroy(params[i])
+      if isSinkTypeForParam(t) and hasDestructor(c, t.skipTypes({tySink})):
+        scope.final.add c.genDestroy(params[i])
   #if optNimV2 in c.graph.config.globalOptions:
   #  injectDefaultCalls(n, c)
   result = optimize processScope(c, scope, body)
-  if sinkParams.len > 0:
-    result = addSinkCopy(c, scope, sinkParams, result)
-
   dbg:
     echo ">---------transformed-to--------->"
     echo renderTree(result, {renderIds})
diff --git a/compiler/trees.nim b/compiler/trees.nim
index 6d9c0272d6..da58878f82 100644
--- a/compiler/trees.nim
+++ b/compiler/trees.nim
@@ -243,32 +243,3 @@ proc isRunnableExamples*(n: PNode): bool =
 
 proc skipAddr*(n: PNode): PNode {.inline.} =
   result = if n.kind in {nkAddr, nkHiddenAddr}: n[0] else: n
-
-proc getPotentialWrites*(n: PNode; mutate: bool; result: var seq[PNode]) =
-  case n.kind:
-  of nkLiterals, nkIdent, nkFormalParams: discard
-  of nkSym:
-    if mutate: result.add n
-  of nkAsgn, nkFastAsgn, nkSinkAsgn:
-    getPotentialWrites(n[0], true, result)
-    getPotentialWrites(n[1], mutate, result)
-  of nkAddr, nkHiddenAddr:
-    getPotentialWrites(n[0], true, result)
-  of nkBracketExpr, nkDotExpr, nkCheckedFieldExpr:
-    getPotentialWrites(n[0], mutate, result)
-  of nkCallKinds:
-    case n.getMagic:
-    of mIncl, mExcl, mInc, mDec, mAppendStrCh, mAppendStrStr, mAppendSeqElem,
-        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy:
-      getPotentialWrites(n[1], true, result)
-      for i in 2..<n.len:
-        getPotentialWrites(n[i], mutate, result)
-    of mSwap, mMove:
-      for i in 1..<n.len:
-        getPotentialWrites(n[i], true, result)
-    else:
-      for i in 1..<n.len:
-        getPotentialWrites(n[i], mutate, result)
-  else:
-    for s in n:
-      getPotentialWrites(s, mutate, result)