From 4d0663096cb4dd41dc4aa18d935df03d3a567f22 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Tue, 9 Jun 2026 20:46:48 +0800
Subject: [PATCH] Revert "fixes #22122; raise effects for complex expressions"
 (#25888)

Reverts nim-lang/Nim#25845

```nim
case ecode
of ECONNABORTED, EPERM, ETIMEDOUT, ENOTCONN:
  getConnectionAbortedError(ecode)
of EMFILE, ENFILE, ENOBUFS, ENOMEM:
  getTransportTooManyError(ecode)
else:
  (ref TransportOsError)(code: ecode,
                         msg: "(" & $int(ecode) & ") " & osErrorMsg(ecode))
```

The compiler inserts a hidden conv for the case expression. Perhaps we
can skip hidden convs to inspect the types that are actually raised
---
 compiler/sempass2.nim          | 22 +---------
 tests/effects/tcase_raises.nim | 74 ----------------------------------
 2 files changed, 1 insertion(+), 95 deletions(-)
 delete mode 100644 tests/effects/tcase_raises.nim

diff --git a/compiler/sempass2.nim b/compiler/sempass2.nim
index 75ad510b1a..7b2be510f9 100644
--- a/compiler/sempass2.nim
+++ b/compiler/sempass2.nim
@@ -497,26 +497,6 @@ proc addRaiseEffect(a: PEffects, e, comesFrom: PNode) =
     if not isDefectException(e.typ):
       throws(a.exc, e, comesFrom)
 
-proc addRaiseEffectsFromExpr(a: PEffects, e, comesFrom: PNode) =
-  if e.isNil:
-    return
-  let x = skipConvCastAndClosure(e)
-  case x.kind
-  of nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr:
-    if x.len > 0:
-      addRaiseEffectsFromExpr(a, x.lastSon, comesFrom)
-  of nkIfExpr, nkIfStmt:
-    for branch in items(x):
-      if branch.len > 0:
-        addRaiseEffectsFromExpr(a, branch.lastSon, comesFrom)
-  of nkCaseStmt:
-    for i in 1..<x.len:
-      let branch = x[i]
-      if branch.len > 0:
-        addRaiseEffectsFromExpr(a, branch.lastSon, comesFrom)
-  else:
-    addRaiseEffect(a, x, x)
-
 proc addTag(a: PEffects, e, comesFrom: PNode) =
   var aa = a.tags
   for i in 0..<aa.len:
@@ -1346,7 +1326,7 @@ proc track(tracked: PEffects, n: PNode) =
     if n[0].kind != nkEmpty:
       n[0].info = n.info
       #throws(tracked.exc, n[0])
-      addRaiseEffectsFromExpr(tracked, n[0], n)
+      addRaiseEffect(tracked, n[0], n)
       for i in 0..<n.safeLen:
         track(tracked, n[i])
       createTypeBoundOps(tracked, n[0].typ, n.info)
diff --git a/tests/effects/tcase_raises.nim b/tests/effects/tcase_raises.nim
deleted file mode 100644
index 166a79d5c2..0000000000
--- a/tests/effects/tcase_raises.nim
+++ /dev/null
@@ -1,74 +0,0 @@
-from std/os import osLastError, osErrorMsg, OSErrorCode, raiseOSError,
-                   newOSError, `==`
-
-{.push raises: [].}
-
-const
-  EPERM* = OSErrorCode(1)
-  ECONNABORTED* = OSErrorCode(53)
-  ETIMEDOUT* = OSErrorCode(60)
-  ENOTCONN* = OSErrorCode(107)
-  EMFILE* = OSErrorCode(24)
-  ENFILE* = OSErrorCode(23)
-  ENOBUFS* = OSErrorCode(55)
-  ENOMEM* = OSErrorCode(12)
-
-type
-  AsyncError* = object of CatchableError
-  TransportErrorBase* = object of AsyncError
-  TransportOsError* = object of TransportErrorBase
-    code*: OSErrorCode
-  TransportTooManyError* = object of TransportErrorBase
-  TransportAbortedError* = object of TransportErrorBase
-
-template getConnectionAbortedError*(
-           code: OSErrorCode
-         ): ref TransportAbortedError =
-  let msg =
-    case code
-    of OSErrorCode(0), ECONNABORTED:
-      "[ECONNABORTED] Connection has been aborted before being accepted"
-    of EPERM:
-      "[EPERM] Firewall rules forbid connection"
-    of ETIMEDOUT:
-      "[ETIMEDOUT] Operation has been timed out"
-    of ENOTCONN:
-      "[ENOTCONN] Transport endpoint is not connected"
-    else:
-      "[" & $int(code) & "] Connection has been aborted"
-  newException(TransportAbortedError, msg)
-
-template getTransportTooManyError*(
-           code = OSErrorCode(0)
-         ): ref TransportTooManyError =
-  let msg =
-    case code
-    of OSErrorCode(0):
-      "Too many open transports"
-    of EMFILE:
-      "[EMFILE] Too many open files in the process"
-    of ENFILE:
-      "[ENFILE] Too many open files in system"
-    of ENOBUFS:
-      "[ENOBUFS] No buffer space available"
-    of ENOMEM:
-      "[ENOMEM] Not enough memory availble"
-    else:
-      "[" & $int(code) & "] Too many open transports"
-  newException(TransportTooManyError, msg)
-
-template getTransportError*(ecode: OSErrorCode): untyped =
-  case ecode
-  of ECONNABORTED, EPERM, ETIMEDOUT, ENOTCONN:
-    getConnectionAbortedError(ecode)
-  of EMFILE, ENFILE, ENOBUFS, ENOMEM:
-    getTransportTooManyError(ecode)
-  else:
-    (ref TransportOsError)(code: ecode,
-                           msg: "(" & $int(ecode) & ") " & osErrorMsg(ecode))
-
-proc raiseTransportError*(err: OSErrorCode) {.
-     raises: [TransportAbortedError, TransportTooManyError, TransportOsError],
-     noreturn.} =
-  ## Raises transport specific OS error.
-  raise getTransportError(err)
\ No newline at end of file