Merge branch 'devel' into araq-icu

compiler/ccgtypes.nim

@@ -2283,3 +2283,21 @@ proc genTypeSection(m: BModule, n: PNode) =
       discard getTypeDescAux(m, s.typ, intSet, descKindFromSymKind(s.kind))
       if m.g.generatedHeader != nil:
         discard getTypeDescAux(m.g.generatedHeader, s.typ, intSet, descKindFromSymKind(s.kind))
+
+# Unlike genCppInitializer which returns just the braced value list (e.g. "{a, b}"),
+# genCppConstructorExpr returns a full type-prefixed expression (e.g. "Foo(a, b)").
+# This is used when a standalone construction expression is needed — e.g. on the
+# right-hand side of an assignment — whereas genCppInitializer is used in variable
+# declarations where the type is already written separately before the initializer.
+proc genCppConstructorExpr(m: BModule, prc: BProc; typ: PType; didGenTemp: var bool): Snippet =
+  var params = ""
+  if typ.itemId in m.g.graph.initializersPerType:
+    let call = m.g.graph.initializersPerType[typ.itemId]
+    if call != nil:
+      var p = prc
+      if p == nil:
+        p = BProc(module: m)
+      params = genCppParamsForCtor(p, call, didGenTemp)
+      if prc == nil:
+        assert p.blocks.len == 0, "BProc belongs to a struct doesnt have blocks"
+  result = getTypeDesc(m, typ, dkVar) & "(" & params & ")"

compiler/cgen.nim

@@ -613,7 +613,7 @@ proc resetLoc(p: BProc, loc: var TLoc) =
   if isImportedCppType(typ):
     var didGenTemp = false
     let rl = rdLoc(loc)
-    let init = genCppInitializer(p.module, p, typ, didGenTemp)
+    let init = genCppConstructorExpr(p.module, p, typ, didGenTemp)
     p.s(cpsStmts).addAssignment(rl, init)
     return
   if optSeqDestructors in p.config.globalOptions and typ.kind in {tyString, tySequence}:

compiler/sem.nim

@@ -89,6 +89,18 @@ proc fitNodePostMatch(c: PContext, formal: PType, arg: PNode): PNode =
     changeType(c, x, formal, check=true)
   result = arg
   result = skipHiddenSubConv(result, c.graph, c.idgen)
+  # Walk through nested statement-list/block expressions to find the innermost
+  # value node. Empty containers (e.g. `@[]`) inside `nkStmtListExpr` wrappers
+  # need their type resolved to match the formal type, otherwise the C codegen
+  # cannot map `tyEmpty` to a concrete type (fixes #25945).
+  var tail = result
+  while tail.kind in {nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr, nkPragmaBlock} and tail.len > 0:
+    tail = tail.lastSon
+
+  if tail.typ != nil and tail.typ.isEmptyContainer and
+        formal.kind notin {tyUntyped, tyBuiltInTypeClass, tyAnything}:
+    changeType(c, tail, formal, check=true)
+
   # mark inserted converter as used:
   var a = result
   if a.kind == nkHiddenDeref: a = a[0]

compiler/sempass2.nim

@@ -93,6 +93,7 @@ type
     graph: ModuleGraph
     c: PContext
     escapingParams: IntSet
+    inNimvmBranch: int
   PEffects = var TEffects
 
 const
@@ -1127,7 +1128,7 @@ proc trackCall(tracked: PEffects; n: PNode) =
   # sfCompileTime` path in `semProcAux`.
   if a.kind == nkSym and a.sym.magic in {mNLen..mNError, mSlurp..mQuoteAst} and
       tracked.owner != nil and tracked.owner.kind in routineKinds and
-      tracked.config.cmd != cmdNimscript:
+      tracked.config.cmd != cmdNimscript and tracked.inNimvmBranch == 0:
     # ...but NOT under `nim e`: nimscript has no codegen backend to protect, and
     # marking a routine `sfCompileTime` makes `semExpr` eagerly fold calls to it
     # at sem time (emConst), where module-level globals it reads have no VM slot
@@ -1483,7 +1484,9 @@ proc track(tracked: PEffects, n: PNode) =
   of nkCaseStmt: trackCase(tracked, n)
   of nkWhen: # This should be a "when nimvm" node.
     let oldState = tracked.init.len
+    inc tracked.inNimvmBranch
     track(tracked, n[0][1])
+    dec tracked.inNimvmBranch
     tracked.init.setLen(oldState)
     track(tracked, n[1][0])
   of nkIfStmt, nkIfExpr: trackIf(tracked, n)