fixes #3770; templates with untyped parameters resolve private fields… (#22014)

fixes #3770; templates with untyped parameters resolve private fields wrongly in generics (#21554)

* fixes #3770; templates with untyped parameters resolve private fields wrongly

* add a test case for #3770

* rename to `nfSkipFieldChecking`

compiler/ast.nim

@@ -505,6 +505,7 @@ type
     nfLastRead  # this node is a last read
     nfFirstWrite# this node is a first write
     nfHasComment # node has a comment
+    nfSkipFieldChecking # node skips field visable checking
 
   TNodeFlags* = set[TNodeFlag]
   TTypeFlag* = enum   # keep below 32 for efficiency reasons (now: 45)
@@ -1071,7 +1072,8 @@ const
                                       nfDotSetter, nfDotField,
                                       nfIsRef, nfIsPtr, nfPreventCg, nfLL,
                                       nfFromTemplate, nfDefaultRefsParam,
-                                      nfExecuteOnReload, nfLastRead, nfFirstWrite}
+                                      nfExecuteOnReload, nfLastRead,
+                                      nfFirstWrite, nfSkipFieldChecking}
   namePos* = 0
   patternPos* = 1    # empty except for term rewriting macros
   genericParamsPos* = 2

compiler/semgnrc.nim

@@ -78,14 +78,18 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
     if macroToExpandSym(s):
       onUse(n.info, s)
       result = semTemplateExpr(c, n, s, {efNoSemCheck})
+      c.friendModules.add(s.owner.getModule)
       result = semGenericStmt(c, result, {}, ctx)
+      discard c.friendModules.pop()
     else:
       result = symChoice(c, n, s, scOpen)
   of skMacro:
     if macroToExpandSym(s):
       onUse(n.info, s)
       result = semMacroExpr(c, n, n, s, {efNoSemCheck})
+      c.friendModules.add(s.owner.getModule)
       result = semGenericStmt(c, result, {}, ctx)
+      discard c.friendModules.pop()
     else:
       result = symChoice(c, n, s, scOpen)
   of skGenericParam:
@@ -249,7 +253,9 @@ proc semGenericStmt(c: PContext, n: PNode,
         if macroToExpand(s) and sc.safeLen <= 1:
           onUse(fn.info, s)
           result = semMacroExpr(c, n, n, s, {efNoSemCheck})
+          c.friendModules.add(s.owner.getModule)
           result = semGenericStmt(c, result, flags, ctx)
+          discard c.friendModules.pop()
         else:
           n[0] = sc
           result = n
@@ -258,7 +264,9 @@ proc semGenericStmt(c: PContext, n: PNode,
         if macroToExpand(s) and sc.safeLen <= 1:
           onUse(fn.info, s)
           result = semTemplateExpr(c, n, s, {efNoSemCheck})
+          c.friendModules.add(s.owner.getModule)
           result = semGenericStmt(c, result, flags, ctx)
+          discard c.friendModules.pop()
         else:
           n[0] = sc
           result = n
@@ -497,6 +505,20 @@ proc semGenericStmt(c: PContext, n: PNode,
   of nkExprColonExpr, nkExprEqExpr:
     checkMinSonsLen(n, 2, c.config)
     result[1] = semGenericStmt(c, n[1], flags, ctx)
+  of nkObjConstr:
+    for i in 0..<n.len:
+      result[i] = semGenericStmt(c, n[i], flags, ctx)
+    if result[0].kind == nkSym:
+      let fmoduleId = getModule(result[0].sym).id
+      var isVisable = false
+      for module in c.friendModules:
+        if module.id == fmoduleId:
+          isVisable = true
+          break
+      if isVisable:
+        for i in 1..<result.len:
+          if result[i].kind == nkExprColonExpr:
+            result[i][1].flags.incl nfSkipFieldChecking
   else:
     for i in 0..<n.len:
       result[i] = semGenericStmt(c, n[i], flags, ctx)

compiler/semobjconstr.nim

@@ -72,7 +72,9 @@ proc semConstrField(c: PContext, flags: TExprFlags,
   let assignment = locateFieldInInitExpr(c, field, initExpr)
   if assignment != nil:
     if nfSem in assignment.flags: return assignment[1]
-    if not fieldVisible(c, field):
+    if nfSkipFieldChecking in assignment[1].flags:
+      discard
+    elif not fieldVisible(c, field):
       localError(c.config, initExpr.info,
         "the field '$1' is not accessible." % [field.name.s])
       return

tests/generics/m3770.nim

@@ -0,0 +1,6 @@
+type
+  Noice* = object
+    hidden: int
+  
+template jjj*: Noice =
+  Noice(hidden: 15)

tests/generics/t3770.nim

@@ -0,0 +1,9 @@
+# bug #3770
+import m3770
+
+doAssert $jjj() == "(hidden: 15)"  # works
+
+proc someGeneric(_: type) =
+  doAssert $jjj() == "(hidden: 15)" # fails: "Error: the field 'hidden' is not accessible."
+
+someGeneric(int)