First steps, the compiler can boot with enforced requiresInit

compiler/ast.nim

@@ -517,8 +517,10 @@ type
     tfPartial,        # type is declared as 'partial'
     tfNotNil,         # type cannot be 'nil'
 
-    tfNeedsInit,      # type constains a "not nil" constraint somewhere or some
+    tfHasRequiresInit,# type constains a "not nil" constraint somewhere or
-                      # other type so that it requires initialization
+                      # a `requiresInit` field, so the default zero init
+                      # is not appropriate
+    tfRequiresInit,   # all fields of the type must be initialized
     tfVarIsPtr,       # 'var' type is translated like 'ptr' even in C++ mode
     tfHasMeta,        # type contains "wildcard" sub-types such as generic params
                       # or other type classes
@@ -1484,11 +1486,11 @@ proc propagateToOwner*(owner, elem: PType; propagateHasAsgn = true) =
     if owner.kind in {tyGenericInst, tyGenericBody, tyGenericInvocation}:
       owner.flags.incl tfNotNil
     elif owner.kind notin HaveTheirOwnEmpty:
-      owner.flags.incl tfNeedsInit
+      owner.flags.incl tfHasRequiresInit
 
-  if tfNeedsInit in elem.flags:
+  if tfRequiresInit in elem.flags:
     if owner.kind in HaveTheirOwnEmpty: discard
-    else: owner.flags.incl tfNeedsInit
+    else: owner.flags.incl tfHasRequiresInit
 
   if elem.isMetaType:
     owner.flags.incl tfHasMeta

compiler/pragmas.nim

@@ -1088,7 +1088,7 @@ proc singlePragma(c: PContext, sym: PSym, n: PNode, i: var int,
       of wRequiresInit:
         noVal(c, it)
         if sym.typ == nil: invalidPragma(c, it)
-        else: incl(sym.typ.flags, tfNeedsInit)
+        else: incl(sym.typ.flags, tfRequiresInit)
       of wByRef:
         noVal(c, it)
         if sym == nil or sym.typ == nil:

compiler/semobjconstr.nim

@@ -138,7 +138,7 @@ proc fieldsPresentInInitExpr(c: PContext, fieldsRecList, initExpr: PNode): strin
 
 proc missingMandatoryFields(c: PContext, fieldsRecList, initExpr: PNode): string =
   for r in directFieldsInRecList(fieldsRecList):
-    if {tfNotNil, tfNeedsInit} * r.sym.typ.flags != {}:
+    if {tfNotNil, tfRequiresInit} * r.sym.typ.flags != {}:
       let assignment = locateFieldInInitExpr(c, r.sym, initExpr)
       if assignment == nil:
         if result.len == 0:
@@ -358,15 +358,10 @@ proc semObjConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
 
   # It's possible that the object was not fully initialized while
   # specifying a .requiresInit. pragma.
-  # XXX: Turn this into an error in the next release
+  if tfRequiresInit in t.flags and initResult != initFull:
-  if tfNeedsInit in t.flags and initResult != initFull:
+    localError(c.config, n.info,
-    # XXX: Disable this warning for now, because tfNeedsInit is propagated
-    # too aggressively from fields to object types (and this is not correct
-    # in case objects)
-    when false: message(n.info, warnUser,
       "object type uses the 'requiresInit' pragma, but not all fields " &
-      "have been initialized. future versions of Nim will treat this as " &
+      "have been initialized.")
-      "an error")
 
   # Since we were traversing the object fields, it's possible that
   # not all of the fields specified in the constructor was visited.

compiler/sempass2.nim

@@ -184,7 +184,7 @@ proc initVar(a: PEffects, n: PNode; volatileCheck: bool) =
 proc initVarViaNew(a: PEffects, n: PNode) =
   if n.kind != nkSym: return
   let s = n.sym
-  if {tfNeedsInit, tfNotNil} * s.typ.flags <= {tfNotNil}:
+  if {tfRequiresInit, tfNotNil} * s.typ.flags <= {tfNotNil}:
     # 'x' is not nil, but that doesn't mean its "not nil" children
     # are initialized:
     initVar(a, n, volatileCheck=true)
@@ -253,7 +253,7 @@ proc useVar(a: PEffects, n: PNode) =
       # If the variable is explicitly marked as .noinit. do not emit any error
       a.init.add s.id
     elif s.id notin a.init:
-      if {tfNeedsInit, tfNotNil} * s.typ.flags != {}:
+      if {tfRequiresInit, tfNotNil} * s.typ.flags != {}:
         message(a.config, n.info, warnProveInit, s.name.s)
       else:
         message(a.config, n.info, warnUninit, s.name.s)
@@ -838,7 +838,7 @@ proc track(tracked: PEffects, n: PNode) =
       # may not look like an assignment, but it is:
       let arg = n[1]
       initVarViaNew(tracked, arg)
-      if arg.typ.len != 0 and {tfNeedsInit} * arg.typ.lastSon.flags != {}:
+      if arg.typ.len != 0 and {tfRequiresInit} * arg.typ.lastSon.flags != {}:
         if a.sym.magic == mNewSeq and n[2].kind in {nkCharLit..nkUInt64Lit} and
             n[2].intVal == 0:
           # var s: seq[notnil];  newSeq(s, 0)  is a special case!
@@ -1203,7 +1203,7 @@ proc trackProc*(c: PContext; s: PSym, body: PNode) =
         createTypeBoundOps(t, typ, param.info)
 
   if not isEmptyType(s.typ[0]) and
-      ({tfNeedsInit, tfNotNil} * s.typ[0].flags != {} or
+      ({tfRequiresInit, tfNotNil} * s.typ[0].flags != {} or
       s.typ[0].skipTypes(abstractInst).kind == tyVar) and
       s.kind in {skProc, skFunc, skConverter, skMethod}:
     var res = s.ast[resultPos].sym # get result symbol

compiler/semstmts.nim

@@ -336,7 +336,7 @@ proc semIdentDef(c: PContext, n: PNode, kind: TSymKind): PSym =
 
 proc checkNilable(c: PContext; v: PSym) =
   if {sfGlobal, sfImportc} * v.flags == {sfGlobal} and
-      {tfNotNil, tfNeedsInit} * v.typ.flags != {}:
+      {tfNotNil, tfRequiresInit} * v.typ.flags != {}:
     if v.astdef.isNil:
       message(c.config, v.info, warnProveInit, v.name.s)
     elif tfNotNil in v.typ.flags and not v.astdef.typ.isNil and tfNotNil notin v.astdef.typ.flags:

compiler/semtypes.nim

@@ -139,7 +139,7 @@ proc semEnum(c: PContext, n: PNode, prev: PType): PType =
     if isPure and (let conflict = strTableInclReportConflict(symbols, e); conflict != nil):
       wrongRedefinition(c, e.info, e.name.s, conflict.info)
     inc(counter)
-  if tfNotNil in e.typ.flags and not hasNull: incl(result.flags, tfNeedsInit)
+  if tfNotNil in e.typ.flags and not hasNull: incl(result.flags, tfRequiresInit)
 
 proc semSet(c: PContext, n: PNode, prev: PType): PType =
   result = newOrPrevType(tySet, prev, c)
@@ -254,15 +254,15 @@ proc semRange(c: PContext, n: PNode, prev: PType): PType =
       result = semRangeAux(c, n[1], prev)
       let n = result.n
       if n[0].kind in {nkCharLit..nkUInt64Lit} and n[0].intVal > 0:
-        incl(result.flags, tfNeedsInit)
+        incl(result.flags, tfRequiresInit)
       elif n[1].kind in {nkCharLit..nkUInt64Lit} and n[1].intVal < 0:
-        incl(result.flags, tfNeedsInit)
+        incl(result.flags, tfRequiresInit)
       elif n[0].kind in {nkFloatLit..nkFloat64Lit} and
           n[0].floatVal > 0.0:
-        incl(result.flags, tfNeedsInit)
+        incl(result.flags, tfRequiresInit)
       elif n[1].kind in {nkFloatLit..nkFloat64Lit} and
           n[1].floatVal < 0.0:
-        incl(result.flags, tfNeedsInit)
+        incl(result.flags, tfRequiresInit)
     else:
       if n[1].kind == nkInfix and considerQuotedIdent(c, n[1][0]).s == "..<":
         localError(c.config, n[0].info, "range types need to be constructed with '..', '..<' is not supported")

tests/types/temptyseqs.nim

@@ -75,16 +75,16 @@ varargso("foo", "bar", "baz")
 
 type
   Flago = enum
-    tfNeedsInit, tfNotNil
+    tfRequiresInit, tfNotNil
 
-var s: set[Flago] = {tfNeedsInit}
+var s: set[Flago] = {tfRequiresInit}
 
-if {tfNeedsInit, tfNotNil} * s != {}:
+if {tfRequiresInit, tfNotNil} * s != {}:
   echo "yes"
 else:
   echo "no"
 
-if {tfNeedsInit, tfNotNil} * s <= {tfNotNil}:
+if {tfRequiresInit, tfNotNil} * s <= {tfNotNil}:
   echo "yes"
 else:
   echo "no"