add tests for nim-lang#23854 and nim-lang#23855, prepare for cleanup

compiler/semcall.nim

@@ -704,10 +704,6 @@ proc semResolvedCall(c: PContext, x: var TCandidate,
     else:
       # For macros and templates, the resolved generic params
       # are added as normal params.
-      # This is not done with unresolved static arguments, as typed macros
-      # cannot be instantiated yet and semMacroExpr/semTemplateExpr will
-      # reject them and delay their instantiation, when fully resolved types
-      # will be added instead.
       c.inheritBindings(x, expectedType)
       for s in instantiateGenericParamList(c, gp, x.bindings):
         case s.kind

compiler/semexprs.nim

@@ -1500,7 +1500,7 @@ proc tryReadingGenericParam(c: PContext, n: PNode, i: PIdent, t: PType): PNode =
         result.typ = makeTypeFromExpr(c, copyTree(result))
       else:
         result = nil
-  of tyGenericParam, tyAnything:
+  of tyFromExpr, tyGenericParam, tyAnything:
     if true or c.inGenericContext > 0:
       result = semGenericStmt(c, n)
       result.typ = makeTypeFromExpr(c, copyTree(result))

compiler/semgnrc.nim

@@ -105,6 +105,8 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
       if s.typ.n != nil:
         result = s.typ.n
       elif c.inGenericContext > 0 and withinConcept notin flags:
+        # fine to give a symbol node a generic type here since
+        # we are in a generic context and `prepareNode` will be called
         result = newSymNodeTypeDesc(s, c.idgen, n.info)
         if canOpenSym(result.sym):
           if genericsOpenSym in c.features:
@@ -137,6 +139,8 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
           result.flags.incl nfDisabledOpenSym
           result.typ = nil
     elif c.inGenericContext > 0 and withinConcept notin flags:
+      # fine to give a symbol node a generic type here since
+      # we are in a generic context and `prepareNode` will be called
       result = newSymNodeTypeDesc(s, c.idgen, n.info)
       if canOpenSym(result.sym):
         if genericsOpenSym in c.features:

tests/generics/t23854.nim

@@ -0,0 +1,65 @@
+# issue #23854
+
+import std/bitops
+
+const WordBitWidth = sizeof(pointer) * 8
+
+func wordsRequired*(bits: int): int {.inline.} =
+  const divShiftor = fastLog2(uint32(WordBitWidth))
+  result = (bits + WordBitWidth - 1) shr divShiftor
+
+type
+  Algebra* = enum
+    BLS12_381
+
+  BigInt*[bits: static int] = object
+    limbs*: array[wordsRequired(bits), uint]
+
+  Fr*[Name: static Algebra] = object
+    residue_form*: BigInt[255]
+
+  Fp*[Name: static Algebra] = object
+    residue_form*: BigInt[381]
+
+  FF*[Name: static Algebra] = Fp[Name] or Fr[Name]
+
+type
+  EC_ShortW_Aff*[F] = object
+    ## Elliptic curve point for a curve in Short Weierstrass form
+    ##   y² = x³ + a x + b
+    ##
+    ## over a field F
+    x*, y*: F
+
+type FieldKind* = enum
+  kBaseField
+  kScalarField
+
+template getBigInt*[Name: static Algebra](T: type FF[Name]): untyped =
+  ## Get the underlying BigInt type.
+  BigInt[123]
+
+func bits*[Name: static Algebra](T: type FF[Name]): static int =
+  T.getBigInt().bits
+
+template getScalarField*(EC: type EC_ShortW_Aff): untyped =
+  Fr[EC.F.Name]
+
+# ------------------------------------------------------------------------------
+
+type
+  ECFFT_Descriptor*[EC] = object
+    ## Metadata for FFT on Elliptic Curve
+    order*: int
+    rootsOfUnity1*: ptr UncheckedArray[BigInt[EC.getScalarField().bits()]]  # Error: in expression 'EC.getScalarField()': identifier expected, but found 'EC.getScalarField'
+    rootsOfUnity2*: ptr UncheckedArray[BigInt[getScalarField(EC).bits()]] # Compiler SIGSEGV: Illegal Storage Access
+
+func new*(T: type ECFFT_Descriptor): T =
+  discard
+
+# ------------------------------------------------------------------------------
+
+proc main() =
+  let ctx = ECFFT_Descriptor[EC_ShortW_Aff[Fp[BLS12_381]]].new()
+
+main()

tests/generics/t23855.nim

@@ -0,0 +1,57 @@
+# issue #23855
+
+import std/bitops
+
+const WordBitWidth = sizeof(pointer) * 8
+
+func wordsRequired*(bits: int): int {.inline.} =
+  const divShiftor = fastLog2(uint32(WordBitWidth))
+  result = (bits + WordBitWidth - 1) shr divShiftor
+
+type
+  Algebra* = enum
+    BLS12_381
+
+  BigInt*[bits: static int] = object
+    limbs*: array[wordsRequired(bits), uint]
+
+  Fr*[Name: static Algebra] = object
+    residue_form*: BigInt[255]
+
+  Fp*[Name: static Algebra] = object
+    residue_form*: BigInt[381]
+
+  FF*[Name: static Algebra] = Fp[Name] or Fr[Name]
+
+template getBigInt*[Name: static Algebra](T: type FF[Name]): untyped =
+  ## Get the underlying BigInt type.
+  BigInt[123]
+
+type
+  EC_ShortW_Aff*[F] = object
+    ## Elliptic curve point for a curve in Short Weierstrass form
+    ##   y² = x³ + a x + b
+    ##
+    ## over a field F
+    x*, y*: F
+
+func bits*[Name: static Algebra](T: type FF[Name]): static int =
+  T.getBigInt().bits
+
+# ------------------------------------------------------------------------------
+
+type
+  ECFFT_Descriptor*[EC] = object
+    ## Metadata for FFT on Elliptic Curve
+    order*: int
+    rootsOfUnity*: ptr UncheckedArray[BigInt[Fr[EC.F.Name].bits()]] # Undeclared identifier `Name`
+
+func new*(T: type ECFFT_Descriptor): T =
+  discard
+
+# ------------------------------------------------------------------------------
+
+proc main() =
+  let ctx = ECFFT_Descriptor[EC_ShortW_Aff[Fp[BLS12_381]]].new()
+
+main()