followup #17777: declaredloc field error msgs now work with generics (#18259)

* followup #17777: declaredloc field error msgs now work with generics

* fix tests

* cleanup

Author: timotheecour

compiler/astmsgs.nim

@@ -2,6 +2,11 @@
 import std/strutils
 import options, ast, msgs
 
+proc typSym*(t: PType): PSym =
+  result = t.sym
+  if result == nil and t.kind == tyGenericInst: # this might need to be refined
+    result = t[0].sym
+
 proc addDeclaredLoc*(result: var string, conf: ConfigRef; sym: PSym) =
   result.add " [$1 declared in $2]" % [sym.kind.toHumanStr, toFileLineCol(conf, sym.info)]
 

compiler/semcall.nim

@@ -326,7 +326,7 @@ proc getMsgDiagnostic(c: PContext, flags: TExprFlags, n, f: PNode): string =
 
   let ident = considerQuotedIdent(c, f, n).s
   if {nfDotField, nfExplicitCall} * n.flags == {nfDotField}:
-    let sym = n[1].typ.sym
+    let sym = n[1].typ.typSym
     var typeHint = ""
     if sym == nil:
       # Perhaps we're in a `compiles(foo.bar)` expression, or
@@ -337,7 +337,8 @@ proc getMsgDiagnostic(c: PContext, flags: TExprFlags, n, f: PNode): string =
       discard
     else:
       typeHint = " for type " & getProcHeader(c.config, sym)
-    result = errUndeclaredField % ident & typeHint & " " & result
+    let suffix = if result.len > 0: " " & result else: ""
+    result = errUndeclaredField % ident & typeHint & suffix
   else:
     if result.len == 0: result = errUndeclaredRoutine % ident
     else: result = errBadRoutine % [ident, result]

tests/errmsgs/tundeclared_field.nim

@@ -2,38 +2,48 @@ discard """
 cmd: '''nim check --hints:off $file'''
 action: reject
 nimout: '''
-tundeclared_field.nim(25, 12) Error: undeclared field: 'bad' for type tundeclared_field.A [type declared in tundeclared_field.nim(22, 8)]
-tundeclared_field.nim(30, 16) Error: undeclared field: 'bad' for type tundeclared_field.A [type declared in tundeclared_field.nim(28, 8)]
-tundeclared_field.nim(36, 4) Error: undeclared field: 'bad' for type tundeclared_field.A [type declared in tundeclared_field.nim(33, 8)]
-tundeclared_field.nim(40, 13) Error: cannot instantiate Foo [type declared in tundeclared_field.nim(39, 8)]
+tundeclared_field.nim(25, 12) Error: undeclared field: 'bad1' for type tundeclared_field.A [type declared in tundeclared_field.nim(22, 8)]
+tundeclared_field.nim(30, 17) Error: undeclared field: 'bad2' for type tundeclared_field.A [type declared in tundeclared_field.nim(28, 8)]
+tundeclared_field.nim(36, 4) Error: undeclared field: 'bad3' for type tundeclared_field.A [type declared in tundeclared_field.nim(33, 8)]
+tundeclared_field.nim(42, 12) Error: undeclared field: 'bad4' for type tundeclared_field.B [type declared in tundeclared_field.nim(39, 8)]
+tundeclared_field.nim(43, 4) Error: undeclared field: 'bad5' for type tundeclared_field.B [type declared in tundeclared_field.nim(39, 8)]
+tundeclared_field.nim(44, 23) Error: undeclared field: 'bad6' for type tundeclared_field.B [type declared in tundeclared_field.nim(39, 8)]
+tundeclared_field.nim(46, 19) Error: undeclared field: 'bad7' for type tundeclared_field.B [type declared in tundeclared_field.nim(39, 8)]
+tundeclared_field.nim(50, 13) Error: cannot instantiate Foo [type declared in tundeclared_field.nim(49, 8)]
 '''
 """
 
-
-
-
-
-
-
-
-
+#[
+xxx in future work, generic instantiations (e.g. `B[int]`) should be shown with their instantiation instead of `tundeclared_field.B`,
+maybe using TPreferedDesc.preferResolved or preferMixed
+]#
 # line 20
 block:
   type A = object
     a0: int
   var a: A
-  discard a.bad
+  discard a.bad1
 
 block:
   type A = object
     a0: int
-  var a = A(bad: 0)
+  var a = A(bad2: 0)
 
 block:
   type A = object
     a0: int
   var a: A
-  a.bad = 0
+  a.bad3 = 0
+
+block:
+  type B[T] = object
+    b0: int
+  var b: B[int]
+  discard b.bad4
+  b.bad5 = 0
+  var b2 = B[int](bad6: 0)
+  type Bi = B[int]
+  var b3 = Bi(bad7: 0)
 
 block:
   type Foo[T: SomeInteger] = object