Merge #216

216: debug: detailed information about visited locations r=saem a=haxscramper

- Add more detailed information about visited locations in the cyclic
  ASTs - show node numbers, and display `<visisted Kind in ID>` (e.g.
  `<visited Sym in 0>`
- Ignore repeated visitations of the `Empty` node - they are reused, so it
  only adds confusion, since ast looks like it is insanely cyclic.
- Fix duplicated `.comment` annotations from the `CommentStmtNode` -
  `addFlags()` and `addComment()` was called twice.



Co-authored-by: haxscramper <haxscramper@gmail.com>

compiler/utils/astrepr.nim

@@ -14,7 +14,7 @@ import
   ],
   experimental/colortext,
   std/[
-    sets,
+    tables,
     strutils,
     strformat,
   ]
@@ -28,6 +28,7 @@ type
     trfPackedFields
     trfSkipAuxError
     trfSymDefined
+    trfIndexVisisted
 
     trfShowSymFlags
     trfShowSymLineInfo
@@ -63,7 +64,8 @@ const treeReprAllFields* = { trfShowSymFlags .. trfShowNodeTypes }
 const defaultTreeReprFlags* = {
   trfPositionIndexed,
   trfReportInfo,
-  trfSkipAuxError
+  trfSkipAuxError,
+  trfIndexVisisted
 } + treeReprAllFields - {
   trfShowNodeLineInfo,
   trfShowSymLineInfo,
@@ -252,12 +254,15 @@ proc treeRepr*(
     maxPath: int           = 1,
     indentIncrease: int = 0
   ): ColText =
+  ## .. include:: tree_repr_doc.rst
+
+
   coloredResult(1)
 
 
-  var visited: HashSet[int]
+  var visited: Table[int, int]
   var res = addr result
-
+  var nodecount = 0
   proc aux(n: PNode, idx: seq[int]) =
     var indent = indentIncrease
     genFields(res[], indent, flags)
@@ -297,32 +302,52 @@ proc treeRepr*(
       add "<nil>" + fgRed
       return
 
-    elif cast[int](n) in visited:
-      add " <visited>"
+    elif not (n.kind == nkEmpty and n.safeLen == 0) and
+         # empty nodes can be reused. Only check for visitation if it is
+         # not an empty (completely empty) node
+         cast[int](n) in visited:
+
+      if trfIndexVisisted in flags:
+        add "<visited "
+        add substr($n.kind, 2) + fgCyan
+        add " at "
+        add $visited[cast[int](n)] + styleDim
+        add ">"
+
+      else:
+        add "<visited>"
+
       return
 
     elif idx.len > maxDepth:
       add " ..."
       return
 
-    visited.incl cast[int](n)
-
+    visited[cast[int](n)] = nodecount
     add substr($n.kind, 2) + fgCyan
 
+    if trfIndexVisisted in flags:
+      add " "
+      add $nodecount + styleDim
+
+    inc nodecount
+
     when defined(useNodeids):
       if trfShowNodeIds in flags:
         hfield("nid")
         add $n.id
 
     proc addComment(sep: bool = true) =
       if trfShowNodeComments in flags and n.comment.len > 0:
-        add "\n"
         var nl = false
         for line in split(n.comment.strip(leading = false), '\n'):
           if nl: add "\n"
           nl = true
 
-          addi indent, "  # " & line + fgCyan
+          addi indent, "  # " + termFg(4, 2, 1)
+          add line + termFg(4, 2, 1)
+
+        add "\n"
 
       elif sep:
         add " "
@@ -397,6 +422,7 @@ proc treeRepr*(
 
       of nkCommentStmt:
         addFlags()
+        add "\n"
         addComment()
 
       of nkError:
@@ -418,7 +444,7 @@ proc treeRepr*(
         discard
 
 
-    if n.kind notin nkNone .. nkNilLit:
+    if n.kind notin {nkNone .. nkNilLit, nkCommentStmt}:
       addFlags()
       if n.len > 0:
         add "\n"

compiler/utils/tree_repr_doc.rst

@@ -1,5 +1,23 @@
 Generate tree representation from `PNode`.
 
+Procedure arguments:
+
+- `conf`: some configuration options are inferred from it, such as
+  `--filenames:canonical`, but it is mostly used to get full paths from
+  file ids
+- `pnode`: node to be printed - can be `nil`, recursive, `nkError` or any
+  other kind form or shape.
+- `flags`: Set of the formatting options for the procedure. Several
+  built-in constants are defined in this module that might be suitable for
+  different debugging or AST exploration tasks.
+- `maxDepth`: Ignore all nodes that are placed deeper than that. Useful to
+  see a high-level overview for large nodes, such as full proc bodies
+- `maxLength`: on each level, print upto that many subnodes. Useful to cut
+  out parts on large `case` trees, toplevel nodes for modules, statement
+  lists and such.
+- `maxPath`: maximum path length for subnodes
+- `indentIncreas`: start tree indentation from certain formatting
+
 Generated output packs in a lot of information - here is a short list of
 features, those will be elaborated on
 
@@ -19,22 +37,6 @@ features, those will be elaborated on
 - symbol definition location if any
 - type symbols definition location if any
 
-Procedure arguments:
-
-- `conf`: some configuration options are inferred from it, such as
-  `--filenames:canonical`, but it is mostly used to get full paths from
-  file ids
-- `pnode`: node to be printed - can be `nil`, recursive, `nkError` or any
-  other kind form or shape.
-- `flags`: Set of the formatting options for the procedure. Several
-  built-in constants are defined in this module that might be suitable for
-  different debugging or AST exploration tasks.
-- `maxDepth`: Ignore all nodes that are placed deeper than that. Useful to
-  see a high-level overview for large nodes, such as full proc bodies
-- `maxLength`: on each level, print upto that many subnodes. Useful to cut
-  out parts on large `case` trees, toplevel nodes for modules, statement
-  lists and such.
-
 
 .. note:: Output examples in the documentation might be slightly different
           from the actual output due to changes in the default formatting