fixes #24850; macro-generated if/else and when/else statements have m… (#24852)

…ismatched indentation with repr

fixes #24850

(cherry picked from commit 29a2e25d1e)

compiler/renderer.nim

@@ -557,8 +557,16 @@ proc lsub(g: TSrcGen; n: PNode): int =
   of nkIfExpr:
     result = lsub(g, n[0][0]) + lsub(g, n[0][1]) + lsons(g, n, 1) +
         len("if_:_")
-  of nkElifExpr: result = lsons(g, n) + len("_elif_:_")
-  of nkElseExpr: result = lsub(g, n[0]) + len("_else:_") # type descriptions
+  of nkElifExpr, nkElifBranch:
+    if isEmptyType(n[1].typ):
+      result = lsons(g, n) + len("elif_:_")
+    else:
+      result = lsons(g, n) + len("_elif_:_")
+  of nkElseExpr, nkElse:
+    if isEmptyType(n[0].typ):
+      result = lsub(g, n[0]) + len("else:_")
+    else:
+      result = lsub(g, n[0]) + len("_else:_") # type descriptions
   of nkTypeOfExpr: result = (if n.len > 0: lsub(g, n[0]) else: 0)+len("typeof()")
   of nkRefTy: result = (if n.len > 0: lsub(g, n[0])+1 else: 0) + len("ref")
   of nkPtrTy: result = (if n.len > 0: lsub(g, n[0])+1 else: 0) + len("ptr")
@@ -601,8 +609,6 @@ proc lsub(g: TSrcGen; n: PNode): int =
   of nkCommentStmt: result = n.comment.len
   of nkOfBranch: result = lcomma(g, n, 0, - 2) + lsub(g, lastSon(n)) + len("of_:_")
   of nkImportAs: result = lsub(g, n[0]) + len("_as_") + lsub(g, n[1])
-  of nkElifBranch: result = lsons(g, n) + len("elif_:_")
-  of nkElse: result = lsub(g, n[0]) + len("else:_")
   of nkFinally: result = lsub(g, n[0]) + len("finally:_")
   of nkGenericParams: result = lcomma(g, n) + 2
   of nkFormalParams:
@@ -1459,15 +1465,30 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
     putWithSpace(g, tkColon, ":")
     if n.len > 0: gsub(g, n[0], 1)
     gsons(g, n, emptyContext, 1)
-  of nkElifExpr:
-    putWithSpace(g, tkElif, " elif")
-    gcond(g, n[0])
-    putWithSpace(g, tkColon, ":")
-    gsub(g, n, 1)
-  of nkElseExpr:
-    put(g, tkElse, " else")
-    putWithSpace(g, tkColon, ":")
-    gsub(g, n, 0)
+  of nkElifExpr, nkElifBranch:
+    if isEmptyType(n[1].typ):
+      optNL(g)
+      putWithSpace(g, tkElif, "elif")
+      gsub(g, n, 0)
+      putWithSpace(g, tkColon, ":")
+      gcoms(g)
+      gstmts(g, n[1], c)
+    else:
+      putWithSpace(g, tkElif, " elif")
+      gcond(g, n[0])
+      putWithSpace(g, tkColon, ":")
+      gsub(g, n, 1)
+  of nkElseExpr, nkElse:
+    if isEmptyType(n[0].typ):
+      optNL(g)
+      put(g, tkElse, "else")
+      putWithSpace(g, tkColon, ":")
+      gcoms(g)
+      gstmts(g, n[0], c)
+    else:
+      put(g, tkElse, " else")
+      putWithSpace(g, tkColon, ":")
+      gsub(g, n, 0)
   of nkTypeOfExpr:
     put(g, tkType, "typeof")
     put(g, tkParLe, "(")
@@ -1729,19 +1750,6 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
   of nkMixinStmt:
     putWithSpace(g, tkMixin, "mixin")
     gcomma(g, n, c)
-  of nkElifBranch:
-    optNL(g)
-    putWithSpace(g, tkElif, "elif")
-    gsub(g, n, 0)
-    putWithSpace(g, tkColon, ":")
-    gcoms(g)
-    gstmts(g, n[1], c)
-  of nkElse:
-    optNL(g)
-    put(g, tkElse, "else")
-    putWithSpace(g, tkColon, ":")
-    gcoms(g)
-    gstmts(g, n[0], c)
   of nkFinally, nkDefer:
     optNL(g)
     if n.kind == nkFinally:

tests/arc/topt_cursor.nim

@@ -9,7 +9,8 @@ var
 try:
   x_cursor = ("hi", 5)
   if cond:
-    x_cursor = ("different", 54) else:
+    x_cursor = ("different", 54)
+  else:
     x_cursor = ("string here", 80)
   echo [
     :tmpD = `$$`(x_cursor)

tests/arc/topt_no_cursor.nim

@@ -128,7 +128,8 @@ if dirExists(this.value):
   var :tmpD
   par = (dir:
     :tmpD = `=dup`(this.value)
-    :tmpD, front: "") else:
+    :tmpD, front: "")
+else:
   var
     :tmpD_1
     :tmpD_2

tests/stdlib/trepr.nim

@@ -326,3 +326,27 @@ do:
 
 static: main()
 main()
+
+import std/macros
+
+# bug #24850
+macro a() =
+  let
+    y = quote do: discard
+    b = nnkIfStmt.newTree(
+          nnkElifExpr.newTree(ident "true", y), nnkElseExpr.newTree(y))
+    d = nnkWhenStmt.newTree(
+          nnkElifExpr.newTree(ident "true", y), nnkElseExpr.newTree(y))
+  doAssert repr(b) == """
+if true:
+  discard
+else:
+  discard"""
+
+  doAssert repr(d) == """
+when true:
+  discard
+else:
+  discard"""
+
+a()