fix dot calls with resolved symbols in templates (#22076)

* fix dot calls with resolved symbols in templates

* make old code work

* fix custom number literals test

* remove leftover debug marker

* enable "bug 9" test too

* fix renderer, add test for #7085

(cherry picked from commit 71801c2)

compiler/ast.nim

@@ -1113,11 +1113,10 @@ const
 
 proc getPIdent*(a: PNode): PIdent {.inline.} =
   ## Returns underlying `PIdent` for `{nkSym, nkIdent}`, or `nil`.
-  # xxx consider whether also returning the 1st ident for {nkOpenSymChoice, nkClosedSymChoice}
-  # which may simplify code.
   case a.kind
   of nkSym: a.sym.name
   of nkIdent: a.ident
+  of nkOpenSymChoice, nkClosedSymChoice: a.sons[0].sym.name
   else: nil
 
 const

compiler/renderer.nim

@@ -376,6 +376,7 @@ proc atom(g: TSrcGen; n: PNode): string =
   of nkEmpty: result = ""
   of nkIdent: result = n.ident.s
   of nkSym: result = n.sym.name.s
+  of nkClosedSymChoice, nkOpenSymChoice: result = n[0].sym.name.s
   of nkStrLit: result = ""; result.addQuoted(n.strVal)
   of nkRStrLit: result = "r\"" & replace(n.strVal, "\"", "\"\"") & '\"'
   of nkTripleStrLit: result = "\"\"\"" & n.strVal & "\"\"\""

compiler/semtempl.nim

@@ -566,6 +566,14 @@ proc semTemplBody(c: var TemplCtx, n: PNode): PNode =
       inc c.noGenSym
       result[1] = semTemplBody(c, n[1])
       dec c.noGenSym
+      if result[1].kind == nkSym and result[1].sym.kind in routineKinds:
+        # prevent `dotTransformation` from rewriting this node to `nkIdent`
+        # by making it a symchoice
+        # in generics this becomes `nkClosedSymChoice` but this breaks code
+        # as the old behavior here was that this became `nkIdent`
+        var choice = newNodeIT(nkOpenSymChoice, n[1].info, newTypeS(tyNone, c.c))
+        choice.add result[1]
+        result[1] = choice
     else:
       result = semTemplBodySons(c, n)
   of nkExprColonExpr, nkExprEqExpr:

tests/lexer/tcustom_numeric_literals.nim

@@ -134,17 +134,14 @@ template main =
 
   block: # bug 1 from https://github.com/nim-lang/Nim/pull/17020#issuecomment-803193947
     macro deb1(a): untyped = newLit a.repr
-    macro deb2(a): untyped = newLit a.lispRepr
+    macro deb2(a): untyped =
+      a[1] = ident($a[1])
+      newLit a.lispRepr
     doAssert deb1(-12'wrap) == "-12'wrap"
     doAssert deb1(-12'nonexistent) == "-12'nonexistent"
     doAssert deb2(-12'nonexistent) == """(DotExpr (RStrLit "-12") (Ident "\'nonexistent"))"""
-    when false: # xxx bug:
-      # this holds:
-      doAssert deb2(-12.wrap2) == """(DotExpr (IntLit -12) (Sym "wrap2"))"""
-      doAssert deb2(-12'wrap) == """(DotExpr (RStrLit "-12") (Sym "\'wrap"))"""
-      # but instead this should hold:
-      doAssert deb2(-12.wrap2) == """(DotExpr (IntLit -12) (Ident "wrap2"))"""
-      doAssert deb2(-12'wrap) == """(DotExpr (RStrLit "-12") (Ident "\'wrap"))"""
+    doAssert deb2(-12.wrap2) == """(DotExpr (IntLit -12) (Ident "wrap2"))"""
+    doAssert deb2(-12'wrap) == """(DotExpr (RStrLit "-12") (Ident "\'wrap"))"""
 
   block: # bug 2 from https://github.com/nim-lang/Nim/pull/17020#issuecomment-803193947
     template toSuf(`'suf`): untyped =
@@ -165,21 +162,16 @@ template main =
     doAssert fn2() == "[[-12]]"
     doAssert fn3() == "[[-12]]"
 
-    when false: # xxx this fails; bug 9 from https://github.com/nim-lang/Nim/pull/17020#issuecomment-803193947
-      #[
-      possible workaround: use `genAst` (https://github.com/nim-lang/Nim/pull/17426) and this:
-      let a3 = `'wrap3`("-128")
-      ]#
-      block:
-        macro metawrap(): untyped =
-          func wrap1(a: string): string = "{" & a & "}"
-          func `'wrap3`(a: string): string = "{" & a & "}"
-          result = quote do:
-            let a1 = wrap1"-128"
-            let a2 = -128'wrap3
-        metawrap()
-        doAssert a1 == "{-128}"
-        doAssert a2 == "{-128}"
+    block: # bug 9 from https://github.com/nim-lang/Nim/pull/17020#issuecomment-803193947
+      macro metawrap(): untyped =
+        func wrap1(a: string): string = "{" & a & "}"
+        func `'wrap3`(a: string): string = "{" & a & "}"
+        result = quote do:
+          let a1 {.inject.} = wrap1"-128"
+          let a2 {.inject.} = -128'wrap3
+      metawrap()
+      doAssert a1 == "{-128}"
+      doAssert a2 == "{-128}"
 
 static: main()
 main()

tests/template/mdotcall.nim

@@ -0,0 +1,22 @@
+# issue #20073
+
+type Foo = object
+proc foo(f: Foo) = discard
+
+template works*() =
+  var f: Foo
+  foo(f)
+
+template boom*() =
+  var f: Foo
+  f.foo() # Error: attempting to call undeclared routine: 'foo'
+  f.foo # Error: undeclared field: 'foo' for type a.Foo
+
+# issue #7085
+
+proc bar(a: string): string =
+  return a & "bar"
+
+template baz*(a: string): string =
+  var b = a.bar()
+  b

tests/template/tdotcall.nim

@@ -0,0 +1,10 @@
+import mdotcall
+
+# issue #20073
+works()
+boom()
+
+# issue #7085
+doAssert baz("hello") == "hellobar"
+doAssert baz"hello" == "hellobar"
+doAssert "hello".baz == "hellobar"