From f7b723c6b628bc5b66655130da5f8d8dc900a19a Mon Sep 17 00:00:00 2001
From: TSUYUSATO Kitsune <make.just.on@gmail.com>
Date: Tue, 2 Feb 2021 07:59:34 +0900
Subject: [PATCH] Parser: refactor 'foo.%` call parsing

Fixed #10296

Currently, `%` call parsing is specialized like `if current_char == '%'`
way in the parser, to avoid a confliction with `%`-string literals.
However, the lexer has `wants_def_or_macro_name` flag for such things,
we should use this instead of custom `if` way.

The commit fixes the formatter also to set `wants_def_or_macro_name`
flag correctly.
---
 spec/compiler/formatter/formatter_spec.cr |  4 ++++
 src/compiler/crystal/syntax/parser.cr     | 25 +++++++++--------------
 src/compiler/crystal/tools/formatter.cr   |  8 ++++++--
 3 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/spec/compiler/formatter/formatter_spec.cr b/spec/compiler/formatter/formatter_spec.cr
index efb9d5f5a747..76cd16bb7a03 100644
--- a/spec/compiler/formatter/formatter_spec.cr
+++ b/spec/compiler/formatter/formatter_spec.cr
@@ -294,6 +294,10 @@ describe Crystal::Formatter do
   assert_format "foo(1, ) do\nend", "foo(1) do\nend"
   assert_format "foo {;1}", "foo { 1 }"
   assert_format "foo {;;1}", "foo { 1 }"
+  assert_format "foo.%(bar)"
+  assert_format "foo.% bar"
+  assert_format "foo.bar(&.%(baz))"
+  assert_format "foo.bar(&.% baz)"
 
   assert_format "foo.bar\n.baz", "foo.bar\n  .baz"
   assert_format "foo.bar.baz\n.qux", "foo.bar.baz\n  .qux"
diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
index 2bd4c821e1e1..630f629cca58 100644
--- a/src/compiler/crystal/syntax/parser.cr
+++ b/src/compiler/crystal/syntax/parser.cr
@@ -637,23 +637,18 @@ module Crystal
 
           @wants_regex = false
 
-          if current_char == '%'
-            next_char
-            @token.type = :"%"
-            @token.column_number += 1
-            skip_space_or_newline
-          else
-            next_token_skip_space_or_newline
+          @wants_def_or_macro_name = true
+          next_token_skip_space_or_newline
+          @wants_def_or_macro_name = false
 
-            if @token.type == :INSTANCE_VAR
-              ivar_name = @token.value.to_s
-              end_location = token_end_location
-              next_token_skip_space
+          if @token.type == :INSTANCE_VAR
+            ivar_name = @token.value.to_s
+            end_location = token_end_location
+            next_token_skip_space
 
-              atomic = ReadInstanceVar.new(atomic, ivar_name).at(location)
-              atomic.end_location = end_location
-              next
-            end
+            atomic = ReadInstanceVar.new(atomic, ivar_name).at(location)
+            atomic.end_location = end_location
+            next
           end
 
           check AtomicWithMethodCheck
diff --git a/src/compiler/crystal/tools/formatter.cr b/src/compiler/crystal/tools/formatter.cr
index b98cb12acb0f..c769d90c0152 100644
--- a/src/compiler/crystal/tools/formatter.cr
+++ b/src/compiler/crystal/tools/formatter.cr
@@ -2555,7 +2555,9 @@ module Crystal
           return false
         end
 
+        @lexer.wants_def_or_macro_name = true
         next_token
+        @lexer.wants_def_or_macro_name = false
         skip_space
         if (@token.type == :NEWLINE) || @wrote_newline
           base_indent = @indent + 2
@@ -2973,8 +2975,10 @@ module Crystal
         write " " if needs_space
         write_token :"&"
         skip_space_or_newline
-        write_token :"."
-        skip_space_or_newline
+        write :"."
+        @lexer.wants_def_or_macro_name = true
+        next_token_skip_space_or_newline
+        @lexer.wants_def_or_macro_name = false
 
         body = node.body
         case body