From 9f4bee30b067acb662ba4f172673538d1cac9280 Mon Sep 17 00:00:00 2001
From: Javed Absar <javed.absar@arm.com>
Date: Tue, 26 Mar 2019 11:16:01 +0000
Subject: [PATCH] [TableGen] Let list elements have a trailing comma

Let lists have an trailing comma to allow cleaner diffs e.g:
  def : Features<[FeatureA,
                  FeatureB,
                 ]>;
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D59247

llvm-svn: 356986
---
 lib/TableGen/TGParser.cpp | 4 ++++
 test/TableGen/ListArgs.td | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/lib/TableGen/TGParser.cpp b/lib/TableGen/TGParser.cpp
index 3fc2e53f208..f9486d4469d 100644
--- a/lib/TableGen/TGParser.cpp
+++ b/lib/TableGen/TGParser.cpp
@@ -2283,6 +2283,10 @@ void TGParser::ParseValueList(SmallVectorImpl<Init*> &Result, Record *CurRec,
   while (Lex.getCode() == tgtok::comma) {
     Lex.Lex();  // Eat the comma
 
+    // ignore trailing comma for lists
+    if (Lex.getCode() == tgtok::r_square)
+      return;
+
     if (ArgsRec && !EltTy) {
       ArrayRef<Init *> TArgs = ArgsRec->getTemplateArgs();
       if (ArgN >= TArgs.size()) {
diff --git a/test/TableGen/ListArgs.td b/test/TableGen/ListArgs.td
index 8714112d137..4d2713a1cab 100644
--- a/test/TableGen/ListArgs.td
+++ b/test/TableGen/ListArgs.td
@@ -10,3 +10,7 @@ class BBB<list<list<int>> vals> : BB<vals>;
 
 def OneB : BBB<[[1,2,3]]>;
 def TwoB : BBB<[[1,2,3],[4,5,6]]>;
+
+def ThreeB: BBB<[[1,2,3],
+                 [4,5,6],
+                ]>;