From c3777ea10388f97d49de26292a3f05dcd6fed8d5 Mon Sep 17 00:00:00 2001
From: Geoffrey Martin-Noble <gcmn@google.com>
Date: Mon, 20 May 2019 11:00:24 -0700
Subject: [PATCH]     Define a string join tablegen utility

--

PiperOrigin-RevId: 249083600
---
 mlir/include/mlir/IR/OpBase.td | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/mlir/include/mlir/IR/OpBase.td b/mlir/include/mlir/IR/OpBase.td
index 48c35e5..429032d 100644
--- a/mlir/include/mlir/IR/OpBase.td
+++ b/mlir/include/mlir/IR/OpBase.td
@@ -27,12 +27,17 @@
 // Common utilities for defining TableGen mechanisms
 //===----------------------------------------------------------------------===//
 
-// Concatenates a list of integers into a string separated with comma.
-class Stringify<list<int> integers> {
-  string result = !foldl(/*init*/!cast<string>(!head(integers)),
-                         /*list*/!tail(integers), prev, cur, prev # ", " # cur);
+// Concatenates a list of strings with a separator (default ", ")
+class StrJoin<list<string> strings, string sep = ", "> {
+  string result =
+      !if(!empty(strings), "",
+          !foldl(!head(strings), !tail(strings), prev, cur, prev # sep # cur));
 }
 
+// Concatenates a list of integers into a string separated with comma.
+class Stringify<list<int> integers> :
+    StrJoin<!foreach(i, integers, !cast<string>(i))>;
+
 //===----------------------------------------------------------------------===//
 // Predicate definitions
 //===----------------------------------------------------------------------===//
@@ -269,11 +274,7 @@ class AnyTypeOf<list<Type> allowedTypes, string description = ""> : Type<
     // Satisfy any of the allowed type's condition
     Or<!foreach(allowedtype, allowedTypes, allowedtype.predicate)>,
     !if(!eq(description, ""),
-        // Join all allowed types' descriptions with " or " as the description
-        // if not provided during template specialization
-        !foldl(!head(allowedTypes).description, !tail(allowedTypes), prev, cur,
-               prev # " or " # cur.description),
-        // Otherwise use the provided one
+        StrJoin<!foreach(t, allowedTypes, t.description), " or ">.result,
         description)>;
 
 // Integer types.
-- 
2.7.4