Remove (attr 0) from tag text format (#3946)

This attribute is always 0 and reserved for future use. In Binayren's
unofficial text format we were writing this field as `(attr 0)`, but we
have recently come to the conclusion that this is not necessary.

Relevant discussion:
https://github.com/WebAssembly/exception-handling/pull/160#discussion_r653254680

1 files changed, 0 insertions, 22 deletions

diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index c688630c3..8bedeab9f 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -3109,14 +3109,6 @@ void SExpressionWasmBuilder::parseImport(Element& s) {
     }
   } else if (kind == ExternalKind::Tag) {
     auto tag = make_unique<Tag>();
-    if (j >= inner.size()) {
-      throw ParseException("tag does not have an attribute", s.line, s.col);
-    }
-    auto& attrElem = *inner[j++];
-    if (!elementStartsWith(attrElem, ATTR) || attrElem.size() != 2) {
-      throw ParseException("invalid attribute", attrElem.line, attrElem.col);
-    }
-    tag->attribute = atoi(attrElem[1]->c_str());
     j = parseTypeUse(inner, j, tag->sig);
     tag->setName(name, hasExplicitName);
     tag->module = module;
@@ -3498,20 +3490,6 @@ void SExpressionWasmBuilder::parseTag(Element& s, bool preParseImport) {
     ex->kind = ExternalKind::Tag;
   }
 
-  // Parse attribute
-  if (i >= s.size()) {
-    throw ParseException("tag does not have an attribute", s.line, s.col);
-  }
-  auto& attrElem = *s[i++];
-  if (!elementStartsWith(attrElem, ATTR) || attrElem.size() != 2) {
-    throw ParseException("invalid attribute", attrElem.line, attrElem.col);
-  }
-  if (!attrElem[1]->isStr()) {
-    throw ParseException(
-      "invalid attribute", attrElem[1]->line, attrElem[1]->col);
-  }
-  tag->attribute = atoi(attrElem[1]->c_str());
-
   // Parse typeuse
   i = parseTypeUse(s, i, tag->sig);