[wasm-split] End module names with : in manifests (#8003)

This makes better distinction of module names and function lists.
Suggested by by @sbc100
(emscripten-core/emscripten#25577 (comment)).

Currently this supports both module names with a `:` and without it for
backwards compatibility and also to pass the CI.

Author: aheejin

src/support/istring.h

@@ -88,6 +88,24 @@ struct IString {
     return startsWith(std::string_view(str));
   }
 
+  bool endsWith(std::string_view suffix) const {
+    // TODO: Use C++20 `ends_with`.
+    if (suffix.size() > str.size()) {
+      return false;
+    }
+    return str.substr(str.size() - suffix.size()) == suffix;
+  }
+  bool endsWith(IString str) const { return endsWith(str.str); }
+
+  // Disambiguate for string literals.
+  template<int N> bool endsWith(const char (&str)[N]) const {
+    return endsWith(std::string_view(str));
+  }
+
+  IString substr(size_t pos, size_t len = std::string_view::npos) const {
+    return IString(str.substr(pos, len));
+  }
+
   size_t size() const { return str.size(); }
 };
 

src/tools/wasm-split/wasm-split.cpp

@@ -419,6 +419,12 @@ void multiSplitModule(const WasmSplitOptions& options) {
     }
     Name name = WasmBinaryReader::escape(line);
     if (newSection) {
+      if (name.endsWith(":")) {
+        name = name.substr(0, name.size() - 1);
+        if (name.size() == 0) {
+          Fatal() << "Module name is empty\n";
+        }
+      }
       if (moduleNameSet.count(name)) {
         Fatal() << "Module name " << name << " is listed more than once\n";
       }

test/lit/wasm-split/multi-split-escape-names.wast.manifest

@@ -1,8 +1,8 @@
-1
+1:
 wasm::Type::getFeatures() const
 
-2
+2:
 wasm::Literal::Literal(std::__2::array<wasm::Literal, 4ul> const&)
 
-3
+3:
 std::operator<<(std::__2::basic_ostream<char, std::__2::char_traits<char>>&, wasm::Module&)

test/lit/wasm-split/multi-split.wast.manifest

@@ -1,8 +1,8 @@
-1
+1:
 A
 
-2
+2:
 B
 
-3
+3:
 C