[clang-format] Recognize percents as format specifiers in protos

[krasimir]

Summary

Frequently, a percent in protos denotes a formatting specifier for string replacement.
Thus it is desirable to keep the percent together with what follows after it.

[djasper]

Ok.. I guess ;)

lib/Format/TokenAnnotator.cpp

if (Style.isCpp()) {
     if (Right.isOneOf(tok::l_brace, tok::less) && Left.is(TT_SelectorName))
       return true;
     // Slashes occur in text protocol extension syntax: [type/type] { ... }.
     if (Left.is(tok::slash) || Right.is(tok::slash))
       return false;
     if (Left.MatchingParen && Left.MatchingParen->is(TT_ProtoExtensionLSquare) &&
         Right.isOneOf(tok::l_brace, tok::less))
       return !Style.Cpp11BracedListStyle;
+    // A percent is probably part of a formatting specification, such as %lld.
+    if (Left.is(tok::percent))
+      return false;
   } else if (Style.Language == FormatStyle::LK_JavaScript) {
     if (Left.is(TT_JsFatArrow))
       return true;
     // for await ( ...
     if (Right.is(tok::l_paren) && Left.is(Keywords.kw_await) && Left.Previous &&
         Left.Previous->is(tok::kw_for))
       return true;
     if (Left.is(Keywords.kw_async) && Right.is(tok::l_paren) &&

unittests/Format/FormatTestProto.cpp

verifyFormat("option (MyProto.options) = {\n"
                "  [ext.t/u] { key: value }\n"
                "  key: value\n"
                "  [t.u/v] <\n"
                "    [ext] { key: value }\n"
                "  >\n"
                "};");
 }
 
+TEST_F(FormatTestProto, NoSpaceAfterPercent) {
+  verifyFormat("option (MyProto.options) = {\n"
+               "  key: %lld\n"
+               "};");
+}
+
 } // end namespace tooling
 } // end namespace clang

unittests/Format/FormatTestTextProto.cpp

verifyFormat("[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
                "}");
   verifyFormat("[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/\n"
                " bbbbbbb] {\n"
                "  [type.type] {\n"
                "    keyyyyyyyyyyyyyy: valuuuuuuuuuuuuuuuuuuuuuuuuue\n"
                "  }\n"
                "}");
 }
+
+TEST_F(FormatTestTextProto, NoSpaceAfterPercent) {
+  verifyFormat("key: %d");
+}
 } // end namespace tooling
 } // end namespace clang