feat(cxx_indexer): Read the semantic field into metadata for #5037 (#…

…5040) This also fixes a possible problem where all fields of a Rule may not be initialized in protobuf_metadata_file.cc.
kythe · Aug 19, 2021 · 06c49fc · 06c49fc
1 parent 2524ef6
commit 06c49fc
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Showing 4 changed files with 28 additions and 6 deletions.
diff --git a/kythe/cxx/common/kythe_metadata_file.cc b/kythe/cxx/common/kythe_metadata_file.cc
@@ -123,16 +123,27 @@ absl::optional<MetadataFile::Rule> MetadataFile::LoadMetaElement(
   }
 
   absl::string_view edge_string = mapping.edge();
-  if (edge_string.empty()) {
+  if (edge_string.empty() && !(mapping.type() == MappingRule::ANCHOR_DEFINES &&
+                               mapping.semantic() != MappingRule::SEMA_NONE)) {
     LOG(WARNING) << "When loading metadata: empty edge.";
     return absl::nullopt;
   }
-
   bool reverse_edge = absl::ConsumePrefix(&edge_string, "%");
   if (mapping.type() == MappingRule::ANCHOR_DEFINES) {
     if (!CheckVName(mapping.vname())) {
       return absl::nullopt;
     }
+    Semantic sema;
+    switch (mapping.semantic()) {
+      case MappingRule::SEMA_WRITE:
+        sema = Semantic::kWrite;
+        break;
+      case MappingRule::SEMA_READ_WRITE:
+        sema = Semantic::kReadWrite;
+        break;
+      default:
+        sema = Semantic::kNone;
+    }
     return MetadataFile::Rule{mapping.begin(),
                               mapping.end(),
                               kythe::common::schema::kDefinesBinding,
@@ -141,7 +152,9 @@ absl::optional<MetadataFile::Rule> MetadataFile::LoadMetaElement(
                               reverse_edge,
                               false,
                               0,
-                              0};
+                              0,
+                              false,
+                              sema};
   } else if (mapping.type() == MappingRule::ANCHOR_ANCHOR) {
     if (!CheckVName(mapping.source_vname())) {
       return absl::nullopt;

diff --git a/kythe/cxx/common/kythe_metadata_file.h b/kythe/cxx/common/kythe_metadata_file.h
@@ -31,6 +31,13 @@ namespace kythe {
 
 class MetadataFile {
  public:
+  /// \brief An additional semantic to apply to the given (C++) node.
+  enum class Semantic {
+    kNone,       ///< No special semantics.
+    kWrite,      ///< Write semantics.
+    kReadWrite,  ///< Read+write semantics.
+  };
+
   /// \brief A single metadata rule.
   struct Rule {
     unsigned begin;        ///< Beginning of the range to match.
@@ -44,6 +51,7 @@ class MetadataFile {
     unsigned anchor_begin;  ///< The beginning of the anchor.
     unsigned anchor_end;    ///< The end of the anchor.
     bool whole_file;        ///< Whether to ignore begin/end
+    Semantic semantic;      ///< Whether to apply special semantics.
   };
 
   /// Creates a new MetadataFile from a list of rules ranging from `begin` to

diff --git a/kythe/cxx/common/protobuf_metadata_file.cc b/kythe/cxx/common/protobuf_metadata_file.cc
@@ -66,7 +66,7 @@ std::unique_ptr<kythe::MetadataFile> ProtobufMetadataSupport::ParseFile(
   std::vector<MetadataFile::Rule> rules;
   int file_rule = -1;
   for (const auto& annotation : info.annotation()) {
-    MetadataFile::Rule rule;
+    MetadataFile::Rule rule{};
     rule.whole_file = false;
     rule.begin = annotation.begin();
     rule.end = annotation.end();
@@ -90,7 +90,7 @@ std::unique_ptr<kythe::MetadataFile> ProtobufMetadataSupport::ParseFile(
   // source file. (Other VNames end up due to the inclusion of
   // forward-declarations early in the .h).
   if (file_rule >= 0) {
-    MetadataFile::Rule rule;
+    MetadataFile::Rule rule{};
     rule.whole_file = true;
     rule.vname = rules[file_rule].vname;
     rule.vname.set_signature("");

diff --git a/kythe/cxx/indexer/cxx/KytheGraphObserver.cc b/kythe/cxx/indexer/cxx/KytheGraphObserver.cc
@@ -400,7 +400,8 @@ void KytheGraphObserver::MetaHookDefines(const MetadataFile& meta,
                                          const VNameRef& decl) {
   auto rules = meta.rules().equal_range(range_begin);
   for (auto rule = rules.first; rule != rules.second; ++rule) {
-    if (rule->second.begin == range_begin && rule->second.end == range_end &&
+    if (rule->second.semantic == MetadataFile::Semantic::kNone &&
+        rule->second.begin == range_begin && rule->second.end == range_end &&
         (rule->second.edge_in == kythe::common::schema::kDefines ||
          rule->second.edge_in == kythe::common::schema::kDefinesBinding)) {
       VNameRef remote(rule->second.vname);