Add ability to find symbols by name

This can be used in lsp projects to find
all symbols in a workspace  that match a string.

https://bugs.swift.org/browse/SR-10806

Author: literalpie

Sources/IndexStoreDB/IndexStoreDB.swift

@@ -80,6 +80,33 @@ public final class IndexStoreDB {
       return body(SymbolOccurrence(occur))
     }
   }
+
+  public func foreachCanonicalSymbolOccurrenceByName(symbolName: String, body: @escaping (SymbolOccurrence) -> Bool) {
+    indexstoredb_for_each_canonical_symbol_occurence_by_name(impl, symbolName) { (occur) -> Bool in
+      body(SymbolOccurrence(occur))
+    }
+  }
+
+  public func findSymbols(matching query: String) -> [SymbolOccurrence] {
+    var symbolNameResults: [String] = []
+    indexstoredb_for_each_symbol_name(impl) { pointer in
+      let str = String(cString: pointer)
+      if str.range(of: query) != nil {
+        symbolNameResults.append(str)
+      }
+      return true
+    }
+    var symbolOccurenceResults: [SymbolOccurrence] = []
+    symbolNameResults.forEach { (symbolName) in
+      foreachCanonicalSymbolOccurrenceByName(symbolName: symbolName) {occurence in
+        if !occurence.location.isSystem {
+          symbolOccurenceResults.append(occurence)
+        }
+        return true
+      }
+    }
+    return symbolOccurenceResults
+  }
 }
 
 public struct SymbolRole: OptionSet {

include/CIndexStoreDB/CIndexStoreDB.h

@@ -85,6 +85,9 @@ typedef _Nullable indexstoredb_indexstore_library_t(^indexstore_library_provider
 /// Returns true to continue.
 typedef bool(^indexstoredb_symbol_occurrence_receiver_t)(_Nonnull indexstoredb_symbol_occurrence_t);
 
+/// Returns true to continue.
+typedef bool(^indexstoredb_for_each_symbol_receiver)(const char *_Nonnull);
+
 INDEXSTOREDB_PUBLIC _Nullable
 indexstoredb_index_t
 indexstoredb_index_create(const char * _Nonnull storePath,
@@ -159,6 +162,16 @@ indexstoredb_error_get_description(_Nonnull indexstoredb_error_t);
 INDEXSTOREDB_PUBLIC void
 indexstoredb_error_dispose(_Nullable indexstoredb_error_t);
 
+INDEXSTOREDB_PUBLIC bool
+indexstoredb_for_each_symbol_name(_Nonnull indexstoredb_index_t index, _Nonnull indexstoredb_for_each_symbol_receiver);
+
+INDEXSTOREDB_PUBLIC bool
+indexstoredb_for_each_canonical_symbol_occurence_by_name(
+    indexstoredb_index_t _Nonnull index,
+    const char *_Nonnull symbolName,
+    indexstoredb_symbol_occurrence_receiver_t _Nonnull receiver
+);
+
 INDEXSTOREDB_END_DECLS
 
 #endif

lib/CIndexStoreDB/CIndexStoreDB.cpp

@@ -144,6 +144,37 @@ indexstoredb_symbol_name(indexstoredb_symbol_t symbol) {
   return obj->value->getName().c_str();
 }
 
+/// loops through each symbol in the index and calls the receiver function with each symbol
+/// @param index an IndexStoreDB object which contains the symbols
+/// @param receiver a function to be called for each symbol, the CString of the symbol will be passed in to this function.
+/// The function should return a boolean indicating whether the looping should continue.
+bool
+indexstoredb_for_each_symbol_name(indexstoredb_index_t index, indexstoredb_for_each_symbol_receiver receiver) {
+  // indexSystem has foreachsymbolName.
+  auto obj = (IndexStoreDBObject<std::shared_ptr<IndexSystem>> *)index;
+  return obj->value->foreachSymbolName([&](StringRef ref) -> bool {
+    return receiver(ref.str().c_str());
+  });
+}
+
+/// loops through each canonical symbol that matches the string, perform the passed in function
+/// @param index an IndexStoreDB object which contains the symbols
+/// @param symbolName the name of the symbol whose canonical occurence should be found
+/// @param receiver a function to be called for each canonical occurence, 
+/// the SymbolOccurenceRef of the symbol will be passed in to this function.
+/// The function should return a boolean indicating whether the looping should continue.
+bool
+indexstoredb_for_each_canonical_symbol_occurence_by_name(
+  indexstoredb_index_t index,
+  const char *_Nonnull symbolName,
+  indexstoredb_symbol_occurrence_receiver_t receiver)
+{
+  auto obj = (IndexStoreDBObject<std::shared_ptr<IndexSystem>> *)index;
+  return obj->value->foreachCanonicalSymbolOccurrenceByName(symbolName, [&](SymbolOccurrenceRef occur) -> bool {
+    return receiver(make_object(occur));
+  });
+}
+
 indexstoredb_symbol_t
 indexstoredb_symbol_occurrence_symbol(indexstoredb_symbol_occurrence_t occur) {
   auto obj = (IndexStoreDBObject<SymbolOccurrenceRef> *)occur;