Cpp: Remove code duplication

The same function was defined inside multiple different source files (in
an anonymous namespace).
Not only is this generally bad practice from a maintenance point of
view, but it also break unity builds (which can speed up compilation
times A LOT).

The fix simply consists in introducing a new Utils file that contains
the single implementation and every source file that uses this function
simply has to be linked against that new file (and include the
corresponding header).

Signed-off-by: Robert Adam <[email protected]>

Author: Krzmbrzl

runtime/Cpp/runtime/src/atn/ArrayPredictionContext.cpp

@@ -8,6 +8,7 @@
 #include <cstring>
 
 #include "atn/SingletonPredictionContext.h"
+#include "atn/Utils.h"
 #include "misc/MurmurHash.h"
 #include "support/Casts.h"
 
@@ -17,10 +18,6 @@ using namespace antlrcpp;
 
 namespace {
 
-  bool cachedHashCodeEqual(size_t lhs, size_t rhs) {
-    return lhs == rhs || lhs == 0 || rhs == 0;
-  }
-
   bool predictionContextEqual(const Ref<const PredictionContext> &lhs, const Ref<const PredictionContext> &rhs) {
     // parent PredictionContext pointers can be null during full context mode and
     // the ctxs are in an ArrayPredictionContext.  If both are null, return true

runtime/Cpp/runtime/src/atn/LexerActionExecutor.cpp

@@ -5,6 +5,7 @@
 
 #include "misc/MurmurHash.h"
 #include "atn/LexerIndexedCustomAction.h"
+#include "atn/Utils.h"
 #include "support/CPPUtils.h"
 #include "support/Arrays.h"
 #include "support/Casts.h"
@@ -18,10 +19,6 @@ using namespace antlrcpp;
 
 namespace {
 
-  bool cachedHashCodeEqual(size_t lhs, size_t rhs) {
-    return lhs == rhs || lhs == 0 || rhs == 0;
-  }
-
   bool lexerActionEqual(const Ref<const LexerAction> &lhs, const Ref<const LexerAction> &rhs) {
     return *lhs == *rhs;
   }

runtime/Cpp/runtime/src/atn/LexerIndexedCustomAction.cpp

@@ -3,6 +3,7 @@
  * can be found in the LICENSE.txt file in the project root.
  */
 
+#include "atn/Utils.h"
 #include "misc/MurmurHash.h"
 #include "Lexer.h"
 #include "support/CPPUtils.h"
@@ -15,14 +16,6 @@ using namespace antlr4::atn;
 using namespace antlr4::misc;
 using namespace antlrcpp;
 
-namespace {
-
-  bool cachedHashCodeEqual(size_t lhs, size_t rhs) {
-    return lhs == rhs || lhs == 0 || rhs == 0;
-  }
-
-}
-
 LexerIndexedCustomAction::LexerIndexedCustomAction(int offset, Ref<const LexerAction> action)
     : LexerAction(LexerActionType::INDEXED_CUSTOM, true), _action(std::move(action)), _offset(offset) {}
 

runtime/Cpp/runtime/src/atn/SingletonPredictionContext.cpp

@@ -7,18 +7,11 @@
 
 #include "support/Casts.h"
 #include "misc/MurmurHash.h"
+#include "atn/Utils.h"
 
 using namespace antlr4::atn;
 using namespace antlrcpp;
 
-namespace {
-
-  bool cachedHashCodeEqual(size_t lhs, size_t rhs) {
-    return lhs == rhs || lhs == 0 || rhs == 0;
-  }
-
-}
-
 SingletonPredictionContext::SingletonPredictionContext(Ref<const PredictionContext> parent, size_t returnState)
     : PredictionContext(PredictionContextType::SINGLETON), parent(std::move(parent)), returnState(returnState) {
   assert(returnState != ATNState::INVALID_STATE_NUMBER);

runtime/Cpp/runtime/src/atn/Utils.cpp

@@ -0,0 +1,16 @@
+/* Copyright (c) 2022 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#include "atn/Utils.h"
+
+namespace antlr4 {
+namespace atn {
+
+  bool cachedHashCodeEqual(size_t lhs, size_t rhs) {
+    return lhs == rhs || lhs == 0 || rhs == 0;
+  }
+
+} // namespace atn
+} // namespace antlr4

runtime/Cpp/runtime/src/atn/Utils.h

@@ -0,0 +1,16 @@
+/* Copyright (c) 2022 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+#include <cstddef>
+
+namespace antlr4 {
+namespace atn {
+
+  bool cachedHashCodeEqual(size_t lhs, size_t rhs);
+
+} // namespace atn
+} // namespace antlr4