Optional additional performance improvement

Author: Stephan202

check_api/src/main/java/com/google/errorprone/VisitorState.java

@@ -771,7 +771,7 @@ private static final class SharedState {
    * Like {@link Elements#getConstantExpression}, but doesn't over-escape single quotes in strings.
    */
   public String getConstantExpression(Object value) {
-    if (!(value instanceof String str)) {
+    if (!(value instanceof CharSequence str)) {
       return getElements().getConstantExpression(value);
     }
 

core/src/main/java/com/google/errorprone/bugpatterns/RobolectricShadowDirectlyOn.java

@@ -73,7 +73,7 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
     MethodSymbol symbol = getSymbol(parent);
     String argReplacement =
         Streams.concat(
-                Stream.of(state.getConstantExpression(symbol.getSimpleName().toString())),
+                Stream.of(state.getConstantExpression(symbol.getSimpleName())),
                 Streams.zip(
                     symbol.getParameters().stream(),
                     parent.getArguments().stream(),

core/src/main/java/com/google/errorprone/bugpatterns/flogger/FloggerArgumentToString.java

@@ -351,7 +351,7 @@ Description unwrapArguments(
     if (!fixed) {
       return NO_MATCH;
     }
-    fix.replace(tree.getArguments().get(0), state.getConstantExpression(sb.toString()));
+    fix.replace(tree.getArguments().get(0), state.getConstantExpression(sb));
     return describeMatch(tree, fix.build());
   }
 

core/src/main/java/com/google/errorprone/bugpatterns/flogger/FloggerStringConcatenation.java

@@ -112,7 +112,7 @@ protected Void defaultAction(Tree tree, Void unused) {
         tree,
         SuggestedFix.replace(
             argument,
-            state.getConstantExpression(formatString.toString())
+            state.getConstantExpression(formatString)
                 + ", "
                 + formatArguments.stream().map(state::getSourceForNode).collect(joining(", "))));
   }

core/src/test/java/com/google/errorprone/VisitorStateTest.java

@@ -106,6 +106,8 @@ public void getConstantExpression() {
     assertThat(visitorState.getConstantExpression("hello \n world"))
         .isEqualTo("\"hello \\n world\"");
     assertThat(visitorState.getConstantExpression('\'')).isEqualTo("'\\''");
+    assertThat(visitorState.getConstantExpression(new StringBuilder("hello ' world")))
+        .isEqualTo("\"hello ' world\"");
   }
 
   // The following is taken from ErrorProneJavacPluginTest. There may be an easier way.