Generalize ConstantPatternCompile

PiperOrigin-RevId: 364667499
google · Mar 23, 2021 · 3e14f54 · 3e14f54
1 parent 456dcf0
commit 3e14f54
Showing 1 changed file with 47 additions and 56 deletions.
diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/ConstantPatternCompile.java b/core/src/main/java/com/google/errorprone/bugpatterns/ConstantPatternCompile.java
@@ -16,33 +16,27 @@
 
 package com.google.errorprone.bugpatterns;
 
+import static com.google.common.base.CaseFormat.LOWER_CAMEL;
+import static com.google.common.base.CaseFormat.UPPER_UNDERSCORE;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.fixes.SuggestedFixes.renameVariableUsages;
+import static com.google.errorprone.matchers.Description.NO_MATCH;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
-import static com.google.errorprone.util.ASTHelpers.getStartPosition;
-import static com.google.errorprone.util.ASTHelpers.getType;
 
-import com.google.common.base.CaseFormat;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker.VariableTreeMatcher;
 import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
-import com.google.errorprone.matchers.Matchers;
-import com.google.errorprone.suppliers.Supplier;
-import com.google.errorprone.suppliers.Suppliers;
 import com.google.errorprone.util.ASTHelpers;
-import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.MethodTree;
-import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
 import com.sun.tools.javac.code.Flags;
 import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
-import com.sun.tools.javac.code.Type;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.NestingKind;
 
@@ -58,64 +52,61 @@
     severity = SUGGESTION)
 public final class ConstantPatternCompile extends BugChecker implements VariableTreeMatcher {
 
-  private static final String PATTERN_CLASS = "java.util.regex.Pattern";
-  private static final Supplier<Type> PATTERN_TYPE = Suppliers.typeFromString(PATTERN_CLASS);
-
   private static final Matcher<ExpressionTree> PATTERN_COMPILE_CHECK =
-      Matchers.<ExpressionTree>anyOf(staticMethod().onClass(PATTERN_CLASS).named("compile"));
+      staticMethod()
+          .onClassAny(
+              "java.util.regex.Pattern"
+              )
+          .named("compile");
 
   @Override
   public Description matchVariable(VariableTree tree, VisitorState state) {
-    Tree parent = state.getPath().getParentPath().getLeaf();
-    if (parent instanceof ClassTree) {
-      return Description.NO_MATCH;
-    }
-    if (!ASTHelpers.isSameType(getType(tree.getType()), PATTERN_TYPE.get(state), state)) {
-      return Description.NO_MATCH;
-    }
-    if (!(tree.getInitializer() instanceof MethodInvocationTree)) {
-      return Description.NO_MATCH;
+    ExpressionTree initializer = tree.getInitializer();
+    if (!PATTERN_COMPILE_CHECK.matches(initializer, state)) {
+      return NO_MATCH;
     }
-    MethodInvocationTree methodInvocationTree = (MethodInvocationTree) tree.getInitializer();
-    if (!PATTERN_COMPILE_CHECK.matches(methodInvocationTree, state)) {
-      return Description.NO_MATCH;
-    }
-    if (!methodInvocationTree.getArguments().stream()
-        .allMatch(ConstantPatternCompile::isArgStaticAndConstant)) {
-      return Description.NO_MATCH;
+    if (!((MethodInvocationTree) initializer)
+        .getArguments().stream().allMatch(ConstantPatternCompile::isArgStaticAndConstant)) {
+      return NO_MATCH;
     }
     MethodTree outerMethodTree = ASTHelpers.findEnclosingNode(state.getPath(), MethodTree.class);
     if (outerMethodTree == null) {
-      return Description.NO_MATCH;
+      return NO_MATCH;
+    }
+    Symbol sym = ASTHelpers.getSymbol(tree);
+    if (sym == null) {
+      return NO_MATCH;
+    }
+    switch (sym.getKind()) {
+      case RESOURCE_VARIABLE:
+        return describeMatch(tree);
+      case LOCAL_VARIABLE:
+        return describeMatch(tree, fixLocal(tree, outerMethodTree, state));
+      default:
+        return NO_MATCH;
     }
-    MethodSymbol sym = ASTHelpers.getSymbol(outerMethodTree);
+  }
+
+  private static SuggestedFix fixLocal(
+      VariableTree tree, MethodTree outerMethodTree, VisitorState state) {
+    MethodSymbol methodSymbol = ASTHelpers.getSymbol(outerMethodTree);
     boolean canUseStatic =
-        (sym != null && sym.owner.enclClass().getNestingKind() == NestingKind.TOP_LEVEL)
+        (methodSymbol != null
+                && methodSymbol.owner.enclClass().getNestingKind() == NestingKind.TOP_LEVEL)
             || outerMethodTree.getModifiers().getFlags().contains(Modifier.STATIC);
-
-    String originalVariableTreeString = state.getSourceForNode(tree);
-    String varName = tree.getName().toString();
-    String upperUnderscoreVarName = CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, varName);
-
-    int typeEndPos = state.getEndPosition(tree.getType());
-    // handle implicit lambda parameter types
-    int searchOffset = typeEndPos == -1 ? 0 : (typeEndPos - getStartPosition(tree));
-    int pos = state.getSourceForNode(tree).indexOf(varName, searchOffset);
-    String variableReplacedString =
-        new StringBuilder(originalVariableTreeString)
-            .replace(pos, pos + varName.length(), upperUnderscoreVarName)
-            .toString();
-
-    String modifiers = "private " + (canUseStatic ? "static " : "") + "final ";
-    String variableTreeString = "\n" + modifiers + variableReplacedString + "\n";
-
-    SuggestedFix fix =
-        SuggestedFix.builder()
-            .merge(renameVariableUsages(tree, upperUnderscoreVarName, state))
-            .postfixWith(outerMethodTree, variableTreeString)
-            .delete(tree)
-            .build();
-    return describeMatch(tree, fix);
+    String newName = LOWER_CAMEL.to(UPPER_UNDERSCORE, tree.getName().toString());
+    String replacement =
+        String.format(
+            "private %s final %s %s = %s;",
+            canUseStatic ? "static " : "",
+            state.getSourceForNode(tree.getType()),
+            newName,
+            state.getSourceForNode(tree.getInitializer()));
+    return SuggestedFix.builder()
+        .merge(renameVariableUsages(tree, newName, state))
+        .postfixWith(outerMethodTree, replacement)
+        .delete(tree)
+        .build();
   }
 
   private static boolean isArgStaticAndConstant(ExpressionTree arg) {