Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
com.google.errorprone.bugpatterns.inlineme.Inliner Maven / Gradle / Ivy
/*
* Copyright 2021 The Error Prone Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.errorprone.bugpatterns.inlineme;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.collect.MoreCollectors.onlyElement;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.util.ASTHelpers.getReceiver;
import static com.google.errorprone.util.ASTHelpers.getSymbol;
import static com.google.errorprone.util.ASTHelpers.hasDirectAnnotationWithSimpleName;
import static com.google.errorprone.util.MoreAnnotations.asStringValue;
import static com.google.errorprone.util.MoreAnnotations.getValue;
import static com.google.errorprone.util.SideEffectAnalysis.hasSideEffect;
import com.google.auto.value.AutoValue;
import com.google.common.base.CharMatcher;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.errorprone.BugPattern;
import com.google.errorprone.ErrorProneFlags;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.bugpatterns.BugChecker.NewClassTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.fixes.SuggestedFixes;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.MoreAnnotations;
import com.sun.source.tree.ExpressionStatementTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Attribute;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.parser.JavaTokenizer;
import com.sun.tools.javac.parser.ScannerFactory;
import com.sun.tools.javac.parser.Tokens.Token;
import com.sun.tools.javac.parser.Tokens.TokenKind;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import java.nio.CharBuffer;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;
/**
* Checker that performs the inlining at call-sites (where the invoked APIs are annotated as
* {@code @InlineMe}).
*/
@BugPattern(
name = "InlineMeInliner",
summary = "Callers of this API should be inlined.",
severity = WARNING,
tags = Inliner.FINDING_TAG)
public final class Inliner extends BugChecker
implements MethodInvocationTreeMatcher, NewClassTreeMatcher {
public static final String FINDING_TAG = "JavaInlineMe";
static final String PREFIX_FLAG = "InlineMe:Prefix";
static final String SKIP_COMMENTS_FLAG = "InlineMe:SkipInliningsWithComments";
private static final Splitter PACKAGE_SPLITTER = Splitter.on('.');
private static final String CHECK_FIX_COMPILES = "InlineMe:CheckFixCompiles";
private static final String INLINE_ME = "InlineMe";
private static final String VALIDATION_DISABLED = "InlineMeValidationDisabled";
private final ImmutableSet apiPrefixes;
private final boolean skipCallsitesWithComments;
private final boolean checkFixCompiles;
public Inliner(ErrorProneFlags flags) {
this.apiPrefixes =
ImmutableSet.copyOf(flags.getSet(PREFIX_FLAG).orElse(ImmutableSet.of()));
this.skipCallsitesWithComments = flags.getBoolean(SKIP_COMMENTS_FLAG).orElse(true);
this.checkFixCompiles = flags.getBoolean(CHECK_FIX_COMPILES).orElse(false);
}
@Override
public Description matchNewClass(NewClassTree tree, VisitorState state) {
MethodSymbol symbol = getSymbol(tree);
if (!hasDirectAnnotationWithSimpleName(symbol, INLINE_ME)) {
return Description.NO_MATCH;
}
ImmutableList callingVars =
tree.getArguments().stream().map(state::getSourceForNode).collect(toImmutableList());
String receiverString = "new " + state.getSourceForNode(tree.getIdentifier());
return match(tree, symbol, callingVars, receiverString, null, state);
}
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
MethodSymbol symbol = getSymbol(tree);
if (!hasDirectAnnotationWithSimpleName(symbol, INLINE_ME)) {
return Description.NO_MATCH;
}
ImmutableList callingVars =
tree.getArguments().stream().map(state::getSourceForNode).collect(toImmutableList());
String receiverString = "";
ExpressionTree receiver = getReceiver(tree);
if (receiver != null) {
receiverString = state.getSourceForNode(receiver);
}
ExpressionTree methodSelectTree = tree.getMethodSelect();
if (methodSelectTree != null) {
String methodSelect = state.getSourceForNode(methodSelectTree);
if ("super".equals(methodSelect)) {
receiverString = methodSelect;
}
// TODO(kak): Can we omit the `this` case? The getReceiver() call above handles `this`
if ("this".equals(methodSelect)) {
receiverString = methodSelect;
}
}
return match(tree, symbol, callingVars, receiverString, receiver, state);
}
private Description match(
ExpressionTree tree,
MethodSymbol symbol,
ImmutableList callingVars,
String receiverString,
ExpressionTree receiver,
VisitorState state) {
checkState(hasDirectAnnotationWithSimpleName(symbol, INLINE_ME));
Api api = Api.create(symbol, state);
if (!matchesApiPrefixes(api)) {
return Description.NO_MATCH;
}
if (skipCallsitesWithComments && stringContainsComments(state.getSourceForNode(tree), state)) {
return Description.NO_MATCH;
}
Attribute.Compound inlineMe =
symbol.getRawAttributes().stream()
.filter(a -> a.type.tsym.getSimpleName().contentEquals(INLINE_ME))
.collect(onlyElement());
SuggestedFix.Builder builder = SuggestedFix.builder();
Map typeNames = new HashMap<>();
for (String newImport : getStrings(inlineMe, "imports")) {
String typeName = Iterables.getLast(PACKAGE_SPLITTER.split(newImport));
String qualifiedTypeName = SuggestedFixes.qualifyType(state, builder, newImport);
typeNames.put(typeName, qualifiedTypeName);
}
for (String newStaticImport : getStrings(inlineMe, "staticImports")) {
builder.addStaticImport(newStaticImport);
}
ImmutableList varNames =
symbol.getParameters().stream()
.map(varSymbol -> varSymbol.getSimpleName().toString())
.collect(toImmutableList());
boolean varargsWithEmptyArguments = false;
if (symbol.isVarArgs()) {
// If we're calling a varargs method, its inlining *should* have the varargs parameter in a
// reasonable position. If there are are 0 arguments, we'll need to do more surgery
if (callingVars.size() == varNames.size() - 1) {
varargsWithEmptyArguments = true;
} else {
ImmutableList nonvarargs = callingVars.subList(0, varNames.size() - 1);
String varargsJoined =
Joiner.on(", ").join(callingVars.subList(varNames.size() - 1, callingVars.size()));
callingVars =
ImmutableList.builderWithExpectedSize(varNames.size())
.addAll(nonvarargs)
.add(varargsJoined)
.build();
}
}
String replacement =
trimTrailingSemicolons(asStringValue(getValue(inlineMe, "replacement").get()).get());
int replacementStart = ((DiagnosticPosition) tree).getStartPosition();
int replacementEnd = state.getEndPosition(tree);
// Special case replacements starting with "this." so the receiver portion is not included in
// the replacement. This avoids overlapping replacement regions for fluent chains.
if (replacement.startsWith("this.") && receiver != null) {
replacementStart = state.getEndPosition(receiver);
replacement = replacement.substring("this".length());
}
if (Strings.isNullOrEmpty(receiverString)) {
replacement = replacement.replaceAll("\\bthis\\.\\b", "");
} else {
if (replacement.equals("this")) { // e.g.: foo.b() -> foo
Tree parent = state.getPath().getParentPath().getLeaf();
// If the receiver is a side-effect-free expression and the whole expression is standalone,
// the receiver likely can't stand on its own (e.g.: "foo;" is not a valid statement while
// "foo.noOpMethod();" is).
if (parent instanceof ExpressionStatementTree && !hasSideEffect(receiver)) {
return describe(parent, SuggestedFix.delete(parent), api);
}
}
replacement = replacement.replaceAll("\\bthis\\b", receiverString);
}
// Qualify imports first, then replace parameter values to avoid clobbering source from the
// inlined method.
for (Map.Entry typeName : typeNames.entrySet()) {
// TODO(b/189535612): we'll need to be smarter about our replacements (to avoid clobbering
// inline parameter comments like /* paramName= */
replacement =
replacement.replaceAll(
"\\b" + Pattern.quote(typeName.getKey()) + "\\b",
Matcher.quoteReplacement(typeName.getValue()));
}
for (int i = 0; i < varNames.size(); i++) {
// Ex: foo(int a, int... others) -> this.bar(a, others)
// If caller passes 0 args in the varargs position, we want to remove the preceding comma to
// make this.bar(a) (as opposed to "this.bar(a, )"
boolean terminalVarargsReplacement = varargsWithEmptyArguments && i == varNames.size() - 1;
String capturePrefixForVarargs = terminalVarargsReplacement ? "(?:,\\s*)?" : "";
// We want to avoid replacing a method invocation with the same name as the method.
Pattern extractArgAndNextToken =
Pattern.compile(
"\\b" + capturePrefixForVarargs + Pattern.quote(varNames.get(i)) + "\\b([^(])");
String replacementResult =
Matcher.quoteReplacement(terminalVarargsReplacement ? "" : callingVars.get(i)) + "$1";
Matcher matcher = extractArgAndNextToken.matcher(replacement);
replacement = matcher.replaceAll(replacementResult);
}
builder.replace(replacementStart, replacementEnd, replacement);
SuggestedFix fix = builder.build();
if (checkFixCompiles && fix.getImportsToAdd().isEmpty()) {
// If there are no new imports being added (then there are no new dependencies). Therefore, we
// can verify that the fix compiles (if CHECK_FIX_COMPILES is enabled).
return SuggestedFixes.compilesWithFix(fix, state)
? describe(tree, fix, api)
: Description.NO_MATCH;
}
return describe(tree, fix, api);
}
// Implementation borrowed from Refaster's comment-checking code.
private static boolean stringContainsComments(String source, VisitorState state) {
JavaTokenizer tokenizer =
new JavaTokenizer(ScannerFactory.instance(state.context), CharBuffer.wrap(source)) {};
for (Token token = tokenizer.readToken();
token.kind != TokenKind.EOF;
token = tokenizer.readToken()) {
if (token.comments != null && !token.comments.isEmpty()) {
return true;
}
}
return false;
}
private static ImmutableList getStrings(Attribute.Compound attribute, String name) {
return getValue(attribute, name)
.map(MoreAnnotations::asStrings)
.orElse(Stream.empty())
.collect(toImmutableList());
}
private Description describe(Tree tree, SuggestedFix fix, Api api) {
return buildDescription(tree).setMessage(api.message()).addFix(fix).build();
}
@AutoValue
abstract static class Api {
private static final Splitter CLASS_NAME_SPLITTER = Splitter.on('.');
static Api create(MethodSymbol method, VisitorState state) {
String extraMessage = "";
if (hasDirectAnnotationWithSimpleName(method, VALIDATION_DISABLED)) {
Attribute.Compound inlineMeValidationDisabled =
method.getRawAttributes().stream()
.filter(a -> a.type.tsym.getSimpleName().contentEquals(VALIDATION_DISABLED))
.collect(onlyElement());
String reason = Iterables.getOnlyElement(getStrings(inlineMeValidationDisabled, "value"));
extraMessage = " NOTE: this is an unvalidated inlining! Reasoning: " + reason;
}
return new AutoValue_Inliner_Api(
method.owner.getQualifiedName().toString(),
method.getSimpleName().toString(),
method.isConstructor(),
extraMessage);
}
abstract String className();
abstract String methodName();
abstract boolean isConstructor();
abstract String extraMessage();
final String message() {
return shortName() + " should be inlined" + extraMessage();
}
/** Returns {@code FullyQualifiedClassName#methodName}. */
final String methodId() {
return String.format("%s#%s", className(), methodName());
}
/**
* Returns a short, human readable description of this API in markdown format (e.g., {@code
* `ClassName.methodName()`}).
*/
final String shortName() {
return String.format("`%s.%s()`", simpleClassName(), methodName());
}
/** Returns the simple class name (e.g., {@code ClassName}). */
final String simpleClassName() {
return Iterables.getLast(CLASS_NAME_SPLITTER.split(className()));
}
}
private boolean matchesApiPrefixes(Api api) {
if (apiPrefixes.isEmpty()) {
return true;
}
for (String apiPrefix : apiPrefixes) {
if (api.methodId().startsWith(apiPrefix)) {
return true;
}
}
return false;
}
private static final CharMatcher SEMICOLON = CharMatcher.is(';');
private static String trimTrailingSemicolons(String s) {
return SEMICOLON.trimTrailingFrom(s);
}
}
